programs/ssl/ssl_server2.c

/*
 *  SSL client with options
 *
 *  Copyright The Mbed TLS Contributors
 *  SPDX-License-Identifier: Apache-2.0
 *
 *  Licensed under the Apache License, Version 2.0 (the "License"); you may
 *  not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

#define MBEDTLS_ALLOW_PRIVATE_ACCESS

#include "ssl_test_lib.h"

#if defined(MBEDTLS_SSL_TEST_IMPOSSIBLE)
int main( void )
{
    mbedtls_printf( MBEDTLS_SSL_TEST_IMPOSSIBLE );
    mbedtls_exit( 0 );
}
#elif !defined(MBEDTLS_SSL_SRV_C)
int main( void )
{
    mbedtls_printf( "MBEDTLS_SSL_SRV_C not defined.\n" );
    mbedtls_exit( 0 );
}
#else /* !MBEDTLS_SSL_TEST_IMPOSSIBLE && MBEDTLS_SSL_SRV_C */

#include <stdint.h>

#if !defined(_MSC_VER)
#include <inttypes.h>
#endif

#if !defined(_WIN32)
#include <signal.h>
#endif

#if defined(MBEDTLS_SSL_CACHE_C)
#include "mbedtls/ssl_cache.h"
#endif

#if defined(MBEDTLS_SSL_TICKET_C)
#include "mbedtls/ssl_ticket.h"
#endif

#if defined(MBEDTLS_SSL_COOKIE_C)
#include "mbedtls/ssl_cookie.h"
#endif

#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) && defined(MBEDTLS_FS_IO)
#define SNI_OPTION
#endif

#if defined(_WIN32)
#include <windows.h>
#endif

#if defined(MBEDTLS_USE_PSA_CRYPTO)
#include "test/psa_crypto_helpers.h"
#endif

/* Size of memory to be allocated for the heap, when using the library's memory
 * management and MBEDTLS_MEMORY_BUFFER_ALLOC_C is enabled. */
#define MEMORY_HEAP_SIZE        120000

#define DFL_SERVER_ADDR         NULL
#define DFL_SERVER_PORT         "4433"
#define DFL_RESPONSE_SIZE       -1
#define DFL_DEBUG_LEVEL         0
#define DFL_NBIO                0
#define DFL_EVENT               0
#define DFL_READ_TIMEOUT        0
#define DFL_CA_FILE             ""
#define DFL_CA_PATH             ""
#define DFL_CRT_FILE            ""
#define DFL_KEY_FILE            ""
#define DFL_KEY_OPAQUE          0
#define DFL_KEY_PWD             ""
#define DFL_CRT_FILE2           ""
#define DFL_KEY_FILE2           ""
#define DFL_KEY_PWD2            ""
#define DFL_ASYNC_OPERATIONS    "-"
#define DFL_ASYNC_PRIVATE_DELAY1 ( -1 )
#define DFL_ASYNC_PRIVATE_DELAY2 ( -1 )
#define DFL_ASYNC_PRIVATE_ERROR  ( 0 )
#define DFL_PSK                 ""
#define DFL_PSK_OPAQUE          0
#define DFL_PSK_LIST_OPAQUE     0
#define DFL_PSK_IDENTITY        "Client_identity"
#define DFL_ECJPAKE_PW          NULL
#define DFL_PSK_LIST            NULL
#define DFL_FORCE_CIPHER        0
#define DFL_TLS1_3_KEX_MODES    MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_ALL
#define DFL_RENEGOTIATION       MBEDTLS_SSL_RENEGOTIATION_DISABLED
#define DFL_ALLOW_LEGACY        -2
#define DFL_RENEGOTIATE         0
#define DFL_RENEGO_DELAY        -2
#define DFL_RENEGO_PERIOD       ( (uint64_t)-1 )
#define DFL_EXCHANGES           1
#define DFL_MIN_VERSION         -1
#define DFL_MAX_VERSION         -1
#define DFL_SHA1                -1
#define DFL_CID_ENABLED         0
#define DFL_CID_VALUE           ""
#define DFL_CID_ENABLED_RENEGO  -1
#define DFL_CID_VALUE_RENEGO    NULL
#define DFL_AUTH_MODE           -1
#define DFL_CERT_REQ_CA_LIST    MBEDTLS_SSL_CERT_REQ_CA_LIST_ENABLED
#define DFL_MFL_CODE            MBEDTLS_SSL_MAX_FRAG_LEN_NONE
#define DFL_TRUNC_HMAC          -1
#define DFL_TICKETS             MBEDTLS_SSL_SESSION_TICKETS_ENABLED
#define DFL_TICKET_TIMEOUT      86400
#define DFL_TICKET_AEAD         MBEDTLS_CIPHER_AES_256_GCM
#define DFL_CACHE_MAX           -1
#define DFL_CACHE_TIMEOUT       -1
#define DFL_SNI                 NULL
#define DFL_ALPN_STRING         NULL
#define DFL_CURVES              NULL
#define DFL_SIG_ALGS            NULL
#define DFL_DHM_FILE            NULL
#define DFL_TRANSPORT           MBEDTLS_SSL_TRANSPORT_STREAM
#define DFL_COOKIES             1
#define DFL_ANTI_REPLAY         -1
#define DFL_HS_TO_MIN           0
#define DFL_HS_TO_MAX           0
#define DFL_DTLS_MTU            -1
#define DFL_BADMAC_LIMIT        -1
#define DFL_DGRAM_PACKING        1
#define DFL_EXTENDED_MS         -1
#define DFL_ETM                 -1
#define DFL_SERIALIZE           0
#define DFL_CONTEXT_FILE        ""
#define DFL_EXTENDED_MS_ENFORCE -1
#define DFL_CA_CALLBACK         0
#define DFL_EAP_TLS             0
#define DFL_REPRODUCIBLE        0
#define DFL_NSS_KEYLOG          0
#define DFL_NSS_KEYLOG_FILE     NULL
#define DFL_QUERY_CONFIG_MODE   0
#define DFL_USE_SRTP            0
#define DFL_SRTP_FORCE_PROFILE  0
#define DFL_SRTP_SUPPORT_MKI    0

#define LONG_RESPONSE "<p>01-blah-blah-blah-blah-blah-blah-blah-blah-blah\r\n" \
    "02-blah-blah-blah-blah-blah-blah-blah-blah-blah-blah-blah-blah-blah\r\n"  \
    "03-blah-blah-blah-blah-blah-blah-blah-blah-blah-blah-blah-blah-blah\r\n"  \
    "04-blah-blah-blah-blah-blah-blah-blah-blah-blah-blah-blah-blah-blah\r\n"  \
    "05-blah-blah-blah-blah-blah-blah-blah-blah-blah-blah-blah-blah-blah\r\n"  \
    "06-blah-blah-blah-blah-blah-blah-blah-blah-blah-blah-blah-blah-blah\r\n"  \
    "07-blah-blah-blah-blah-blah-blah-blah-blah-blah-blah-blah-blah</p>\r\n"

/* Uncomment LONG_RESPONSE at the end of HTTP_RESPONSE to test sending longer
 * packets (for fragmentation purposes) */
#define HTTP_RESPONSE \
    "HTTP/1.0 200 OK\r\nContent-Type: text/html\r\n\r\n" \
    "<h2>mbed TLS Test Server</h2>\r\n" \
    "<p>Successful connection using: %s</p>\r\n" // LONG_RESPONSE

/*
 * Size of the basic I/O buffer. Able to hold our default response.
 *
 * You will need to adapt the mbedtls_ssl_get_bytes_avail() test in ssl-opt.sh
 * if you change this value to something outside the range <= 100 or > 500
 */
#define DFL_IO_BUF_LEN      200

#if defined(MBEDTLS_X509_CRT_PARSE_C)
#if defined(MBEDTLS_FS_IO)
#define USAGE_IO \
    "    ca_file=%%s          The single file containing the top-level CA(s) you fully trust\n" \
    "                        default: \"\" (pre-loaded)\n" \
    "                        use \"none\" to skip loading any top-level CAs.\n" \
    "    ca_path=%%s          The path containing the top-level CA(s) you fully trust\n" \
    "                        default: \"\" (pre-loaded) (overrides ca_file)\n" \
    "                        use \"none\" to skip loading any top-level CAs.\n" \
    "    crt_file=%%s         Your own cert and chain (in bottom to top order, top may be omitted)\n" \
    "                        default: see note after key_file2\n" \
    "    key_file=%%s         default: see note after key_file2\n" \
    "    key_pwd=%%s          Password for key specified by key_file argument\n"\
    "                        default: none\n" \
    "    crt_file2=%%s        Your second cert and chain (in bottom to top order, top may be omitted)\n" \
    "                        default: see note after key_file2\n" \
    "    key_file2=%%s        default: see note below\n" \
    "                        note: if neither crt_file/key_file nor crt_file2/key_file2 are used,\n" \
    "                              preloaded certificate(s) and key(s) are used if available\n" \
    "    key_pwd2=%%s         Password for key specified by key_file2 argument\n"\
    "                        default: none\n" \
    "    dhm_file=%%s        File containing Diffie-Hellman parameters\n" \
    "                       default: preloaded parameters\n"
#else
#define USAGE_IO \
    "\n"                                                    \
    "    No file operations available (MBEDTLS_FS_IO not defined)\n" \
    "\n"
#endif /* MBEDTLS_FS_IO */
#else
#define USAGE_IO ""
#endif /* MBEDTLS_X509_CRT_PARSE_C */
#if defined(MBEDTLS_USE_PSA_CRYPTO) && defined(MBEDTLS_X509_CRT_PARSE_C)
#define USAGE_KEY_OPAQUE \
    "    key_opaque=%%d       Handle your private keys as if they were opaque\n" \
    "                        default: 0 (disabled)\n"
#else
#define USAGE_KEY_OPAQUE ""
#endif

#if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
#define USAGE_SSL_ASYNC \
    "    async_operations=%%c...   d=decrypt, s=sign (default: -=off)\n" \
    "    async_private_delay1=%%d  Asynchronous delay for key_file or preloaded key\n" \
    "    async_private_delay2=%%d  Asynchronous delay for key_file2 and sni\n" \
    "                              default: -1 (not asynchronous)\n" \
    "    async_private_error=%%d   Async callback error injection (default=0=none,\n" \
    "                              1=start, 2=cancel, 3=resume, negative=first time only)"
#else
#define USAGE_SSL_ASYNC ""
#endif /* MBEDTLS_SSL_ASYNC_PRIVATE */

#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
#define USAGE_CID \
    "    cid=%%d             Disable (0) or enable (1) the use of the DTLS Connection ID extension.\n" \
    "                       default: 0 (disabled)\n"     \
    "    cid_renego=%%d      Disable (0) or enable (1) the use of the DTLS Connection ID extension during renegotiation.\n" \
    "                       default: same as 'cid' parameter\n"     \
    "    cid_val=%%s          The CID to use for incoming messages (in hex, without 0x).\n"  \
    "                        default: \"\"\n" \
    "    cid_val_renego=%%s   The CID to use for incoming messages (in hex, without 0x) after renegotiation.\n"  \
    "                        default: same as 'cid_val' parameter\n"
#else /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
#define USAGE_CID ""
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */

#if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED)
#define USAGE_PSK_RAW                                               \
    "    psk=%%s              default: \"\" (disabled)\n"     \
    "                          The PSK values are in hex, without 0x.\n" \
    "    psk_list=%%s         default: \"\"\n"                          \
    "                          A list of (PSK identity, PSK value) pairs.\n" \
    "                          The PSK values are in hex, without 0x.\n" \
    "                          id1,psk1[,id2,psk2[,...]]\n"             \
    "    psk_identity=%%s     default: \"Client_identity\"\n"
#if defined(MBEDTLS_USE_PSA_CRYPTO)
#define USAGE_PSK_SLOT                          \
    "    psk_opaque=%%d       default: 0 (don't use opaque static PSK)\n"     \
    "                          Enable this to store the PSK configured through command line\n" \
    "                          parameter `psk` in a PSA-based key slot.\n" \
    "                          Note: Currently only supported in conjunction with\n"                  \
    "                          the use of min_version to force TLS 1.2 and force_ciphersuite \n"      \
    "                          to force a particular PSK-only ciphersuite.\n"                         \
    "                          Note: This is to test integration of PSA-based opaque PSKs with\n"     \
    "                          Mbed TLS only. Production systems are likely to configure Mbed TLS\n"  \
    "                          with prepopulated key slots instead of importing raw key material.\n" \
    "    psk_list_opaque=%%d  default: 0 (don't use opaque dynamic PSKs)\n"     \
    "                          Enable this to store the list of dynamically chosen PSKs configured\n" \
    "                          through the command line parameter `psk_list` in PSA-based key slots.\n" \
    "                          Note: Currently only supported in conjunction with\n" \
    "                          the use of min_version to force TLS 1.2 and force_ciphersuite \n" \
    "                          to force a particular PSK-only ciphersuite.\n" \
    "                          Note: This is to test integration of PSA-based opaque PSKs with\n" \
    "                          Mbed TLS only. Production systems are likely to configure Mbed TLS\n" \
    "                          with prepopulated key slots instead of importing raw key material.\n"
#else
#define USAGE_PSK_SLOT ""
#endif /* MBEDTLS_USE_PSA_CRYPTO */
#define USAGE_PSK USAGE_PSK_RAW USAGE_PSK_SLOT
#else
#define USAGE_PSK ""
#endif /* MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED */
#if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK)
#define USAGE_CA_CALLBACK                       \
    "   ca_callback=%%d       default: 0 (disabled)\n"      \
    "                         Enable this to use the trusted certificate callback function\n"
#else
#define USAGE_CA_CALLBACK ""
#endif /* MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK */
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
#define USAGE_TICKETS                                       \
    "    tickets=%%d          default: 1 (enabled)\n"       \
    "    ticket_timeout=%%d   default: 86400 (one day)\n"   \
    "    ticket_aead=%%s      default: \"AES-256-GCM\"\n"
#else
#define USAGE_TICKETS ""
#endif /* MBEDTLS_SSL_SESSION_TICKETS */

#define USAGE_EAP_TLS                                       \
    "    eap_tls=%%d          default: 0 (disabled)\n"
#define USAGE_NSS_KEYLOG                                    \
    "    nss_keylog=%%d          default: 0 (disabled)\n"   \
    "                             This cannot be used with eap_tls=1\n"
#define USAGE_NSS_KEYLOG_FILE                               \
    "    nss_keylog_file=%%s\n"
#if defined(MBEDTLS_SSL_DTLS_SRTP)
#define USAGE_SRTP \
    "    use_srtp=%%d         default: 0 (disabled)\n" \
    "    srtp_force_profile=%%d  default: 0 (all enabled)\n"   \
    "                        available profiles:\n"       \
    "                        1 - SRTP_AES128_CM_HMAC_SHA1_80\n"  \
    "                        2 - SRTP_AES128_CM_HMAC_SHA1_32\n"  \
    "                        3 - SRTP_NULL_HMAC_SHA1_80\n"       \
    "                        4 - SRTP_NULL_HMAC_SHA1_32\n"       \
    "    support_mki=%%d     default: 0 (not supported)\n"
#else /* MBEDTLS_SSL_DTLS_SRTP */
#define USAGE_SRTP ""
#endif

#if defined(MBEDTLS_SSL_CACHE_C)
#define USAGE_CACHE                                             \
    "    cache_max=%%d        default: cache default (50)\n"    \
    "    cache_timeout=%%d    default: cache default (1d)\n"
#else
#define USAGE_CACHE ""
#endif /* MBEDTLS_SSL_CACHE_C */

#if defined(SNI_OPTION)
#if defined(MBEDTLS_X509_CRL_PARSE_C)
#define SNI_CRL              ",crl"
#else
#define SNI_CRL              ""
#endif

#define USAGE_SNI                                                           \
    "    sni=%%s              name1,cert1,key1,ca1"SNI_CRL",auth1[,...]\n"  \
    "                        default: disabled\n"
#else
#define USAGE_SNI ""
#endif /* SNI_OPTION */

#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
#define USAGE_MAX_FRAG_LEN                                      \
    "    max_frag_len=%%d     default: 16384 (tls default)\n"   \
    "                        options: 512, 1024, 2048, 4096\n"
#else
#define USAGE_MAX_FRAG_LEN ""
#endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */

#if defined(MBEDTLS_SSL_ALPN)
#define USAGE_ALPN \
    "    alpn=%%s             default: \"\" (disabled)\n"   \
    "                        example: spdy/1,http/1.1\n"
#else
#define USAGE_ALPN ""
#endif /* MBEDTLS_SSL_ALPN */

#if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY)
#define USAGE_COOKIES \
    "    cookies=0/1/-1      default: 1 (enabled)\n"        \
    "                        0: disabled, -1: library default (broken)\n"
#else
#define USAGE_COOKIES ""
#endif

#if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
#define USAGE_ANTI_REPLAY \
    "    anti_replay=0/1     default: (library default: enabled)\n"
#else
#define USAGE_ANTI_REPLAY ""
#endif

#define USAGE_BADMAC_LIMIT \
    "    badmac_limit=%%d     default: (library default: disabled)\n"

#if defined(MBEDTLS_SSL_PROTO_DTLS)
#define USAGE_DTLS \
    "    dtls=%%d             default: 0 (TLS)\n"                           \
    "    hs_timeout=%%d-%%d    default: (library default: 1000-60000)\n"    \
    "                        range of DTLS handshake timeouts in millisecs\n" \
    "    mtu=%%d              default: (library default: unlimited)\n"  \
    "    dgram_packing=%%d    default: 1 (allowed)\n"                   \
    "                        allow or forbid packing of multiple\n" \
    "                        records within a single datgram.\n"
#else
#define USAGE_DTLS ""
#endif

#if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
#define USAGE_EMS \
    "    extended_ms=0/1     default: (library default: on)\n"
#else
#define USAGE_EMS ""
#endif

#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
#define USAGE_ETM \
    "    etm=0/1             default: (library default: on)\n"
#else
#define USAGE_ETM ""
#endif

#define USAGE_REPRODUCIBLE \
    "    reproducible=0/1     default: 0 (disabled)\n"

#if defined(MBEDTLS_SSL_RENEGOTIATION)
#define USAGE_RENEGO \
    "    renegotiation=%%d    default: 0 (disabled)\n"      \
    "    renegotiate=%%d      default: 0 (disabled)\n"      \
    "    renego_delay=%%d     default: -2 (library default)\n" \
    "    renego_period=%%d    default: (2^64 - 1 for TLS, 2^48 - 1 for DTLS)\n"
#else
#define USAGE_RENEGO ""
#endif

#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
#define USAGE_ECJPAKE \
    "    ecjpake_pw=%%s       default: none (disabled)\n"
#else
#define USAGE_ECJPAKE ""
#endif

#if defined(MBEDTLS_ECP_C)
#define USAGE_CURVES \
    "    curves=a,b,c,d      default: \"default\" (library default)\n"  \
    "                        example: \"secp521r1,brainpoolP512r1\"\n"  \
    "                        - use \"none\" for empty list\n"           \
    "                        - see mbedtls_ecp_curve_list()\n"          \
    "                          for acceptable curve names\n"
#else
#define USAGE_CURVES ""
#endif

#if defined(MBEDTLS_SSL_PROTO_TLS1_3) && \
    defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
#define USAGE_SIG_ALGS \
    "    sig_algs=a,b,c,d      default: \"default\" (library default)\n"  \
    "                          example: \"ecdsa_secp256r1_sha256,ecdsa_secp384r1_sha384\"\n"
#else
#define USAGE_SIG_ALGS ""
#endif

