Release Mbed Crypto 0.1.0a
diff --git a/library/psa_crypto.c b/library/psa_crypto.c
new file mode 100644
index 0000000..4408b45
--- /dev/null
+++ b/library/psa_crypto.c
@@ -0,0 +1,3513 @@
+/*
+ *  PSA crypto layer on top of Mbed Crypto crypto
+ */
+/*  Copyright (C) 2018, ARM Limited, All Rights Reserved
+ *  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.
+ *
+ *  This file is part of Mbed Crypto (https://tls.mbed.org)
+ */
+
+#if !defined(MBEDCRYPTO_CONFIG_FILE)
+#include "mbedcrypto/config.h"
+#else
+#include MBEDCRYPTO_CONFIG_FILE
+#endif
+
+#if defined(MBEDCRYPTO_PSA_CRYPTO_C)
+/*
+ * In case MBEDCRYPTO_PSA_CRYPTO_SPM is defined the code is built for SPM (Secure
+ * Partition Manager) integration which separate the code into two parts
+ * NSPE (Non-Secure Process Environment) and SPE (Secure Process Environment).
+ * In this mode an additional header file should be included.
+ */
+#if defined(MBEDCRYPTO_PSA_CRYPTO_SPM)
+/*
+ * PSA_CRYPTO_SECURE means that this file is compiled to the SPE side.
+ * some headers will be affected by this flag.
+ */
+#define PSA_CRYPTO_SECURE 1
+#include "crypto_spe.h"
+#endif
+
+#include "psa/crypto.h"
+
+#include <stdlib.h>
+#include <string.h>
+#if defined(MBEDCRYPTO_PLATFORM_C)
+#include "mbedcrypto/platform.h"
+#else
+#define mbedcrypto_calloc calloc
+#define mbedcrypto_free   free
+#endif
+
+#include "mbedcrypto/arc4.h"
+#include "mbedcrypto/asn1.h"
+#include "mbedcrypto/bignum.h"
+#include "mbedcrypto/blowfish.h"
+#include "mbedcrypto/camellia.h"
+#include "mbedcrypto/cipher.h"
+#include "mbedcrypto/ccm.h"
+#include "mbedcrypto/cmac.h"
+#include "mbedcrypto/ctr_drbg.h"
+#include "mbedcrypto/des.h"
+#include "mbedcrypto/ecp.h"
+#include "mbedcrypto/entropy.h"
+#include "mbedcrypto/error.h"
+#include "mbedcrypto/gcm.h"
+#include "mbedcrypto/md2.h"
+#include "mbedcrypto/md4.h"
+#include "mbedcrypto/md5.h"
+#include "mbedcrypto/md.h"
+#include "mbedcrypto/md_internal.h"
+#include "mbedcrypto/pk.h"
+#include "mbedcrypto/pk_internal.h"
+#include "mbedcrypto/ripemd160.h"
+#include "mbedcrypto/rsa.h"
+#include "mbedcrypto/sha1.h"
+#include "mbedcrypto/sha256.h"
+#include "mbedcrypto/sha512.h"
+#include "mbedcrypto/xtea.h"
+
+
+
+#define ARRAY_LENGTH( array ) ( sizeof( array ) / sizeof( *( array ) ) )
+
+/* Implementation that should never be optimized out by the compiler */
+static void mbedcrypto_zeroize( void *v, size_t n )
+{
+    volatile unsigned char *p = v; while( n-- ) *p++ = 0;
+}
+
+/* constant-time buffer comparison */
+static inline int safer_memcmp( const uint8_t *a, const uint8_t *b, size_t n )
+{
+    size_t i;
+    unsigned char diff = 0;
+
+    for( i = 0; i < n; i++ )
+        diff |= a[i] ^ b[i];
+
+    return( diff );
+}
+
+
+
+/****************************************************************/
+/* Global data, support functions and library management */
+/****************************************************************/
+
+/* Number of key slots (plus one because 0 is not used).
+ * The value is a compile-time constant for now, for simplicity. */
+#define PSA_KEY_SLOT_COUNT 32
+
+typedef struct
+{
+    psa_key_type_t type;
+    psa_key_policy_t policy;
+    psa_key_lifetime_t lifetime;
+    union
+    {
+        struct raw_data
+        {
+            uint8_t *data;
+            size_t bytes;
+        } raw;
+#if defined(MBEDCRYPTO_RSA_C)
+        mbedcrypto_rsa_context *rsa;
+#endif /* MBEDCRYPTO_RSA_C */
+#if defined(MBEDCRYPTO_ECP_C)
+        mbedcrypto_ecp_keypair *ecp;
+#endif /* MBEDCRYPTO_ECP_C */
+    } data;
+} key_slot_t;
+
+static int key_type_is_raw_bytes( psa_key_type_t type )
+{
+    psa_key_type_t category = type & PSA_KEY_TYPE_CATEGORY_MASK;
+    return( category == PSA_KEY_TYPE_RAW_DATA ||
+            category == PSA_KEY_TYPE_CATEGORY_SYMMETRIC );
+}
+
+typedef struct
+{
+    int initialized;
+    mbedcrypto_entropy_context entropy;
+    mbedcrypto_ctr_drbg_context ctr_drbg;
+    key_slot_t key_slots[PSA_KEY_SLOT_COUNT];
+} psa_global_data_t;
+
+static psa_global_data_t global_data;
+
+static psa_status_t mbedcrypto_to_psa_error( int ret )
+{
+    /* If there's both a high-level code and low-level code, dispatch on
+     * the high-level code. */
+    switch( ret < -0x7f ? - ( -ret & 0x7f80 ) : ret )
+    {
+        case 0:
+            return( PSA_SUCCESS );
+
+        case MBEDCRYPTO_ERR_AES_INVALID_KEY_LENGTH:
+        case MBEDCRYPTO_ERR_AES_INVALID_INPUT_LENGTH:
+        case MBEDCRYPTO_ERR_AES_FEATURE_UNAVAILABLE:
+            return( PSA_ERROR_NOT_SUPPORTED );
+        case MBEDCRYPTO_ERR_AES_HW_ACCEL_FAILED:
+            return( PSA_ERROR_HARDWARE_FAILURE );
+
+        case MBEDCRYPTO_ERR_ARC4_HW_ACCEL_FAILED:
+            return( PSA_ERROR_HARDWARE_FAILURE );
+
+        case MBEDCRYPTO_ERR_ASN1_OUT_OF_DATA:
+        case MBEDCRYPTO_ERR_ASN1_UNEXPECTED_TAG:
+        case MBEDCRYPTO_ERR_ASN1_INVALID_LENGTH:
+        case MBEDCRYPTO_ERR_ASN1_LENGTH_MISMATCH:
+        case MBEDCRYPTO_ERR_ASN1_INVALID_DATA:
+            return( PSA_ERROR_INVALID_ARGUMENT );
+        case MBEDCRYPTO_ERR_ASN1_ALLOC_FAILED:
+            return( PSA_ERROR_INSUFFICIENT_MEMORY );
+        case MBEDCRYPTO_ERR_ASN1_BUF_TOO_SMALL:
+            return( PSA_ERROR_BUFFER_TOO_SMALL );
+
+        case MBEDCRYPTO_ERR_BLOWFISH_INVALID_KEY_LENGTH:
+        case MBEDCRYPTO_ERR_BLOWFISH_INVALID_INPUT_LENGTH:
+            return( PSA_ERROR_NOT_SUPPORTED );
+        case MBEDCRYPTO_ERR_BLOWFISH_HW_ACCEL_FAILED:
+            return( PSA_ERROR_HARDWARE_FAILURE );
+
+        case MBEDCRYPTO_ERR_CAMELLIA_INVALID_KEY_LENGTH:
+        case MBEDCRYPTO_ERR_CAMELLIA_INVALID_INPUT_LENGTH:
+            return( PSA_ERROR_NOT_SUPPORTED );
+        case MBEDCRYPTO_ERR_CAMELLIA_HW_ACCEL_FAILED:
+            return( PSA_ERROR_HARDWARE_FAILURE );
+
+        case MBEDCRYPTO_ERR_CCM_BAD_INPUT:
+            return( PSA_ERROR_INVALID_ARGUMENT );
+        case MBEDCRYPTO_ERR_CCM_AUTH_FAILED:
+            return( PSA_ERROR_INVALID_SIGNATURE );
+        case MBEDCRYPTO_ERR_CCM_HW_ACCEL_FAILED:
+            return( PSA_ERROR_HARDWARE_FAILURE );
+
+        case MBEDCRYPTO_ERR_CIPHER_FEATURE_UNAVAILABLE:
+            return( PSA_ERROR_NOT_SUPPORTED );
+        case MBEDCRYPTO_ERR_CIPHER_BAD_INPUT_DATA:
+            return( PSA_ERROR_INVALID_ARGUMENT );
+        case MBEDCRYPTO_ERR_CIPHER_ALLOC_FAILED:
+            return( PSA_ERROR_INSUFFICIENT_MEMORY );
+        case MBEDCRYPTO_ERR_CIPHER_INVALID_PADDING:
+            return( PSA_ERROR_INVALID_PADDING );
+        case MBEDCRYPTO_ERR_CIPHER_FULL_BLOCK_EXPECTED:
+            return( PSA_ERROR_BAD_STATE );
+        case MBEDCRYPTO_ERR_CIPHER_AUTH_FAILED:
+            return( PSA_ERROR_INVALID_SIGNATURE );
+        case MBEDCRYPTO_ERR_CIPHER_INVALID_CONTEXT:
+            return( PSA_ERROR_TAMPERING_DETECTED );
+        case MBEDCRYPTO_ERR_CIPHER_HW_ACCEL_FAILED:
+            return( PSA_ERROR_HARDWARE_FAILURE );
+
+        case MBEDCRYPTO_ERR_CMAC_HW_ACCEL_FAILED:
+            return( PSA_ERROR_HARDWARE_FAILURE );
+
+        case MBEDCRYPTO_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED:
+            return( PSA_ERROR_INSUFFICIENT_ENTROPY );
+        case MBEDCRYPTO_ERR_CTR_DRBG_REQUEST_TOO_BIG:
+        case MBEDCRYPTO_ERR_CTR_DRBG_INPUT_TOO_BIG:
+            return( PSA_ERROR_NOT_SUPPORTED );
+        case MBEDCRYPTO_ERR_CTR_DRBG_FILE_IO_ERROR:
+            return( PSA_ERROR_INSUFFICIENT_ENTROPY );
+
+        case MBEDCRYPTO_ERR_DES_INVALID_INPUT_LENGTH:
+            return( PSA_ERROR_NOT_SUPPORTED );
+        case MBEDCRYPTO_ERR_DES_HW_ACCEL_FAILED:
+            return( PSA_ERROR_HARDWARE_FAILURE );
+
+        case MBEDCRYPTO_ERR_ENTROPY_NO_SOURCES_DEFINED:
+        case MBEDCRYPTO_ERR_ENTROPY_NO_STRONG_SOURCE:
+        case MBEDCRYPTO_ERR_ENTROPY_SOURCE_FAILED:
+            return( PSA_ERROR_INSUFFICIENT_ENTROPY );
+
+        case MBEDCRYPTO_ERR_GCM_AUTH_FAILED:
+            return( PSA_ERROR_INVALID_SIGNATURE );
+        case MBEDCRYPTO_ERR_GCM_BAD_INPUT:
+            return( PSA_ERROR_NOT_SUPPORTED );
+        case MBEDCRYPTO_ERR_GCM_HW_ACCEL_FAILED:
+            return( PSA_ERROR_HARDWARE_FAILURE );
+
+        case MBEDCRYPTO_ERR_MD2_HW_ACCEL_FAILED:
+        case MBEDCRYPTO_ERR_MD4_HW_ACCEL_FAILED:
+        case MBEDCRYPTO_ERR_MD5_HW_ACCEL_FAILED:
+            return( PSA_ERROR_HARDWARE_FAILURE );
+
+        case MBEDCRYPTO_ERR_MD_FEATURE_UNAVAILABLE:
+            return( PSA_ERROR_NOT_SUPPORTED );
+        case MBEDCRYPTO_ERR_MD_BAD_INPUT_DATA:
+            return( PSA_ERROR_INVALID_ARGUMENT );
+        case MBEDCRYPTO_ERR_MD_ALLOC_FAILED:
+            return( PSA_ERROR_INSUFFICIENT_MEMORY );
+        case MBEDCRYPTO_ERR_MD_FILE_IO_ERROR:
+            return( PSA_ERROR_STORAGE_FAILURE );
+        case MBEDCRYPTO_ERR_MD_HW_ACCEL_FAILED:
+            return( PSA_ERROR_HARDWARE_FAILURE );
+
+        case MBEDCRYPTO_ERR_PK_ALLOC_FAILED:
+            return( PSA_ERROR_INSUFFICIENT_MEMORY );
+        case MBEDCRYPTO_ERR_PK_TYPE_MISMATCH:
+        case MBEDCRYPTO_ERR_PK_BAD_INPUT_DATA:
+            return( PSA_ERROR_INVALID_ARGUMENT );
+        case MBEDCRYPTO_ERR_PK_FILE_IO_ERROR:
+            return( PSA_ERROR_STORAGE_FAILURE );
+        case MBEDCRYPTO_ERR_PK_KEY_INVALID_VERSION:
+        case MBEDCRYPTO_ERR_PK_KEY_INVALID_FORMAT:
+            return( PSA_ERROR_INVALID_ARGUMENT );
+        case MBEDCRYPTO_ERR_PK_UNKNOWN_PK_ALG:
+            return( PSA_ERROR_NOT_SUPPORTED );
+        case MBEDCRYPTO_ERR_PK_PASSWORD_REQUIRED:
+        case MBEDCRYPTO_ERR_PK_PASSWORD_MISMATCH:
+            return( PSA_ERROR_NOT_PERMITTED );
+        case MBEDCRYPTO_ERR_PK_INVALID_PUBKEY:
+            return( PSA_ERROR_INVALID_ARGUMENT );
+        case MBEDCRYPTO_ERR_PK_INVALID_ALG:
+        case MBEDCRYPTO_ERR_PK_UNKNOWN_NAMED_CURVE:
+        case MBEDCRYPTO_ERR_PK_FEATURE_UNAVAILABLE:
+            return( PSA_ERROR_NOT_SUPPORTED );
+        case MBEDCRYPTO_ERR_PK_SIG_LEN_MISMATCH:
+            return( PSA_ERROR_INVALID_SIGNATURE );
+        case MBEDCRYPTO_ERR_PK_HW_ACCEL_FAILED:
+            return( PSA_ERROR_HARDWARE_FAILURE );
+
+        case MBEDCRYPTO_ERR_RIPEMD160_HW_ACCEL_FAILED:
+            return( PSA_ERROR_HARDWARE_FAILURE );
+
+        case MBEDCRYPTO_ERR_RSA_BAD_INPUT_DATA:
+            return( PSA_ERROR_INVALID_ARGUMENT );
+        case MBEDCRYPTO_ERR_RSA_INVALID_PADDING:
+            return( PSA_ERROR_INVALID_PADDING );
+        case MBEDCRYPTO_ERR_RSA_KEY_GEN_FAILED:
+            return( PSA_ERROR_HARDWARE_FAILURE );
+        case MBEDCRYPTO_ERR_RSA_KEY_CHECK_FAILED:
+            return( PSA_ERROR_INVALID_ARGUMENT );
+        case MBEDCRYPTO_ERR_RSA_PUBLIC_FAILED:
+        case MBEDCRYPTO_ERR_RSA_PRIVATE_FAILED:
+            return( PSA_ERROR_TAMPERING_DETECTED );
+        case MBEDCRYPTO_ERR_RSA_VERIFY_FAILED:
+            return( PSA_ERROR_INVALID_SIGNATURE );
+        case MBEDCRYPTO_ERR_RSA_OUTPUT_TOO_LARGE:
+            return( PSA_ERROR_BUFFER_TOO_SMALL );
+        case MBEDCRYPTO_ERR_RSA_RNG_FAILED:
+            return( PSA_ERROR_INSUFFICIENT_MEMORY );
+        case MBEDCRYPTO_ERR_RSA_UNSUPPORTED_OPERATION:
+            return( PSA_ERROR_NOT_SUPPORTED );
+        case MBEDCRYPTO_ERR_RSA_HW_ACCEL_FAILED:
+            return( PSA_ERROR_HARDWARE_FAILURE );
+
+        case MBEDCRYPTO_ERR_SHA1_HW_ACCEL_FAILED:
+        case MBEDCRYPTO_ERR_SHA256_HW_ACCEL_FAILED:
+        case MBEDCRYPTO_ERR_SHA512_HW_ACCEL_FAILED:
+            return( PSA_ERROR_HARDWARE_FAILURE );
+
+        case MBEDCRYPTO_ERR_XTEA_INVALID_INPUT_LENGTH:
+            return( PSA_ERROR_INVALID_ARGUMENT );
+        case MBEDCRYPTO_ERR_XTEA_HW_ACCEL_FAILED:
+            return( PSA_ERROR_HARDWARE_FAILURE );
+
+        case MBEDCRYPTO_ERR_ECP_BAD_INPUT_DATA:
+        case MBEDCRYPTO_ERR_ECP_INVALID_KEY:
+            return( PSA_ERROR_INVALID_ARGUMENT );
+        case MBEDCRYPTO_ERR_ECP_BUFFER_TOO_SMALL:
+            return( PSA_ERROR_BUFFER_TOO_SMALL );
+        case MBEDCRYPTO_ERR_ECP_FEATURE_UNAVAILABLE:
+            return( PSA_ERROR_NOT_SUPPORTED );
+        case MBEDCRYPTO_ERR_ECP_SIG_LEN_MISMATCH:
+        case MBEDCRYPTO_ERR_ECP_VERIFY_FAILED:
+            return( PSA_ERROR_INVALID_SIGNATURE );
+        case MBEDCRYPTO_ERR_ECP_ALLOC_FAILED:
+            return( PSA_ERROR_INSUFFICIENT_MEMORY );
+        case MBEDCRYPTO_ERR_ECP_HW_ACCEL_FAILED:
+            return( PSA_ERROR_HARDWARE_FAILURE );
+
+        default:
+            return( PSA_ERROR_UNKNOWN_ERROR );
+    }
+}
+
+/* Retrieve a key slot, occupied or not. */
+static psa_status_t psa_get_key_slot( psa_key_slot_t key,
+                                      key_slot_t **p_slot )
+{
+    /* 0 is not a valid slot number under any circumstance. This
+     * implementation provides slots number 1 to N where N is the
+     * number of available slots. */
+    if( key == 0 || key > ARRAY_LENGTH( global_data.key_slots ) )
+        return( PSA_ERROR_INVALID_ARGUMENT );
+
+    *p_slot = &global_data.key_slots[key - 1];
+    return( PSA_SUCCESS );
+}
+
+/* Retrieve an empty key slot (slot with no key data, but possibly
+ * with some metadata such as a policy). */
+static psa_status_t psa_get_empty_key_slot( psa_key_slot_t key,
+                                            key_slot_t **p_slot )
+{
+    psa_status_t status;
+    key_slot_t *slot = NULL;
+
+    *p_slot = NULL;
+
+    status = psa_get_key_slot( key, &slot );
+    if( status != PSA_SUCCESS )
+        return( status );
+
+    if( slot->type != PSA_KEY_TYPE_NONE )
+        return( PSA_ERROR_OCCUPIED_SLOT );
+
+    *p_slot = slot;
+    return( status );
+}
+
+/** Retrieve a slot which must contain a key. The key must have allow all the
+ * usage flags set in \p usage. If \p alg is nonzero, the key must allow
+ * operations with this algorithm. */
+static psa_status_t psa_get_key_from_slot( psa_key_slot_t key,
+                                           key_slot_t **p_slot,
+                                           psa_key_usage_t usage,
+                                           psa_algorithm_t alg )
+{
+    psa_status_t status;
+    key_slot_t *slot = NULL;
+
+    *p_slot = NULL;
+
+    status = psa_get_key_slot( key, &slot );
+    if( status != PSA_SUCCESS )
+        return( status );
+    if( slot->type == PSA_KEY_TYPE_NONE )
+        return( PSA_ERROR_EMPTY_SLOT );
+
+    /* Enforce that usage policy for the key slot contains all the flags
+     * required by the usage parameter. There is one exception: public
+     * keys can always be exported, so we treat public key objects as
+     * if they had the export flag. */
+    if( PSA_KEY_TYPE_IS_PUBLIC_KEY( slot->type ) )
+        usage &= ~PSA_KEY_USAGE_EXPORT;
+    if( ( slot->policy.usage & usage ) != usage )
+        return( PSA_ERROR_NOT_PERMITTED );
+    if( alg != 0 && ( alg != slot->policy.alg ) )
+        return( PSA_ERROR_NOT_PERMITTED );
+
+    *p_slot = slot;
+    return( PSA_SUCCESS );
+}
+
+
+
+/****************************************************************/
+/* Key management */
+/****************************************************************/
+
+#if defined(MBEDCRYPTO_ECP_C)
+static psa_ecc_curve_t mbedcrypto_ecc_group_to_psa( mbedcrypto_ecp_group_id grpid )
+{
+    switch( grpid )
+    {
+        case MBEDCRYPTO_ECP_DP_SECP192R1:
+            return( PSA_ECC_CURVE_SECP192R1 );
+        case MBEDCRYPTO_ECP_DP_SECP224R1:
+            return( PSA_ECC_CURVE_SECP224R1 );
+        case MBEDCRYPTO_ECP_DP_SECP256R1:
+            return( PSA_ECC_CURVE_SECP256R1 );
+        case MBEDCRYPTO_ECP_DP_SECP384R1:
+            return( PSA_ECC_CURVE_SECP384R1 );
+        case MBEDCRYPTO_ECP_DP_SECP521R1:
+            return( PSA_ECC_CURVE_SECP521R1 );
+        case MBEDCRYPTO_ECP_DP_BP256R1:
+            return( PSA_ECC_CURVE_BRAINPOOL_P256R1 );
+        case MBEDCRYPTO_ECP_DP_BP384R1:
+            return( PSA_ECC_CURVE_BRAINPOOL_P384R1 );
+        case MBEDCRYPTO_ECP_DP_BP512R1:
+            return( PSA_ECC_CURVE_BRAINPOOL_P512R1 );
+        case MBEDCRYPTO_ECP_DP_CURVE25519:
+            return( PSA_ECC_CURVE_CURVE25519 );
+        case MBEDCRYPTO_ECP_DP_SECP192K1:
+            return( PSA_ECC_CURVE_SECP192K1 );
+        case MBEDCRYPTO_ECP_DP_SECP224K1:
+            return( PSA_ECC_CURVE_SECP224K1 );
+        case MBEDCRYPTO_ECP_DP_SECP256K1:
+            return( PSA_ECC_CURVE_SECP256K1 );
+        case MBEDCRYPTO_ECP_DP_CURVE448:
+            return( PSA_ECC_CURVE_CURVE448 );
+        default:
+            return( 0 );
+    }
+}
+
+static mbedcrypto_ecp_group_id mbedcrypto_ecc_group_of_psa( psa_ecc_curve_t curve )
+{
+    switch( curve )
+    {
+        case PSA_ECC_CURVE_SECP192R1:
+            return( MBEDCRYPTO_ECP_DP_SECP192R1 );
+        case PSA_ECC_CURVE_SECP224R1:
+            return( MBEDCRYPTO_ECP_DP_SECP224R1 );
+        case PSA_ECC_CURVE_SECP256R1:
+            return( MBEDCRYPTO_ECP_DP_SECP256R1 );
+        case PSA_ECC_CURVE_SECP384R1:
+            return( MBEDCRYPTO_ECP_DP_SECP384R1 );
+        case PSA_ECC_CURVE_SECP521R1:
+            return( MBEDCRYPTO_ECP_DP_SECP521R1 );
+        case PSA_ECC_CURVE_BRAINPOOL_P256R1:
+            return( MBEDCRYPTO_ECP_DP_BP256R1 );
+        case PSA_ECC_CURVE_BRAINPOOL_P384R1:
+            return( MBEDCRYPTO_ECP_DP_BP384R1 );
+        case PSA_ECC_CURVE_BRAINPOOL_P512R1:
+            return( MBEDCRYPTO_ECP_DP_BP512R1 );
+        case PSA_ECC_CURVE_CURVE25519:
+            return( MBEDCRYPTO_ECP_DP_CURVE25519 );
+        case PSA_ECC_CURVE_SECP192K1:
+            return( MBEDCRYPTO_ECP_DP_SECP192K1 );
+        case PSA_ECC_CURVE_SECP224K1:
+            return( MBEDCRYPTO_ECP_DP_SECP224K1 );
+        case PSA_ECC_CURVE_SECP256K1:
+            return( MBEDCRYPTO_ECP_DP_SECP256K1 );
+        case PSA_ECC_CURVE_CURVE448:
+            return( MBEDCRYPTO_ECP_DP_CURVE448 );
+        default:
+            return( MBEDCRYPTO_ECP_DP_NONE );
+    }
+}
+#endif /* defined(MBEDCRYPTO_ECP_C) */
+
+static psa_status_t prepare_raw_data_slot( psa_key_type_t type,
+                                           size_t bits,
+                                           struct raw_data *raw )
+{
+    /* Check that the bit size is acceptable for the key type */
+    switch( type )
+    {
+        case PSA_KEY_TYPE_RAW_DATA:
+            if( bits == 0 )
+            {
+                raw->bytes = 0;
+                raw->data = NULL;
+                return( PSA_SUCCESS );
+            }
+            break;
+#if defined(MBEDCRYPTO_MD_C)
+        case PSA_KEY_TYPE_HMAC:
+#endif
+        case PSA_KEY_TYPE_DERIVE:
+            break;
+#if defined(MBEDCRYPTO_AES_C)
+        case PSA_KEY_TYPE_AES:
+            if( bits != 128 && bits != 192 && bits != 256 )
+                return( PSA_ERROR_INVALID_ARGUMENT );
+            break;
+#endif
+#if defined(MBEDCRYPTO_CAMELLIA_C)
+        case PSA_KEY_TYPE_CAMELLIA:
+            if( bits != 128 && bits != 192 && bits != 256 )
+                return( PSA_ERROR_INVALID_ARGUMENT );
+            break;
+#endif
+#if defined(MBEDCRYPTO_DES_C)
+        case PSA_KEY_TYPE_DES:
+            if( bits != 64 && bits != 128 && bits != 192 )
+                return( PSA_ERROR_INVALID_ARGUMENT );
+            break;
+#endif
+#if defined(MBEDCRYPTO_ARC4_C)
+        case PSA_KEY_TYPE_ARC4:
+            if( bits < 8 || bits > 2048 )
+                return( PSA_ERROR_INVALID_ARGUMENT );
+            break;
+#endif
+        default:
+            return( PSA_ERROR_NOT_SUPPORTED );
+    }
+    if( bits % 8 != 0 )
+        return( PSA_ERROR_INVALID_ARGUMENT );
+
+    /* Allocate memory for the key */
+    raw->bytes = PSA_BITS_TO_BYTES( bits );
+    raw->data = mbedcrypto_calloc( 1, raw->bytes );
+    if( raw->data == NULL )
+    {
+        raw->bytes = 0;
+        return( PSA_ERROR_INSUFFICIENT_MEMORY );
+    }
+    return( PSA_SUCCESS );
+}
+
+#if defined(MBEDCRYPTO_RSA_C) && defined(MBEDCRYPTO_PK_PARSE_C)
+static psa_status_t psa_import_rsa_key( mbedcrypto_pk_context *pk,
+                                        mbedcrypto_rsa_context **p_rsa )
+{
+    if( mbedcrypto_pk_get_type( pk ) != MBEDCRYPTO_PK_RSA )
+        return( PSA_ERROR_INVALID_ARGUMENT );
+    else
+    {
+        mbedcrypto_rsa_context *rsa = mbedcrypto_pk_rsa( *pk );
+        size_t bits = mbedcrypto_rsa_get_bitlen( rsa );
+        if( bits > PSA_VENDOR_RSA_MAX_KEY_BITS )
+            return( PSA_ERROR_NOT_SUPPORTED );
+        *p_rsa = rsa;
+        return( PSA_SUCCESS );
+    }
+}
+#endif /* defined(MBEDCRYPTO_RSA_C) && defined(MBEDCRYPTO_PK_PARSE_C) */
+
+#if defined(MBEDCRYPTO_ECP_C) && defined(MBEDCRYPTO_PK_PARSE_C)
+static psa_status_t psa_import_ecp_key( psa_ecc_curve_t expected_curve,
+                                        mbedcrypto_pk_context *pk,
+                                        mbedcrypto_ecp_keypair **p_ecp )
+{
+    if( mbedcrypto_pk_get_type( pk ) != MBEDCRYPTO_PK_ECKEY )
+        return( PSA_ERROR_INVALID_ARGUMENT );
+    else
+    {
+        mbedcrypto_ecp_keypair *ecp = mbedcrypto_pk_ec( *pk );
+        psa_ecc_curve_t actual_curve = mbedcrypto_ecc_group_to_psa( ecp->grp.id );
+        if( actual_curve != expected_curve )
+            return( PSA_ERROR_INVALID_ARGUMENT );
+        *p_ecp = ecp;
+        return( PSA_SUCCESS );
+    }
+}
+#endif /* defined(MBEDCRYPTO_ECP_C) && defined(MBEDCRYPTO_PK_PARSE_C) */
+
+psa_status_t psa_import_key( psa_key_slot_t key,
+                             psa_key_type_t type,
+                             const uint8_t *data,
+                             size_t data_length )
+{
+    key_slot_t *slot;
+    psa_status_t status = PSA_SUCCESS;
+    status = psa_get_empty_key_slot( key, &slot );
+    if( status != PSA_SUCCESS )
+        return( status );
+
+    if( key_type_is_raw_bytes( type ) )
+    {
+        /* Ensure that a bytes-to-bit conversion won't overflow. */
+        if( data_length > SIZE_MAX / 8 )
+            return( PSA_ERROR_NOT_SUPPORTED );
+        status = prepare_raw_data_slot( type,
+                                        PSA_BYTES_TO_BITS( data_length ),
+                                        &slot->data.raw );
+        if( status != PSA_SUCCESS )
+            return( status );
+        if( data_length != 0 )
+            memcpy( slot->data.raw.data, data, data_length );
+    }
+    else
+#if defined(MBEDCRYPTO_PK_PARSE_C)
+    if( PSA_KEY_TYPE_IS_RSA( type ) || PSA_KEY_TYPE_IS_ECC( type ) )
+    {
+        int ret;
+        mbedcrypto_pk_context pk;
+        mbedcrypto_pk_init( &pk );
+
+        /* Parse the data. */
+        if( PSA_KEY_TYPE_IS_KEYPAIR( type ) )
+            ret = mbedcrypto_pk_parse_key( &pk, data, data_length, NULL, 0 );
+        else
+            ret = mbedcrypto_pk_parse_public_key( &pk, data, data_length );
+        if( ret != 0 )
+            return( mbedcrypto_to_psa_error( ret ) );
+
+        /* We have something that the pkparse module recognizes.