#if defined(MBEDTLS_SSL_CONTEXT_SERIALIZATION)
#define USAGE_SERIALIZATION \
    "    serialize=%%d        default: 0 (do not serialize/deserialize)\n"     \
    "                        options: 1 (serialize)\n"                         \
    "                                 2 (serialize with re-initialization)\n"  \
    "    context_file=%%s     The file path to write a serialized connection\n"\
    "                        in the form of base64 code (serialize option\n"   \
    "                        must be set)\n"                                   \
    "                         default: \"\" (do nothing)\n"                    \
    "                         option: a file path\n"
#else
#define USAGE_SERIALIZATION ""
#endif

#if defined(MBEDTLS_SSL_PROTO_TLS1_3)
#define USAGE_TLS1_3_KEY_EXCHANGE_MODES \
    "    tls13_kex_modes=%%s   default: all\n"     \
    "                          options: psk, psk_ephemeral, ephemeral, ephemeral_all, psk_all, all\n"
#else
#define USAGE_TLS1_3_KEY_EXCHANGE_MODES ""
#endif /* MBEDTLS_SSL_PROTO_TLS1_3 */


/* USAGE is arbitrarily split to stay under the portable string literal
 * length limit: 4095 bytes in C99. */
#define USAGE1 \
    "\n usage: ssl_server2 param=<>...\n"                   \
    "\n acceptable parameters:\n"                           \
    "    server_addr=%%s      default: (all interfaces)\n"  \
    "    server_port=%%d      default: 4433\n"              \
    "    debug_level=%%d      default: 0 (disabled)\n"      \
    "    buffer_size=%%d      default: 200 \n" \
    "                         (minimum: 1)\n" \
    "    response_size=%%d    default: about 152 (basic response)\n" \
    "                          (minimum: 0, max: 16384)\n" \
    "                          increases buffer_size if bigger\n"\
    "    nbio=%%d             default: 0 (blocking I/O)\n"  \
    "                        options: 1 (non-blocking), 2 (added delays)\n" \
    "    event=%%d            default: 0 (loop)\n"                            \
    "                        options: 1 (level-triggered, implies nbio=1),\n" \
    "    read_timeout=%%d     default: 0 ms (no timeout)\n"    \
    "\n"                                                    \
    USAGE_DTLS                                              \
    USAGE_SRTP                                              \
    USAGE_COOKIES                                           \
    USAGE_ANTI_REPLAY                                       \
    USAGE_BADMAC_LIMIT                                      \
    "\n"
#define USAGE2 \
    "    auth_mode=%%s        default: (library default: none)\n"      \
    "                        options: none, optional, required\n" \
    "    cert_req_ca_list=%%d default: 1 (send ca list)\n"  \
    "                        options: 1 (send ca list), 0 (don't send)\n" \
    USAGE_IO                                                \
    USAGE_KEY_OPAQUE                                        \
    "\n"                                                    \
    USAGE_PSK                                               \
    USAGE_CA_CALLBACK                                       \
    USAGE_ECJPAKE                                           \
    "\n"
#define USAGE3 \
    "    allow_legacy=%%d     default: (library default: no)\n"      \
    USAGE_RENEGO                                            \
    "    exchanges=%%d        default: 1\n"                 \
    "\n"                                                    \
    USAGE_TICKETS                                           \
    USAGE_EAP_TLS                                           \
    USAGE_REPRODUCIBLE                                      \
    USAGE_NSS_KEYLOG                                        \
    USAGE_NSS_KEYLOG_FILE                                   \
    USAGE_CACHE                                             \
    USAGE_MAX_FRAG_LEN                                      \
    USAGE_ALPN                                              \
    USAGE_EMS                                               \
    USAGE_ETM                                               \
    USAGE_CURVES                                            \
    USAGE_SIG_ALGS                                          \
    "\n"

#if defined(MBEDTLS_SSL_PROTO_TLS1_3)
#define TLS1_3_VERSION_OPTIONS  ", tls13"
#else /* MBEDTLS_SSL_PROTO_TLS1_3 */
#define TLS1_3_VERSION_OPTIONS  ""
#endif /* !MBEDTLS_SSL_PROTO_TLS1_3 */

#define USAGE4 \
    USAGE_SSL_ASYNC                                         \
    USAGE_SNI                                               \
    "    allow_sha1=%%d       default: 0\n"                                   \
    "    min_version=%%s      default: (library default: tls12)\n"            \
    "    max_version=%%s      default: (library default: tls12)\n"            \
    "    force_version=%%s    default: \"\" (none)\n"                         \
    "                         options: tls12, dtls12" TLS1_3_VERSION_OPTIONS  \
    "\n\n"                                                                    \
    "    force_ciphersuite=<name>    default: all enabled\n"                  \
    USAGE_TLS1_3_KEY_EXCHANGE_MODES                                           \
    "    query_config=<name>         return 0 if the specified\n"             \
    "                                configuration macro is defined and 1\n"  \
    "                                otherwise. The expansion of the macro\n" \
    "                                is printed if it is defined\n"           \
    USAGE_SERIALIZATION                                                       \
    " acceptable ciphersuite names:\n"

#define ALPN_LIST_SIZE    10
#define CURVE_LIST_SIZE   20
#define SIG_ALG_LIST_SIZE 5

#define PUT_UINT64_BE(out_be,in_le,i)                                   \
{                                                                       \
    (out_be)[(i) + 0] = (unsigned char)( ( (in_le) >> 56 ) & 0xFF );    \
    (out_be)[(i) + 1] = (unsigned char)( ( (in_le) >> 48 ) & 0xFF );    \
    (out_be)[(i) + 2] = (unsigned char)( ( (in_le) >> 40 ) & 0xFF );    \
    (out_be)[(i) + 3] = (unsigned char)( ( (in_le) >> 32 ) & 0xFF );    \
    (out_be)[(i) + 4] = (unsigned char)( ( (in_le) >> 24 ) & 0xFF );    \
    (out_be)[(i) + 5] = (unsigned char)( ( (in_le) >> 16 ) & 0xFF );    \
    (out_be)[(i) + 6] = (unsigned char)( ( (in_le) >> 8  ) & 0xFF );    \
    (out_be)[(i) + 7] = (unsigned char)( ( (in_le) >> 0  ) & 0xFF );    \
}

/* This is global so it can be easily accessed by callback functions */
rng_context_t rng;

/*
 * global options
 */
struct options
{
    const char *server_addr;    /* address on which the ssl service runs    */
    const char *server_port;    /* port on which the ssl service runs       */
    int debug_level;            /* level of debugging                       */
    int nbio;                   /* should I/O be blocking?                  */
    int event;                  /* loop or event-driven IO? level or edge triggered? */
    uint32_t read_timeout;      /* timeout on mbedtls_ssl_read() in milliseconds    */
    int response_size;          /* pad response with header to requested size */
    uint16_t buffer_size;       /* IO buffer size */
    const char *ca_file;        /* the file with the CA certificate(s)      */
    const char *ca_path;        /* the path with the CA certificate(s) reside */
    const char *crt_file;       /* the file with the server certificate     */
    const char *key_file;       /* the file with the server key             */
    int key_opaque;             /* handle private key as if it were opaque  */
    const char *key_pwd;        /* the password for the server key          */
    const char *crt_file2;      /* the file with the 2nd server certificate */
    const char *key_file2;      /* the file with the 2nd server key         */
    const char *key_pwd2;       /* the password for the 2nd server key      */
    const char *async_operations; /* supported SSL asynchronous operations  */
    int async_private_delay1;   /* number of times f_async_resume needs to be called for key 1, or -1 for no async */
    int async_private_delay2;   /* number of times f_async_resume needs to be called for key 2, or -1 for no async */
    int async_private_error;    /* inject error in async private callback */
#if defined(MBEDTLS_USE_PSA_CRYPTO)
    int psk_opaque;
    int psk_list_opaque;
#endif
#if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK)
    int ca_callback;            /* Use callback for trusted certificate list */
#endif
    const char *psk;            /* the pre-shared key                       */
    const char *psk_identity;   /* the pre-shared key identity              */
    char *psk_list;             /* list of PSK id/key pairs for callback    */
    const char *ecjpake_pw;     /* the EC J-PAKE password                   */
    int force_ciphersuite[2];   /* protocol/ciphersuite to use, or all      */
#if defined(MBEDTLS_SSL_PROTO_TLS1_3)
    int tls13_kex_modes;        /* supported TLS 1.3 key exchange modes     */
#endif /* MBEDTLS_SSL_PROTO_TLS1_3 */
    int renegotiation;          /* enable / disable renegotiation           */
    int allow_legacy;           /* allow legacy renegotiation               */
    int renegotiate;            /* attempt renegotiation?                   */
    int renego_delay;           /* delay before enforcing renegotiation     */
    uint64_t renego_period;     /* period for automatic renegotiation       */
    int exchanges;              /* number of data exchanges                 */
    int min_version;            /* minimum protocol version accepted        */
    int max_version;            /* maximum protocol version accepted        */
    int allow_sha1;             /* flag for SHA-1 support                   */
    int auth_mode;              /* verify mode for connection               */
    int cert_req_ca_list;       /* should we send the CA list?              */
    unsigned char mfl_code;     /* code for maximum fragment length         */
    int trunc_hmac;             /* accept truncated hmac?                   */
    int tickets;                /* enable / disable session tickets         */
    int ticket_timeout;         /* session ticket lifetime                  */
    int ticket_aead;            /* session ticket protection                */
    int cache_max;              /* max number of session cache entries      */
    int cache_timeout;          /* expiration delay of session cache entries */
    char *sni;                  /* string describing sni information        */
    const char *curves;         /* list of supported elliptic curves        */
    const char *sig_algs;       /* supported TLS 1.3 signature algorithms   */
    const char *alpn_string;    /* ALPN supported protocols                 */
    const char *dhm_file;       /* the file with the DH parameters          */
    int extended_ms;            /* allow negotiation of extended MS?        */
    int etm;                    /* allow negotiation of encrypt-then-MAC?   */
    int transport;              /* TLS or DTLS?                             */
    int cookies;                /* Use cookies for DTLS? -1 to break them   */
    int anti_replay;            /* Use anti-replay for DTLS? -1 for default */
    uint32_t hs_to_min;         /* Initial value of DTLS handshake timer    */
    uint32_t hs_to_max;         /* Max value of DTLS handshake timer        */
    int dtls_mtu;               /* UDP Maximum tranport unit for DTLS       */
    int dgram_packing;          /* allow/forbid datagram packing            */
    int badmac_limit;           /* Limit of records with bad MAC            */
    int eap_tls;                /* derive EAP-TLS keying material?          */
    int nss_keylog;             /* export NSS key log material              */
    const char *nss_keylog_file; /* NSS key log file                        */
    int cid_enabled;            /* whether to use the CID extension or not  */
    int cid_enabled_renego;     /* whether to use the CID extension or not
                                 * during renegotiation                     */
    const char *cid_val;        /* the CID to use for incoming messages     */
    int serialize;              /* serialize/deserialize connection         */
    const char *context_file;   /* the file to write a serialized connection
                                 * in the form of base64 code (serialize
                                 * option must be set)                      */
    const char *cid_val_renego; /* the CID to use for incoming messages
                                 * after renegotiation                      */
    int reproducible;           /* make communication reproducible          */
    int query_config_mode;      /* whether to read config                   */
    int use_srtp;               /* Support SRTP                             */
    int force_srtp_profile;     /* SRTP protection profile to use or all    */
    int support_mki;            /* The dtls mki mki support                 */
} opt;

#include "ssl_test_common_source.c"

/*
 * Return authmode from string, or -1 on error
 */
static int get_auth_mode( const char *s )
{
    if( strcmp( s, "none" ) == 0 )
        return( MBEDTLS_SSL_VERIFY_NONE );
    if( strcmp( s, "optional" ) == 0 )
        return( MBEDTLS_SSL_VERIFY_OPTIONAL );
    if( strcmp( s, "required" ) == 0 )
        return( MBEDTLS_SSL_VERIFY_REQUIRED );

    return( -1 );
}

/*
 * Used by sni_parse and psk_parse to handle coma-separated lists
 */
#define GET_ITEM( dst )         \
    do                          \
    {                           \
        (dst) = p;              \
        while( *p != ',' )      \
            if( ++p > end )     \
                goto error;     \
        *p++ = '\0';            \
    } while( 0 )

#if defined(SNI_OPTION)
typedef struct _sni_entry sni_entry;

struct _sni_entry {
    const char *name;
    mbedtls_x509_crt *cert;
    mbedtls_pk_context *key;
    mbedtls_x509_crt* ca;
    mbedtls_x509_crl* crl;
    int authmode;
    sni_entry *next;
};

void sni_free( sni_entry *head )
{
    sni_entry *cur = head, *next;

    while( cur != NULL )
    {
        mbedtls_x509_crt_free( cur->cert );
        mbedtls_free( cur->cert );

        mbedtls_pk_free( cur->key );
        mbedtls_free( cur->key );

        mbedtls_x509_crt_free( cur->ca );
        mbedtls_free( cur->ca );
#if defined(MBEDTLS_X509_CRL_PARSE_C)
        mbedtls_x509_crl_free( cur->crl );
        mbedtls_free( cur->crl );
#endif
        next = cur->next;
        mbedtls_free( cur );
        cur = next;
    }
}

/*
 * Parse a string of sextuples name1,crt1,key1,ca1,crl1,auth1[,...]
 * into a usable sni_entry list. For ca1, crl1, auth1, the special value
 * '-' means unset. If ca1 is unset, then crl1 is ignored too.
 *
 * Modifies the input string! This is not production quality!
 */
sni_entry *sni_parse( char *sni_string )
{
    sni_entry *cur = NULL, *new = NULL;
    char *p = sni_string;
    char *end = p;
    char *crt_file, *key_file, *ca_file, *auth_str;
#if defined(MBEDTLS_X509_CRL_PARSE_C)
    char *crl_file;
#endif

    while( *end != '\0' )
        ++end;
    *end = ',';

    while( p <= end )
    {
        if( ( new = mbedtls_calloc( 1, sizeof( sni_entry ) ) ) == NULL )
        {
            sni_free( cur );
            return( NULL );
        }

        GET_ITEM( new->name );
        GET_ITEM( crt_file );
        GET_ITEM( key_file );
        GET_ITEM( ca_file );
#if defined(MBEDTLS_X509_CRL_PARSE_C)
        GET_ITEM( crl_file );
#endif
        GET_ITEM( auth_str );

        if( ( new->cert = mbedtls_calloc( 1, sizeof( mbedtls_x509_crt ) ) ) == NULL ||
            ( new->key = mbedtls_calloc( 1, sizeof( mbedtls_pk_context ) ) ) == NULL )
            goto error;

        mbedtls_x509_crt_init( new->cert );
        mbedtls_pk_init( new->key );

        if( mbedtls_x509_crt_parse_file( new->cert, crt_file ) != 0 ||
            mbedtls_pk_parse_keyfile( new->key, key_file, "", rng_get, &rng ) != 0 )
            goto error;

        if( strcmp( ca_file, "-" ) != 0 )
        {
            if( ( new->ca = mbedtls_calloc( 1, sizeof( mbedtls_x509_crt ) ) ) == NULL )
                goto error;

            mbedtls_x509_crt_init( new->ca );

            if( mbedtls_x509_crt_parse_file( new->ca, ca_file ) != 0 )
                goto error;
        }

#if defined(MBEDTLS_X509_CRL_PARSE_C)
        if( strcmp( crl_file, "-" ) != 0 )
        {
            if( ( new->crl = mbedtls_calloc( 1, sizeof( mbedtls_x509_crl ) ) ) == NULL )
                goto error;

            mbedtls_x509_crl_init( new->crl );

            if( mbedtls_x509_crl_parse_file( new->crl, crl_file ) != 0 )
                goto error;
        }
#endif

        if( strcmp( auth_str, "-" ) != 0 )
        {
            if( ( new->authmode = get_auth_mode( auth_str ) ) < 0 )
                goto error;
        }
        else
            new->authmode = DFL_AUTH_MODE;

        new->next = cur;
        cur = new;
    }

    return( cur );

error:
    sni_free( new );
    sni_free( cur );
    return( NULL );
}

/*
 * SNI callback.
 */
int sni_callback( void *p_info, mbedtls_ssl_context *ssl,
                  const unsigned char *name, size_t name_len )
{
    const sni_entry *cur = (const sni_entry *) p_info;

    while( cur != NULL )
    {
        if( name_len == strlen( cur->name ) &&
            memcmp( name, cur->name, name_len ) == 0 )
        {
            if( cur->ca != NULL )
                mbedtls_ssl_set_hs_ca_chain( ssl, cur->ca, cur->crl );

            if( cur->authmode != DFL_AUTH_MODE )
                mbedtls_ssl_set_hs_authmode( ssl, cur->authmode );

            return( mbedtls_ssl_set_hs_own_cert( ssl, cur->cert, cur->key ) );
        }

        cur = cur->next;
    }

    return( -1 );
}

#endif /* SNI_OPTION */

#if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED)

typedef struct _psk_entry psk_entry;

struct _psk_entry
{
    const char *name;
    size_t key_len;
    unsigned char key[MBEDTLS_PSK_MAX_LEN];
#if defined(MBEDTLS_USE_PSA_CRYPTO)
    mbedtls_svc_key_id_t slot;
#endif /* MBEDTLS_USE_PSA_CRYPTO */
    psk_entry *next;
};

/*
 * Free a list of psk_entry's
 */
int psk_free( psk_entry *head )
{
    psk_entry *next;

    while( head != NULL )
    {
#if defined(MBEDTLS_USE_PSA_CRYPTO)
        psa_status_t status;
        mbedtls_svc_key_id_t const slot = head->slot;

        if( MBEDTLS_SVC_KEY_ID_GET_KEY_ID( slot ) != 0 )
        {
            status = psa_destroy_key( slot );
            if( status != PSA_SUCCESS )
                return( status );
        }
#endif /* MBEDTLS_USE_PSA_CRYPTO */

        next = head->next;
        mbedtls_free( head );
        head = next;
    }

    return( 0 );
}

/*
 * Parse a string of pairs name1,key1[,name2,key2[,...]]
 * into a usable psk_entry list.
 *
 * Modifies the input string! This is not production quality!
 */
psk_entry *psk_parse( char *psk_string )
{
    psk_entry *cur = NULL, *new = NULL;
    char *p = psk_string;
    char *end = p;
    char *key_hex;

    while( *end != '\0' )
        ++end;
    *end = ',';

    while( p <= end )
    {
        if( ( new = mbedtls_calloc( 1, sizeof( psk_entry ) ) ) == NULL )
            goto error;

        memset( new, 0, sizeof( psk_entry ) );

        GET_ITEM( new->name );
        GET_ITEM( key_hex );

        if( mbedtls_test_unhexify( new->key, MBEDTLS_PSK_MAX_LEN,
                                   key_hex, &new->key_len ) != 0 )
            goto error;

        new->next = cur;
        cur = new;
    }

    return( cur );

error:
    psk_free( new );
    psk_free( cur );
    return( 0 );
}

/*
 * PSK callback
 */
int psk_callback( void *p_info, mbedtls_ssl_context *ssl,
                  const unsigned char *name, size_t name_len )
{
    psk_entry *cur = (psk_entry *) p_info;

    while( cur != NULL )
    {
        if( name_len == strlen( cur->name ) &&
            memcmp( name, cur->name, name_len ) == 0 )
        {
#if defined(MBEDTLS_USE_PSA_CRYPTO)
            if( MBEDTLS_SVC_KEY_ID_GET_KEY_ID( cur->slot ) != 0 )
                return( mbedtls_ssl_set_hs_psk_opaque( ssl, cur->slot ) );
            else
#endif
            return( mbedtls_ssl_set_hs_psk( ssl, cur->key, cur->key_len ) );
        }

        cur = cur->next;
    }

    return( -1 );
}
#endif /* MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED */

static mbedtls_net_context listen_fd, client_fd;