+         * If it has the expected type and passes any type-specific
+         * checks, store it. */
+#if defined(MBEDCRYPTO_RSA_C)
+        if( PSA_KEY_TYPE_IS_RSA( type ) )
+            status = psa_import_rsa_key( &pk, &slot->data.rsa );
+        else
+#endif /* MBEDCRYPTO_RSA_C */
+#if defined(MBEDCRYPTO_ECP_C)
+        if( PSA_KEY_TYPE_IS_ECC( type ) )
+            status = psa_import_ecp_key( PSA_KEY_TYPE_GET_CURVE( type ),
+                                         &pk, &slot->data.ecp );
+        else
+#endif /* MBEDCRYPTO_ECP_C */
+        {
+            status = PSA_ERROR_NOT_SUPPORTED;
+        }
+
+        /* Free the content of the pk object only on error. On success,
+         * the content of the object has been stored in the slot. */
+        if( status != PSA_SUCCESS )
+        {
+            mbedcrypto_pk_free( &pk );
+            return( status );
+        }
+    }
+    else
+#endif /* defined(MBEDCRYPTO_PK_PARSE_C) */
+    {
+        return( PSA_ERROR_NOT_SUPPORTED );
+    }
+
+    slot->type = type;
+    return( PSA_SUCCESS );
+}
+
+psa_status_t psa_destroy_key( psa_key_slot_t key )
+{
+    key_slot_t *slot;
+    psa_status_t status;
+
+    status = psa_get_key_slot( key, &slot );
+    if( status != PSA_SUCCESS )
+        return( status );
+
+    if( slot->type == PSA_KEY_TYPE_NONE )
+    {
+        /* No key material to clean, but do zeroize the slot below to wipe
+         * metadata such as policies. */
+    }
+    else if( key_type_is_raw_bytes( slot->type ) )
+    {
+        mbedcrypto_free( slot->data.raw.data );
+    }
+    else
+#if defined(MBEDCRYPTO_RSA_C)
+    if( PSA_KEY_TYPE_IS_RSA( slot->type ) )
+    {
+        mbedcrypto_rsa_free( slot->data.rsa );
+        mbedcrypto_free( slot->data.rsa );
+    }
+    else
+#endif /* defined(MBEDCRYPTO_RSA_C) */
+#if defined(MBEDCRYPTO_ECP_C)
+    if( PSA_KEY_TYPE_IS_ECC( slot->type ) )
+    {
+        mbedcrypto_ecp_keypair_free( slot->data.ecp );
+        mbedcrypto_free( slot->data.ecp );
+    }
+    else
+#endif /* defined(MBEDCRYPTO_ECP_C) */
+    {
+        /* Shouldn't happen: the key type is not any type that we
+         * put in. */
+        return( PSA_ERROR_TAMPERING_DETECTED );
+    }
+
+    mbedcrypto_zeroize( slot, sizeof( *slot ) );
+    return( PSA_SUCCESS );
+}
+
+/* Return the size of the key in the given slot, in bits. */
+static size_t psa_get_key_bits( const key_slot_t *slot )
+{
+    if( key_type_is_raw_bytes( slot->type ) )
+        return( slot->data.raw.bytes * 8 );
+#if defined(MBEDCRYPTO_RSA_C)
+    if( PSA_KEY_TYPE_IS_RSA( slot->type ) )
+        return( mbedcrypto_rsa_get_bitlen( slot->data.rsa ) );
+#endif /* defined(MBEDCRYPTO_RSA_C) */
+#if defined(MBEDCRYPTO_ECP_C)
+    if( PSA_KEY_TYPE_IS_ECC( slot->type ) )
+        return( slot->data.ecp->grp.pbits );
+#endif /* defined(MBEDCRYPTO_ECP_C) */
+    /* Shouldn't happen except on an empty slot. */
+    return( 0 );
+}
+
+psa_status_t psa_get_key_information( psa_key_slot_t key,
+                                      psa_key_type_t *type,
+                                      size_t *bits )
+{
+    key_slot_t *slot;
+    psa_status_t status;
+
+    if( type != NULL )
+        *type = 0;
+    if( bits != NULL )
+        *bits = 0;
+    status = psa_get_key_slot( key, &slot );
+    if( status != PSA_SUCCESS )
+        return( status );
+
+    if( slot->type == PSA_KEY_TYPE_NONE )
+        return( PSA_ERROR_EMPTY_SLOT );
+    if( type != NULL )
+        *type = slot->type;
+    if( bits != NULL )
+        *bits = psa_get_key_bits( slot );
+    return( PSA_SUCCESS );
+}
+
+static  psa_status_t psa_internal_export_key( psa_key_slot_t key,
+                                              uint8_t *data,
+                                              size_t data_size,
+                                              size_t *data_length,
+                                              int export_public_key )
+{
+    key_slot_t *slot;
+    psa_status_t status;
+    /* Exporting a public key doesn't require a usage flag. If we're
+     * called by psa_export_public_key(), don't require the EXPORT flag.
+     * If we're called by psa_export_key(), do require the EXPORT flag;
+     * if the key turns out to be public key object, psa_get_key_from_slot()
+     * will ignore this flag. */
+    psa_key_usage_t usage = export_public_key ? 0 : PSA_KEY_USAGE_EXPORT;
+
+    /* Set the key to empty now, so that even when there are errors, we always
+     * set data_length to a value between 0 and data_size. On error, setting
+     * the key to empty is a good choice because an empty key representation is
+     * unlikely to be accepted anywhere. */
+    *data_length = 0;
+
+    status = psa_get_key_from_slot( key, &slot, usage, 0 );
+    if( status != PSA_SUCCESS )
+        return( status );
+    if( export_public_key && ! PSA_KEY_TYPE_IS_ASYMMETRIC( slot->type ) )
+        return( PSA_ERROR_INVALID_ARGUMENT );
+
+    if( key_type_is_raw_bytes( slot->type ) )
+    {
+        if( slot->data.raw.bytes > data_size )
+            return( PSA_ERROR_BUFFER_TOO_SMALL );
+        if( slot->data.raw.bytes != 0 )
+            memcpy( data, slot->data.raw.data, slot->data.raw.bytes );
+        *data_length = slot->data.raw.bytes;
+        return( PSA_SUCCESS );
+    }
+    else
+    {
+#if defined(MBEDCRYPTO_PK_WRITE_C)
+        if( PSA_KEY_TYPE_IS_RSA( slot->type ) ||
+            PSA_KEY_TYPE_IS_ECC( slot->type ) )
+        {
+            mbedcrypto_pk_context pk;
+            int ret;
+            if( PSA_KEY_TYPE_IS_RSA( slot->type ) )
+            {
+#if defined(MBEDCRYPTO_RSA_C)
+                mbedcrypto_pk_init( &pk );
+                pk.pk_info = &mbedcrypto_rsa_info;
+                pk.pk_ctx = slot->data.rsa;
+#else
+                return( PSA_ERROR_NOT_SUPPORTED );
+#endif
+            }
+            else
+            {
+#if defined(MBEDCRYPTO_ECP_C)
+                mbedcrypto_pk_init( &pk );
+                pk.pk_info = &mbedcrypto_eckey_info;
+                pk.pk_ctx = slot->data.ecp;
+#else
+                return( PSA_ERROR_NOT_SUPPORTED );
+#endif
+            }
+            if( export_public_key || PSA_KEY_TYPE_IS_PUBLIC_KEY( slot->type ) )
+                ret = mbedcrypto_pk_write_pubkey_der( &pk, data, data_size );
+            else
+                ret = mbedcrypto_pk_write_key_der( &pk, data, data_size );
+            if( ret < 0 )
+            {
+                /* If data_size is 0 then data may be NULL and then the
+                 * call to memset would have undefined behavior. */
+                if( data_size != 0 )
+                    memset( data, 0, data_size );
+                return( mbedcrypto_to_psa_error( ret ) );
+            }
+            /* The mbedcrypto_pk_xxx functions write to the end of the buffer.
+             * Move the data to the beginning and erase remaining data
+             * at the original location. */
+            if( 2 * (size_t) ret <= data_size )
+            {
+                memcpy( data, data + data_size - ret, ret );
+                memset( data + data_size - ret, 0, ret );
+            }
+            else if( (size_t) ret < data_size )
+            {
+                memmove( data, data + data_size - ret, ret );
+                memset( data + ret, 0, data_size - ret );
+            }
+            *data_length = ret;
+            return( PSA_SUCCESS );
+        }
+        else
+#endif /* defined(MBEDCRYPTO_PK_WRITE_C) */
+        {
+            /* This shouldn't happen in the reference implementation, but
+               it is valid for a special-purpose implementation to omit
+               support for exporting certain key types. */
+            return( PSA_ERROR_NOT_SUPPORTED );
+        }
+    }
+}
+
+psa_status_t psa_export_key( psa_key_slot_t key,
+                             uint8_t *data,
+                             size_t data_size,
+                             size_t *data_length )
+{
+    return( psa_internal_export_key( key, data, data_size,
+                                     data_length, 0 ) );
+}
+
+psa_status_t psa_export_public_key( psa_key_slot_t key,
+                                    uint8_t *data,
+                                    size_t data_size,
+                                    size_t *data_length )
+{
+    return( psa_internal_export_key( key, data, data_size,
+                                     data_length, 1 ) );
+}
+
+
+
+/****************************************************************/
+/* Message digests */
+/****************************************************************/
+
+static const mbedcrypto_md_info_t *mbedcrypto_md_info_from_psa( psa_algorithm_t alg )
+{
+    switch( alg )
+    {
+#if defined(MBEDCRYPTO_MD2_C)
+        case PSA_ALG_MD2:
+            return( &mbedcrypto_md2_info );
+#endif
+#if defined(MBEDCRYPTO_MD4_C)
+        case PSA_ALG_MD4:
+            return( &mbedcrypto_md4_info );
+#endif
+#if defined(MBEDCRYPTO_MD5_C)
+        case PSA_ALG_MD5:
+            return( &mbedcrypto_md5_info );
+#endif
+#if defined(MBEDCRYPTO_RIPEMD160_C)
+        case PSA_ALG_RIPEMD160:
+            return( &mbedcrypto_ripemd160_info );
+#endif
+#if defined(MBEDCRYPTO_SHA1_C)
+        case PSA_ALG_SHA_1:
+            return( &mbedcrypto_sha1_info );
+#endif
+#if defined(MBEDCRYPTO_SHA256_C)
+        case PSA_ALG_SHA_224:
+            return( &mbedcrypto_sha224_info );
+        case PSA_ALG_SHA_256:
+            return( &mbedcrypto_sha256_info );
+#endif
+#if defined(MBEDCRYPTO_SHA512_C)
+        case PSA_ALG_SHA_384:
+            return( &mbedcrypto_sha384_info );
+        case PSA_ALG_SHA_512:
+            return( &mbedcrypto_sha512_info );
+#endif
+        default:
+            return( NULL );
+    }
+}
+
+psa_status_t psa_hash_abort( psa_hash_operation_t *operation )
+{
+    switch( operation->alg )
+    {
+        case 0:
+            /* The object has (apparently) been initialized but it is not
+             * in use. It's ok to call abort on such an object, and there's
+             * nothing to do. */
+            break;
+#if defined(MBEDCRYPTO_MD2_C)
+        case PSA_ALG_MD2:
+            mbedcrypto_md2_free( &operation->ctx.md2 );
+            break;
+#endif
+#if defined(MBEDCRYPTO_MD4_C)
+        case PSA_ALG_MD4:
+            mbedcrypto_md4_free( &operation->ctx.md4 );
+            break;
+#endif
+#if defined(MBEDCRYPTO_MD5_C)
+        case PSA_ALG_MD5:
+            mbedcrypto_md5_free( &operation->ctx.md5 );
+            break;
+#endif
+#if defined(MBEDCRYPTO_RIPEMD160_C)
+        case PSA_ALG_RIPEMD160:
+            mbedcrypto_ripemd160_free( &operation->ctx.ripemd160 );
+            break;
+#endif
+#if defined(MBEDCRYPTO_SHA1_C)
+        case PSA_ALG_SHA_1:
+            mbedcrypto_sha1_free( &operation->ctx.sha1 );
+            break;
+#endif
+#if defined(MBEDCRYPTO_SHA256_C)
+        case PSA_ALG_SHA_224:
+        case PSA_ALG_SHA_256:
+            mbedcrypto_sha256_free( &operation->ctx.sha256 );
+            break;
+#endif
+#if defined(MBEDCRYPTO_SHA512_C)
+        case PSA_ALG_SHA_384:
+        case PSA_ALG_SHA_512:
+            mbedcrypto_sha512_free( &operation->ctx.sha512 );
+            break;
+#endif
+        default:
+            return( PSA_ERROR_BAD_STATE );
+    }
+    operation->alg = 0;
+    return( PSA_SUCCESS );
+}
+
+psa_status_t psa_hash_setup( psa_hash_operation_t *operation,
+                             psa_algorithm_t alg )
+{
+    int ret;
+    operation->alg = 0;
+    switch( alg )
+    {
+#if defined(MBEDCRYPTO_MD2_C)
+        case PSA_ALG_MD2:
+            mbedcrypto_md2_init( &operation->ctx.md2 );
+            ret = mbedcrypto_md2_starts_ret( &operation->ctx.md2 );
+            break;
+#endif
+#if defined(MBEDCRYPTO_MD4_C)
+        case PSA_ALG_MD4:
+            mbedcrypto_md4_init( &operation->ctx.md4 );
+            ret = mbedcrypto_md4_starts_ret( &operation->ctx.md4 );
+            break;
+#endif
+#if defined(MBEDCRYPTO_MD5_C)
+        case PSA_ALG_MD5:
+            mbedcrypto_md5_init( &operation->ctx.md5 );
+            ret = mbedcrypto_md5_starts_ret( &operation->ctx.md5 );
+            break;
+#endif
+#if defined(MBEDCRYPTO_RIPEMD160_C)
+        case PSA_ALG_RIPEMD160:
+            mbedcrypto_ripemd160_init( &operation->ctx.ripemd160 );
+            ret = mbedcrypto_ripemd160_starts_ret( &operation->ctx.ripemd160 );
+            break;
+#endif
+#if defined(MBEDCRYPTO_SHA1_C)
+        case PSA_ALG_SHA_1:
+            mbedcrypto_sha1_init( &operation->ctx.sha1 );
+            ret = mbedcrypto_sha1_starts_ret( &operation->ctx.sha1 );
+            break;
+#endif
+#if defined(MBEDCRYPTO_SHA256_C)
+        case PSA_ALG_SHA_224:
+            mbedcrypto_sha256_init( &operation->ctx.sha256 );
+            ret = mbedcrypto_sha256_starts_ret( &operation->ctx.sha256, 1 );
+            break;
+        case PSA_ALG_SHA_256:
+            mbedcrypto_sha256_init( &operation->ctx.sha256 );
+            ret = mbedcrypto_sha256_starts_ret( &operation->ctx.sha256, 0 );
+            break;
+#endif
+#if defined(MBEDCRYPTO_SHA512_C)
+        case PSA_ALG_SHA_384:
+            mbedcrypto_sha512_init( &operation->ctx.sha512 );
+            ret = mbedcrypto_sha512_starts_ret( &operation->ctx.sha512, 1 );
+            break;
+        case PSA_ALG_SHA_512:
+            mbedcrypto_sha512_init( &operation->ctx.sha512 );
+            ret = mbedcrypto_sha512_starts_ret( &operation->ctx.sha512, 0 );
+            break;
+#endif
+        default:
+            return( PSA_ALG_IS_HASH( alg ) ?