/* Interruption handler to ensure clean exit (for valgrind testing) */
#if !defined(_WIN32)
static int received_sigterm = 0;
void term_handler( int sig )
{
    ((void) sig);
    received_sigterm = 1;
    mbedtls_net_free( &listen_fd ); /* causes mbedtls_net_accept() to abort */
    mbedtls_net_free( &client_fd ); /* causes net_read() to abort */
}
#endif

/** Return true if \p ret is a status code indicating that there is an
 * operation in progress on an SSL connection, and false if it indicates
 * success or a fatal error.
 *
 * The possible operations in progress are:
 *
 * - A read, when the SSL input buffer does not contain a full message.
 * - A write, when the SSL output buffer contains some data that has not
 *   been sent over the network yet.
 * - An asynchronous callback that has not completed yet. */
static int mbedtls_status_is_ssl_in_progress( int ret )
{
    return( ret == MBEDTLS_ERR_SSL_WANT_READ ||
            ret == MBEDTLS_ERR_SSL_WANT_WRITE ||
            ret == MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS );
}

#if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
typedef struct
{
    mbedtls_x509_crt *cert; /*!< Certificate corresponding to the key */
    mbedtls_pk_context *pk; /*!< Private key */
    unsigned delay; /*!< Number of resume steps to go through */
    unsigned pk_owned : 1; /*!< Whether to free the pk object on exit */
} ssl_async_key_slot_t;

typedef enum {
    SSL_ASYNC_INJECT_ERROR_NONE = 0, /*!< Let the callbacks succeed */
    SSL_ASYNC_INJECT_ERROR_START, /*!< Inject error during start */
    SSL_ASYNC_INJECT_ERROR_CANCEL, /*!< Close the connection after async start */
    SSL_ASYNC_INJECT_ERROR_RESUME, /*!< Inject error during resume */
#define SSL_ASYNC_INJECT_ERROR_MAX SSL_ASYNC_INJECT_ERROR_RESUME
} ssl_async_inject_error_t;

typedef struct
{
    ssl_async_key_slot_t slots[4]; /* key, key2, sni1, sni2 */
    size_t slots_used;
    ssl_async_inject_error_t inject_error;
    int (*f_rng)(void *, unsigned char *, size_t);
    void *p_rng;
} ssl_async_key_context_t;

int ssl_async_set_key( ssl_async_key_context_t *ctx,
                       mbedtls_x509_crt *cert,
                       mbedtls_pk_context *pk,
                       int pk_take_ownership,
                       unsigned delay )
{
    if( ctx->slots_used >= sizeof( ctx->slots ) / sizeof( *ctx->slots ) )
        return( -1 );
    ctx->slots[ctx->slots_used].cert = cert;
    ctx->slots[ctx->slots_used].pk = pk;
    ctx->slots[ctx->slots_used].delay = delay;
    ctx->slots[ctx->slots_used].pk_owned = pk_take_ownership;
    ++ctx->slots_used;
    return( 0 );
}

#define SSL_ASYNC_INPUT_MAX_SIZE 512

typedef enum
{
    ASYNC_OP_SIGN,
    ASYNC_OP_DECRYPT,
} ssl_async_operation_type_t;
/* Note that the enum above and the array below need to be kept in sync!
 * `ssl_async_operation_names[op]` is the name of op for each value `op`
 * of type `ssl_async_operation_type_t`. */
static const char *const ssl_async_operation_names[] =
{
    "sign",
    "decrypt",
};

typedef struct
{
    unsigned slot;
    ssl_async_operation_type_t operation_type;
    mbedtls_md_type_t md_alg;
    unsigned char input[SSL_ASYNC_INPUT_MAX_SIZE];
    size_t input_len;
    unsigned remaining_delay;
} ssl_async_operation_context_t;

static int ssl_async_start( mbedtls_ssl_context *ssl,
                            mbedtls_x509_crt *cert,
                            ssl_async_operation_type_t op_type,
                            mbedtls_md_type_t md_alg,
                            const unsigned char *input,
                            size_t input_len )
{
    ssl_async_key_context_t *config_data =
        mbedtls_ssl_conf_get_async_config_data( ssl->conf );
    unsigned slot;
    ssl_async_operation_context_t *ctx = NULL;
    const char *op_name = ssl_async_operation_names[op_type];

    {
        char dn[100];
        if( mbedtls_x509_dn_gets( dn, sizeof( dn ), &cert->subject ) > 0 )
            mbedtls_printf( "Async %s callback: looking for DN=%s\n",
                            op_name, dn );
    }

    /* Look for a private key that matches the public key in cert.
     * Since this test code has the private key inside Mbed TLS,
     * we call mbedtls_pk_check_pair to match a private key with the
     * public key. */
    for( slot = 0; slot < config_data->slots_used; slot++ )
    {
        if( mbedtls_pk_check_pair( &cert->pk,
                                   config_data->slots[slot].pk,
                                   rng_get, &rng ) == 0 )
            break;
    }
    if( slot == config_data->slots_used )
    {
        mbedtls_printf( "Async %s callback: no key matches this certificate.\n",
                        op_name );
        return( MBEDTLS_ERR_SSL_HW_ACCEL_FALLTHROUGH );
    }
    mbedtls_printf( "Async %s callback: using key slot %u, delay=%u.\n",
                    op_name, slot, config_data->slots[slot].delay );

    if( config_data->inject_error == SSL_ASYNC_INJECT_ERROR_START )
    {
        mbedtls_printf( "Async %s callback: injected error\n", op_name );
        return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE );
    }

    if( input_len > SSL_ASYNC_INPUT_MAX_SIZE )
        return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );

    ctx = mbedtls_calloc( 1, sizeof( *ctx ) );
    if( ctx == NULL )
        return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
    ctx->slot = slot;
    ctx->operation_type = op_type;
    ctx->md_alg = md_alg;
    memcpy( ctx->input, input, input_len );
    ctx->input_len = input_len;
    ctx->remaining_delay = config_data->slots[slot].delay;
    mbedtls_ssl_set_async_operation_data( ssl, ctx );

    if( ctx->remaining_delay == 0 )
        return( 0 );
    else
        return( MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS );
}

static int ssl_async_sign( mbedtls_ssl_context *ssl,
                           mbedtls_x509_crt *cert,
                           mbedtls_md_type_t md_alg,
                           const unsigned char *hash,
                           size_t hash_len )
{
    return( ssl_async_start( ssl, cert,
                             ASYNC_OP_SIGN, md_alg,
                             hash, hash_len ) );
}

static int ssl_async_decrypt( mbedtls_ssl_context *ssl,
                              mbedtls_x509_crt *cert,
                              const unsigned char *input,
                              size_t input_len )
{
    return( ssl_async_start( ssl, cert,
                             ASYNC_OP_DECRYPT, MBEDTLS_MD_NONE,
                             input, input_len ) );
}

static int ssl_async_resume( mbedtls_ssl_context *ssl,
                             unsigned char *output,
                             size_t *output_len,
                             size_t output_size )
{
    ssl_async_operation_context_t *ctx = mbedtls_ssl_get_async_operation_data( ssl );
    ssl_async_key_context_t *config_data =
        mbedtls_ssl_conf_get_async_config_data( ssl->conf );
    ssl_async_key_slot_t *key_slot = &config_data->slots[ctx->slot];
    int ret;
    const char *op_name;

    if( ctx->remaining_delay > 0 )
    {
        --ctx->remaining_delay;
        mbedtls_printf( "Async resume (slot %u): call %u more times.\n",
                        ctx->slot, ctx->remaining_delay );
        return( MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS );
    }

    switch( ctx->operation_type )
    {
        case ASYNC_OP_DECRYPT:
            ret = mbedtls_pk_decrypt( key_slot->pk,
                                      ctx->input, ctx->input_len,
                                      output, output_len, output_size,
                                      config_data->f_rng, config_data->p_rng );
            break;
        case ASYNC_OP_SIGN:
            ret = mbedtls_pk_sign( key_slot->pk,
                                   ctx->md_alg,
                                   ctx->input, ctx->input_len,
                                   output, output_size, output_len,
                                   config_data->f_rng, config_data->p_rng );
            break;
        default:
            mbedtls_printf( "Async resume (slot %u): unknown operation type %ld. This shouldn't happen.\n",
                            ctx->slot, (long) ctx->operation_type );
            mbedtls_free( ctx );
            return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE );
            break;
    }

    op_name = ssl_async_operation_names[ctx->operation_type];

    if( config_data->inject_error == SSL_ASYNC_INJECT_ERROR_RESUME )
    {
        mbedtls_printf( "Async resume callback: %s done but injected error\n",
                        op_name );
        mbedtls_free( ctx );
        return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE );
    }

    mbedtls_printf( "Async resume (slot %u): %s done, status=%d.\n",
                    ctx->slot, op_name, ret );
    mbedtls_free( ctx );
    return( ret );
}

static void ssl_async_cancel( mbedtls_ssl_context *ssl )
{
    ssl_async_operation_context_t *ctx = mbedtls_ssl_get_async_operation_data( ssl );
    mbedtls_printf( "Async cancel callback.\n" );
    mbedtls_free( ctx );
}
#endif /* MBEDTLS_SSL_ASYNC_PRIVATE */

#if defined(MBEDTLS_USE_PSA_CRYPTO)
static psa_status_t psa_setup_psk_key_slot( mbedtls_svc_key_id_t *slot,
                                            psa_algorithm_t alg,
                                            unsigned char *psk,
                                            size_t psk_len )
{
    psa_status_t status;
    psa_key_attributes_t key_attributes;

    key_attributes = psa_key_attributes_init();
    psa_set_key_usage_flags( &key_attributes, PSA_KEY_USAGE_DERIVE );
    psa_set_key_algorithm( &key_attributes, alg );
    psa_set_key_type( &key_attributes, PSA_KEY_TYPE_DERIVE );

    status = psa_import_key( &key_attributes, psk, psk_len, slot );
    if( status != PSA_SUCCESS )
    {
        fprintf( stderr, "IMPORT\n" );
        return( status );
    }

    return( PSA_SUCCESS );
}
#endif /* MBEDTLS_USE_PSA_CRYPTO */

#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
int report_cid_usage( mbedtls_ssl_context *ssl,
                      const char *additional_description )
{
    int ret;
    unsigned char peer_cid[ MBEDTLS_SSL_CID_OUT_LEN_MAX ];
    size_t peer_cid_len;
    int cid_negotiated;

    if( opt.transport != MBEDTLS_SSL_TRANSPORT_DATAGRAM )
        return( 0 );

    /* Check if the use of a CID has been negotiated */
    ret = mbedtls_ssl_get_peer_cid( ssl, &cid_negotiated,
                                    peer_cid, &peer_cid_len );
    if( ret != 0 )
    {
        mbedtls_printf( " failed\n  ! mbedtls_ssl_get_peer_cid returned -0x%x\n\n",
                        (unsigned int) -ret );
        return( ret );
    }

    if( cid_negotiated == MBEDTLS_SSL_CID_DISABLED )
    {
        if( opt.cid_enabled == MBEDTLS_SSL_CID_ENABLED )
        {
            mbedtls_printf( "(%s) Use of Connection ID was not offered by client.\n",
                            additional_description );
        }
    }
    else
    {
        size_t idx=0;
        mbedtls_printf( "(%s) Use of Connection ID has been negotiated.\n",
                        additional_description );
        mbedtls_printf( "(%s) Peer CID (length %u Bytes): ",
                        additional_description,
                        (unsigned) peer_cid_len );
        while( idx < peer_cid_len )
        {
            mbedtls_printf( "%02x ", peer_cid[ idx ] );
            idx++;
        }
        mbedtls_printf( "\n" );
    }

    return( 0 );
}
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */

int main( int argc, char *argv[] )
{
    int ret = 0, len, written, frags, exchanges_left;
    int query_config_ret = 0;
    io_ctx_t io_ctx;
    unsigned char* buf = 0;
#if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED)
#if defined(MBEDTLS_USE_PSA_CRYPTO)
    psa_algorithm_t alg = 0;
    mbedtls_svc_key_id_t psk_slot = MBEDTLS_SVC_KEY_ID_INIT;
#endif /* MBEDTLS_USE_PSA_CRYPTO */
    unsigned char psk[MBEDTLS_PSK_MAX_LEN];
    size_t psk_len = 0;
    psk_entry *psk_info = NULL;
#endif
    const char *pers = "ssl_server2";
    unsigned char client_ip[16] = { 0 };
    size_t cliip_len;
#if defined(MBEDTLS_SSL_COOKIE_C)
    mbedtls_ssl_cookie_ctx cookie_ctx;
#endif

#if defined(MBEDTLS_X509_CRT_PARSE_C)
    mbedtls_x509_crt_profile crt_profile_for_test = mbedtls_x509_crt_profile_default;
#endif
    mbedtls_ssl_context ssl;
    mbedtls_ssl_config conf;
#if defined(MBEDTLS_TIMING_C)
    mbedtls_timing_delay_context timer;
#endif
#if defined(MBEDTLS_SSL_RENEGOTIATION)
    unsigned char renego_period[8] = { 0 };
#endif
#if defined(MBEDTLS_X509_CRT_PARSE_C)
    uint32_t flags;
    mbedtls_x509_crt cacert;
    mbedtls_x509_crt srvcert;
    mbedtls_pk_context pkey;
    mbedtls_x509_crt srvcert2;
    mbedtls_pk_context pkey2;
#if defined(MBEDTLS_USE_PSA_CRYPTO)
    mbedtls_svc_key_id_t key_slot = MBEDTLS_SVC_KEY_ID_INIT; /* invalid key slot */
    mbedtls_svc_key_id_t key_slot2 = MBEDTLS_SVC_KEY_ID_INIT; /* invalid key slot */
#endif
    int key_cert_init = 0, key_cert_init2 = 0;
#if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
    ssl_async_key_context_t ssl_async_keys;
#endif /* MBEDTLS_SSL_ASYNC_PRIVATE */
#endif /* MBEDTLS_X509_CRT_PARSE_C */
#if defined(MBEDTLS_DHM_C) && defined(MBEDTLS_FS_IO)
    mbedtls_dhm_context dhm;
#endif
#if defined(MBEDTLS_SSL_CACHE_C)
    mbedtls_ssl_cache_context cache;
#endif
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
    mbedtls_ssl_ticket_context ticket_ctx;
#endif
#if defined(SNI_OPTION)
    sni_entry *sni_info = NULL;
#endif
#if defined(MBEDTLS_ECP_C)
    uint16_t group_list[CURVE_LIST_SIZE];
    const mbedtls_ecp_curve_info * curve_cur;
#endif
#if defined(MBEDTLS_SSL_ALPN)
    const char *alpn_list[ALPN_LIST_SIZE];
#endif
#if defined(MBEDTLS_MEMORY_BUFFER_ALLOC_C)
    unsigned char alloc_buf[MEMORY_HEAP_SIZE];
#endif
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
    unsigned char cid[MBEDTLS_SSL_CID_IN_LEN_MAX];
    unsigned char cid_renego[MBEDTLS_SSL_CID_IN_LEN_MAX];
    size_t cid_len = 0;
    size_t cid_renego_len = 0;
#endif
#if defined(MBEDTLS_SSL_CONTEXT_SERIALIZATION)
    unsigned char *context_buf = NULL;
    size_t context_buf_len = 0;
#endif

#if defined(MBEDTLS_SSL_PROTO_TLS1_3) && \
    defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
    uint16_t sig_alg_list[SIG_ALG_LIST_SIZE];
#endif /* MBEDTLS_SSL_PROTO_TLS1_3 && MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */

    int i;
    char *p, *q;
    const int *list;
#if defined(MBEDTLS_USE_PSA_CRYPTO)
    psa_status_t status;
#endif
    unsigned char eap_tls_keymaterial[16];
    unsigned char eap_tls_iv[8];
    const char* eap_tls_label = "client EAP encryption";
    eap_tls_keys eap_tls_keying;
#if defined( MBEDTLS_SSL_DTLS_SRTP )
    /*! master keys and master salt for SRTP generated during handshake */
     unsigned char dtls_srtp_key_material[MBEDTLS_TLS_SRTP_MAX_KEY_MATERIAL_LENGTH];
     const char* dtls_srtp_label = "EXTRACTOR-dtls_srtp";
     dtls_srtp_keys dtls_srtp_keying;
     const mbedtls_ssl_srtp_profile default_profiles[] = {
         MBEDTLS_TLS_SRTP_AES128_CM_HMAC_SHA1_80,
         MBEDTLS_TLS_SRTP_AES128_CM_HMAC_SHA1_32,
         MBEDTLS_TLS_SRTP_NULL_HMAC_SHA1_80,
         MBEDTLS_TLS_SRTP_NULL_HMAC_SHA1_32,
         MBEDTLS_TLS_SRTP_UNSET
     };
#endif /* MBEDTLS_SSL_DTLS_SRTP */

#if defined(MBEDTLS_MEMORY_BUFFER_ALLOC_C)
    mbedtls_memory_buffer_alloc_init( alloc_buf, sizeof(alloc_buf) );
#if defined(MBEDTLS_MEMORY_DEBUG)
    size_t current_heap_memory, peak_heap_memory, heap_blocks;
#endif  /* MBEDTLS_MEMORY_DEBUG */
#endif  /* MBEDTLS_MEMORY_BUFFER_ALLOC_C */

#if defined(MBEDTLS_TEST_HOOKS)
    test_hooks_init( );
#endif /* MBEDTLS_TEST_HOOKS */

    /*
     * Make sure memory references are valid in case we exit early.
     */
    mbedtls_net_init( &client_fd );
    mbedtls_net_init( &listen_fd );
    mbedtls_ssl_init( &ssl );
    mbedtls_ssl_config_init( &conf );
    rng_init( &rng );
#if defined(MBEDTLS_X509_CRT_PARSE_C)
    mbedtls_x509_crt_init( &cacert );
    mbedtls_x509_crt_init( &srvcert );
    mbedtls_pk_init( &pkey );
    mbedtls_x509_crt_init( &srvcert2 );
    mbedtls_pk_init( &pkey2 );
#if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
    memset( &ssl_async_keys, 0, sizeof( ssl_async_keys ) );
#endif
#endif
#if defined(MBEDTLS_DHM_C) && defined(MBEDTLS_FS_IO)
    mbedtls_dhm_init( &dhm );
#endif
#if defined(MBEDTLS_SSL_CACHE_C)
    mbedtls_ssl_cache_init( &cache );
#endif
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
    mbedtls_ssl_ticket_init( &ticket_ctx );
#endif
#if defined(MBEDTLS_SSL_ALPN)
    memset( (void *) alpn_list, 0, sizeof( alpn_list ) );
#endif
#if defined(MBEDTLS_SSL_COOKIE_C)
    mbedtls_ssl_cookie_init( &cookie_ctx );
#endif

#if defined(MBEDTLS_USE_PSA_CRYPTO)
    status = psa_crypto_init();
    if( status != PSA_SUCCESS )
    {
        mbedtls_fprintf( stderr, "Failed to initialize PSA Crypto implementation: %d\n",
                         (int) status );
        ret = MBEDTLS_ERR_SSL_HW_ACCEL_FAILED;
        goto exit;
    }
#endif  /* MBEDTLS_USE_PSA_CRYPTO */
#if defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG)
    mbedtls_test_enable_insecure_external_rng( );
#endif  /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */

#if !defined(_WIN32)
    /* Abort cleanly on SIGTERM and SIGINT */
    signal( SIGTERM, term_handler );
    signal( SIGINT, term_handler );
#endif

    if( argc == 0 )
    {
    usage:
        if( ret == 0 )
            ret = 1;

        mbedtls_printf( USAGE1 );
        mbedtls_printf( USAGE2 );
        mbedtls_printf( USAGE3 );
        mbedtls_printf( USAGE4 );

        list = mbedtls_ssl_list_ciphersuites();
        while( *list )
        {
            mbedtls_printf(" %-42s", mbedtls_ssl_get_ciphersuite_name( *list ) );
            list++;
            if( !*list )
                break;
            mbedtls_printf(" %s\n", mbedtls_ssl_get_ciphersuite_name( *list ) );
            list++;
        }
        mbedtls_printf("\n");
        goto exit;
    }

    opt.buffer_size         = DFL_IO_BUF_LEN;
    opt.server_addr         = DFL_SERVER_ADDR;
    opt.server_port         = DFL_SERVER_PORT;
    opt.debug_level         = DFL_DEBUG_LEVEL;
    opt.event               = DFL_EVENT;
    opt.response_size       = DFL_RESPONSE_SIZE;
    opt.nbio                = DFL_NBIO;
    opt.cid_enabled         = DFL_CID_ENABLED;
    opt.cid_enabled_renego  = DFL_CID_ENABLED_RENEGO;
    opt.cid_val             = DFL_CID_VALUE;
    opt.cid_val_renego      = DFL_CID_VALUE_RENEGO;
    opt.read_timeout        = DFL_READ_TIMEOUT;
    opt.ca_file             = DFL_CA_FILE;
    opt.ca_path             = DFL_CA_PATH;
    opt.crt_file            = DFL_CRT_FILE;
    opt.key_file            = DFL_KEY_FILE;
    opt.key_opaque          = DFL_KEY_OPAQUE;
    opt.key_pwd             = DFL_KEY_PWD;
    opt.crt_file2           = DFL_CRT_FILE2;
    opt.key_file2           = DFL_KEY_FILE2;
    opt.key_pwd2            = DFL_KEY_PWD2;
    opt.async_operations    = DFL_ASYNC_OPERATIONS;
    opt.async_private_delay1 = DFL_ASYNC_PRIVATE_DELAY1;
    opt.async_private_delay2 = DFL_ASYNC_PRIVATE_DELAY2;
    opt.async_private_error = DFL_ASYNC_PRIVATE_ERROR;
    opt.psk                 = DFL_PSK;
#if defined(MBEDTLS_USE_PSA_CRYPTO)
    opt.psk_opaque          = DFL_PSK_OPAQUE;
    opt.psk_list_opaque     = DFL_PSK_LIST_OPAQUE;
#endif
#if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK)
    opt.ca_callback         = DFL_CA_CALLBACK;
#endif
    opt.psk_identity        = DFL_PSK_IDENTITY;
    opt.psk_list            = DFL_PSK_LIST;
    opt.ecjpake_pw          = DFL_ECJPAKE_PW;
    opt.force_ciphersuite[0]= DFL_FORCE_CIPHER;
#if defined(MBEDTLS_SSL_PROTO_TLS1_3)
    opt.tls13_kex_modes     = DFL_TLS1_3_KEX_MODES;
#endif /* MBEDTLS_SSL_PROTO_TLS1_3 */
    opt.renegotiation       = DFL_RENEGOTIATION;
    opt.allow_legacy        = DFL_ALLOW_LEGACY;
    opt.renegotiate         = DFL_RENEGOTIATE;
    opt.renego_delay        = DFL_RENEGO_DELAY;
    opt.renego_period       = DFL_RENEGO_PERIOD;
    opt.exchanges           = DFL_EXCHANGES;
    opt.min_version         = DFL_MIN_VERSION;
    opt.max_version         = DFL_MAX_VERSION;
    opt.allow_sha1          = DFL_SHA1;
    opt.auth_mode           = DFL_AUTH_MODE;
    opt.cert_req_ca_list    = DFL_CERT_REQ_CA_LIST;
    opt.mfl_code            = DFL_MFL_CODE;
    opt.trunc_hmac          = DFL_TRUNC_HMAC;
    opt.tickets             = DFL_TICKETS;
    opt.ticket_timeout      = DFL_TICKET_TIMEOUT;
    opt.ticket_aead         = DFL_TICKET_AEAD;
    opt.cache_max           = DFL_CACHE_MAX;
    opt.cache_timeout       = DFL_CACHE_TIMEOUT;
    opt.sni                 = DFL_SNI;
    opt.alpn_string         = DFL_ALPN_STRING;
    opt.curves              = DFL_CURVES;
    opt.sig_algs            = DFL_SIG_ALGS;
    opt.dhm_file            = DFL_DHM_FILE;
    opt.transport           = DFL_TRANSPORT;
    opt.cookies             = DFL_COOKIES;
    opt.anti_replay         = DFL_ANTI_REPLAY;
    opt.hs_to_min           = DFL_HS_TO_MIN;
    opt.hs_to_max           = DFL_HS_TO_MAX;
    opt.dtls_mtu            = DFL_DTLS_MTU;
    opt.dgram_packing       = DFL_DGRAM_PACKING;
    opt.badmac_limit        = DFL_BADMAC_LIMIT;
    opt.extended_ms         = DFL_EXTENDED_MS;
    opt.etm                 = DFL_ETM;
    opt.serialize           = DFL_SERIALIZE;
    opt.context_file        = DFL_CONTEXT_FILE;
    opt.eap_tls             = DFL_EAP_TLS;
    opt.reproducible        = DFL_REPRODUCIBLE;
    opt.nss_keylog          = DFL_NSS_KEYLOG;
    opt.nss_keylog_file     = DFL_NSS_KEYLOG_FILE;
    opt.query_config_mode   = DFL_QUERY_CONFIG_MODE;
    opt.use_srtp            = DFL_USE_SRTP;
    opt.force_srtp_profile  = DFL_SRTP_FORCE_PROFILE;
    opt.support_mki         = DFL_SRTP_SUPPORT_MKI;

    for( i = 1; i < argc; i++ )
    {
        p = argv[i];
        if( ( q = strchr( p, '=' ) ) == NULL )
            goto usage;
        *q++ = '\0';

        if( strcmp( p, "server_port" ) == 0 )
            opt.server_port = q;
        else if( strcmp( p, "server_addr" ) == 0 )
            opt.server_addr = q;
        else if( strcmp( p, "dtls" ) == 0 )
        {
            int t = atoi( q );
            if( t == 0 )
                opt.transport = MBEDTLS_SSL_TRANSPORT_STREAM;
            else if( t == 1 )
                opt.transport = MBEDTLS_SSL_TRANSPORT_DATAGRAM;
            else
                goto usage;
        }
        else if( strcmp( p, "debug_level" ) == 0 )
        {
            opt.debug_level = atoi( q );
            if( opt.debug_level < 0 || opt.debug_level > 65535 )
                goto usage;
        }
        else if( strcmp( p, "nbio" ) == 0 )
        {
            opt.nbio = atoi( q );
            if( opt.nbio < 0 || opt.nbio > 2 )
                goto usage;
        }
        else if( strcmp( p, "event" ) == 0 )
        {
            opt.event = atoi( q );
            if( opt.event < 0 || opt.event > 2 )
                goto usage;
        }
        else if( strcmp( p, "read_timeout" ) == 0 )
            opt.read_timeout = atoi( q );
        else if( strcmp( p, "buffer_size" ) == 0 )
        {
            opt.buffer_size = atoi( q );
            if( opt.buffer_size < 1 )
                goto usage;
        }
        else if( strcmp( p, "response_size" ) == 0 )
        {
            opt.response_size = atoi( q );
            if( opt.response_size < 0 || opt.response_size > MBEDTLS_SSL_OUT_CONTENT_LEN )
                goto usage;
            if( opt.buffer_size < opt.response_size )
                opt.buffer_size = opt.response_size;
        }
        else if( strcmp( p, "ca_file" ) == 0 )
            opt.ca_file = q;
        else if( strcmp( p, "ca_path" ) == 0 )
            opt.ca_path = q;
        else if( strcmp( p, "crt_file" ) == 0 )
            opt.crt_file = q;
        else if( strcmp( p, "key_file" ) == 0 )
            opt.key_file = q;
        else if( strcmp( p, "key_pwd" ) == 0 )
            opt.key_pwd = q;
#if defined(MBEDTLS_USE_PSA_CRYPTO) && defined(MBEDTLS_X509_CRT_PARSE_C)
        else if( strcmp( p, "key_opaque" ) == 0 )
            opt.key_opaque = atoi( q );
#endif
        else if( strcmp( p, "crt_file2" ) == 0 )
            opt.crt_file2 = q;
        else if( strcmp( p, "key_file2" ) == 0 )
            opt.key_file2 = q;
        else if( strcmp( p, "key_pwd2" ) == 0 )
            opt.key_pwd2 = q;
        else if( strcmp( p, "dhm_file" ) == 0 )
            opt.dhm_file = q;
#if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
        else if( strcmp( p, "async_operations" ) == 0 )
            opt.async_operations = q;
        else if( strcmp( p, "async_private_delay1" ) == 0 )
            opt.async_private_delay1 = atoi( q );
        else if( strcmp( p, "async_private_delay2" ) == 0 )
            opt.async_private_delay2 = atoi( q );
        else if( strcmp( p, "async_private_error" ) == 0 )
        {
            int n = atoi( q );
            if( n < -SSL_ASYNC_INJECT_ERROR_MAX ||
                n > SSL_ASYNC_INJECT_ERROR_MAX )
            {
                ret = 2;
                goto usage;
            }
            opt.async_private_error = n;
        }
#endif /* MBEDTLS_SSL_ASYNC_PRIVATE */
#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
        else if( strcmp( p, "cid" ) == 0 )
        {
            opt.cid_enabled = atoi( q );
            if( opt.cid_enabled != 0 && opt.cid_enabled != 1 )
                goto usage;
        }
        else if( strcmp( p, "cid_renego" ) == 0 )
        {
            opt.cid_enabled_renego = atoi( q );
            if( opt.cid_enabled_renego != 0 && opt.cid_enabled_renego != 1 )
                goto usage;
        }
        else if( strcmp( p, "cid_val" ) == 0 )
        {
            opt.cid_val = q;
        }
        else if( strcmp( p, "cid_val_renego" ) == 0 )
        {
            opt.cid_val_renego = q;
        }
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
        else if( strcmp( p, "psk" ) == 0 )
            opt.psk = q;
#if defined(MBEDTLS_USE_PSA_CRYPTO)
        else if( strcmp( p, "psk_opaque" ) == 0 )
            opt.psk_opaque = atoi( q );
        else if( strcmp( p, "psk_list_opaque" ) == 0 )
            opt.psk_list_opaque = atoi( q );
#endif
#if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK)
        else if( strcmp( p, "ca_callback" ) == 0)
            opt.ca_callback = atoi( q );
#endif
        else if( strcmp( p, "psk_identity" ) == 0 )
            opt.psk_identity = q;
        else if( strcmp( p, "psk_list" ) == 0 )
            opt.psk_list = q;
        else if( strcmp( p, "ecjpake_pw" ) == 0 )
            opt.ecjpake_pw = q;
        else if( strcmp( p, "force_ciphersuite" ) == 0 )
        {
            opt.force_ciphersuite[0] = mbedtls_ssl_get_ciphersuite_id( q );

            if( opt.force_ciphersuite[0] == 0 )
            {
                ret = 2;
                goto usage;
            }
            opt.force_ciphersuite[1] = 0;
        }
        else if( strcmp( p, "curves" ) == 0 )
            opt.curves = q;
#if defined(MBEDTLS_SSL_PROTO_TLS1_3) && \
    defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
        else if( strcmp( p, "sig_algs" ) == 0 )
            opt.sig_algs = q;
#endif /* MBEDTLS_SSL_PROTO_TLS1_3 && MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
        else if( strcmp( p, "renegotiation" ) == 0 )
        {
            opt.renegotiation = (atoi( q )) ?
                MBEDTLS_SSL_RENEGOTIATION_ENABLED :
                MBEDTLS_SSL_RENEGOTIATION_DISABLED;
        }
        else if( strcmp( p, "allow_legacy" ) == 0 )
        {
            switch( atoi( q ) )
            {
                case -1:
                    opt.allow_legacy = MBEDTLS_SSL_LEGACY_BREAK_HANDSHAKE;
                    break;
                case 0:
                    opt.allow_legacy = MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION;
                    break;
                case 1:
                    opt.allow_legacy = MBEDTLS_SSL_LEGACY_ALLOW_RENEGOTIATION;
                    break;
                default: goto usage;
            }
        }
        else if( strcmp( p, "renegotiate" ) == 0 )
        {
            opt.renegotiate = atoi( q );
            if( opt.renegotiate < 0 || opt.renegotiate > 1 )
                goto usage;
        }
        else if( strcmp( p, "renego_delay" ) == 0 )
        {
            opt.renego_delay = atoi( q );
        }
        else if( strcmp( p, "renego_period" ) == 0 )
        {
#if defined(_MSC_VER)
            opt.renego_period = _strtoui64( q, NULL, 10 );
#else
            if( sscanf( q, "%" SCNu64, &opt.renego_period ) != 1 )
                goto usage;
#endif /* _MSC_VER */
            if( opt.renego_period < 2 )
                goto usage;
        }
        else if( strcmp( p, "exchanges" ) == 0 )
        {
            opt.exchanges = atoi( q );
            if( opt.exchanges < 0 )
                goto usage;
        }
#if defined(MBEDTLS_SSL_PROTO_TLS1_3)
        else if( strcmp( p, "tls13_kex_modes" ) == 0 )
        {
            if( strcmp( q, "psk" ) == 0 )
                opt.tls13_kex_modes = MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK;
            else if( strcmp(q, "psk_ephemeral" ) == 0 )
                opt.tls13_kex_modes = MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL;
            else if( strcmp(q, "ephemeral" ) == 0 )
                opt.tls13_kex_modes = MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL;
            else if( strcmp(q, "ephemeral_all" ) == 0 )
                opt.tls13_kex_modes = MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ALL;
            else if( strcmp( q, "psk_all" ) == 0 )
                opt.tls13_kex_modes = MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ALL;
            else if( strcmp( q, "all" ) == 0 )
                opt.tls13_kex_modes = MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_ALL;
            else goto usage;
        }
#endif /* MBEDTLS_SSL_PROTO_TLS1_3 */

        else if( strcmp( p, "min_version" ) == 0 )
        {
            if( strcmp( q, "tls12" ) == 0 ||
                     strcmp( q, "dtls12" ) == 0 )
                opt.min_version = MBEDTLS_SSL_MINOR_VERSION_3;
#if defined(MBEDTLS_SSL_PROTO_TLS1_3)
            else if( strcmp( q, "tls13" ) == 0 )
                opt.min_version = MBEDTLS_SSL_MINOR_VERSION_4;
#endif /* MBEDTLS_SSL_PROTO_TLS1_3 */
            else
                goto usage;
        }
        else if( strcmp( p, "max_version" ) == 0 )
        {
            if( strcmp( q, "tls12" ) == 0 ||
                     strcmp( q, "dtls12" ) == 0 )
                opt.max_version = MBEDTLS_SSL_MINOR_VERSION_3;
#if defined(MBEDTLS_SSL_PROTO_TLS1_3)
            else if( strcmp( q, "tls13" ) == 0 )
                opt.max_version = MBEDTLS_SSL_MINOR_VERSION_4;
#endif /* MBEDTLS_SSL_PROTO_TLS1_3 */
            else
                goto usage;
        }
        else if( strcmp( p, "allow_sha1" ) == 0 )
        {
            switch( atoi( q ) )
            {
                case 0:     opt.allow_sha1 = 0;   break;
                case 1:     opt.allow_sha1 = 1;    break;
                default:    goto usage;
            }
        }
        else if( strcmp( p, "force_version" ) == 0 )
        {
            if( strcmp( q, "tls12" ) == 0 )
            {
                opt.min_version = MBEDTLS_SSL_MINOR_VERSION_3;
                opt.max_version = MBEDTLS_SSL_MINOR_VERSION_3;
            }
            else if( strcmp( q, "dtls12" ) == 0 )
            {
                opt.min_version = MBEDTLS_SSL_MINOR_VERSION_3;
                opt.max_version = MBEDTLS_SSL_MINOR_VERSION_3;
                opt.transport = MBEDTLS_SSL_TRANSPORT_DATAGRAM;
            }
#if defined(MBEDTLS_SSL_PROTO_TLS1_3)
            else if( strcmp( q, "tls13" ) == 0 )
            {
                opt.min_version = MBEDTLS_SSL_MINOR_VERSION_4;
                opt.max_version = MBEDTLS_SSL_MINOR_VERSION_4;
            }
#endif /* MBEDTLS_SSL_PROTO_TLS1_3 */
            else
                goto usage;
        }
        else if( strcmp( p, "auth_mode" ) == 0 )
        {
            if( ( opt.auth_mode = get_auth_mode( q ) ) < 0 )
                goto usage;
        }
        else if( strcmp( p, "cert_req_ca_list" ) == 0 )
        {
            opt.cert_req_ca_list = atoi( q );
            if( opt.cert_req_ca_list < 0 || opt.cert_req_ca_list > 1 )
                goto usage;
        }
        else if( strcmp( p, "max_frag_len" ) == 0 )
        {
            if( strcmp( q, "512" ) == 0 )
                opt.mfl_code = MBEDTLS_SSL_MAX_FRAG_LEN_512;
            else if( strcmp( q, "1024" ) == 0 )
                opt.mfl_code = MBEDTLS_SSL_MAX_FRAG_LEN_1024;
            else if( strcmp( q, "2048" ) == 0 )
                opt.mfl_code = MBEDTLS_SSL_MAX_FRAG_LEN_2048;
            else if( strcmp( q, "4096" ) == 0 )
                opt.mfl_code = MBEDTLS_SSL_MAX_FRAG_LEN_4096;
            else
                goto usage;
        }
        else if( strcmp( p, "alpn" ) == 0 )
        {
            opt.alpn_string = q;
        }
        else if( strcmp( p, "trunc_hmac" ) == 0 )
        {
            switch( atoi( q ) )
            {
                case 0: opt.trunc_hmac = MBEDTLS_SSL_TRUNC_HMAC_DISABLED; break;
                case 1: opt.trunc_hmac = MBEDTLS_SSL_TRUNC_HMAC_ENABLED; break;
                default: goto usage;
            }
        }
        else if( strcmp( p, "extended_ms" ) == 0 )
        {
            switch( atoi( q ) )
            {
                case 0:
                    opt.extended_ms = MBEDTLS_SSL_EXTENDED_MS_DISABLED;
                    break;
                case 1:
                    opt.extended_ms = MBEDTLS_SSL_EXTENDED_MS_ENABLED;
                    break;
                default: goto usage;
            }
        }
        else if( strcmp( p, "etm" ) == 0 )
        {
            switch( atoi( q ) )
            {
                case 0: opt.etm = MBEDTLS_SSL_ETM_DISABLED; break;
                case 1: opt.etm = MBEDTLS_SSL_ETM_ENABLED; break;
                default: goto usage;
            }
        }
        else if( strcmp( p, "tickets" ) == 0 )
        {
            opt.tickets = atoi( q );
            if( opt.tickets < 0 || opt.tickets > 1 )
                goto usage;
        }
        else if( strcmp( p, "ticket_timeout" ) == 0 )
        {
            opt.ticket_timeout = atoi( q );
            if( opt.ticket_timeout < 0 )
                goto usage;
        }
        else if( strcmp( p, "ticket_aead" ) == 0 )
        {
            const mbedtls_cipher_info_t *ci = mbedtls_cipher_info_from_string( q );