+                    PSA_ERROR_NOT_SUPPORTED :
+                    PSA_ERROR_INVALID_ARGUMENT );
+    }
+    if( ret == 0 )
+        operation->alg = alg;
+    else
+        psa_hash_abort( operation );
+    return( mbedcrypto_to_psa_error( ret ) );
+}
+
+psa_status_t psa_hash_update( psa_hash_operation_t *operation,
+                              const uint8_t *input,
+                              size_t input_length )
+{
+    int ret;
+
+    /* Don't require hash implementations to behave correctly on a
+     * zero-length input, which may have an invalid pointer. */
+    if( input_length == 0 )
+        return( PSA_SUCCESS );
+
+    switch( operation->alg )
+    {
+#if defined(MBEDCRYPTO_MD2_C)
+        case PSA_ALG_MD2:
+            ret = mbedcrypto_md2_update_ret( &operation->ctx.md2,
+                                          input, input_length );
+            break;
+#endif
+#if defined(MBEDCRYPTO_MD4_C)
+        case PSA_ALG_MD4:
+            ret = mbedcrypto_md4_update_ret( &operation->ctx.md4,
+                                          input, input_length );
+            break;
+#endif
+#if defined(MBEDCRYPTO_MD5_C)
+        case PSA_ALG_MD5:
+            ret = mbedcrypto_md5_update_ret( &operation->ctx.md5,
+                                          input, input_length );
+            break;
+#endif
+#if defined(MBEDCRYPTO_RIPEMD160_C)
+        case PSA_ALG_RIPEMD160:
+            ret = mbedcrypto_ripemd160_update_ret( &operation->ctx.ripemd160,
+                                                input, input_length );
+            break;
+#endif
+#if defined(MBEDCRYPTO_SHA1_C)
+        case PSA_ALG_SHA_1:
+            ret = mbedcrypto_sha1_update_ret( &operation->ctx.sha1,
+                                           input, input_length );
+            break;
+#endif
+#if defined(MBEDCRYPTO_SHA256_C)
+        case PSA_ALG_SHA_224:
+        case PSA_ALG_SHA_256:
+            ret = mbedcrypto_sha256_update_ret( &operation->ctx.sha256,
+                                             input, input_length );
+            break;
+#endif
+#if defined(MBEDCRYPTO_SHA512_C)
+        case PSA_ALG_SHA_384:
+        case PSA_ALG_SHA_512:
+            ret = mbedcrypto_sha512_update_ret( &operation->ctx.sha512,
+                                             input, input_length );
+            break;
+#endif
+        default:
+            ret = MBEDCRYPTO_ERR_MD_BAD_INPUT_DATA;
+            break;
+    }
+
+    if( ret != 0 )
+        psa_hash_abort( operation );
+    return( mbedcrypto_to_psa_error( ret ) );
+}
+
+psa_status_t psa_hash_finish( psa_hash_operation_t *operation,
+                              uint8_t *hash,
+                              size_t hash_size,
+                              size_t *hash_length )
+{
+    int ret;
+    size_t actual_hash_length = PSA_HASH_SIZE( operation->alg );
+
+    /* Fill the output buffer with something that isn't a valid hash
+     * (barring an attack on the hash and deliberately-crafted input),
+     * in case the caller doesn't check the return status properly. */
+    *hash_length = hash_size;
+    /* If hash_size is 0 then hash may be NULL and then the
+     * call to memset would have undefined behavior. */
+    if( hash_size != 0 )
+        memset( hash, '!', hash_size );
+
+    if( hash_size < actual_hash_length )
+        return( PSA_ERROR_BUFFER_TOO_SMALL );
+
+    switch( operation->alg )
+    {
+#if defined(MBEDCRYPTO_MD2_C)
+        case PSA_ALG_MD2:
+            ret = mbedcrypto_md2_finish_ret( &operation->ctx.md2, hash );
+            break;
+#endif
+#if defined(MBEDCRYPTO_MD4_C)
+        case PSA_ALG_MD4:
+            ret = mbedcrypto_md4_finish_ret( &operation->ctx.md4, hash );
+            break;
+#endif
+#if defined(MBEDCRYPTO_MD5_C)
+        case PSA_ALG_MD5:
+            ret = mbedcrypto_md5_finish_ret( &operation->ctx.md5, hash );
+            break;
+#endif
+#if defined(MBEDCRYPTO_RIPEMD160_C)
+        case PSA_ALG_RIPEMD160:
+            ret = mbedcrypto_ripemd160_finish_ret( &operation->ctx.ripemd160, hash );
+            break;
+#endif
+#if defined(MBEDCRYPTO_SHA1_C)
+        case PSA_ALG_SHA_1:
+            ret = mbedcrypto_sha1_finish_ret( &operation->ctx.sha1, hash );
+            break;
+#endif
+#if defined(MBEDCRYPTO_SHA256_C)
+        case PSA_ALG_SHA_224:
+        case PSA_ALG_SHA_256:
+            ret = mbedcrypto_sha256_finish_ret( &operation->ctx.sha256, hash );
+            break;
+#endif
+#if defined(MBEDCRYPTO_SHA512_C)
+        case PSA_ALG_SHA_384:
+        case PSA_ALG_SHA_512:
+            ret = mbedcrypto_sha512_finish_ret( &operation->ctx.sha512, hash );
+            break;
+#endif
+        default:
+            ret = MBEDCRYPTO_ERR_MD_BAD_INPUT_DATA;
+            break;
+    }
+
+    if( ret == 0 )
+    {
+        *hash_length = actual_hash_length;
+        return( psa_hash_abort( operation ) );
+    }
+    else
+    {
+        psa_hash_abort( operation );
+        return( mbedcrypto_to_psa_error( ret ) );
+    }
+}
+
+psa_status_t psa_hash_verify( psa_hash_operation_t *operation,
+                              const uint8_t *hash,
+                              size_t hash_length )
+{
+    uint8_t actual_hash[MBEDCRYPTO_MD_MAX_SIZE];
+    size_t actual_hash_length;
+    psa_status_t status = psa_hash_finish( operation,
+                                           actual_hash, sizeof( actual_hash ),
+                                           &actual_hash_length );
+    if( status != PSA_SUCCESS )
+        return( status );
+    if( actual_hash_length != hash_length )
+        return( PSA_ERROR_INVALID_SIGNATURE );
+    if( safer_memcmp( hash, actual_hash, actual_hash_length ) != 0 )
+        return( PSA_ERROR_INVALID_SIGNATURE );
+    return( PSA_SUCCESS );
+}
+
+
+
+/****************************************************************/
+/* MAC */
+/****************************************************************/
+
+static const mbedcrypto_cipher_info_t *mbedcrypto_cipher_info_from_psa(
+    psa_algorithm_t alg,
+    psa_key_type_t key_type,
+    size_t key_bits,
+    mbedcrypto_cipher_id_t* cipher_id )
+{
+    mbedcrypto_cipher_mode_t mode;
+    mbedcrypto_cipher_id_t cipher_id_tmp;
+
+    if( PSA_ALG_IS_CIPHER( alg ) || PSA_ALG_IS_AEAD( alg ) )
+    {
+        if( PSA_ALG_IS_BLOCK_CIPHER( alg ) )
+        {
+            alg &= ~PSA_ALG_BLOCK_CIPHER_PADDING_MASK;
+        }
+
+        switch( alg )
+        {
+            case PSA_ALG_STREAM_CIPHER_BASE:
+                mode = MBEDCRYPTO_MODE_STREAM;
+                break;
+            case PSA_ALG_CBC_BASE:
+                mode = MBEDCRYPTO_MODE_CBC;
+                break;
+            case PSA_ALG_CFB_BASE:
+                mode = MBEDCRYPTO_MODE_CFB;
+                break;
+            case PSA_ALG_OFB_BASE:
+                mode = MBEDCRYPTO_MODE_OFB;
+                break;
+            case PSA_ALG_CTR:
+                mode = MBEDCRYPTO_MODE_CTR;
+                break;
+            case PSA_ALG_CCM:
+                mode = MBEDCRYPTO_MODE_CCM;
+                break;
+            case PSA_ALG_GCM:
+                mode = MBEDCRYPTO_MODE_GCM;
+                break;
+            default:
+                return( NULL );
+        }
+    }
+    else if( alg == PSA_ALG_CMAC )
+        mode = MBEDCRYPTO_MODE_ECB;
+    else if( alg == PSA_ALG_GMAC )
+        mode = MBEDCRYPTO_MODE_GCM;
+    else
+        return( NULL );
+
+    switch( key_type )
+    {
+        case PSA_KEY_TYPE_AES:
+            cipher_id_tmp = MBEDCRYPTO_CIPHER_ID_AES;
+            break;
+        case PSA_KEY_TYPE_DES:
+            /* key_bits is 64 for Single-DES, 128 for two-key Triple-DES,
+             * and 192 for three-key Triple-DES. */
+            if( key_bits == 64 )
+                cipher_id_tmp = MBEDCRYPTO_CIPHER_ID_DES;
+            else
+                cipher_id_tmp = MBEDCRYPTO_CIPHER_ID_3DES;
+            /* mbedcrypto doesn't recognize two-key Triple-DES as an algorithm,
+             * but two-key Triple-DES is functionally three-key Triple-DES
+             * with K1=K3, so that's how we present it to mbedcrypto. */
+            if( key_bits == 128 )
+                key_bits = 192;
+            break;
+        case PSA_KEY_TYPE_CAMELLIA:
+            cipher_id_tmp = MBEDCRYPTO_CIPHER_ID_CAMELLIA;
+            break;
+        case PSA_KEY_TYPE_ARC4:
+            cipher_id_tmp = MBEDCRYPTO_CIPHER_ID_ARC4;
+            break;
+        default:
+            return( NULL );
+    }
+    if( cipher_id != NULL )
+        *cipher_id = cipher_id_tmp;
+
+    return( mbedcrypto_cipher_info_from_values( cipher_id_tmp,
+                                             (int) key_bits, mode ) );
+}
+
+static size_t psa_get_hash_block_size( psa_algorithm_t alg )
+{
+    switch( alg )
+    {
+        case PSA_ALG_MD2:
+            return( 16 );
+        case PSA_ALG_MD4:
+            return( 64 );
+        case PSA_ALG_MD5:
+            return( 64 );
+        case PSA_ALG_RIPEMD160:
+            return( 64 );
+        case PSA_ALG_SHA_1:
+            return( 64 );
+        case PSA_ALG_SHA_224:
+            return( 64 );
+        case PSA_ALG_SHA_256:
+            return( 64 );
+        case PSA_ALG_SHA_384:
+            return( 128 );
+        case PSA_ALG_SHA_512:
+            return( 128 );
+        default:
+            return( 0 );
+    }
+}
+
+/* Initialize the MAC operation structure. Once this function has been
+ * called, psa_mac_abort can run and will do the right thing. */
+static psa_status_t psa_mac_init( psa_mac_operation_t *operation,
+                                  psa_algorithm_t alg )
+{
+    psa_status_t status = PSA_ERROR_NOT_SUPPORTED;
+
+    operation->alg = alg;
+    operation->key_set = 0;
+    operation->iv_set = 0;
+    operation->iv_required = 0;
+    operation->has_input = 0;
+    operation->is_sign = 0;
+
+#if defined(MBEDCRYPTO_CMAC_C)
+    if( alg == PSA_ALG_CMAC )
+    {
+        operation->iv_required = 0;
+        mbedcrypto_cipher_init( &operation->ctx.cmac );
+        status = PSA_SUCCESS;
+    }
+    else
+#endif /* MBEDCRYPTO_CMAC_C */
+#if defined(MBEDCRYPTO_MD_C)
+    if( PSA_ALG_IS_HMAC( operation->alg ) )
+    {
+        /* We'll set up the hash operation later in psa_hmac_setup_internal. */
+        operation->ctx.hmac.hash_ctx.alg = 0;
+        status = PSA_SUCCESS;
+    }
+    else
+#endif /* MBEDCRYPTO_MD_C */
+    {
+        if( ! PSA_ALG_IS_MAC( alg ) )
+            status = PSA_ERROR_INVALID_ARGUMENT;
+    }
+
+    if( status != PSA_SUCCESS )
+        memset( operation, 0, sizeof( *operation ) );
+    return( status );
+}
+
+#if defined(MBEDCRYPTO_MD_C)
+static psa_status_t psa_hmac_abort_internal( psa_hmac_internal_data *hmac )
+{
+    mbedcrypto_zeroize( hmac->opad, sizeof( hmac->opad ) );
+    return( psa_hash_abort( &hmac->hash_ctx ) );
+}
+#endif /* MBEDCRYPTO_MD_C */
+
+psa_status_t psa_mac_abort( psa_mac_operation_t *operation )
+{
+    if( operation->alg == 0 )
+    {
+        /* The object has (apparently) been initialized but it is not
+         * in use. It's ok to call abort on such an object, and there's
+         * nothing to do. */
+        return( PSA_SUCCESS );
+    }
+    else
+#if defined(MBEDCRYPTO_CMAC_C)
+    if( operation->alg == PSA_ALG_CMAC )
+    {
+        mbedcrypto_cipher_free( &operation->ctx.cmac );
+    }
+    else
+#endif /* MBEDCRYPTO_CMAC_C */
+#if defined(MBEDCRYPTO_MD_C)
+    if( PSA_ALG_IS_HMAC( operation->alg ) )
+    {
+        psa_hmac_abort_internal( &operation->ctx.hmac );
+    }
+    else
+#endif /* MBEDCRYPTO_MD_C */
+    {
+        /* Sanity check (shouldn't happen: operation->alg should
+         * always have been initialized to a valid value). */
+        goto bad_state;
+    }
+
+    operation->alg = 0;
+    operation->key_set = 0;
+    operation->iv_set = 0;
+    operation->iv_required = 0;
+    operation->has_input = 0;
+    operation->is_sign = 0;
+
+    return( PSA_SUCCESS );
+
+bad_state:
+    /* If abort is called on an uninitialized object, we can't trust
+     * anything. Wipe the object in case it contains confidential data.
+     * This may result in a memory leak if a pointer gets overwritten,
+     * but it's too late to do anything about this. */
+    memset( operation, 0, sizeof( *operation ) );
+    return( PSA_ERROR_BAD_STATE );
+}
+
+#if defined(MBEDCRYPTO_CMAC_C)
+static int psa_cmac_setup( psa_mac_operation_t *operation,
+                           size_t key_bits,
+                           key_slot_t *slot,
+                           const mbedcrypto_cipher_info_t *cipher_info )
+{
+    int ret;
+
+    operation->mac_size = cipher_info->block_size;
+
+    ret = mbedcrypto_cipher_setup( &operation->ctx.cmac, cipher_info );
+    if( ret != 0 )
+        return( ret );
+
+    ret = mbedcrypto_cipher_cmac_starts( &operation->ctx.cmac,
+                                      slot->data.raw.data,
+                                      key_bits );
+    return( ret );
+}
+#endif /* MBEDCRYPTO_CMAC_C */
+
+#if defined(MBEDCRYPTO_MD_C)
+static psa_status_t psa_hmac_setup_internal( psa_hmac_internal_data *hmac,
+                                             const uint8_t *key,
+                                             size_t key_length,
+                                             psa_algorithm_t hash_alg )
+{
+    unsigned char ipad[PSA_HMAC_MAX_HASH_BLOCK_SIZE];
+    size_t i;
+    size_t hash_size = PSA_HASH_SIZE( hash_alg );
+    size_t block_size = psa_get_hash_block_size( hash_alg );
+    psa_status_t status;
+
+    /* Sanity checks on block_size, to guarantee that there won't be a buffer
+     * overflow below. This should never trigger if the hash algorithm
+     * is implemented correctly. */
+    /* The size checks against the ipad and opad buffers cannot be written
+     * `block_size > sizeof( ipad ) || block_size > sizeof( hmac->opad )`
+     * because that triggers -Wlogical-op on GCC 7.3. */
+    if( block_size > sizeof( ipad ) )
+        return( PSA_ERROR_NOT_SUPPORTED );
+    if( block_size > sizeof( hmac->opad ) )
+        return( PSA_ERROR_NOT_SUPPORTED );
+    if( block_size < hash_size )
+        return( PSA_ERROR_NOT_SUPPORTED );
+
+    if( key_length > block_size )
+    {
+        status = psa_hash_setup( &hmac->hash_ctx, hash_alg );
+        if( status != PSA_SUCCESS )
+            goto cleanup;
+        status = psa_hash_update( &hmac->hash_ctx, key, key_length );
+        if( status != PSA_SUCCESS )
+            goto cleanup;
+        status = psa_hash_finish( &hmac->hash_ctx,
+                                  ipad, sizeof( ipad ), &key_length );
+        if( status != PSA_SUCCESS )
+            goto cleanup;
+    }
+    /* A 0-length key is not commonly used in HMAC when used as a MAC,
+     * but it is permitted. It is common when HMAC is used in HKDF, for
+     * example. Don't call `memcpy` in the 0-length because `key` could be
+     * an invalid pointer which would make the behavior undefined. */
+    else if( key_length != 0 )
+        memcpy( ipad, key, key_length );
+
+    /* ipad contains the key followed by garbage. Xor and fill with 0x36
+     * to create the ipad value. */
+    for( i = 0; i < key_length; i++ )
+        ipad[i] ^= 0x36;
+    memset( ipad + key_length, 0x36, block_size - key_length );
+
+    /* Copy the key material from ipad to opad, flipping the requisite bits,
+     * and filling the rest of opad with the requisite constant. */
+    for( i = 0; i < key_length; i++ )
+        hmac->opad[i] = ipad[i] ^ 0x36 ^ 0x5C;
+    memset( hmac->opad + key_length, 0x5C, block_size - key_length );