            if( ci == NULL )
                goto usage;
            opt.ticket_aead = mbedtls_cipher_info_get_type( ci );
        }
        else if( strcmp( p, "cache_max" ) == 0 )
        {
            opt.cache_max = atoi( q );
            if( opt.cache_max < 0 )
                goto usage;
        }
        else if( strcmp( p, "cache_timeout" ) == 0 )
        {
            opt.cache_timeout = atoi( q );
            if( opt.cache_timeout < 0 )
                goto usage;
        }
        else if( strcmp( p, "cookies" ) == 0 )
        {
            opt.cookies = atoi( q );
            if( opt.cookies < -1 || opt.cookies > 1)
                goto usage;
        }
        else if( strcmp( p, "anti_replay" ) == 0 )
        {
            opt.anti_replay = atoi( q );
            if( opt.anti_replay < 0 || opt.anti_replay > 1)
                goto usage;
        }
        else if( strcmp( p, "badmac_limit" ) == 0 )
        {
            opt.badmac_limit = atoi( q );
            if( opt.badmac_limit < 0 )
                goto usage;
        }
        else if( strcmp( p, "hs_timeout" ) == 0 )
        {
            if( ( p = strchr( q, '-' ) ) == NULL )
                goto usage;
            *p++ = '\0';
            opt.hs_to_min = atoi( q );
            opt.hs_to_max = atoi( p );
            if( opt.hs_to_min == 0 || opt.hs_to_max < opt.hs_to_min )
                goto usage;
        }
        else if( strcmp( p, "mtu" ) == 0 )
        {
            opt.dtls_mtu = atoi( q );
            if( opt.dtls_mtu < 0 )
                goto usage;
        }
        else if( strcmp( p, "dgram_packing" ) == 0 )
        {
            opt.dgram_packing = atoi( q );
            if( opt.dgram_packing != 0 &&
                opt.dgram_packing != 1 )
            {
                goto usage;
            }
        }
        else if( strcmp( p, "sni" ) == 0 )
        {
            opt.sni = q;
        }
        else if( strcmp( p, "query_config" ) == 0 )
        {
            opt.query_config_mode = 1;
            query_config_ret = query_config( q );
            goto exit;
        }
        else if( strcmp( p, "serialize") == 0 )
        {
            opt.serialize = atoi( q );
            if( opt.serialize < 0 || opt.serialize > 2)
                goto usage;
        }
        else if( strcmp( p, "context_file") == 0 )
        {
            opt.context_file = q;
        }
        else if( strcmp( p, "eap_tls" ) == 0 )
        {
            opt.eap_tls = atoi( q );
            if( opt.eap_tls < 0 || opt.eap_tls > 1 )
                goto usage;
        }
        else if( strcmp( p, "reproducible" ) == 0 )
        {
            opt.reproducible = 1;
        }
        else if( strcmp( p, "nss_keylog" ) == 0 )
        {
            opt.nss_keylog = atoi( q );
            if( opt.nss_keylog < 0 || opt.nss_keylog > 1 )
                goto usage;
        }
        else if( strcmp( p, "nss_keylog_file" ) == 0 )
        {
            opt.nss_keylog_file = q;
        }
        else if( strcmp( p, "use_srtp" ) == 0 )
        {
            opt.use_srtp = atoi ( q );
        }
        else if( strcmp( p, "srtp_force_profile" ) == 0 )
        {
            opt.force_srtp_profile = atoi( q );
        }
        else if( strcmp( p, "support_mki" ) == 0 )
        {
            opt.support_mki = atoi( q );
        }
        else
            goto usage;
    }

    if( opt.nss_keylog != 0 && opt.eap_tls != 0 )
    {
        mbedtls_printf( "Error: eap_tls and nss_keylog options cannot be used together.\n" );
        goto usage;
    }

    /* Event-driven IO is incompatible with the above custom
     * receive and send functions, as the polling builds on
     * refers to the underlying net_context. */
    if( opt.event == 1 && opt.nbio != 1 )
    {
        mbedtls_printf( "Warning: event-driven IO mandates nbio=1 - overwrite\n" );
        opt.nbio = 1;
    }

#if defined(MBEDTLS_DEBUG_C)
    mbedtls_debug_set_threshold( opt.debug_level );
#endif
    buf = mbedtls_calloc( 1, opt.buffer_size + 1 );
    if( buf == NULL )
    {
        mbedtls_printf( "Could not allocate %u bytes\n", opt.buffer_size );
        ret = 3;
        goto exit;
    }

#if defined(MBEDTLS_USE_PSA_CRYPTO)
    if( opt.psk_opaque != 0 )
    {
        if( strlen( opt.psk ) == 0 )
        {
            mbedtls_printf( "psk_opaque set but no psk to be imported specified.\n" );
            ret = 2;
            goto usage;
        }

        if( opt.force_ciphersuite[0] <= 0 )
        {
            mbedtls_printf( "opaque PSKs are only supported in conjunction with forcing TLS 1.2 and a PSK-only ciphersuite through the 'force_ciphersuite' option.\n" );
            ret = 2;
            goto usage;
        }
    }

    if( opt.psk_list_opaque != 0 )
    {
        if( opt.psk_list == NULL )
        {
            mbedtls_printf( "psk_slot set but no psk to be imported specified.\n" );
            ret = 2;
            goto usage;
        }

        if( opt.force_ciphersuite[0] <= 0 )
        {
            mbedtls_printf( "opaque PSKs are only supported in conjunction with forcing TLS 1.2 and a PSK-only ciphersuite through the 'force_ciphersuite' option.\n" );
            ret = 2;
            goto usage;
        }
    }
#endif /* MBEDTLS_USE_PSA_CRYPTO */

    if( opt.force_ciphersuite[0] > 0 )
    {
        const mbedtls_ssl_ciphersuite_t *ciphersuite_info;
        ciphersuite_info =
            mbedtls_ssl_ciphersuite_from_id( opt.force_ciphersuite[0] );

        if( opt.max_version != -1 &&
            ciphersuite_info->min_minor_ver > opt.max_version )
        {
            mbedtls_printf( "forced ciphersuite not allowed with this protocol version\n" );
            ret = 2;
            goto usage;
        }
        if( opt.min_version != -1 &&
            ciphersuite_info->max_minor_ver < opt.min_version )
        {
            mbedtls_printf( "forced ciphersuite not allowed with this protocol version\n" );
            ret = 2;
            goto usage;
        }

        /* If we select a version that's not supported by
         * this suite, then there will be no common ciphersuite... */
        if( opt.max_version == -1 ||
            opt.max_version > ciphersuite_info->max_minor_ver )
        {
            opt.max_version = ciphersuite_info->max_minor_ver;
        }
        if( opt.min_version < ciphersuite_info->min_minor_ver )
        {
            opt.min_version = ciphersuite_info->min_minor_ver;
        }

#if defined(MBEDTLS_USE_PSA_CRYPTO)
        if( opt.psk_opaque != 0 || opt.psk_list_opaque != 0 )
        {
            /* Ensure that the chosen ciphersuite is PSK-only; we must know
             * the ciphersuite in advance to set the correct policy for the
             * PSK key slot. This limitation might go away in the future. */
            if( ciphersuite_info->key_exchange != MBEDTLS_KEY_EXCHANGE_PSK ||
                opt.min_version != MBEDTLS_SSL_MINOR_VERSION_3 )
            {
                mbedtls_printf( "opaque PSKs are only supported in conjunction with forcing TLS 1.2 and a PSK-only ciphersuite through the 'force_ciphersuite' option.\n" );
                ret = 2;
                goto usage;
            }

            /* Determine KDF algorithm the opaque PSK will be used in. */
#if defined(MBEDTLS_SHA384_C)
            if( ciphersuite_info->mac == MBEDTLS_MD_SHA384 )
                alg = PSA_ALG_TLS12_PSK_TO_MS(PSA_ALG_SHA_384);
            else
#endif /* MBEDTLS_SHA384_C */
                alg = PSA_ALG_TLS12_PSK_TO_MS(PSA_ALG_SHA_256);
        }
#endif /* MBEDTLS_USE_PSA_CRYPTO */
    }

#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
    if( mbedtls_test_unhexify( cid, sizeof( cid ),
                               opt.cid_val, &cid_len ) != 0 )
    {
        mbedtls_printf( "CID not valid hex\n" );
        goto exit;
    }

    /* Keep CID settings for renegotiation unless
     * specified otherwise. */
    if( opt.cid_enabled_renego == DFL_CID_ENABLED_RENEGO )
        opt.cid_enabled_renego = opt.cid_enabled;
    if( opt.cid_val_renego == DFL_CID_VALUE_RENEGO )
        opt.cid_val_renego = opt.cid_val;

    if( mbedtls_test_unhexify( cid_renego, sizeof( cid_renego ),
                               opt.cid_val_renego, &cid_renego_len ) != 0 )
    {
        mbedtls_printf( "CID not valid hex\n" );
        goto exit;
    }
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */

#if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED)
    /*
     * Unhexify the pre-shared key and parse the list if any given
     */
    if( mbedtls_test_unhexify( psk, sizeof( psk ),
                               opt.psk, &psk_len ) != 0 )
    {
        mbedtls_printf( "pre-shared key not valid hex\n" );
        goto exit;
    }

    if( opt.psk_list != NULL )
    {
        if( ( psk_info = psk_parse( opt.psk_list ) ) == NULL )
        {
            mbedtls_printf( "psk_list invalid" );
            goto exit;
        }
    }
#endif /* MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED */

#if defined(MBEDTLS_ECP_C)
    if( opt.curves != NULL )
    {
        p = (char *) opt.curves;
        i = 0;

        if( strcmp( p, "none" ) == 0 )
        {
            group_list[0] = 0;
        }
        else if( strcmp( p, "default" ) != 0 )
        {
            /* Leave room for a final NULL in curve list */
            while( i < CURVE_LIST_SIZE - 1 && *p != '\0' )
            {
                q = p;

                /* Terminate the current string */
                while( *p != ',' && *p != '\0' )
                    p++;
                if( *p == ',' )
                    *p++ = '\0';

                if( ( curve_cur = mbedtls_ecp_curve_info_from_name( q ) ) != NULL )
                {
                    group_list[i++] = curve_cur->tls_id;
                }
                else
                {
                    mbedtls_printf( "unknown curve %s\n", q );
                    mbedtls_printf( "supported curves: " );
                    for( curve_cur = mbedtls_ecp_curve_list();
                         curve_cur->grp_id != MBEDTLS_ECP_DP_NONE;
                         curve_cur++ )
                    {
                        mbedtls_printf( "%s ", curve_cur->name );
                    }
                    mbedtls_printf( "\n" );
                    goto exit;
                }
            }

            mbedtls_printf("Number of curves: %d\n", i );

            if( i == CURVE_LIST_SIZE - 1 && *p != '\0' )
            {
                mbedtls_printf( "curves list too long, maximum %d",
                                CURVE_LIST_SIZE - 1  );
                goto exit;
            }

            group_list[i] = 0;
        }
    }
#endif /* MBEDTLS_ECP_C */

#if defined(MBEDTLS_SSL_PROTO_TLS1_3) && \
    defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
    if( opt.sig_algs != NULL )
    {
        p = (char *) opt.sig_algs;
        i = 0;

        /* Leave room for a final MBEDTLS_TLS1_3_SIG_NONE in signature algorithm list (sig_alg_list). */
        while( i < SIG_ALG_LIST_SIZE - 1 && *p != '\0' )
        {
            q = p;

            /* Terminate the current string */
            while( *p != ',' && *p != '\0' )
                p++;
            if( *p == ',' )
                *p++ = '\0';

            if( strcmp( q, "ecdsa_secp256r1_sha256" ) == 0 )
            {
                sig_alg_list[i++] = MBEDTLS_TLS1_3_SIG_ECDSA_SECP256R1_SHA256;
            }
            else if( strcmp( q, "ecdsa_secp384r1_sha384" ) == 0 )
            {
                sig_alg_list[i++] = MBEDTLS_TLS1_3_SIG_ECDSA_SECP384R1_SHA384;
            }
            else if( strcmp( q, "ecdsa_secp521r1_sha512" ) == 0 )
            {
                sig_alg_list[i++] = MBEDTLS_TLS1_3_SIG_ECDSA_SECP521R1_SHA512;
            }
            else
            {
                mbedtls_printf( "unknown signature algorithm %s\n", q );
                mbedtls_printf( "supported signature algorithms: " );
                mbedtls_printf( "ecdsa_secp256r1_sha256 " );
                mbedtls_printf( "ecdsa_secp384r1_sha384 " );
                mbedtls_printf( "ecdsa_secp521r1_sha512 " );
                mbedtls_printf( "\n" );
                goto exit;
            }
        }

        if( i == ( SIG_ALG_LIST_SIZE - 1 ) && *p != '\0' )
        {
            mbedtls_printf( "signature algorithm list too long, maximum %d",
                            SIG_ALG_LIST_SIZE - 1 );
            goto exit;
        }

        sig_alg_list[i] = MBEDTLS_TLS1_3_SIG_NONE;
    }
#endif /* MBEDTLS_SSL_PROTO_TLS1_3 && MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */

#if defined(MBEDTLS_SSL_ALPN)
    if( opt.alpn_string != NULL )
    {
        p = (char *) opt.alpn_string;
        i = 0;

        /* Leave room for a final NULL in alpn_list */
        while( i < ALPN_LIST_SIZE - 1 && *p != '\0' )
        {
            alpn_list[i++] = p;

            /* Terminate the current string and move on to next one */
            while( *p != ',' && *p != '\0' )
                p++;
            if( *p == ',' )
                *p++ = '\0';
        }
    }
#endif /* MBEDTLS_SSL_ALPN */

    /*
     * 0. Initialize the RNG and the session data
     */
    mbedtls_printf( "\n  . Seeding the random number generator..." );
    fflush( stdout );

    ret = rng_seed( &rng, opt.reproducible, pers );
    if( ret != 0 )
        goto exit;
    mbedtls_printf( " ok\n" );

#if defined(MBEDTLS_X509_CRT_PARSE_C)
    /*
     * 1.1. Load the trusted CA
     */
    mbedtls_printf( "  . Loading the CA root certificate ..." );
    fflush( stdout );

    if( strcmp( opt.ca_path, "none" ) == 0 ||
        strcmp( opt.ca_file, "none" ) == 0 )
    {
        ret = 0;
    }
    else
#if defined(MBEDTLS_FS_IO)
    if( strlen( opt.ca_path ) )
        ret = mbedtls_x509_crt_parse_path( &cacert, opt.ca_path );
    else if( strlen( opt.ca_file ) )
        ret = mbedtls_x509_crt_parse_file( &cacert, opt.ca_file );
    else
#endif
    {
#if defined(MBEDTLS_PEM_PARSE_C)
        for( i = 0; mbedtls_test_cas[i] != NULL; i++ )
        {
            ret = mbedtls_x509_crt_parse( &cacert,
                                  (const unsigned char *) mbedtls_test_cas[i],
                                  mbedtls_test_cas_len[i] );
            if( ret != 0 )
                break;
        }
        if( ret == 0 )
#endif /* MBEDTLS_PEM_PARSE_C */
        for( i = 0; mbedtls_test_cas_der[i] != NULL; i++ )
        {
            ret = mbedtls_x509_crt_parse_der( &cacert,
                         (const unsigned char *) mbedtls_test_cas_der[i],
                         mbedtls_test_cas_der_len[i] );
            if( ret != 0 )
                break;
        }
    }
    if( ret < 0 )
    {
        mbedtls_printf( " failed\n  !  mbedtls_x509_crt_parse returned -0x%x\n\n", (unsigned int) -ret );
        goto exit;
    }

    mbedtls_printf( " ok (%d skipped)\n", ret );

    /*
     * 1.2. Load own certificate and private key
     */
    mbedtls_printf( "  . Loading the server cert. and key..." );
    fflush( stdout );

#if defined(MBEDTLS_FS_IO)
    if( strlen( opt.crt_file ) && strcmp( opt.crt_file, "none" ) != 0 )
    {
        key_cert_init++;
        if( ( ret = mbedtls_x509_crt_parse_file( &srvcert, opt.crt_file ) ) != 0 )
        {
            mbedtls_printf( " failed\n  !  mbedtls_x509_crt_parse_file returned -0x%x\n\n",
                    (unsigned int) -ret );
            goto exit;
        }
    }
    if( strlen( opt.key_file ) && strcmp( opt.key_file, "none" ) != 0 )
    {
        key_cert_init++;
        if( ( ret = mbedtls_pk_parse_keyfile( &pkey, opt.key_file,
                                              opt.key_pwd, rng_get, &rng ) ) != 0 )
        {
            mbedtls_printf( " failed\n  !  mbedtls_pk_parse_keyfile returned -0x%x\n\n", (unsigned int) -ret );
            goto exit;
        }
    }
    if( key_cert_init == 1 )
    {
        mbedtls_printf( " failed\n  !  crt_file without key_file or vice-versa\n\n" );
        goto exit;
    }

    if( strlen( opt.crt_file2 ) && strcmp( opt.crt_file2, "none" ) != 0 )
    {
        key_cert_init2++;
        if( ( ret = mbedtls_x509_crt_parse_file( &srvcert2, opt.crt_file2 ) ) != 0 )
        {
            mbedtls_printf( " failed\n  !  mbedtls_x509_crt_parse_file(2) returned -0x%x\n\n",
                    (unsigned int) -ret );
            goto exit;
        }
    }
    if( strlen( opt.key_file2 ) && strcmp( opt.key_file2, "none" ) != 0 )
    {
        key_cert_init2++;
        if( ( ret = mbedtls_pk_parse_keyfile( &pkey2, opt.key_file2,
                                              opt.key_pwd2, rng_get, &rng ) ) != 0 )
        {
            mbedtls_printf( " failed\n  !  mbedtls_pk_parse_keyfile(2) returned -0x%x\n\n",
                            (unsigned int) -ret );
            goto exit;
        }
    }
    if( key_cert_init2 == 1 )
    {
        mbedtls_printf( " failed\n  !  crt_file2 without key_file2 or vice-versa\n\n" );
        goto exit;
    }
#endif
    if( key_cert_init == 0 &&
        strcmp( opt.crt_file, "none" ) != 0 &&
        strcmp( opt.key_file, "none" ) != 0 &&
        key_cert_init2 == 0 &&
        strcmp( opt.crt_file2, "none" ) != 0 &&
        strcmp( opt.key_file2, "none" ) != 0 )
    {
#if defined(MBEDTLS_RSA_C)
        if( ( ret = mbedtls_x509_crt_parse( &srvcert,
                                    (const unsigned char *) mbedtls_test_srv_crt_rsa,
                                    mbedtls_test_srv_crt_rsa_len ) ) != 0 )
        {
            mbedtls_printf( " failed\n  !  mbedtls_x509_crt_parse returned -0x%x\n\n",
                            (unsigned int) -ret );
            goto exit;
        }
        if( ( ret = mbedtls_pk_parse_key( &pkey,
                                  (const unsigned char *) mbedtls_test_srv_key_rsa,
                                  mbedtls_test_srv_key_rsa_len, NULL, 0,
                                  rng_get, &rng ) ) != 0 )
        {
            mbedtls_printf( " failed\n  !  mbedtls_pk_parse_key returned -0x%x\n\n",
                            (unsigned int) -ret );
            goto exit;
        }
        key_cert_init = 2;
#endif /* MBEDTLS_RSA_C */
#if defined(MBEDTLS_ECDSA_C)
        if( ( ret = mbedtls_x509_crt_parse( &srvcert2,
                                    (const unsigned char *) mbedtls_test_srv_crt_ec,
                                    mbedtls_test_srv_crt_ec_len ) ) != 0 )
        {
            mbedtls_printf( " failed\n  !  x509_crt_parse2 returned -0x%x\n\n",
                            (unsigned int) -ret );
            goto exit;
        }
        if( ( ret = mbedtls_pk_parse_key( &pkey2,
                                  (const unsigned char *) mbedtls_test_srv_key_ec,
                                  mbedtls_test_srv_key_ec_len, NULL, 0,
                                  rng_get, &rng ) ) != 0 )
        {
            mbedtls_printf( " failed\n  !  pk_parse_key2 returned -0x%x\n\n",
                            (unsigned int) -ret );
            goto exit;
        }
        key_cert_init2 = 2;
#endif /* MBEDTLS_ECDSA_C */
    }