+
+    status = psa_hash_setup( &hmac->hash_ctx, hash_alg );
+    if( status != PSA_SUCCESS )
+        goto cleanup;
+
+    status = psa_hash_update( &hmac->hash_ctx, ipad, block_size );
+
+cleanup:
+    mbedcrypto_zeroize( ipad, key_length );
+
+    return( status );
+}
+#endif /* MBEDCRYPTO_MD_C */
+
+static psa_status_t psa_mac_setup( psa_mac_operation_t *operation,
+                                   psa_key_slot_t key,
+                                   psa_algorithm_t alg,
+                                   int is_sign )
+{
+    psa_status_t status;
+    key_slot_t *slot;
+    size_t key_bits;
+    psa_key_usage_t usage =
+        is_sign ? PSA_KEY_USAGE_SIGN : PSA_KEY_USAGE_VERIFY;
+
+    status = psa_mac_init( operation, alg );
+    if( status != PSA_SUCCESS )
+        return( status );
+    if( is_sign )
+        operation->is_sign = 1;
+
+    status = psa_get_key_from_slot( key, &slot, usage, alg );
+    if( status != PSA_SUCCESS )
+        goto exit;
+    key_bits = psa_get_key_bits( slot );
+
+#if defined(MBEDCRYPTO_CMAC_C)
+    if( alg == PSA_ALG_CMAC )
+    {
+        const mbedcrypto_cipher_info_t *cipher_info =
+            mbedcrypto_cipher_info_from_psa( alg, slot->type, key_bits, NULL );
+        int ret;
+        if( cipher_info == NULL )
+        {
+            status = PSA_ERROR_NOT_SUPPORTED;
+            goto exit;
+        }
+        operation->mac_size = cipher_info->block_size;
+        ret = psa_cmac_setup( operation, key_bits, slot, cipher_info );
+        status = mbedcrypto_to_psa_error( ret );
+    }
+    else
+#endif /* MBEDCRYPTO_CMAC_C */
+#if defined(MBEDCRYPTO_MD_C)
+    if( PSA_ALG_IS_HMAC( alg ) )
+    {
+        psa_algorithm_t hash_alg = PSA_ALG_HMAC_HASH( alg );
+        if( hash_alg == 0 )
+        {
+            status = PSA_ERROR_NOT_SUPPORTED;
+            goto exit;
+        }
+
+        operation->mac_size = PSA_HASH_SIZE( hash_alg );
+        /* Sanity check. This shouldn't fail on a valid configuration. */
+        if( operation->mac_size == 0 ||
+            operation->mac_size > sizeof( operation->ctx.hmac.opad ) )
+        {
+            status = PSA_ERROR_NOT_SUPPORTED;
+            goto exit;
+        }
+
+        if( slot->type != PSA_KEY_TYPE_HMAC )
+        {
+            status = PSA_ERROR_INVALID_ARGUMENT;
+            goto exit;
+        }
+
+        status = psa_hmac_setup_internal( &operation->ctx.hmac,
+                                          slot->data.raw.data,
+                                          slot->data.raw.bytes,
+                                          hash_alg );
+    }
+    else
+#endif /* MBEDCRYPTO_MD_C */
+    {
+        status = PSA_ERROR_NOT_SUPPORTED;
+    }
+
+exit:
+    if( status != PSA_SUCCESS )
+    {
+        psa_mac_abort( operation );
+    }
+    else
+    {
+        operation->key_set = 1;
+    }
+    return( status );
+}
+
+psa_status_t psa_mac_sign_setup( psa_mac_operation_t *operation,
+                                 psa_key_slot_t key,
+                                 psa_algorithm_t alg )
+{
+    return( psa_mac_setup( operation, key, alg, 1 ) );
+}
+
+psa_status_t psa_mac_verify_setup( psa_mac_operation_t *operation,
+                                   psa_key_slot_t key,
+                                   psa_algorithm_t alg )
+{
+    return( psa_mac_setup( operation, key, alg, 0 ) );
+}
+
+psa_status_t psa_mac_update( psa_mac_operation_t *operation,
+                             const uint8_t *input,
+                             size_t input_length )
+{
+    psa_status_t status = PSA_ERROR_BAD_STATE;
+    if( ! operation->key_set )
+        goto cleanup;
+    if( operation->iv_required && ! operation->iv_set )
+        goto cleanup;
+    operation->has_input = 1;
+
+#if defined(MBEDCRYPTO_CMAC_C)
+    if( operation->alg == PSA_ALG_CMAC )
+    {
+        int ret = mbedcrypto_cipher_cmac_update( &operation->ctx.cmac,
+                                              input, input_length );
+        status = mbedcrypto_to_psa_error( ret );
+    }
+    else
+#endif /* MBEDCRYPTO_CMAC_C */
+#if defined(MBEDCRYPTO_MD_C)
+    if( PSA_ALG_IS_HMAC( operation->alg ) )
+    {
+        status = psa_hash_update( &operation->ctx.hmac.hash_ctx, input,
+                                  input_length );
+    }
+    else
+#endif /* MBEDCRYPTO_MD_C */
+    {
+        /* This shouldn't happen if `operation` was initialized by
+         * a setup function. */
+        status = PSA_ERROR_BAD_STATE;
+    }
+
+cleanup:
+    if( status != PSA_SUCCESS )
+        psa_mac_abort( operation );
+    return( status );
+}
+
+#if defined(MBEDCRYPTO_MD_C)
+static psa_status_t psa_hmac_finish_internal( psa_hmac_internal_data *hmac,
+                                              uint8_t *mac,
+                                              size_t mac_size )
+{
+    unsigned char tmp[MBEDCRYPTO_MD_MAX_SIZE];
+    psa_algorithm_t hash_alg = hmac->hash_ctx.alg;
+    size_t hash_size = 0;
+    size_t block_size = psa_get_hash_block_size( hash_alg );
+    psa_status_t status;
+
+    status = psa_hash_finish( &hmac->hash_ctx, tmp, sizeof( tmp ), &hash_size );
+    if( status != PSA_SUCCESS )
+        return( status );
+    /* From here on, tmp needs to be wiped. */
+
+    status = psa_hash_setup( &hmac->hash_ctx, hash_alg );
+    if( status != PSA_SUCCESS )
+        goto exit;
+
+    status = psa_hash_update( &hmac->hash_ctx, hmac->opad, block_size );
+    if( status != PSA_SUCCESS )
+        goto exit;
+
+    status = psa_hash_update( &hmac->hash_ctx, tmp, hash_size );
+    if( status != PSA_SUCCESS )
+        goto exit;
+
+    status = psa_hash_finish( &hmac->hash_ctx, mac, mac_size, &hash_size );
+
+exit:
+    mbedcrypto_zeroize( tmp, hash_size );
+    return( status );
+}
+#endif /* MBEDCRYPTO_MD_C */
+
+static psa_status_t psa_mac_finish_internal( psa_mac_operation_t *operation,
+                                             uint8_t *mac,
+                                             size_t mac_size )
+{
+    if( ! operation->key_set )
+        return( PSA_ERROR_BAD_STATE );
+    if( operation->iv_required && ! operation->iv_set )
+        return( PSA_ERROR_BAD_STATE );
+
+    if( mac_size < operation->mac_size )
+        return( PSA_ERROR_BUFFER_TOO_SMALL );
+
+#if defined(MBEDCRYPTO_CMAC_C)
+    if( operation->alg == PSA_ALG_CMAC )
+    {
+        int ret = mbedcrypto_cipher_cmac_finish( &operation->ctx.cmac, mac );
+        return( mbedcrypto_to_psa_error( ret ) );
+    }
+    else
+#endif /* MBEDCRYPTO_CMAC_C */
+#if defined(MBEDCRYPTO_MD_C)
+    if( PSA_ALG_IS_HMAC( operation->alg ) )
+    {
+        return( psa_hmac_finish_internal( &operation->ctx.hmac,
+                                          mac, mac_size ) );
+    }
+    else
+#endif /* MBEDCRYPTO_MD_C */
+    {
+        /* This shouldn't happen if `operation` was initialized by
+         * a setup function. */
+        return( PSA_ERROR_BAD_STATE );
+    }
+}
+
+psa_status_t psa_mac_sign_finish( psa_mac_operation_t *operation,
+                                  uint8_t *mac,
+                                  size_t mac_size,
+                                  size_t *mac_length )
+{
+    psa_status_t status;
+
+    /* Fill the output buffer with something that isn't a valid mac
+     * (barring an attack on the mac and deliberately-crafted input),
+     * in case the caller doesn't check the return status properly. */
+    *mac_length = mac_size;
+    /* If mac_size is 0 then mac may be NULL and then the
+     * call to memset would have undefined behavior. */
+    if( mac_size != 0 )
+        memset( mac, '!', mac_size );
+
+    if( ! operation->is_sign )
+    {
+        status = PSA_ERROR_BAD_STATE;
+        goto cleanup;
+    }
+
+    status = psa_mac_finish_internal( operation, mac, mac_size );
+
+cleanup:
+    if( status == PSA_SUCCESS )
+    {
+        status = psa_mac_abort( operation );
+        if( status == PSA_SUCCESS )
+            *mac_length = operation->mac_size;
+        else
+            memset( mac, '!', mac_size );
+    }
+    else
+        psa_mac_abort( operation );
+    return( status );
+}
+
+psa_status_t psa_mac_verify_finish( psa_mac_operation_t *operation,
+                                    const uint8_t *mac,
+                                    size_t mac_length )
+{
+    uint8_t actual_mac[PSA_MAC_MAX_SIZE];
+    psa_status_t status;
+
+    if( operation->is_sign )
+    {
+        status = PSA_ERROR_BAD_STATE;
+        goto cleanup;
+    }
+    if( operation->mac_size != mac_length )
+    {
+        status = PSA_ERROR_INVALID_SIGNATURE;
+        goto cleanup;
+    }
+
+    status = psa_mac_finish_internal( operation,
+                                      actual_mac, sizeof( actual_mac ) );
+
+    if( safer_memcmp( mac, actual_mac, mac_length ) != 0 )
+        status = PSA_ERROR_INVALID_SIGNATURE;
+
+cleanup:
+    if( status == PSA_SUCCESS )
+        status = psa_mac_abort( operation );
+    else
+        psa_mac_abort( operation );
+
+    return( status );
+}
+
+
+
+/****************************************************************/
+/* Asymmetric cryptography */
+/****************************************************************/
+
+#if defined(MBEDCRYPTO_RSA_C)
+/* Decode the hash algorithm from alg and store the mbedcrypto encoding in
+ * md_alg. Verify that the hash length is acceptable. */
+static psa_status_t psa_rsa_decode_md_type( psa_algorithm_t alg,
+                                            size_t hash_length,
+                                            mbedcrypto_md_type_t *md_alg )
+{
+    psa_algorithm_t hash_alg = PSA_ALG_SIGN_GET_HASH( alg );
+    const mbedcrypto_md_info_t *md_info = mbedcrypto_md_info_from_psa( hash_alg );
+    *md_alg = mbedcrypto_md_get_type( md_info );
+
+    /* The Mbed Crypto RSA module uses an unsigned int for hash length
+     * parameters. Validate that it fits so that we don't risk an
+     * overflow later. */
+#if SIZE_MAX > UINT_MAX
+    if( hash_length > UINT_MAX )
+        return( PSA_ERROR_INVALID_ARGUMENT );
+#endif
+
+#if defined(MBEDCRYPTO_PKCS1_V15)
+    /* For PKCS#1 v1.5 signature, if using a hash, the hash length
+     * must be correct. */
+    if( PSA_ALG_IS_RSA_PKCS1V15_SIGN( alg ) &&
+        alg != PSA_ALG_RSA_PKCS1V15_SIGN_RAW )
+    {
+        if( md_info == NULL )
+            return( PSA_ERROR_NOT_SUPPORTED );
+        if( mbedcrypto_md_get_size( md_info ) != hash_length )
+            return( PSA_ERROR_INVALID_ARGUMENT );
+    }
+#endif /* MBEDCRYPTO_PKCS1_V15 */
+
+#if defined(MBEDCRYPTO_PKCS1_V21)
+    /* PSS requires a hash internally. */
+    if( PSA_ALG_IS_RSA_PSS( alg ) )
+    {
+        if( md_info == NULL )
+            return( PSA_ERROR_NOT_SUPPORTED );
+    }
+#endif /* MBEDCRYPTO_PKCS1_V21 */
+
+    return( PSA_SUCCESS );
+}
+
+static psa_status_t psa_rsa_sign( mbedcrypto_rsa_context *rsa,
+                                  psa_algorithm_t alg,
+                                  const uint8_t *hash,
+                                  size_t hash_length,
+                                  uint8_t *signature,
+                                  size_t signature_size,
+                                  size_t *signature_length )
+{
+    psa_status_t status;
+    int ret;
+    mbedcrypto_md_type_t md_alg;
+
+    status = psa_rsa_decode_md_type( alg, hash_length, &md_alg );
+    if( status != PSA_SUCCESS )
+        return( status );
+
+    if( signature_size < mbedcrypto_rsa_get_len( rsa ) )
+        return( PSA_ERROR_BUFFER_TOO_SMALL );
+
+#if defined(MBEDCRYPTO_PKCS1_V15)
+    if( PSA_ALG_IS_RSA_PKCS1V15_SIGN( alg ) )
+    {
+        mbedcrypto_rsa_set_padding( rsa, MBEDCRYPTO_RSA_PKCS_V15,
+                                 MBEDCRYPTO_MD_NONE );
+        ret = mbedcrypto_rsa_pkcs1_sign( rsa,
+                                      mbedcrypto_ctr_drbg_random,
+                                      &global_data.ctr_drbg,
+                                      MBEDCRYPTO_RSA_PRIVATE,
+                                      md_alg,
+                                      (unsigned int) hash_length,
+                                      hash,
+                                      signature );
+    }
+    else
+#endif /* MBEDCRYPTO_PKCS1_V15 */
+#if defined(MBEDCRYPTO_PKCS1_V21)
+    if( PSA_ALG_IS_RSA_PSS( alg ) )
+    {
+        mbedcrypto_rsa_set_padding( rsa, MBEDCRYPTO_RSA_PKCS_V21, md_alg );
+        ret = mbedcrypto_rsa_rsassa_pss_sign( rsa,
+                                           mbedcrypto_ctr_drbg_random,
+                                           &global_data.ctr_drbg,
+                                           MBEDCRYPTO_RSA_PRIVATE,
+                                           MBEDCRYPTO_MD_NONE,
+                                           (unsigned int) hash_length,
+                                           hash,
+                                           signature );
+    }
+    else
+#endif /* MBEDCRYPTO_PKCS1_V21 */
+    {
+        return( PSA_ERROR_INVALID_ARGUMENT );
+    }
+
+    if( ret == 0 )
+        *signature_length = mbedcrypto_rsa_get_len( rsa );
+    return( mbedcrypto_to_psa_error( ret ) );
+}
+
+static psa_status_t psa_rsa_verify( mbedcrypto_rsa_context *rsa,
+                                    psa_algorithm_t alg,
+                                    const uint8_t *hash,
+                                    size_t hash_length,
+                                    const uint8_t *signature,
+                                    size_t signature_length )
+{
+    psa_status_t status;
+    int ret;
+    mbedcrypto_md_type_t md_alg;
+
+    status = psa_rsa_decode_md_type( alg, hash_length, &md_alg );
+    if( status != PSA_SUCCESS )
+        return( status );
+
+    if( signature_length < mbedcrypto_rsa_get_len( rsa ) )
+        return( PSA_ERROR_BUFFER_TOO_SMALL );
+
+#if defined(MBEDCRYPTO_PKCS1_V15)
+    if( PSA_ALG_IS_RSA_PKCS1V15_SIGN( alg ) )
+    {
+        mbedcrypto_rsa_set_padding( rsa, MBEDCRYPTO_RSA_PKCS_V15,
+                                 MBEDCRYPTO_MD_NONE );
+        ret = mbedcrypto_rsa_pkcs1_verify( rsa,
+                                        mbedcrypto_ctr_drbg_random,
+                                        &global_data.ctr_drbg,
+                                        MBEDCRYPTO_RSA_PUBLIC,
+                                        md_alg,
+                                        (unsigned int) hash_length,
+                                        hash,
+                                        signature );
+    }
+    else
+#endif /* MBEDCRYPTO_PKCS1_V15 */
+#if defined(MBEDCRYPTO_PKCS1_V21)
+    if( PSA_ALG_IS_RSA_PSS( alg ) )
+    {
+        mbedcrypto_rsa_set_padding( rsa, MBEDCRYPTO_RSA_PKCS_V21, md_alg );
+        ret = mbedcrypto_rsa_rsassa_pss_verify( rsa,
+                                             mbedcrypto_ctr_drbg_random,
+                                             &global_data.ctr_drbg,
+                                             MBEDCRYPTO_RSA_PUBLIC,
+                                             MBEDCRYPTO_MD_NONE,
+                                             (unsigned int) hash_length,
+                                             hash,
+                                             signature );
+    }
+    else
+#endif /* MBEDCRYPTO_PKCS1_V21 */
+    {
+        return( PSA_ERROR_INVALID_ARGUMENT );
+    }
+    return( mbedcrypto_to_psa_error( ret ) );
+}
+#endif /* MBEDCRYPTO_RSA_C */
+
+#if defined(MBEDCRYPTO_ECDSA_C)
+/* `ecp` cannot be const because `ecp->grp` needs to be non-const