#if defined(MBEDTLS_USE_PSA_CRYPTO)
    if( opt.key_opaque != 0 )
    {
        if ( mbedtls_pk_get_type( &pkey ) == MBEDTLS_PK_ECKEY )
        {
            if( ( ret = mbedtls_pk_wrap_as_opaque( &pkey, &key_slot,
                                                PSA_ALG_ANY_HASH ) ) != 0 )
            {
                mbedtls_printf( " failed\n  !  "
                                "mbedtls_pk_wrap_as_opaque returned -0x%x\n\n", (unsigned int)  -ret );
                goto exit;
            }
        }

        if ( mbedtls_pk_get_type( &pkey2 ) == MBEDTLS_PK_ECKEY )
        {
            if( ( ret = mbedtls_pk_wrap_as_opaque( &pkey2, &key_slot2,
                                                PSA_ALG_ANY_HASH ) ) != 0 )
            {
                mbedtls_printf( " failed\n  !  "
                                "mbedtls_pk_wrap_as_opaque returned -0x%x\n\n", (unsigned int)  -ret );
                goto exit;
            }
        }
    }
#endif /* MBEDTLS_USE_PSA_CRYPTO */

    mbedtls_printf( " ok (key types: %s - %s)\n", mbedtls_pk_get_name( &pkey ), mbedtls_pk_get_name( &pkey2 ) );
#endif /* MBEDTLS_X509_CRT_PARSE_C */

#if defined(MBEDTLS_DHM_C) && defined(MBEDTLS_FS_IO)
    if( opt.dhm_file != NULL )
    {
        mbedtls_printf( "  . Loading DHM parameters..." );
        fflush( stdout );

        if( ( ret = mbedtls_dhm_parse_dhmfile( &dhm, opt.dhm_file ) ) != 0 )
        {
            mbedtls_printf( " failed\n  ! mbedtls_dhm_parse_dhmfile returned -0x%04X\n\n",
                     (unsigned int) -ret );
            goto exit;
        }

        mbedtls_printf( " ok\n" );
    }
#endif

#if defined(SNI_OPTION)
    if( opt.sni != NULL )
    {
        mbedtls_printf( "  . Setting up SNI information..." );
        fflush( stdout );

        if( ( sni_info = sni_parse( opt.sni ) ) == NULL )
        {
            mbedtls_printf( " failed\n" );
            goto exit;
        }

        mbedtls_printf( " ok\n" );
    }
#endif /* SNI_OPTION */

    /*
     * 2. Setup stuff
     */
    mbedtls_printf( "  . Setting up the SSL/TLS structure..." );
    fflush( stdout );

    if( ( ret = mbedtls_ssl_config_defaults( &conf,
                    MBEDTLS_SSL_IS_SERVER,
                    opt.transport,
                    MBEDTLS_SSL_PRESET_DEFAULT ) ) != 0 )
    {
        mbedtls_printf( " failed\n  ! mbedtls_ssl_config_defaults returned -0x%x\n\n", (unsigned int) -ret );
        goto exit;
    }

#if defined(MBEDTLS_X509_CRT_PARSE_C)
    /* The default algorithms profile disables SHA-1, but our tests still
       rely on it heavily. Hence we allow it here. A real-world server
       should use the default profile unless there is a good reason not to. */
    if( opt.allow_sha1 > 0 )
    {
        crt_profile_for_test.allowed_mds |= MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA1 );
        mbedtls_ssl_conf_cert_profile( &conf, &crt_profile_for_test );
        mbedtls_ssl_conf_sig_algs( &conf, ssl_sig_algs_for_test );
    }
#endif /* MBEDTLS_X509_CRT_PARSE_C */

    if( opt.auth_mode != DFL_AUTH_MODE )
        mbedtls_ssl_conf_authmode( &conf, opt.auth_mode );

    if( opt.cert_req_ca_list != DFL_CERT_REQ_CA_LIST )
        mbedtls_ssl_conf_cert_req_ca_list( &conf, opt.cert_req_ca_list );

#if defined(MBEDTLS_SSL_PROTO_DTLS)
    if( opt.hs_to_min != DFL_HS_TO_MIN || opt.hs_to_max != DFL_HS_TO_MAX )
        mbedtls_ssl_conf_handshake_timeout( &conf, opt.hs_to_min, opt.hs_to_max );

    if( opt.dgram_packing != DFL_DGRAM_PACKING )
        mbedtls_ssl_set_datagram_packing( &ssl, opt.dgram_packing );
#endif /* MBEDTLS_SSL_PROTO_DTLS */

#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
    if( ( ret = mbedtls_ssl_conf_max_frag_len( &conf, opt.mfl_code ) ) != 0 )
    {
        mbedtls_printf( " failed\n  ! mbedtls_ssl_conf_max_frag_len returned %d\n\n", ret );
        goto exit;
    }
#endif

#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
    if( opt.cid_enabled == 1 || opt.cid_enabled_renego == 1 )
    {
        if( opt.cid_enabled == 1        &&
            opt.cid_enabled_renego == 1 &&
            cid_len != cid_renego_len )
        {
            mbedtls_printf( "CID length must not change during renegotiation\n" );
            goto usage;
        }

        if( opt.cid_enabled == 1 )
            ret = mbedtls_ssl_conf_cid( &conf, cid_len,
                                        MBEDTLS_SSL_UNEXPECTED_CID_IGNORE );
        else
            ret = mbedtls_ssl_conf_cid( &conf, cid_renego_len,
                                        MBEDTLS_SSL_UNEXPECTED_CID_IGNORE );

        if( ret != 0 )
        {
            mbedtls_printf( " failed\n  ! mbedtls_ssl_conf_cid_len returned -%#04x\n\n",
                            (unsigned int) -ret );
            goto exit;
        }
    }
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */

#if defined(MBEDTLS_SSL_DTLS_SRTP)
    const mbedtls_ssl_srtp_profile forced_profile[] = { opt.force_srtp_profile, MBEDTLS_TLS_SRTP_UNSET };
    if( opt.use_srtp == 1 )
    {
        if( opt.force_srtp_profile != 0 )
        {
            ret = mbedtls_ssl_conf_dtls_srtp_protection_profiles( &conf, forced_profile );
        }
        else
        {
            ret = mbedtls_ssl_conf_dtls_srtp_protection_profiles( &conf, default_profiles );
        }

        if( ret != 0 )
        {
            mbedtls_printf( " failed\n  ! mbedtls_ssl_conf_dtls_srtp_protection_profiles returned %d\n\n", ret );
            goto exit;
        }

        mbedtls_ssl_conf_srtp_mki_value_supported( &conf,
                                                   opt.support_mki ?
                                                   MBEDTLS_SSL_DTLS_SRTP_MKI_SUPPORTED :
                                                   MBEDTLS_SSL_DTLS_SRTP_MKI_UNSUPPORTED );

    }
    else if( opt.force_srtp_profile != 0 )
    {
        mbedtls_printf( " failed\n  ! must enable use_srtp to force srtp profile\n\n" );
        goto exit;
    }
#endif /* MBEDTLS_SSL_DTLS_SRTP */

#if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
    if( opt.extended_ms != DFL_EXTENDED_MS )
        mbedtls_ssl_conf_extended_master_secret( &conf, opt.extended_ms );
#endif

#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
    if( opt.etm != DFL_ETM )
        mbedtls_ssl_conf_encrypt_then_mac( &conf, opt.etm );
#endif

#if defined(MBEDTLS_SSL_ALPN)
    if( opt.alpn_string != NULL )
        if( ( ret = mbedtls_ssl_conf_alpn_protocols( &conf, alpn_list ) ) != 0 )
        {
            mbedtls_printf( " failed\n  ! mbedtls_ssl_conf_alpn_protocols returned %d\n\n", ret );
            goto exit;
        }
#endif

    if (opt.reproducible)
    {
#if defined(MBEDTLS_HAVE_TIME)
#if defined(MBEDTLS_PLATFORM_TIME_ALT)
        mbedtls_platform_set_time( dummy_constant_time );
#else
        fprintf( stderr, "Warning: reproducible option used without constant time\n" );
#endif
#endif  /* MBEDTLS_HAVE_TIME */
    }
    mbedtls_ssl_conf_rng( &conf, rng_get, &rng );
    mbedtls_ssl_conf_dbg( &conf, my_debug, stdout );

#if defined(MBEDTLS_SSL_CACHE_C)
    if( opt.cache_max != -1 )
        mbedtls_ssl_cache_set_max_entries( &cache, opt.cache_max );

    if( opt.cache_timeout != -1 )
        mbedtls_ssl_cache_set_timeout( &cache, opt.cache_timeout );

    mbedtls_ssl_conf_session_cache( &conf, &cache,
                                   mbedtls_ssl_cache_get,
                                   mbedtls_ssl_cache_set );
#endif

#if defined(MBEDTLS_SSL_SESSION_TICKETS)
    if( opt.tickets == MBEDTLS_SSL_SESSION_TICKETS_ENABLED )
    {
        if( ( ret = mbedtls_ssl_ticket_setup( &ticket_ctx,
                        rng_get, &rng,
                        opt.ticket_aead,
                        opt.ticket_timeout ) ) != 0 )
        {
            mbedtls_printf( " failed\n  ! mbedtls_ssl_ticket_setup returned %d\n\n", ret );
            goto exit;
        }

        mbedtls_ssl_conf_session_tickets_cb( &conf,
                mbedtls_ssl_ticket_write,
                mbedtls_ssl_ticket_parse,
                &ticket_ctx );
    }
#endif

#if defined(MBEDTLS_SSL_PROTO_DTLS)
    if( opt.transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
    {
#if defined(MBEDTLS_SSL_COOKIE_C)
        if( opt.cookies > 0 )
        {
            if( ( ret = mbedtls_ssl_cookie_setup( &cookie_ctx,
                                                  rng_get, &rng ) ) != 0 )
            {
                mbedtls_printf( " failed\n  ! mbedtls_ssl_cookie_setup returned %d\n\n", ret );
                goto exit;
            }

            mbedtls_ssl_conf_dtls_cookies( &conf, mbedtls_ssl_cookie_write, mbedtls_ssl_cookie_check,
                                       &cookie_ctx );
        }
        else
#endif /* MBEDTLS_SSL_COOKIE_C */
#if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY)
        if( opt.cookies == 0 )
        {
            mbedtls_ssl_conf_dtls_cookies( &conf, NULL, NULL, NULL );
        }
        else
#endif /* MBEDTLS_SSL_DTLS_HELLO_VERIFY */
        {
            ; /* Nothing to do */
        }

#if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
        if( opt.anti_replay != DFL_ANTI_REPLAY )
            mbedtls_ssl_conf_dtls_anti_replay( &conf, opt.anti_replay );
#endif

        if( opt.badmac_limit != DFL_BADMAC_LIMIT )
            mbedtls_ssl_conf_dtls_badmac_limit( &conf, opt.badmac_limit );
    }
#endif /* MBEDTLS_SSL_PROTO_DTLS */

    if( opt.force_ciphersuite[0] != DFL_FORCE_CIPHER )
        mbedtls_ssl_conf_ciphersuites( &conf, opt.force_ciphersuite );

#if defined(MBEDTLS_SSL_PROTO_TLS1_3)
    mbedtls_ssl_conf_tls13_key_exchange_modes( &conf, opt.tls13_kex_modes );
#endif /* MBEDTLS_SSL_PROTO_TLS1_3 */

    if( opt.allow_legacy != DFL_ALLOW_LEGACY )
        mbedtls_ssl_conf_legacy_renegotiation( &conf, opt.allow_legacy );
#if defined(MBEDTLS_SSL_RENEGOTIATION)
    mbedtls_ssl_conf_renegotiation( &conf, opt.renegotiation );

    if( opt.renego_delay != DFL_RENEGO_DELAY )
        mbedtls_ssl_conf_renegotiation_enforced( &conf, opt.renego_delay );

    if( opt.renego_period != DFL_RENEGO_PERIOD )
    {
        PUT_UINT64_BE( renego_period, opt.renego_period, 0 );
        mbedtls_ssl_conf_renegotiation_period( &conf, renego_period );
    }
#endif

#if defined(MBEDTLS_X509_CRT_PARSE_C)
    if( strcmp( opt.ca_path, "none" ) != 0 &&
        strcmp( opt.ca_file, "none" ) != 0 )
    {
#if defined(MBEDTLS_X509_TRUSTED_CERTIFICATE_CALLBACK)
        if( opt.ca_callback != 0 )
            mbedtls_ssl_conf_ca_cb( &conf, ca_callback, &cacert);
        else
#endif
            mbedtls_ssl_conf_ca_chain( &conf, &cacert, NULL );
    }
    if( key_cert_init )
    {
        mbedtls_pk_context *pk = &pkey;
#if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
        if( opt.async_private_delay1 >= 0 )
        {
            ret = ssl_async_set_key( &ssl_async_keys, &srvcert, pk, 0,
                                     opt.async_private_delay1 );
            if( ret < 0 )
            {
                mbedtls_printf( "  Test error: ssl_async_set_key failed (%d)\n",
                                ret );
                goto exit;
            }
            pk = NULL;
        }
#endif /* MBEDTLS_SSL_ASYNC_PRIVATE */
        if( ( ret = mbedtls_ssl_conf_own_cert( &conf, &srvcert, pk ) ) != 0 )
        {
            mbedtls_printf( " failed\n  ! mbedtls_ssl_conf_own_cert returned %d\n\n", ret );
            goto exit;
        }
    }
    if( key_cert_init2 )
    {
        mbedtls_pk_context *pk = &pkey2;
#if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
        if( opt.async_private_delay2 >= 0 )
        {
            ret = ssl_async_set_key( &ssl_async_keys, &srvcert2, pk, 0,
                                     opt.async_private_delay2 );
            if( ret < 0 )
            {
                mbedtls_printf( "  Test error: ssl_async_set_key failed (%d)\n",
                                ret );
                goto exit;
            }
            pk = NULL;
        }
#endif /* MBEDTLS_SSL_ASYNC_PRIVATE */
        if( ( ret = mbedtls_ssl_conf_own_cert( &conf, &srvcert2, pk ) ) != 0 )
        {
            mbedtls_printf( " failed\n  ! mbedtls_ssl_conf_own_cert returned %d\n\n", ret );
            goto exit;
        }
    }

#if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
    if( opt.async_operations[0] != '-' )
    {
        mbedtls_ssl_async_sign_t *sign = NULL;
        mbedtls_ssl_async_decrypt_t *decrypt = NULL;
        const char *r;
        for( r = opt.async_operations; *r; r++ )
        {
            switch( *r )
            {
            case 'd':
                decrypt = ssl_async_decrypt;
                break;
            case 's':
                sign = ssl_async_sign;
                break;
            }
        }
        ssl_async_keys.inject_error = ( opt.async_private_error < 0 ?
                                        - opt.async_private_error :
                                        opt.async_private_error );
        ssl_async_keys.f_rng = rng_get;
        ssl_async_keys.p_rng = &rng;
        mbedtls_ssl_conf_async_private_cb( &conf,
                                           sign,
                                           decrypt,
                                           ssl_async_resume,
                                           ssl_async_cancel,
                                           &ssl_async_keys );
    }
#endif /* MBEDTLS_SSL_ASYNC_PRIVATE */
#endif /* MBEDTLS_X509_CRT_PARSE_C */

#if defined(SNI_OPTION)
    if( opt.sni != NULL )
    {
        mbedtls_ssl_conf_sni( &conf, sni_callback, sni_info );
#if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
        if( opt.async_private_delay2 >= 0 )
        {
            sni_entry *cur;
            for( cur = sni_info; cur != NULL; cur = cur->next )
            {
                ret = ssl_async_set_key( &ssl_async_keys,
                                         cur->cert, cur->key, 1,
                                         opt.async_private_delay2 );
                if( ret < 0 )
                {
                    mbedtls_printf( "  Test error: ssl_async_set_key failed (%d)\n",
                                    ret );
                    goto exit;
                }
                cur->key = NULL;
            }
        }
#endif /* MBEDTLS_SSL_ASYNC_PRIVATE */
    }
#endif

#if defined(MBEDTLS_ECP_C)
    if( opt.curves != NULL &&
        strcmp( opt.curves, "default" ) != 0 )
    {
        mbedtls_ssl_conf_groups( &conf, group_list );
    }
#endif

#if defined(MBEDTLS_SSL_PROTO_TLS1_3)
    if( opt.sig_algs != NULL )
        mbedtls_ssl_conf_sig_algs( &conf, sig_alg_list );
#endif /* MBEDTLS_SSL_PROTO_TLS1_3 */

#if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED)

    if( strlen( opt.psk ) != 0 && strlen( opt.psk_identity ) != 0 )
    {
#if defined(MBEDTLS_USE_PSA_CRYPTO)
        if( opt.psk_opaque != 0 )
        {
            /* The algorithm has already been determined earlier. */
            status = psa_setup_psk_key_slot( &psk_slot, alg, psk, psk_len );
            if( status != PSA_SUCCESS )
            {
                fprintf( stderr, "SETUP FAIL\n" );
                ret = MBEDTLS_ERR_SSL_HW_ACCEL_FAILED;
                goto exit;
            }
            if( ( ret = mbedtls_ssl_conf_psk_opaque( &conf, psk_slot,
                             (const unsigned char *) opt.psk_identity,
                             strlen( opt.psk_identity ) ) ) != 0 )
            {
                mbedtls_printf( " failed\n  ! mbedtls_ssl_conf_psk_opaque returned %d\n\n",
                                ret );
                goto exit;
            }
        }
        else
#endif /* MBEDTLS_USE_PSA_CRYPTO */
        if( psk_len > 0 )
        {
            ret = mbedtls_ssl_conf_psk( &conf, psk, psk_len,
                                     (const unsigned char *) opt.psk_identity,
                                     strlen( opt.psk_identity ) );
            if( ret != 0 )
            {
                mbedtls_printf( "  failed\n  mbedtls_ssl_conf_psk returned -0x%04X\n\n", (unsigned int) -ret );
                goto exit;
            }
        }
    }

    if( opt.psk_list != NULL )
    {
#if defined(MBEDTLS_USE_PSA_CRYPTO)
        if( opt.psk_list_opaque != 0 )
        {
            psk_entry *cur_psk;
            for( cur_psk = psk_info; cur_psk != NULL; cur_psk = cur_psk->next )
            {

                status = psa_setup_psk_key_slot( &cur_psk->slot, alg,
                                                 cur_psk->key,
                                                 cur_psk->key_len );
                if( status != PSA_SUCCESS )
                {
                    ret = MBEDTLS_ERR_SSL_HW_ACCEL_FAILED;
                    goto exit;
                }
            }
        }
#endif /* MBEDTLS_USE_PSA_CRYPTO */

        mbedtls_ssl_conf_psk_cb( &conf, psk_callback, psk_info );
    }
#endif

#if defined(MBEDTLS_DHM_C)
    /*
     * Use different group than default DHM group
     */
#if defined(MBEDTLS_FS_IO)
    if( opt.dhm_file != NULL )
        ret = mbedtls_ssl_conf_dh_param_ctx( &conf, &dhm );
#endif
    if( ret != 0 )
    {
        mbedtls_printf( "  failed\n  mbedtls_ssl_conf_dh_param returned -0x%04X\n\n", (unsigned int) -ret );
        goto exit;
    }
#endif

    if( opt.min_version != DFL_MIN_VERSION )
        mbedtls_ssl_conf_min_version( &conf, MBEDTLS_SSL_MAJOR_VERSION_3, opt.min_version );

    if( opt.max_version != DFL_MIN_VERSION )
        mbedtls_ssl_conf_max_version( &conf, MBEDTLS_SSL_MAJOR_VERSION_3, opt.max_version );

    if( ( ret = mbedtls_ssl_setup( &ssl, &conf ) ) != 0 )
    {
        mbedtls_printf( " failed\n  ! mbedtls_ssl_setup returned -0x%x\n\n", (unsigned int) -ret );
        goto exit;
    }

    if( opt.eap_tls != 0 )
    {
        mbedtls_ssl_set_export_keys_cb( &ssl, eap_tls_key_derivation,
                                        &eap_tls_keying );
    }
    else if( opt.nss_keylog != 0 )
    {
        mbedtls_ssl_set_export_keys_cb( &ssl,
                                        nss_keylog_export,
                                        NULL );
    }
#if defined( MBEDTLS_SSL_DTLS_SRTP )
    else if( opt.use_srtp != 0 )
    {
        mbedtls_ssl_set_export_keys_cb( &ssl, dtls_srtp_key_derivation,
                                        &dtls_srtp_keying );
    }
#endif /* MBEDTLS_SSL_DTLS_SRTP */

    io_ctx.ssl = &ssl;
    io_ctx.net = &client_fd;
    mbedtls_ssl_set_bio( &ssl, &io_ctx, send_cb, recv_cb,
                         opt.nbio == 0 ? recv_timeout_cb : NULL );

#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
    if( opt.transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
    {
        if( ( ret = mbedtls_ssl_set_cid( &ssl, opt.cid_enabled,
                                         cid, cid_len ) ) != 0 )
        {
            mbedtls_printf( " failed\n  ! mbedtls_ssl_set_cid returned %d\n\n",
                            ret );
            goto exit;
        }
    }
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */

#if defined(MBEDTLS_SSL_PROTO_DTLS)
    if( opt.dtls_mtu != DFL_DTLS_MTU )
        mbedtls_ssl_set_mtu( &ssl, opt.dtls_mtu );
#endif

#if defined(MBEDTLS_TIMING_C)
    mbedtls_ssl_set_timer_cb( &ssl, &timer, mbedtls_timing_set_delay,
                                            mbedtls_timing_get_delay );
#endif

    mbedtls_printf( " ok\n" );

    /*
     * 3. Setup the listening TCP socket
     */
    mbedtls_printf( "  . Bind on %s://%s:%s/ ...",
            opt.transport == MBEDTLS_SSL_TRANSPORT_STREAM ? "tcp" : "udp",
            opt.server_addr ? opt.server_addr : "*",
            opt.server_port );
    fflush( stdout );

    if( ( ret = mbedtls_net_bind( &listen_fd, opt.server_addr, opt.server_port,
                          opt.transport == MBEDTLS_SSL_TRANSPORT_STREAM ?
                          MBEDTLS_NET_PROTO_TCP : MBEDTLS_NET_PROTO_UDP ) ) != 0 )
    {
        mbedtls_printf( " failed\n  ! mbedtls_net_bind returned -0x%x\n\n", (unsigned int) -ret );
        goto exit;
    }
    mbedtls_printf( " ok\n" );

reset:
#if !defined(_WIN32)
    if( received_sigterm )
    {
        mbedtls_printf( " interrupted by SIGTERM (not in net_accept())\n" );
        if( ret == MBEDTLS_ERR_NET_INVALID_CONTEXT )
            ret = 0;

        goto exit;
    }
#endif

    if( ret == MBEDTLS_ERR_SSL_CLIENT_RECONNECT )
    {
        mbedtls_printf( "  ! Client initiated reconnection from same port\n" );
        goto handshake;
    }

#ifdef MBEDTLS_ERROR_C
    if( ret != 0 )
    {
        char error_buf[100];
        mbedtls_strerror( ret, error_buf, 100 );
        mbedtls_printf("Last error was: %d - %s\n\n", ret, error_buf );
    }
#endif

    mbedtls_net_free( &client_fd );

    mbedtls_ssl_session_reset( &ssl );

    /*
     * 3. Wait until a client connects
     */
    mbedtls_printf( "  . Waiting for a remote connection ..." );
    fflush( stdout );

    if( ( ret = mbedtls_net_accept( &listen_fd, &client_fd,
                    client_ip, sizeof( client_ip ), &cliip_len ) ) != 0 )
    {
#if !defined(_WIN32)
        if( received_sigterm )
        {
            mbedtls_printf( " interrupted by SIGTERM (in net_accept())\n" );
            if( ret == MBEDTLS_ERR_NET_ACCEPT_FAILED )
                ret = 0;

            goto exit;
        }
#endif

        mbedtls_printf( " failed\n  ! mbedtls_net_accept returned -0x%x\n\n", (unsigned int) -ret );
        goto exit;
    }

    if( opt.nbio > 0 )
        ret = mbedtls_net_set_nonblock( &client_fd );
    else
        ret = mbedtls_net_set_block( &client_fd );
    if( ret != 0 )
    {
        mbedtls_printf( " failed\n  ! net_set_(non)block() returned -0x%x\n\n", (unsigned int) -ret );
        goto exit;
    }

    mbedtls_ssl_conf_read_timeout( &conf, opt.read_timeout );

#if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY)
    if( opt.transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
    {
        if( ( ret = mbedtls_ssl_set_client_transport_id( &ssl,
                        client_ip, cliip_len ) ) != 0 )
        {
            mbedtls_printf( " failed\n  ! mbedtls_ssl_set_client_transport_id() returned -0x%x\n\n",
                            (unsigned int) -ret );
            goto exit;
        }
    }
#endif /* MBEDTLS_SSL_DTLS_HELLO_VERIFY */

#if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
    if( opt.ecjpake_pw != DFL_ECJPAKE_PW )
    {
        if( ( ret = mbedtls_ssl_set_hs_ecjpake_password( &ssl,
                        (const unsigned char *) opt.ecjpake_pw,
                                        strlen( opt.ecjpake_pw ) ) ) != 0 )
        {
            mbedtls_printf( " failed\n  ! mbedtls_ssl_set_hs_ecjpake_password returned %d\n\n", ret );
            goto exit;
        }
    }
#endif

    mbedtls_printf( " ok\n" );

    /*
     * 4. Handshake
     */
handshake:
    mbedtls_printf( "  . Performing the SSL/TLS handshake..." );
    fflush( stdout );

    while( ( ret = mbedtls_ssl_handshake( &ssl ) ) != 0 )
    {
#if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
        if( ret == MBEDTLS_ERR_SSL_ASYNC_IN_PROGRESS &&
            ssl_async_keys.inject_error == SSL_ASYNC_INJECT_ERROR_CANCEL )
        {
            mbedtls_printf( " cancelling on injected error\n" );
            break;
        }
#endif /* MBEDTLS_SSL_ASYNC_PRIVATE */

        if( ! mbedtls_status_is_ssl_in_progress( ret ) )
            break;

        /* For event-driven IO, wait for socket to become available */
        if( opt.event == 1 /* level triggered IO */ )
        {
#if defined(MBEDTLS_TIMING_C)
            ret = idle( &client_fd, &timer, ret );
#else
            ret = idle( &client_fd, ret );
#endif
            if( ret != 0 )
                goto reset;
        }
    }

    if( ret == MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED )
    {
        mbedtls_printf( " hello verification requested\n" );
        ret = 0;
        goto reset;
    }
    else if( ret != 0 )
    {
        mbedtls_printf( " failed\n  ! mbedtls_ssl_handshake returned -0x%x\n\n", (unsigned int) -ret );

#if defined(MBEDTLS_X509_CRT_PARSE_C)
        if( ret == MBEDTLS_ERR_X509_CERT_VERIFY_FAILED )
        {
            char vrfy_buf[512];
            flags = mbedtls_ssl_get_verify_result( &ssl );

            x509_crt_verify_info( vrfy_buf, sizeof( vrfy_buf ), "  ! ", flags );

            mbedtls_printf( "%s\n", vrfy_buf );
        }
#endif

#if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
        if( opt.async_private_error < 0 )
            /* Injected error only the first time round, to test reset */
            ssl_async_keys.inject_error = SSL_ASYNC_INJECT_ERROR_NONE;
#endif
        goto reset;
    }
    else /* ret == 0 */
    {
        int suite_id = mbedtls_ssl_get_ciphersuite_id_from_ssl( &ssl );
        const mbedtls_ssl_ciphersuite_t *ciphersuite_info;
        ciphersuite_info = mbedtls_ssl_ciphersuite_from_id( suite_id );

        mbedtls_printf( " ok\n    [ Protocol is %s ]\n"
                             "    [ Ciphersuite is %s ]\n"
                             "    [ Key size is %u ]\n",
          mbedtls_ssl_get_version( &ssl ),
          mbedtls_ssl_ciphersuite_get_name( ciphersuite_info ),
          (unsigned int)
            mbedtls_ssl_ciphersuite_get_cipher_key_bitlen( ciphersuite_info ) );
    }

    if( ( ret = mbedtls_ssl_get_record_expansion( &ssl ) ) >= 0 )
        mbedtls_printf( "    [ Record expansion is %d ]\n", ret );
    else
        mbedtls_printf( "    [ Record expansion is unknown ]\n" );

#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
    mbedtls_printf( "    [ Maximum incoming record payload length is %u ]\n",
                    (unsigned int) mbedtls_ssl_get_max_in_record_payload( &ssl ) );
    mbedtls_printf( "    [ Maximum outgoing record payload length is %u ]\n",
                    (unsigned int) mbedtls_ssl_get_max_out_record_payload( &ssl ) );
#endif

#if defined(MBEDTLS_SSL_ALPN)
    if( opt.alpn_string != NULL )
    {
        const char *alp = mbedtls_ssl_get_alpn_protocol( &ssl );
        mbedtls_printf( "    [ Application Layer Protocol is %s ]\n",
                alp ? alp : "(none)" );
    }
#endif

#if defined(MBEDTLS_X509_CRT_PARSE_C)
    /*
     * 5. Verify the client certificate
     */
    mbedtls_printf( "  . Verifying peer X.509 certificate..." );

    if( ( flags = mbedtls_ssl_get_verify_result( &ssl ) ) != 0 )
    {
        char vrfy_buf[512];

        mbedtls_printf( " failed\n" );

        x509_crt_verify_info( vrfy_buf, sizeof( vrfy_buf ), "  ! ", flags );
        mbedtls_printf( "%s\n", vrfy_buf );
    }
    else
        mbedtls_printf( " ok\n" );

#if !defined(MBEDTLS_X509_REMOVE_INFO)
    if( mbedtls_ssl_get_peer_cert( &ssl ) != NULL )
    {
        char crt_buf[512];

        mbedtls_printf( "  . Peer certificate information    ...\n" );
        mbedtls_x509_crt_info( crt_buf, sizeof( crt_buf ), "      ",
                       mbedtls_ssl_get_peer_cert( &ssl ) );
        mbedtls_printf( "%s\n", crt_buf );
    }
#endif /* MBEDTLS_X509_REMOVE_INFO */
#endif /* MBEDTLS_X509_CRT_PARSE_C */

    if( opt.eap_tls != 0 )
    {
        size_t j = 0;

        if( ( ret = mbedtls_ssl_tls_prf( eap_tls_keying.tls_prf_type,
                                         eap_tls_keying.master_secret,
                                         sizeof( eap_tls_keying.master_secret ),
                                         eap_tls_label,
                                         eap_tls_keying.randbytes,
                                         sizeof( eap_tls_keying.randbytes ),
                                         eap_tls_keymaterial,
                                         sizeof( eap_tls_keymaterial ) ) )
                                         != 0 )
        {
            mbedtls_printf( " failed\n  ! mbedtls_ssl_tls_prf returned -0x%x\n\n",
                            (unsigned int) -ret );
            goto reset;
        }

        mbedtls_printf( "    EAP-TLS key material is:" );
        for( j = 0; j < sizeof( eap_tls_keymaterial ); j++ )
        {
            if( j % 8 == 0 )
                mbedtls_printf("\n    ");
            mbedtls_printf("%02x ", eap_tls_keymaterial[j] );
        }
        mbedtls_printf("\n");

        if( ( ret = mbedtls_ssl_tls_prf( eap_tls_keying.tls_prf_type, NULL, 0,
                                         eap_tls_label,
                                         eap_tls_keying.randbytes,
                                         sizeof( eap_tls_keying.randbytes ),
                                         eap_tls_iv,
                                         sizeof( eap_tls_iv ) ) ) != 0 )
         {
             mbedtls_printf( " failed\n  ! mbedtls_ssl_tls_prf returned -0x%x\n\n",
                             (unsigned int) -ret );
             goto reset;
         }

        mbedtls_printf( "    EAP-TLS IV is:" );
        for( j = 0; j < sizeof( eap_tls_iv ); j++ )
        {
            if( j % 8 == 0 )
                mbedtls_printf("\n    ");
            mbedtls_printf("%02x ", eap_tls_iv[j] );
        }
        mbedtls_printf("\n");
    }

#if defined( MBEDTLS_SSL_DTLS_SRTP )
    else if( opt.use_srtp != 0  )
    {
        size_t j = 0;
        mbedtls_dtls_srtp_info dtls_srtp_negotiation_result;
        mbedtls_ssl_get_dtls_srtp_negotiation_result( &ssl, &dtls_srtp_negotiation_result );

        if( dtls_srtp_negotiation_result.chosen_dtls_srtp_profile
                                == MBEDTLS_TLS_SRTP_UNSET )
        {
            mbedtls_printf( "    Unable to negotiate "
                            "the use of DTLS-SRTP\n" );
        }
        else
        {
            if( ( ret = mbedtls_ssl_tls_prf( dtls_srtp_keying.tls_prf_type,
                                             dtls_srtp_keying.master_secret,
                                             sizeof( dtls_srtp_keying.master_secret ),
                                             dtls_srtp_label,
                                             dtls_srtp_keying.randbytes,
                                             sizeof( dtls_srtp_keying.randbytes ),
                                             dtls_srtp_key_material,
                                             sizeof( dtls_srtp_key_material ) ) )
                                             != 0 )
            {
                mbedtls_printf( " failed\n  ! mbedtls_ssl_tls_prf returned -0x%x\n\n",
                                (unsigned int) -ret );
                goto exit;
            }

            mbedtls_printf( "    DTLS-SRTP key material is:" );
            for( j = 0; j < sizeof( dtls_srtp_key_material ); j++ )
            {
                if( j % 8 == 0 )
                    mbedtls_printf( "\n    " );
                mbedtls_printf( "%02x ", dtls_srtp_key_material[j] );
            }
            mbedtls_printf( "\n" );

            /* produce a less readable output used to perform automatic checks
             * - compare client and server output
             * - interop test with openssl which client produces this kind of output
             */
            mbedtls_printf( "    Keying material: " );
            for( j = 0; j < sizeof( dtls_srtp_key_material ); j++ )
            {
                mbedtls_printf( "%02X", dtls_srtp_key_material[j] );
            }
            mbedtls_printf( "\n" );

            if ( dtls_srtp_negotiation_result.mki_len > 0 )
            {
                mbedtls_printf( "    DTLS-SRTP mki value: " );
                for( j = 0; j < dtls_srtp_negotiation_result.mki_len; j++ )
                {
                    mbedtls_printf( "%02X", dtls_srtp_negotiation_result.mki_value[j] );
                }
            }
            else
            {
                mbedtls_printf( "    DTLS-SRTP no mki value negotiated" );
            }
            mbedtls_printf( "\n" );

        }
    }
#endif /* MBEDTLS_SSL_DTLS_SRTP */

#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
    ret = report_cid_usage( &ssl, "initial handshake" );
    if( ret != 0 )
        goto exit;

    if( opt.transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
    {
        if( ( ret = mbedtls_ssl_set_cid( &ssl, opt.cid_enabled_renego,
                                         cid_renego, cid_renego_len ) ) != 0 )
        {
            mbedtls_printf( " failed\n  ! mbedtls_ssl_set_cid returned %d\n\n",
                            ret );
            goto exit;
        }
    }
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */

#if defined(MBEDTLS_MEMORY_DEBUG)
    mbedtls_memory_buffer_alloc_cur_get( &current_heap_memory, &heap_blocks );
    mbedtls_memory_buffer_alloc_max_get( &peak_heap_memory, &heap_blocks );
    mbedtls_printf( "Heap memory usage after handshake: %lu bytes. Peak memory usage was %lu\n",
                    (unsigned long) current_heap_memory, (unsigned long) peak_heap_memory );
#endif  /* MBEDTLS_MEMORY_DEBUG */

    if( opt.exchanges == 0 )
        goto close_notify;

    exchanges_left = opt.exchanges;
data_exchange:
    /*
     * 6. Read the HTTP Request
     */
    mbedtls_printf( "  < Read from client:" );
    fflush( stdout );

    /*
     * TLS and DTLS need different reading styles (stream vs datagram)
     */
    if( opt.transport == MBEDTLS_SSL_TRANSPORT_STREAM )
    {
        do
        {
            int terminated = 0;
            len = opt.buffer_size - 1;
            memset( buf, 0, opt.buffer_size );
            ret = mbedtls_ssl_read( &ssl, buf, len );

            if( mbedtls_status_is_ssl_in_progress( ret ) )
            {
                if( opt.event == 1 /* level triggered IO */ )
                {
#if defined(MBEDTLS_TIMING_C)
                    idle( &client_fd, &timer, ret );
#else
                    idle( &client_fd, ret );
#endif
                }

                continue;
            }

            if( ret <= 0 )
            {
                switch( ret )
                {
                    case MBEDTLS_ERR_SSL_PEER_CLOSE_NOTIFY:
                        mbedtls_printf( " connection was closed gracefully\n" );
                        goto close_notify;

                    case 0:
                    case MBEDTLS_ERR_NET_CONN_RESET:
                        mbedtls_printf( " connection was reset by peer\n" );
                        ret = MBEDTLS_ERR_NET_CONN_RESET;
                        goto reset;

                    default:
                        mbedtls_printf( " mbedtls_ssl_read returned -0x%x\n", (unsigned int) -ret );
                        goto reset;
                }
            }

            if( mbedtls_ssl_get_bytes_avail( &ssl ) == 0 )
            {
                len = ret;
                buf[len] = '\0';
                mbedtls_printf( " %d bytes read\n\n%s\n", len, (char *) buf );