+ * for mbedcrypto_ecdsa_sign() and mbedcrypto_ecdsa_sign_det()
+ * (even though these functions don't modify it). */
+static psa_status_t psa_ecdsa_sign( mbedcrypto_ecp_keypair *ecp,
+                                    psa_algorithm_t alg,
+                                    const uint8_t *hash,
+                                    size_t hash_length,
+                                    uint8_t *signature,
+                                    size_t signature_size,
+                                    size_t *signature_length )
+{
+    int ret;
+    mbedcrypto_mpi r, s;
+    size_t curve_bytes = PSA_BITS_TO_BYTES( ecp->grp.pbits );
+    mbedcrypto_mpi_init( &r );
+    mbedcrypto_mpi_init( &s );
+
+    if( signature_size < 2 * curve_bytes )
+    {
+        ret = MBEDCRYPTO_ERR_ECP_BUFFER_TOO_SMALL;
+        goto cleanup;
+    }
+
+    if( PSA_ALG_DSA_IS_DETERMINISTIC( alg ) )
+    {
+        psa_algorithm_t hash_alg = PSA_ALG_SIGN_GET_HASH( alg );
+        const mbedcrypto_md_info_t *md_info = mbedcrypto_md_info_from_psa( hash_alg );
+        mbedcrypto_md_type_t md_alg = mbedcrypto_md_get_type( md_info );
+        MBEDCRYPTO_MPI_CHK( mbedcrypto_ecdsa_sign_det( &ecp->grp, &r, &s, &ecp->d,
+                                                 hash, hash_length,
+                                                 md_alg ) );
+    }
+    else
+    {
+        MBEDCRYPTO_MPI_CHK( mbedcrypto_ecdsa_sign( &ecp->grp, &r, &s, &ecp->d,
+                                             hash, hash_length,
+                                             mbedcrypto_ctr_drbg_random,
+                                             &global_data.ctr_drbg ) );
+    }
+
+    MBEDCRYPTO_MPI_CHK( mbedcrypto_mpi_write_binary( &r,
+                                               signature,
+                                               curve_bytes ) );
+    MBEDCRYPTO_MPI_CHK( mbedcrypto_mpi_write_binary( &s,
+                                               signature + curve_bytes,
+                                               curve_bytes ) );
+
+cleanup:
+    mbedcrypto_mpi_free( &r );
+    mbedcrypto_mpi_free( &s );
+    if( ret == 0 )
+        *signature_length = 2 * curve_bytes;
+    return( mbedcrypto_to_psa_error( ret ) );
+}
+
+static psa_status_t psa_ecdsa_verify( mbedcrypto_ecp_keypair *ecp,
+                                      const uint8_t *hash,
+                                      size_t hash_length,
+                                      const uint8_t *signature,
+                                      size_t signature_length )
+{
+    int ret;
+    mbedcrypto_mpi r, s;
+    size_t curve_bytes = PSA_BITS_TO_BYTES( ecp->grp.pbits );
+    mbedcrypto_mpi_init( &r );
+    mbedcrypto_mpi_init( &s );
+
+    if( signature_length != 2 * curve_bytes )
+        return( PSA_ERROR_INVALID_SIGNATURE );
+
+    MBEDCRYPTO_MPI_CHK( mbedcrypto_mpi_read_binary( &r,
+                                              signature,
+                                              curve_bytes ) );
+    MBEDCRYPTO_MPI_CHK( mbedcrypto_mpi_read_binary( &s,
+                                              signature + curve_bytes,
+                                              curve_bytes ) );
+
+    ret = mbedcrypto_ecdsa_verify( &ecp->grp, hash, hash_length,
+                                &ecp->Q, &r, &s );
+
+cleanup:
+    mbedcrypto_mpi_free( &r );
+    mbedcrypto_mpi_free( &s );
+    return( mbedcrypto_to_psa_error( ret ) );
+}
+#endif /* MBEDCRYPTO_ECDSA_C */
+
+psa_status_t psa_asymmetric_sign( psa_key_slot_t key,
+                                  psa_algorithm_t alg,
+                                  const uint8_t *hash,
+                                  size_t hash_length,
+                                  uint8_t *signature,
+                                  size_t signature_size,
+                                  size_t *signature_length )
+{
+    key_slot_t *slot;
+    psa_status_t status;
+
+    *signature_length = signature_size;
+
+    status = psa_get_key_from_slot( key, &slot, PSA_KEY_USAGE_SIGN, alg );
+    if( status != PSA_SUCCESS )
+        goto exit;
+    if( ! PSA_KEY_TYPE_IS_KEYPAIR( slot->type ) )
+    {
+        status = PSA_ERROR_INVALID_ARGUMENT;
+        goto exit;
+    }
+
+#if defined(MBEDCRYPTO_RSA_C)
+    if( slot->type == PSA_KEY_TYPE_RSA_KEYPAIR )
+    {
+        status = psa_rsa_sign( slot->data.rsa,
+                               alg,
+                               hash, hash_length,
+                               signature, signature_size,
+                               signature_length );
+    }
+    else
+#endif /* defined(MBEDCRYPTO_RSA_C) */
+#if defined(MBEDCRYPTO_ECP_C)
+    if( PSA_KEY_TYPE_IS_ECC( slot->type ) )
+    {
+#if defined(MBEDCRYPTO_ECDSA_C)
+        if( PSA_ALG_IS_ECDSA( alg ) )
+            status = psa_ecdsa_sign( slot->data.ecp,
+                                     alg,
+                                     hash, hash_length,
+                                     signature, signature_size,
+                                     signature_length );
+        else
+#endif /* defined(MBEDCRYPTO_ECDSA_C) */
+        {
+            status = PSA_ERROR_INVALID_ARGUMENT;
+        }
+    }
+    else
+#endif /* defined(MBEDCRYPTO_ECP_C) */
+    {
+        status = PSA_ERROR_NOT_SUPPORTED;
+    }
+
+exit:
+    /* Fill the unused part of the output buffer (the whole buffer on error,
+     * the trailing part on success) with something that isn't a valid mac
+     * (barring an attack on the mac and deliberately-crafted input),
+     * in case the caller doesn't check the return status properly. */
+    if( status == PSA_SUCCESS )
+        memset( signature + *signature_length, '!',
+                signature_size - *signature_length );
+    else if( signature_size != 0 )
+        memset( signature, '!', signature_size );
+    /* If signature_size is 0 then we have nothing to do. We must not call
+     * memset because signature may be NULL in this case. */
+    return( status );
+}
+
+psa_status_t psa_asymmetric_verify( psa_key_slot_t key,
+                                    psa_algorithm_t alg,
+                                    const uint8_t *hash,
+                                    size_t hash_length,
+                                    const uint8_t *signature,
+                                    size_t signature_length )
+{
+    key_slot_t *slot;
+    psa_status_t status;
+
+    status = psa_get_key_from_slot( key, &slot, PSA_KEY_USAGE_VERIFY, alg );
+    if( status != PSA_SUCCESS )
+        return( status );
+
+#if defined(MBEDCRYPTO_RSA_C)
+    if( PSA_KEY_TYPE_IS_RSA( slot->type ) )
+    {
+        return( psa_rsa_verify( slot->data.rsa,
+                                alg,
+                                hash, hash_length,
+                                signature, signature_length ) );
+    }
+    else
+#endif /* defined(MBEDCRYPTO_RSA_C) */
+#if defined(MBEDCRYPTO_ECP_C)
+    if( PSA_KEY_TYPE_IS_ECC( slot->type ) )
+    {
+#if defined(MBEDCRYPTO_ECDSA_C)
+        if( PSA_ALG_IS_ECDSA( alg ) )
+            return( psa_ecdsa_verify( slot->data.ecp,
+                                      hash, hash_length,
+                                      signature, signature_length ) );
+        else
+#endif /* defined(MBEDCRYPTO_ECDSA_C) */
+        {
+            return( PSA_ERROR_INVALID_ARGUMENT );
+        }
+    }
+    else
+#endif /* defined(MBEDCRYPTO_ECP_C) */
+    {
+        return( PSA_ERROR_NOT_SUPPORTED );
+    }
+}
+
+#if defined(MBEDCRYPTO_RSA_C) && defined(MBEDCRYPTO_PKCS1_V21)
+static void psa_rsa_oaep_set_padding_mode( psa_algorithm_t alg,
+                                           mbedcrypto_rsa_context *rsa )
+{
+    psa_algorithm_t hash_alg = PSA_ALG_RSA_OAEP_GET_HASH( alg );
+    const mbedcrypto_md_info_t *md_info = mbedcrypto_md_info_from_psa( hash_alg );
+    mbedcrypto_md_type_t md_alg = mbedcrypto_md_get_type( md_info );
+    mbedcrypto_rsa_set_padding( rsa, MBEDCRYPTO_RSA_PKCS_V21, md_alg );
+}
+#endif /* defined(MBEDCRYPTO_RSA_C) && defined(MBEDCRYPTO_PKCS1_V21) */
+
+psa_status_t psa_asymmetric_encrypt( psa_key_slot_t key,
+                                     psa_algorithm_t alg,
+                                     const uint8_t *input,
+                                     size_t input_length,
+                                     const uint8_t *salt,
+                                     size_t salt_length,
+                                     uint8_t *output,
+                                     size_t output_size,
+                                     size_t *output_length )
+{
+    key_slot_t *slot;
+    psa_status_t status;
+
+    (void) input;
+    (void) input_length;
+    (void) salt;
+    (void) output;
+    (void) output_size;
+
+    *output_length = 0;
+
+    if( ! PSA_ALG_IS_RSA_OAEP( alg ) && salt_length != 0 )
+        return( PSA_ERROR_INVALID_ARGUMENT );
+
+    status = psa_get_key_from_slot( key, &slot, PSA_KEY_USAGE_ENCRYPT, alg );
+    if( status != PSA_SUCCESS )
+        return( status );
+    if( ! ( PSA_KEY_TYPE_IS_PUBLIC_KEY( slot->type ) ||
+            PSA_KEY_TYPE_IS_KEYPAIR( slot->type ) ) )
+        return( PSA_ERROR_INVALID_ARGUMENT );
+
+#if defined(MBEDCRYPTO_RSA_C)
+    if( PSA_KEY_TYPE_IS_RSA( slot->type ) )
+    {
+        mbedcrypto_rsa_context *rsa = slot->data.rsa;
+        int ret;
+        if( output_size < mbedcrypto_rsa_get_len( rsa ) )
+            return( PSA_ERROR_INVALID_ARGUMENT );
+#if defined(MBEDCRYPTO_PKCS1_V15)
+        if( alg == PSA_ALG_RSA_PKCS1V15_CRYPT )
+        {
+            ret = mbedcrypto_rsa_pkcs1_encrypt( rsa,
+                                             mbedcrypto_ctr_drbg_random,
+                                             &global_data.ctr_drbg,
+                                             MBEDCRYPTO_RSA_PUBLIC,
+                                             input_length,
+                                             input,
+                                             output );
+        }
+        else
+#endif /* MBEDCRYPTO_PKCS1_V15 */
+#if defined(MBEDCRYPTO_PKCS1_V21)
+        if( PSA_ALG_IS_RSA_OAEP( alg ) )
+        {
+            psa_rsa_oaep_set_padding_mode( alg, rsa );
+            ret = mbedcrypto_rsa_rsaes_oaep_encrypt( rsa,
+                                                  mbedcrypto_ctr_drbg_random,
+                                                  &global_data.ctr_drbg,
+                                                  MBEDCRYPTO_RSA_PUBLIC,
+                                                  salt, salt_length,
+                                                  input_length,
+                                                  input,
+                                                  output );
+        }
+        else
+#endif /* MBEDCRYPTO_PKCS1_V21 */
+        {
+            return( PSA_ERROR_INVALID_ARGUMENT );
+        }
+        if( ret == 0 )
+            *output_length = mbedcrypto_rsa_get_len( rsa );
+        return( mbedcrypto_to_psa_error( ret ) );
+    }
+    else
+#endif /* defined(MBEDCRYPTO_RSA_C) */
+    {
+        return( PSA_ERROR_NOT_SUPPORTED );
+    }
+}
+
+psa_status_t psa_asymmetric_decrypt( psa_key_slot_t key,
+                                     psa_algorithm_t alg,
+                                     const uint8_t *input,
+                                     size_t input_length,
+                                     const uint8_t *salt,
+                                     size_t salt_length,
+                                     uint8_t *output,
+                                     size_t output_size,
+                                     size_t *output_length )
+{
+    key_slot_t *slot;
+    psa_status_t status;
+
+    (void) input;
+    (void) input_length;
+    (void) salt;
+    (void) output;
+    (void) output_size;
+
+    *output_length = 0;
+
+    if( ! PSA_ALG_IS_RSA_OAEP( alg ) && salt_length != 0 )
+        return( PSA_ERROR_INVALID_ARGUMENT );
+
+    status = psa_get_key_from_slot( key, &slot, PSA_KEY_USAGE_DECRYPT, alg );
+    if( status != PSA_SUCCESS )
+        return( status );
+    if( ! PSA_KEY_TYPE_IS_KEYPAIR( slot->type ) )
+        return( PSA_ERROR_INVALID_ARGUMENT );
+
+#if defined(MBEDCRYPTO_RSA_C)
+    if( slot->type == PSA_KEY_TYPE_RSA_KEYPAIR )
+    {
+        mbedcrypto_rsa_context *rsa = slot->data.rsa;
+        int ret;
+
+        if( input_length != mbedcrypto_rsa_get_len( rsa ) )
+            return( PSA_ERROR_INVALID_ARGUMENT );
+
+#if defined(MBEDCRYPTO_PKCS1_V15)
+        if( alg == PSA_ALG_RSA_PKCS1V15_CRYPT )
+        {
+            ret = mbedcrypto_rsa_pkcs1_decrypt( rsa,
+                                             mbedcrypto_ctr_drbg_random,
+                                             &global_data.ctr_drbg,
+                                             MBEDCRYPTO_RSA_PRIVATE,
+                                             output_length,
+                                             input,
+                                             output,
+                                             output_size );
+        }
+        else
+#endif /* MBEDCRYPTO_PKCS1_V15 */
+#if defined(MBEDCRYPTO_PKCS1_V21)
+        if( PSA_ALG_IS_RSA_OAEP( alg ) )
+        {
+            psa_rsa_oaep_set_padding_mode( alg, rsa );
+            ret = mbedcrypto_rsa_rsaes_oaep_decrypt( rsa,
+                                                  mbedcrypto_ctr_drbg_random,
+                                                  &global_data.ctr_drbg,
+                                                  MBEDCRYPTO_RSA_PRIVATE,
+                                                  salt, salt_length,
+                                                  output_length,
+                                                  input,
+                                                  output,
+                                                  output_size );
+        }
+        else
+#endif /* MBEDCRYPTO_PKCS1_V21 */
+        {
+            return( PSA_ERROR_INVALID_ARGUMENT );
+        }
+
+        return( mbedcrypto_to_psa_error( ret ) );
+    }
+    else
+#endif /* defined(MBEDCRYPTO_RSA_C) */
+    {
+        return( PSA_ERROR_NOT_SUPPORTED );
+    }
+}
+
+
+
+/****************************************************************/
+/* Symmetric cryptography */
+/****************************************************************/
+
+/* Initialize the cipher operation structure. Once this function has been
+ * called, psa_cipher_abort can run and will do the right thing. */
+static psa_status_t psa_cipher_init( psa_cipher_operation_t *operation,
+                                     psa_algorithm_t alg )
+{
+    if( ! PSA_ALG_IS_CIPHER( alg ) )
+    {
+        memset( operation, 0, sizeof( *operation ) );
+        return( PSA_ERROR_INVALID_ARGUMENT );
+    }
+
+    operation->alg = alg;
+    operation->key_set = 0;
+    operation->iv_set = 0;
+    operation->iv_required = 1;
+    operation->iv_size = 0;
+    operation->block_size = 0;
+    mbedcrypto_cipher_init( &operation->ctx.cipher );
+    return( PSA_SUCCESS );
+}
+
+static psa_status_t psa_cipher_setup( psa_cipher_operation_t *operation,
+                                      psa_key_slot_t key,
+                                      psa_algorithm_t alg,
+                                      mbedcrypto_operation_t cipher_operation )
+{
+    int ret = MBEDCRYPTO_ERR_CIPHER_FEATURE_UNAVAILABLE;
+    psa_status_t status;
+    key_slot_t *slot;
+    size_t key_bits;
+    const mbedcrypto_cipher_info_t *cipher_info = NULL;
+    psa_key_usage_t usage = ( cipher_operation == MBEDCRYPTO_ENCRYPT ?