                /* End of message should be detected according to the syntax of the
                 * application protocol (eg HTTP), just use a dummy test here. */
                if( buf[len - 1] == '\n' )
                    terminated = 1;
            }
            else
            {
                int extra_len, ori_len;
                unsigned char *larger_buf;

                ori_len = ret;
                extra_len = (int) mbedtls_ssl_get_bytes_avail( &ssl );

                larger_buf = mbedtls_calloc( 1, ori_len + extra_len + 1 );
                if( larger_buf == NULL )
                {
                    mbedtls_printf( "  ! memory allocation failed\n" );
                    ret = 1;
                    goto reset;
                }

                memset( larger_buf, 0, ori_len + extra_len );
                memcpy( larger_buf, buf, ori_len );

                /* This read should never fail and get the whole cached data */
                ret = mbedtls_ssl_read( &ssl, larger_buf + ori_len, extra_len );
                if( ret != extra_len ||
                    mbedtls_ssl_get_bytes_avail( &ssl ) != 0 )
                {
                    mbedtls_printf( "  ! mbedtls_ssl_read failed on cached data\n" );
                    ret = 1;
                    goto reset;
                }

                larger_buf[ori_len + extra_len] = '\0';
                mbedtls_printf( " %d bytes read (%d + %d)\n\n%s\n",
                        ori_len + extra_len, ori_len, extra_len,
                        (char *) larger_buf );

                /* End of message should be detected according to the syntax of the
                 * application protocol (eg HTTP), just use a dummy test here. */
                if( larger_buf[ori_len + extra_len - 1] == '\n' )
                    terminated = 1;

                mbedtls_free( larger_buf );
            }

            if( terminated )
            {
                ret = 0;
                break;
            }
        }
        while( 1 );
    }
    else /* Not stream, so datagram */
    {
        len = opt.buffer_size - 1;
        memset( buf, 0, opt.buffer_size );

        do
        {
            /* Without the call to `mbedtls_ssl_check_pending`, it might
             * happen that the client sends application data in the same
             * datagram as the Finished message concluding the handshake.
             * In this case, the application data would be ready to be
             * processed while the underlying transport wouldn't signal
             * any further incoming data.
             *
             * See the test 'Event-driven I/O: session-id resume, UDP packing'
             * in tests/ssl-opt.sh.
             */

            /* For event-driven IO, wait for socket to become available */
            if( mbedtls_ssl_check_pending( &ssl ) == 0 &&
                opt.event == 1 /* level triggered IO */ )
            {
#if defined(MBEDTLS_TIMING_C)
                idle( &client_fd, &timer, MBEDTLS_ERR_SSL_WANT_READ );
#else
                idle( &client_fd, MBEDTLS_ERR_SSL_WANT_READ );
#endif
            }

            ret = mbedtls_ssl_read( &ssl, buf, len );

            /* Note that even if `mbedtls_ssl_check_pending` returns true,
             * it can happen that the subsequent call to `mbedtls_ssl_read`
             * returns `MBEDTLS_ERR_SSL_WANT_READ`, because the pending messages
             * might be discarded (e.g. because they are retransmissions). */
        }
        while( mbedtls_status_is_ssl_in_progress( ret ) );

        if( ret <= 0 )
        {
            switch( ret )
            {
                case MBEDTLS_ERR_SSL_PEER_CLOSE_NOTIFY:
                    mbedtls_printf( " connection was closed gracefully\n" );
                    ret = 0;
                    goto close_notify;

                default:
                    mbedtls_printf( " mbedtls_ssl_read returned -0x%x\n", (unsigned int) -ret );
                    goto reset;
            }
        }

        len = ret;
        buf[len] = '\0';
        mbedtls_printf( " %d bytes read\n\n%s", len, (char *) buf );
        ret = 0;
    }

    /*
     * 7a. Request renegotiation while client is waiting for input from us.
     * (only on the first exchange, to be able to test retransmission)
     */
#if defined(MBEDTLS_SSL_RENEGOTIATION)
    if( opt.renegotiate && exchanges_left == opt.exchanges )
    {
        mbedtls_printf( "  . Requestion renegotiation..." );
        fflush( stdout );

        while( ( ret = mbedtls_ssl_renegotiate( &ssl ) ) != 0 )
        {
            if( ! mbedtls_status_is_ssl_in_progress( ret ) )
            {
                mbedtls_printf( " failed\n  ! mbedtls_ssl_renegotiate returned %d\n\n", ret );
                goto reset;
            }

            /* For event-driven IO, wait for socket to become available */
            if( opt.event == 1 /* level triggered IO */ )
            {
#if defined(MBEDTLS_TIMING_C)
                idle( &client_fd, &timer, ret );
#else
                idle( &client_fd, ret );
#endif
            }
        }

        mbedtls_printf( " ok\n" );
    }
#endif /* MBEDTLS_SSL_RENEGOTIATION */

#if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
    ret = report_cid_usage( &ssl, "after renegotiation" );
    if( ret != 0 )
        goto exit;
#endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */

    /*
     * 7. Write the 200 Response
     */
    mbedtls_printf( "  > Write to client:" );
    fflush( stdout );

    len = sprintf( (char *) buf, HTTP_RESPONSE,
                   mbedtls_ssl_get_ciphersuite( &ssl ) );

    /* Add padding to the response to reach opt.response_size in length */
    if( opt.response_size != DFL_RESPONSE_SIZE &&
        len < opt.response_size )
    {
        memset( buf + len, 'B', opt.response_size - len );
        len += opt.response_size - len;
    }

    /* Truncate if response size is smaller than the "natural" size */
    if( opt.response_size != DFL_RESPONSE_SIZE &&
        len > opt.response_size )
    {
        len = opt.response_size;

        /* Still end with \r\n unless that's really not possible */
        if( len >= 2 ) buf[len - 2] = '\r';
        if( len >= 1 ) buf[len - 1] = '\n';
    }

    if( opt.transport == MBEDTLS_SSL_TRANSPORT_STREAM )
    {
        for( written = 0, frags = 0; written < len; written += ret, frags++ )
        {
            while( ( ret = mbedtls_ssl_write( &ssl, buf + written, len - written ) )
                           <= 0 )
            {
                if( ret == MBEDTLS_ERR_NET_CONN_RESET )
                {
                    mbedtls_printf( " failed\n  ! peer closed the connection\n\n" );
                    goto reset;
                }

                if( ! mbedtls_status_is_ssl_in_progress( ret ) )
                {
                    mbedtls_printf( " failed\n  ! mbedtls_ssl_write returned %d\n\n", ret );
                    goto reset;
                }

                /* For event-driven IO, wait for socket to become available */
                if( opt.event == 1 /* level triggered IO */ )
                {
#if defined(MBEDTLS_TIMING_C)
                    idle( &client_fd, &timer, ret );
#else
                    idle( &client_fd, ret );
#endif
                }
            }
        }
    }
    else /* Not stream, so datagram */
    {
        while( 1 )
        {
            ret = mbedtls_ssl_write( &ssl, buf, len );

            if( ! mbedtls_status_is_ssl_in_progress( ret ) )
                break;

            /* For event-driven IO, wait for socket to become available */
            if( opt.event == 1 /* level triggered IO */ )
            {
#if defined(MBEDTLS_TIMING_C)
                idle( &client_fd, &timer, ret );
#else
                idle( &client_fd, ret );
#endif
            }
        }

        if( ret < 0 )
        {
            mbedtls_printf( " failed\n  ! mbedtls_ssl_write returned %d\n\n", ret );
            goto reset;
        }

        frags = 1;
        written = ret;
    }

    buf[written] = '\0';
    mbedtls_printf( " %d bytes written in %d fragments\n\n%s\n", written, frags, (char *) buf );
    ret = 0;

    /*
     * 7b. Simulate serialize/deserialize and go back to data exchange
     */
#if defined(MBEDTLS_SSL_CONTEXT_SERIALIZATION)
    if( opt.serialize != 0 )
    {
        size_t buf_len;

        mbedtls_printf( "  . Serializing live connection..." );

        ret = mbedtls_ssl_context_save( &ssl, NULL, 0, &buf_len );
        if( ret != MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL )
        {
            mbedtls_printf( " failed\n  ! mbedtls_ssl_context_save returned "
                            "-0x%x\n\n", (unsigned int) -ret );

            goto exit;
        }

        if( ( context_buf = mbedtls_calloc( 1, buf_len ) ) == NULL )
        {
            mbedtls_printf( " failed\n  ! Couldn't allocate buffer for "
                            "serialized context" );

            goto exit;
        }
        context_buf_len = buf_len;

        if( ( ret = mbedtls_ssl_context_save( &ssl, context_buf,
                                              buf_len, &buf_len ) ) != 0 )
        {
            mbedtls_printf( " failed\n  ! mbedtls_ssl_context_save returned "
                            "-0x%x\n\n", (unsigned int) -ret );

            goto exit;
        }

        mbedtls_printf( " ok\n" );

        /* Save serialized context to the 'opt.context_file' as a base64 code */
        if( 0 < strlen( opt.context_file ) )
        {
            FILE *b64_file;
            uint8_t *b64_buf;
            size_t b64_len;

            mbedtls_printf( "  . Save serialized context to a file... " );

            mbedtls_base64_encode( NULL, 0, &b64_len, context_buf, buf_len );

            if( ( b64_buf = mbedtls_calloc( 1, b64_len ) ) == NULL )
            {
                mbedtls_printf( "failed\n  ! Couldn't allocate buffer for "
                                "the base64 code\n" );
                goto exit;
            }

            if( ( ret = mbedtls_base64_encode( b64_buf, b64_len, &b64_len,
                                               context_buf, buf_len ) ) != 0 )
            {
                mbedtls_printf( "failed\n  ! mbedtls_base64_encode returned "
                            "-0x%x\n", (unsigned int) -ret );
                mbedtls_free( b64_buf );
                goto exit;
            }

            if( ( b64_file = fopen( opt.context_file, "w" ) ) == NULL )
            {
                mbedtls_printf( "failed\n  ! Cannot open '%s' for writing.\n",
                                opt.context_file );
                mbedtls_free( b64_buf );
                goto exit;
            }

            if( b64_len != fwrite( b64_buf, 1, b64_len, b64_file ) )
            {
                mbedtls_printf( "failed\n  ! fwrite(%ld bytes) failed\n",
                                (long) b64_len );
                mbedtls_free( b64_buf );
                fclose( b64_file );
                goto exit;
            }

            mbedtls_free( b64_buf );
            fclose( b64_file );

            mbedtls_printf( "ok\n" );
        }

        /*
         * This simulates a workflow where you have a long-lived server
         * instance, potentially with a pool of ssl_context objects, and you
         * just want to re-use one while the connection is inactive: in that
         * case you can just reset() it, and then it's ready to receive
         * serialized data from another connection (or the same here).
         */
        if( opt.serialize == 1 )
        {
            /* nothing to do here, done by context_save() already */
            mbedtls_printf( "  . Context has been reset... ok\n" );
        }

        /*
         * This simulates a workflow where you have one server instance per
         * connection, and want to release it entire when the connection is
         * inactive, and spawn it again when needed again - this would happen
         * between ssl_free() and ssl_init() below, together with any other
         * teardown/startup code needed - for example, preparing the
         * ssl_config again (see section 3 "setup stuff" in this file).
         */
        if( opt.serialize == 2 )
        {
            mbedtls_printf( "  . Freeing and reinitializing context..." );

            mbedtls_ssl_free( &ssl );

            mbedtls_ssl_init( &ssl );

            if( ( ret = mbedtls_ssl_setup( &ssl, &conf ) ) != 0 )
            {
                mbedtls_printf( " failed\n  ! mbedtls_ssl_setup returned "
                                "-0x%x\n\n", (unsigned int) -ret );
                goto exit;
            }

            /*
             * This illustrates the minimum amount of things you need to set
             * up, however you could set up much more if desired, for example
             * if you want to share your set up code between the case of
             * establishing a new connection and this case.
             */
            if( opt.nbio == 2 )
                mbedtls_ssl_set_bio( &ssl, &client_fd, delayed_send,
                                     delayed_recv, NULL );
            else
                mbedtls_ssl_set_bio( &ssl, &client_fd, mbedtls_net_send,
                            mbedtls_net_recv,
                            opt.nbio == 0 ? mbedtls_net_recv_timeout : NULL );

#if defined(MBEDTLS_TIMING_C)
                mbedtls_ssl_set_timer_cb( &ssl, &timer,
                                          mbedtls_timing_set_delay,
                                          mbedtls_timing_get_delay );
#endif /* MBEDTLS_TIMING_C */

            mbedtls_printf( " ok\n" );
        }

        mbedtls_printf( "  . Deserializing connection..." );

        if( ( ret = mbedtls_ssl_context_load( &ssl, context_buf,
                                              buf_len ) ) != 0 )
        {
            mbedtls_printf( "failed\n  ! mbedtls_ssl_context_load returned "
                            "-0x%x\n\n", (unsigned int) -ret );

            goto exit;
        }

        mbedtls_free( context_buf );
        context_buf = NULL;
        context_buf_len = 0;

        mbedtls_printf( " ok\n" );
    }
#endif /* MBEDTLS_SSL_CONTEXT_SERIALIZATION */

    /*
     * 7c. Continue doing data exchanges?
     */
    if( --exchanges_left > 0 )
        goto data_exchange;

    /*
     * 8. Done, cleanly close the connection
     */
close_notify:
    mbedtls_printf( "  . Closing the connection..." );

    /* No error checking, the connection might be closed already */
    do ret = mbedtls_ssl_close_notify( &ssl );
    while( ret == MBEDTLS_ERR_SSL_WANT_WRITE );
    ret = 0;

    mbedtls_printf( " done\n" );

    goto reset;

    /*
     * Cleanup and exit
     */
exit:
#ifdef MBEDTLS_ERROR_C
    if( ret != 0 )
    {
        char error_buf[100];
        mbedtls_strerror( ret, error_buf, 100 );
        mbedtls_printf("Last error was: -0x%X - %s\n\n", (unsigned int) -ret, error_buf );
    }
#endif

    if( opt.query_config_mode == DFL_QUERY_CONFIG_MODE )
    {
        mbedtls_printf( "  . Cleaning up..." );
        fflush( stdout );
    }

    mbedtls_net_free( &client_fd );
    mbedtls_net_free( &listen_fd );

    mbedtls_ssl_free( &ssl );
    mbedtls_ssl_config_free( &conf );

#if defined(MBEDTLS_SSL_CACHE_C)
    mbedtls_ssl_cache_free( &cache );
#endif
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
    mbedtls_ssl_ticket_free( &ticket_ctx );
#endif
#if defined(MBEDTLS_SSL_COOKIE_C)
    mbedtls_ssl_cookie_free( &cookie_ctx );
#endif

#if defined(MBEDTLS_SSL_CONTEXT_SERIALIZATION)
    if( context_buf != NULL )
        mbedtls_platform_zeroize( context_buf, context_buf_len );
    mbedtls_free( context_buf );
#endif

#if defined(SNI_OPTION)
    sni_free( sni_info );
#endif

#if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED)
    ret = psk_free( psk_info );
    if( ( ret != 0 ) && ( opt.query_config_mode == DFL_QUERY_CONFIG_MODE ) )
        mbedtls_printf( "Failed to list of opaque PSKs - error was %d\n", ret );
#endif

#if defined(MBEDTLS_X509_CRT_PARSE_C)
    mbedtls_x509_crt_free( &cacert );
    mbedtls_x509_crt_free( &srvcert );
    mbedtls_pk_free( &pkey );
    mbedtls_x509_crt_free( &srvcert2 );
    mbedtls_pk_free( &pkey2 );
#if defined(MBEDTLS_USE_PSA_CRYPTO)
    psa_destroy_key( key_slot );
    psa_destroy_key( key_slot2 );
#endif
#endif

#if defined(MBEDTLS_DHM_C) && defined(MBEDTLS_FS_IO)
    mbedtls_dhm_free( &dhm );
#endif

#if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
    for( i = 0; (size_t) i < ssl_async_keys.slots_used; i++ )
    {
        if( ssl_async_keys.slots[i].pk_owned )
        {
            mbedtls_pk_free( ssl_async_keys.slots[i].pk );
            mbedtls_free( ssl_async_keys.slots[i].pk );
            ssl_async_keys.slots[i].pk = NULL;
        }
    }
#endif

#if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED) && \
    defined(MBEDTLS_USE_PSA_CRYPTO)
    if( opt.psk_opaque != 0 )
    {
        /* This is ok even if the slot hasn't been
         * initialized (we might have jumed here
         * immediately because of bad cmd line params,
         * for example). */
        status = psa_destroy_key( psk_slot );
        if( ( status != PSA_SUCCESS ) &&
            ( opt.query_config_mode == DFL_QUERY_CONFIG_MODE ) )
        {
            mbedtls_printf( "Failed to destroy key slot %u - error was %d",
                            (unsigned) MBEDTLS_SVC_KEY_ID_GET_KEY_ID( psk_slot ),
                            (int) status );
        }
    }
#endif /* MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED &&
          MBEDTLS_USE_PSA_CRYPTO */

#if defined(MBEDTLS_USE_PSA_CRYPTO)
    const char* message = mbedtls_test_helper_is_psa_leaking();
    if( message )
    {
        if( ret == 0 )
            ret = 1;
        mbedtls_printf( "PSA memory leak detected: %s\n",  message);
    }
#endif

    /* For builds with MBEDTLS_TEST_USE_PSA_CRYPTO_RNG psa crypto
     * resources are freed by rng_free(). */
#if defined(MBEDTLS_USE_PSA_CRYPTO) && \
    !defined(MBEDTLS_TEST_USE_PSA_CRYPTO_RNG)
    mbedtls_psa_crypto_free( );
#endif

    rng_free( &rng );

    mbedtls_free( buf );

#if defined(MBEDTLS_TEST_HOOKS)
    /* Let test hooks detect errors such as resource leaks.
     * Don't do it in query_config mode, because some test code prints
     * information to stdout and this gets mixed with the regular output. */
    if( opt.query_config_mode == DFL_QUERY_CONFIG_MODE )
    {
        if( test_hooks_failure_detected( ) )
        {
            if( ret == 0 )
                ret = 1;
            mbedtls_printf( "Test hooks detected errors.\n" );
        }
    }
    test_hooks_free( );
#endif /* MBEDTLS_TEST_HOOKS */

#if defined(MBEDTLS_MEMORY_BUFFER_ALLOC_C)
#if defined(MBEDTLS_MEMORY_DEBUG)
    mbedtls_memory_buffer_alloc_status();
#endif
    mbedtls_memory_buffer_alloc_free();
#endif  /* MBEDTLS_MEMORY_BUFFER_ALLOC_C */

    if( opt.query_config_mode == DFL_QUERY_CONFIG_MODE )
    {
        mbedtls_printf( " done.\n" );

#if defined(_WIN32)
        mbedtls_printf( "  + Press Enter to exit this program.\n" );
        fflush( stdout ); getchar();
#endif
    }

    // Shell can not handle large exit numbers -> 1 for errors
    if( ret < 0 )
        ret = 1;

    if( opt.query_config_mode == DFL_QUERY_CONFIG_MODE )
        mbedtls_exit( ret );
    else
        mbedtls_exit( query_config_ret );
}
#endif /* !MBEDTLS_SSL_TEST_IMPOSSIBLE && MBEDTLS_SSL_SRV_C */