+                              PSA_KEY_USAGE_ENCRYPT :
+                              PSA_KEY_USAGE_DECRYPT );
+
+    status = psa_cipher_init( operation, alg );
+    if( status != PSA_SUCCESS )
+        return( status );
+
+    status = psa_get_key_from_slot( key, &slot, usage, alg);
+    if( status != PSA_SUCCESS )
+        return( status );
+    key_bits = psa_get_key_bits( slot );
+
+    cipher_info = mbedcrypto_cipher_info_from_psa( alg, slot->type, key_bits, NULL );
+    if( cipher_info == NULL )
+        return( PSA_ERROR_NOT_SUPPORTED );
+
+    ret = mbedcrypto_cipher_setup( &operation->ctx.cipher, cipher_info );
+    if( ret != 0 )
+    {
+        psa_cipher_abort( operation );
+        return( mbedcrypto_to_psa_error( ret ) );
+    }
+
+#if defined(MBEDCRYPTO_DES_C)
+    if( slot->type == PSA_KEY_TYPE_DES && key_bits == 128 )
+    {
+        /* Two-key Triple-DES is 3-key Triple-DES with K1=K3 */
+        unsigned char keys[24];
+        memcpy( keys, slot->data.raw.data, 16 );
+        memcpy( keys + 16, slot->data.raw.data, 8 );
+        ret = mbedcrypto_cipher_setkey( &operation->ctx.cipher,
+                                     keys,
+                                     192, cipher_operation );
+    }
+    else
+#endif
+    {
+        ret = mbedcrypto_cipher_setkey( &operation->ctx.cipher,
+                                     slot->data.raw.data,
+                                     (int) key_bits, cipher_operation );
+    }
+    if( ret != 0 )
+    {
+        psa_cipher_abort( operation );
+        return( mbedcrypto_to_psa_error( ret ) );
+    }
+
+#if defined(MBEDCRYPTO_CIPHER_MODE_WITH_PADDING)
+    if( ( alg & ~PSA_ALG_BLOCK_CIPHER_PADDING_MASK ) == PSA_ALG_CBC_BASE )
+    {
+        psa_algorithm_t padding_mode = alg & PSA_ALG_BLOCK_CIPHER_PADDING_MASK;
+        mbedcrypto_cipher_padding_t mode;
+
+        switch ( padding_mode )
+        {
+            case PSA_ALG_BLOCK_CIPHER_PAD_PKCS7:
+                mode = MBEDCRYPTO_PADDING_PKCS7;
+                break;
+            case PSA_ALG_BLOCK_CIPHER_PAD_NONE:
+                mode = MBEDCRYPTO_PADDING_NONE;
+                break;
+            default:
+                psa_cipher_abort( operation );
+                return( PSA_ERROR_INVALID_ARGUMENT );
+        }
+        ret = mbedcrypto_cipher_set_padding_mode( &operation->ctx.cipher, mode );
+        if( ret != 0 )
+        {
+            psa_cipher_abort( operation );
+            return( mbedcrypto_to_psa_error( ret ) );
+        }
+    }
+#endif //MBEDCRYPTO_CIPHER_MODE_WITH_PADDING
+
+    operation->key_set = 1;
+    operation->block_size = ( PSA_ALG_IS_BLOCK_CIPHER( alg ) ?
+                              PSA_BLOCK_CIPHER_BLOCK_SIZE( slot->type ) :
+                              1 );
+    if( PSA_ALG_IS_BLOCK_CIPHER( alg ) || alg == PSA_ALG_CTR )
+    {
+        operation->iv_size = PSA_BLOCK_CIPHER_BLOCK_SIZE( slot->type );
+    }
+
+    return( PSA_SUCCESS );
+}
+
+psa_status_t psa_cipher_encrypt_setup( psa_cipher_operation_t *operation,
+                                       psa_key_slot_t key,
+                                       psa_algorithm_t alg )
+{
+    return( psa_cipher_setup( operation, key, alg, MBEDCRYPTO_ENCRYPT ) );
+}
+
+psa_status_t psa_cipher_decrypt_setup( psa_cipher_operation_t *operation,
+                                       psa_key_slot_t key,
+                                       psa_algorithm_t alg )
+{
+    return( psa_cipher_setup( operation, key, alg, MBEDCRYPTO_DECRYPT ) );
+}
+
+psa_status_t psa_cipher_generate_iv( psa_cipher_operation_t *operation,
+                                     unsigned char *iv,
+                                     size_t iv_size,
+                                     size_t *iv_length )
+{
+    int ret = PSA_SUCCESS;
+    if( operation->iv_set || ! operation->iv_required )
+        return( PSA_ERROR_BAD_STATE );
+    if( iv_size < operation->iv_size )
+    {
+        ret = PSA_ERROR_BUFFER_TOO_SMALL;
+        goto exit;
+    }
+    ret = mbedcrypto_ctr_drbg_random( &global_data.ctr_drbg,
+                                   iv, operation->iv_size );
+    if( ret != 0 )
+    {
+        ret = mbedcrypto_to_psa_error( ret );
+        goto exit;
+    }
+
+    *iv_length = operation->iv_size;
+    ret = psa_cipher_set_iv( operation, iv, *iv_length );
+
+exit:
+    if( ret != PSA_SUCCESS )
+        psa_cipher_abort( operation );
+    return( ret );
+}
+
+psa_status_t psa_cipher_set_iv( psa_cipher_operation_t *operation,
+                                const unsigned char *iv,
+                                size_t iv_length )
+{
+    int ret = PSA_SUCCESS;
+    if( operation->iv_set || ! operation->iv_required )
+        return( PSA_ERROR_BAD_STATE );
+    if( iv_length != operation->iv_size )
+    {
+        psa_cipher_abort( operation );
+        return( PSA_ERROR_INVALID_ARGUMENT );
+    }
+    ret =  mbedcrypto_cipher_set_iv( &operation->ctx.cipher, iv, iv_length );
+    if( ret != 0 )
+    {
+        psa_cipher_abort( operation );
+        return( mbedcrypto_to_psa_error( ret ) );
+    }
+
+    operation->iv_set = 1;
+
+    return( PSA_SUCCESS );
+}
+
+psa_status_t psa_cipher_update( psa_cipher_operation_t *operation,
+                                const uint8_t *input,
+                                size_t input_length,
+                                unsigned char *output,
+                                size_t output_size,
+                                size_t *output_length )
+{
+    int ret = MBEDCRYPTO_ERR_CIPHER_FEATURE_UNAVAILABLE;
+    size_t expected_output_size;
+    if( PSA_ALG_IS_BLOCK_CIPHER( operation->alg ) )
+    {
+        /* Take the unprocessed partial block left over from previous
+         * update calls, if any, plus the input to this call. Remove
+         * the last partial block, if any. You get the data that will be
+         * output in this call. */
+        expected_output_size =
+            ( operation->ctx.cipher.unprocessed_len + input_length )
+            / operation->block_size * operation->block_size;
+    }
+    else
+    {
+        expected_output_size = input_length;
+    }
+    if( output_size < expected_output_size )
+        return( PSA_ERROR_BUFFER_TOO_SMALL );
+
+    ret = mbedcrypto_cipher_update( &operation->ctx.cipher, input,
+                                 input_length, output, output_length );
+    if( ret != 0 )
+    {
+        psa_cipher_abort( operation );
+        return( mbedcrypto_to_psa_error( ret ) );
+    }
+
+    return( PSA_SUCCESS );
+}
+
+psa_status_t psa_cipher_finish( psa_cipher_operation_t *operation,
+                                uint8_t *output,
+                                size_t output_size,
+                                size_t *output_length )
+{
+    psa_status_t status = PSA_ERROR_UNKNOWN_ERROR;
+    int cipher_ret = MBEDCRYPTO_ERR_CIPHER_FEATURE_UNAVAILABLE;
+    uint8_t temp_output_buffer[MBEDCRYPTO_MAX_BLOCK_LENGTH];
+
+    if( ! operation->key_set )
+    {
+        status = PSA_ERROR_BAD_STATE;
+        goto error;
+    }
+    if( operation->iv_required && ! operation->iv_set )
+    {
+        status = PSA_ERROR_BAD_STATE;
+        goto error;
+    }
+    if( operation->ctx.cipher.operation == MBEDCRYPTO_ENCRYPT &&
+        PSA_ALG_IS_BLOCK_CIPHER( operation->alg ) )
+    {
+        psa_algorithm_t padding_mode =
+            operation->alg & PSA_ALG_BLOCK_CIPHER_PADDING_MASK;
+        if( operation->ctx.cipher.unprocessed_len >= operation->block_size )
+        {
+            status = PSA_ERROR_TAMPERING_DETECTED;
+            goto error;
+        }
+        if( padding_mode == PSA_ALG_BLOCK_CIPHER_PAD_NONE )
+        {
+            if( operation->ctx.cipher.unprocessed_len != 0 )
+            {
+                status = PSA_ERROR_INVALID_ARGUMENT;
+                goto error;
+            }
+        }
+    }
+
+    cipher_ret = mbedcrypto_cipher_finish( &operation->ctx.cipher,
+                                        temp_output_buffer,
+                                        output_length );
+    if( cipher_ret != 0 )
+    {
+        status = mbedcrypto_to_psa_error( cipher_ret );
+        goto error;
+    }
+
+    if( *output_length == 0 )
+        ; /* Nothing to copy. Note that output may be NULL in this case. */
+    else if( output_size >= *output_length )
+        memcpy( output, temp_output_buffer, *output_length );
+    else
+    {
+        status = PSA_ERROR_BUFFER_TOO_SMALL;
+        goto error;
+    }
+
+    mbedcrypto_zeroize( temp_output_buffer, sizeof( temp_output_buffer ) );
+    status = psa_cipher_abort( operation );
+
+    return( status );
+
+error:
+
+    *output_length = 0;
+
+    mbedcrypto_zeroize( temp_output_buffer, sizeof( temp_output_buffer ) );
+    (void) psa_cipher_abort( operation );
+
+    return( status );
+}
+
+psa_status_t psa_cipher_abort( psa_cipher_operation_t *operation )
+{
+    if( operation->alg == 0 )
+    {
+        /* The object has (apparently) been initialized but it is not
+         * in use. It's ok to call abort on such an object, and there's
+         * nothing to do. */
+        return( PSA_SUCCESS );
+    }
+
+    /* Sanity check (shouldn't happen: operation->alg should
+     * always have been initialized to a valid value). */
+    if( ! PSA_ALG_IS_CIPHER( operation->alg ) )
+        return( PSA_ERROR_BAD_STATE );
+
+    mbedcrypto_cipher_free( &operation->ctx.cipher );
+
+    operation->alg = 0;
+    operation->key_set = 0;
+    operation->iv_set = 0;
+    operation->iv_size = 0;
+    operation->block_size = 0;
+    operation->iv_required = 0;
+
+    return( PSA_SUCCESS );
+}
+
+
+
+/****************************************************************/
+/* Key Policy */
+/****************************************************************/
+
+#if !defined(MBEDCRYPTO_PSA_CRYPTO_SPM)
+void psa_key_policy_init( psa_key_policy_t *policy )
+{
+    memset( policy, 0, sizeof( *policy ) );
+}
+
+void psa_key_policy_set_usage( psa_key_policy_t *policy,
+                               psa_key_usage_t usage,
+                               psa_algorithm_t alg )
+{
+    policy->usage = usage;
+    policy->alg = alg;
+}
+
+psa_key_usage_t psa_key_policy_get_usage( const psa_key_policy_t *policy )
+{
+    return( policy->usage );
+}
+
+psa_algorithm_t psa_key_policy_get_algorithm( const psa_key_policy_t *policy )
+{
+    return( policy->alg );
+}
+#endif /* !defined(MBEDCRYPTO_PSA_CRYPTO_SPM) */
+
+psa_status_t psa_set_key_policy( psa_key_slot_t key,
+                                 const psa_key_policy_t *policy )
+{
+    key_slot_t *slot;
+    psa_status_t status;
+
+    if( policy == NULL )
+        return( PSA_ERROR_INVALID_ARGUMENT );
+
+    status = psa_get_empty_key_slot( key, &slot );
+    if( status != PSA_SUCCESS )
+        return( status );
+
+    if( ( policy->usage & ~( PSA_KEY_USAGE_EXPORT |
+                             PSA_KEY_USAGE_ENCRYPT |
+                             PSA_KEY_USAGE_DECRYPT |
+                             PSA_KEY_USAGE_SIGN |
+                             PSA_KEY_USAGE_VERIFY |
+                             PSA_KEY_USAGE_DERIVE ) ) != 0 )
+        return( PSA_ERROR_INVALID_ARGUMENT );
+
+    slot->policy = *policy;
+
+    return( PSA_SUCCESS );
+}
+
+psa_status_t psa_get_key_policy( psa_key_slot_t key,
+                                 psa_key_policy_t *policy )
+{
+    key_slot_t *slot;
+    psa_status_t status;
+
+    if( policy == NULL )
+        return( PSA_ERROR_INVALID_ARGUMENT );
+
+    status = psa_get_key_slot( key, &slot );
+    if( status != PSA_SUCCESS )
+        return( status );
+
+    *policy = slot->policy;
+
+    return( PSA_SUCCESS );
+}
+
+
+
+/****************************************************************/
+/* Key Lifetime */
+/****************************************************************/
+
+psa_status_t psa_get_key_lifetime( psa_key_slot_t key,
+                                   psa_key_lifetime_t *lifetime )
+{
+    key_slot_t *slot;
+    psa_status_t status;
+
+    status = psa_get_key_slot( key, &slot );
+    if( status != PSA_SUCCESS )
+        return( status );
+
+    *lifetime = slot->lifetime;
+
+    return( PSA_SUCCESS );
+}
+
+psa_status_t psa_set_key_lifetime( psa_key_slot_t key,
+                                   psa_key_lifetime_t lifetime )
+{
+    key_slot_t *slot;
+    psa_status_t status;
+
+    if( lifetime != PSA_KEY_LIFETIME_VOLATILE &&
+        lifetime != PSA_KEY_LIFETIME_PERSISTENT &&
+        lifetime != PSA_KEY_LIFETIME_WRITE_ONCE)
+        return( PSA_ERROR_INVALID_ARGUMENT );
+
+    status = psa_get_empty_key_slot( key, &slot );
+    if( status != PSA_SUCCESS )
+        return( status );
+
+    if( lifetime != PSA_KEY_LIFETIME_VOLATILE )
+        return( PSA_ERROR_NOT_SUPPORTED );
+
+    slot->lifetime = lifetime;
+
+    return( PSA_SUCCESS );
+}
+
+
+
+/****************************************************************/
+/* AEAD */
+/****************************************************************/
+
+psa_status_t psa_aead_encrypt( psa_key_slot_t key,
+                               psa_algorithm_t alg,
+                               const uint8_t *nonce,
+                               size_t nonce_length,
+                               const uint8_t *additional_data,
+                               size_t additional_data_length,
+                               const uint8_t *plaintext,
+                               size_t plaintext_length,
+                               uint8_t *ciphertext,
+                               size_t ciphertext_size,
+                               size_t *ciphertext_length )
+{
+    int ret;
+    psa_status_t status;
+    key_slot_t *slot;
+    size_t key_bits;
+    uint8_t *tag;
+    size_t tag_length;
+    mbedcrypto_cipher_id_t cipher_id;
+    const mbedcrypto_cipher_info_t *cipher_info = NULL;
+
+    *ciphertext_length = 0;
+
+    status = psa_get_key_from_slot( key, &slot, PSA_KEY_USAGE_ENCRYPT, alg );
+    if( status != PSA_SUCCESS )
+        return( status );
+    key_bits = psa_get_key_bits( slot );
+
+    cipher_info = mbedcrypto_cipher_info_from_psa( alg, slot->type,
+                                                key_bits, &cipher_id );
+    if( cipher_info == NULL )
+        return( PSA_ERROR_NOT_SUPPORTED );
+
+    if( ( slot->type & PSA_KEY_TYPE_CATEGORY_MASK ) !=
+        PSA_KEY_TYPE_CATEGORY_SYMMETRIC )
+        return( PSA_ERROR_INVALID_ARGUMENT );
+
+    if( alg == PSA_ALG_GCM )
+    {
+        mbedcrypto_gcm_context gcm;
+        tag_length = 16;
+
+        if( PSA_BLOCK_CIPHER_BLOCK_SIZE( slot->type ) != 16 )
+            return( PSA_ERROR_INVALID_ARGUMENT );
+
+        //make sure we have place to hold the tag in the ciphertext buffer
+        if( ciphertext_size < ( plaintext_length + tag_length ) )
+            return( PSA_ERROR_BUFFER_TOO_SMALL );
+
+        //update the tag pointer to point to the end of the ciphertext_length
+        tag = ciphertext + plaintext_length;
+
+        mbedcrypto_gcm_init( &gcm );
+        ret = mbedcrypto_gcm_setkey( &gcm, cipher_id,
+                                  slot->data.raw.data,
+                                  (unsigned int) key_bits );
+        if( ret != 0 )
+        {
+            mbedcrypto_gcm_free( &gcm );
+            return( mbedcrypto_to_psa_error( ret ) );
+        }
+        ret = mbedcrypto_gcm_crypt_and_tag( &gcm, MBEDCRYPTO_GCM_ENCRYPT,
+                                         plaintext_length, nonce,
+                                         nonce_length, additional_data,
+                                         additional_data_length, plaintext,
+                                         ciphertext, tag_length, tag );
+        mbedcrypto_gcm_free( &gcm );
+    }
+    else if( alg == PSA_ALG_CCM )
+    {
+        mbedcrypto_ccm_context ccm;
+        tag_length = 16;
+
+        if( PSA_BLOCK_CIPHER_BLOCK_SIZE( slot->type ) != 16 )
+            return( PSA_ERROR_INVALID_ARGUMENT );
+
+        if( nonce_length < 7 || nonce_length > 13 )
+            return( PSA_ERROR_INVALID_ARGUMENT );
+
+        //make sure we have place to hold the tag in the ciphertext buffer
+        if( ciphertext_size < ( plaintext_length + tag_length ) )
+            return( PSA_ERROR_BUFFER_TOO_SMALL );
+
+        //update the tag pointer to point to the end of the ciphertext_length
+        tag = ciphertext + plaintext_length;
+
+        mbedcrypto_ccm_init( &ccm );
+        ret = mbedcrypto_ccm_setkey( &ccm, cipher_id,
+                                  slot->data.raw.data,
+                                  (unsigned int) key_bits );
+        if( ret != 0 )
+        {
+            mbedcrypto_ccm_free( &ccm );
+            return( mbedcrypto_to_psa_error( ret ) );
+        }
+        ret = mbedcrypto_ccm_encrypt_and_tag( &ccm, plaintext_length,
+                                           nonce, nonce_length,
+                                           additional_data,
+                                           additional_data_length,
+                                           plaintext, ciphertext,
+                                           tag, tag_length );
+        mbedcrypto_ccm_free( &ccm );
+    }
+    else
+    {
+        return( PSA_ERROR_NOT_SUPPORTED );
+    }
+
+    if( ret != 0 )
+    {
+        /* If ciphertext_size is 0 then ciphertext may be NULL and then the
+         * call to memset would have undefined behavior. */
+        if( ciphertext_size != 0 )
+            memset( ciphertext, 0, ciphertext_size );
+        return( mbedcrypto_to_psa_error( ret ) );
+    }
+
+    *ciphertext_length = plaintext_length + tag_length;
+    return( PSA_SUCCESS );
+}
+
+/* Locate the tag in a ciphertext buffer containing the encrypted data
+ * followed by the tag. Return the length of the part preceding the tag in
+ * *plaintext_length. This is the size of the plaintext in modes where
+ * the encrypted data has the same size as the plaintext, such as
+ * CCM and GCM. */
+static psa_status_t psa_aead_unpadded_locate_tag( size_t tag_length,
+                                                  const uint8_t *ciphertext,
+                                                  size_t ciphertext_length,
+                                                  size_t plaintext_size,
+                                                  const uint8_t **p_tag )
+{
+    size_t payload_length;
+    if( tag_length > ciphertext_length )
+        return( PSA_ERROR_INVALID_ARGUMENT );
+    payload_length = ciphertext_length - tag_length;
+    if( payload_length > plaintext_size )
+        return( PSA_ERROR_BUFFER_TOO_SMALL );
+    *p_tag = ciphertext + payload_length;
+    return( PSA_SUCCESS );
+}
+
+psa_status_t psa_aead_decrypt( psa_key_slot_t key,
+                               psa_algorithm_t alg,
+                               const uint8_t *nonce,
+                               size_t nonce_length,
+                               const uint8_t *additional_data,
+                               size_t additional_data_length,
+                               const uint8_t *ciphertext,
+                               size_t ciphertext_length,
+                               uint8_t *plaintext,
+                               size_t plaintext_size,
+                               size_t *plaintext_length )
+{
+    int ret;
+    psa_status_t status;
+    key_slot_t *slot;
+    size_t key_bits;
+    const uint8_t *tag;
+    size_t tag_length;
+    mbedcrypto_cipher_id_t cipher_id;
+    const mbedcrypto_cipher_info_t *cipher_info = NULL;
+
+    *plaintext_length = 0;
+
+    status = psa_get_key_from_slot( key, &slot, PSA_KEY_USAGE_DECRYPT, alg );
+    if( status != PSA_SUCCESS )
+        return( status );
+    key_bits = psa_get_key_bits( slot );
+
+    cipher_info = mbedcrypto_cipher_info_from_psa( alg, slot->type,
+                                                key_bits, &cipher_id );
+    if( cipher_info == NULL )
+        return( PSA_ERROR_NOT_SUPPORTED );
+
+    if( ( slot->type & PSA_KEY_TYPE_CATEGORY_MASK ) !=
+        PSA_KEY_TYPE_CATEGORY_SYMMETRIC )
+        return( PSA_ERROR_INVALID_ARGUMENT );
+
+    if( alg == PSA_ALG_GCM )
+    {
+        mbedcrypto_gcm_context gcm;
+
+        tag_length = 16;
+        status = psa_aead_unpadded_locate_tag( tag_length,
+                                               ciphertext, ciphertext_length,
+                                               plaintext_size, &tag );
+        if( status != PSA_SUCCESS )
+            return( status );
+
+        mbedcrypto_gcm_init( &gcm );
+        ret = mbedcrypto_gcm_setkey( &gcm, cipher_id,
+                                  slot->data.raw.data,
+                                  (unsigned int) key_bits );
+        if( ret != 0 )
+        {
+            mbedcrypto_gcm_free( &gcm );
+            return( mbedcrypto_to_psa_error( ret ) );
+        }
+
+        ret = mbedcrypto_gcm_auth_decrypt( &gcm,
+                                        ciphertext_length - tag_length,
+                                        nonce, nonce_length,
+                                        additional_data,
+                                        additional_data_length,
+                                        tag, tag_length,
+                                        ciphertext, plaintext );
+        mbedcrypto_gcm_free( &gcm );
+    }
+    else if( alg == PSA_ALG_CCM )
+    {
+        mbedcrypto_ccm_context ccm;
+
+        if( nonce_length < 7 || nonce_length > 13 )
+            return( PSA_ERROR_INVALID_ARGUMENT );
+
+        tag_length = 16;
+        status = psa_aead_unpadded_locate_tag( tag_length,
+                                               ciphertext, ciphertext_length,
+                                               plaintext_size, &tag );
+        if( status != PSA_SUCCESS )
+            return( status );
+
+        mbedcrypto_ccm_init( &ccm );
+        ret = mbedcrypto_ccm_setkey( &ccm, cipher_id,
+                                  slot->data.raw.data,
+                                  (unsigned int) key_bits );
+        if( ret != 0 )
+        {
+            mbedcrypto_ccm_free( &ccm );
+            return( mbedcrypto_to_psa_error( ret ) );
+        }
+        ret = mbedcrypto_ccm_auth_decrypt( &ccm, ciphertext_length - tag_length,
+                                        nonce, nonce_length,
+                                        additional_data,
+                                        additional_data_length,
+                                        ciphertext, plaintext,
+                                        tag, tag_length );
+        mbedcrypto_ccm_free( &ccm );
+    }
+    else
+    {
+        return( PSA_ERROR_NOT_SUPPORTED );
+    }
+
+    if( ret != 0 )
+    {
+        /* If plaintext_size is 0 then plaintext may be NULL and then the
+         * call to memset has undefined behavior. */
+        if( plaintext_size != 0 )
+            memset( plaintext, 0, plaintext_size );
+    }
+    else
+        *plaintext_length = ciphertext_length - tag_length;
+
+    return( mbedcrypto_to_psa_error( ret ) );
+}
+
+
+
+/****************************************************************/
+/* Generators */
+/****************************************************************/
+
+psa_status_t psa_generator_abort( psa_crypto_generator_t *generator )
+{
+    psa_status_t status = PSA_SUCCESS;
+    if( generator->alg == 0 )
+    {
+        /* The object has (apparently) been initialized but it is not
+         * in use. It's ok to call abort on such an object, and there's
+         * nothing to do. */
+    }
+    else
+#if defined(MBEDCRYPTO_MD_C)
+    if( PSA_ALG_IS_HKDF( generator->alg ) )
+    {
+        mbedcrypto_free( generator->ctx.hkdf.info );
+        status = psa_hmac_abort_internal( &generator->ctx.hkdf.hmac );
+    }
+    else
+#endif /* MBEDCRYPTO_MD_C */
+    {
+        status = PSA_ERROR_BAD_STATE;
+    }
+    memset( generator, 0, sizeof( *generator ) );
+    return( status );
+}
+
+
+psa_status_t psa_get_generator_capacity(const psa_crypto_generator_t *generator,
+                                        size_t *capacity)
+{
+    *capacity = generator->capacity;
+    return( PSA_SUCCESS );
+}
+
+#if defined(MBEDCRYPTO_MD_C)
+/* Read some bytes from an HKDF-based generator. This performs a chunk
+ * of the expand phase of the HKDF algorithm. */
+static psa_status_t psa_generator_hkdf_read( psa_hkdf_generator_t *hkdf,
+                                             psa_algorithm_t hash_alg,
+                                             uint8_t *output,
+                                             size_t output_length )
+{
+    uint8_t hash_length = PSA_HASH_SIZE( hash_alg );
+    psa_status_t status;
+
+    while( output_length != 0 )
+    {
+        /* Copy what remains of the current block */
+        uint8_t n = hash_length - hkdf->offset_in_block;
+        if( n > output_length )
+            n = (uint8_t) output_length;
+        memcpy( output, hkdf->output_block + hkdf->offset_in_block, n );
+        output += n;
+        output_length -= n;
+        hkdf->offset_in_block += n;
+        if( output_length == 0 )
+            break;
+        /* We can't be wanting more output after block 0xff, otherwise
+         * the capacity check in psa_generator_read() would have
+         * prevented this call. It could happen only if the generator
+         * object was corrupted or if this function is called directly
+         * inside the library. */
+        if( hkdf->block_number == 0xff )
+            return( PSA_ERROR_BAD_STATE );
+
+        /* We need a new block */
+        ++hkdf->block_number;
+        hkdf->offset_in_block = 0;
+        status = psa_hmac_setup_internal( &hkdf->hmac,
+                                          hkdf->prk, hash_length,
+                                          hash_alg );
+        if( status != PSA_SUCCESS )
+            return( status );
+        if( hkdf->block_number != 1 )
+        {
+            status = psa_hash_update( &hkdf->hmac.hash_ctx,
+                                      hkdf->output_block,
+                                      hash_length );
+            if( status != PSA_SUCCESS )
+                return( status );
+        }
+        status = psa_hash_update( &hkdf->hmac.hash_ctx,
+                                  hkdf->info,
+                                  hkdf->info_length );
+        if( status != PSA_SUCCESS )
+            return( status );
+        status = psa_hash_update( &hkdf->hmac.hash_ctx,
+                                  &hkdf->block_number, 1 );
+        if( status != PSA_SUCCESS )
+            return( status );
+        status = psa_hmac_finish_internal( &hkdf->hmac,
+                                           hkdf->output_block,
+                                           sizeof( hkdf->output_block ) );
+        if( status != PSA_SUCCESS )
+            return( status );
+    }
+
+    return( PSA_SUCCESS );
+}
+#endif /* MBEDCRYPTO_MD_C */
+
+psa_status_t psa_generator_read( psa_crypto_generator_t *generator,
+                                 uint8_t *output,
+                                 size_t output_length )
+{
+    psa_status_t status;
+
+    if( output_length > generator->capacity )
+    {
+        generator->capacity = 0;
+        /* Go through the error path to wipe all confidential data now
+         * that the generator object is useless. */
+        status = PSA_ERROR_INSUFFICIENT_CAPACITY;
+        goto exit;
+    }
+    if( output_length == 0 &&
+        generator->capacity == 0 && generator->alg == 0 )
+    {
+        /* Edge case: this is a blank or finished generator, and 0
+         * bytes were requested. The right error in this case could
+         * be either INSUFFICIENT_CAPACITY or BAD_STATE. Return
+         * INSUFFICIENT_CAPACITY, which is right for a finished
+         * generator, for consistency with the case when
+         * output_length > 0. */
+        return( PSA_ERROR_INSUFFICIENT_CAPACITY );
+    }
+    generator->capacity -= output_length;
+
+#if defined(MBEDCRYPTO_MD_C)
+    if( PSA_ALG_IS_HKDF( generator->alg ) )
+    {
+        psa_algorithm_t hash_alg = PSA_ALG_HKDF_GET_HASH( generator->alg );
+        status = psa_generator_hkdf_read( &generator->ctx.hkdf, hash_alg,
+                                          output, output_length );
+    }
+    else
+#endif /* MBEDCRYPTO_MD_C */
+    {
+        return( PSA_ERROR_BAD_STATE );
+    }
+
+exit:
+    if( status != PSA_SUCCESS )
+    {
+        psa_generator_abort( generator );
+        memset( output, '!', output_length );
+    }
+    return( status );
+}
+
+#if defined(MBEDCRYPTO_DES_C)
+static void psa_des_set_key_parity( uint8_t *data, size_t data_size )
+{
+    if( data_size >= 8 )
+        mbedcrypto_des_key_set_parity( data );
+    if( data_size >= 16 )
+        mbedcrypto_des_key_set_parity( data + 8 );
+    if( data_size >= 24 )
+        mbedcrypto_des_key_set_parity( data + 16 );
+}
+#endif /* MBEDCRYPTO_DES_C */
+
+psa_status_t psa_generator_import_key( psa_key_slot_t key,
+                                       psa_key_type_t type,
+                                       size_t bits,
+                                       psa_crypto_generator_t *generator )
+{
+    uint8_t *data = NULL;
+    size_t bytes = PSA_BITS_TO_BYTES( bits );
+    psa_status_t status;
+
+    if( ! key_type_is_raw_bytes( type ) )
+        return( PSA_ERROR_INVALID_ARGUMENT );
+    if( bits % 8 != 0 )
+        return( PSA_ERROR_INVALID_ARGUMENT );
+    data = mbedcrypto_calloc( 1, bytes );
+    if( data == NULL )
+        return( PSA_ERROR_INSUFFICIENT_MEMORY );
+
+    status = psa_generator_read( generator, data, bytes );
+    if( status != PSA_SUCCESS )
+        goto exit;
+#if defined(MBEDCRYPTO_DES_C)
+    if( type == PSA_KEY_TYPE_DES )
+        psa_des_set_key_parity( data, bytes );
+#endif /* MBEDCRYPTO_DES_C */
+    status = psa_import_key( key, type, data, bytes );
+
+exit:
+    mbedcrypto_free( data );
+    return( status );
+}
+
+
+
+/****************************************************************/
+/* Key derivation */
+/****************************************************************/
+
+/* Set up an HKDF-based generator. This is exactly the extract phase
+ * of the HKDF algorithm. */
+static psa_status_t psa_generator_hkdf_setup( psa_hkdf_generator_t *hkdf,
+                                              key_slot_t *slot,
+                                              psa_algorithm_t hash_alg,
+                                              const uint8_t *salt,
+                                              size_t salt_length,
+                                              const uint8_t *label,
+                                              size_t label_length )
+{
+    psa_status_t status;
+    status = psa_hmac_setup_internal( &hkdf->hmac,
+                                      salt, salt_length,
+                                      PSA_ALG_HMAC_HASH( hash_alg ) );
+    if( status != PSA_SUCCESS )
+        return( status );
+    status = psa_hash_update( &hkdf->hmac.hash_ctx,
+                              slot->data.raw.data,
+                              slot->data.raw.bytes );
+    if( status != PSA_SUCCESS )
+        return( status );
+    status = psa_hmac_finish_internal( &hkdf->hmac,
+                                       hkdf->prk,
+                                       sizeof( hkdf->prk ) );
+    if( status != PSA_SUCCESS )
+        return( status );
+    hkdf->offset_in_block = PSA_HASH_SIZE( hash_alg );
+    hkdf->block_number = 0;
+    hkdf->info_length = label_length;
+    if( label_length != 0 )
+    {
+        hkdf->info = mbedcrypto_calloc( 1, label_length );
+        if( hkdf->info == NULL )
+            return( PSA_ERROR_INSUFFICIENT_MEMORY );
+        memcpy( hkdf->info, label, label_length );
+    }
+    return( PSA_SUCCESS );
+}
+
+psa_status_t psa_key_derivation( psa_crypto_generator_t *generator,
+                                 psa_key_slot_t key,
+                                 psa_algorithm_t alg,
+                                 const uint8_t *salt,
+                                 size_t salt_length,
+                                 const uint8_t *label,
+                                 size_t label_length,
+                                 size_t capacity )
+{
+    key_slot_t *slot;
+    psa_status_t status;
+
+    if( generator->alg != 0 )
+        return( PSA_ERROR_BAD_STATE );
+
+    status = psa_get_key_from_slot( key, &slot, PSA_KEY_USAGE_DERIVE, alg );
+    if( status != PSA_SUCCESS )
+        return( status );
+    if( slot->type != PSA_KEY_TYPE_DERIVE )
+        return( PSA_ERROR_INVALID_ARGUMENT );
+
+    if( ! PSA_ALG_IS_KEY_DERIVATION( alg ) )
+        return( PSA_ERROR_INVALID_ARGUMENT );
+
+#if defined(MBEDCRYPTO_MD_C)
+    if( PSA_ALG_IS_HKDF( alg ) )
+    {
+        psa_algorithm_t hash_alg = PSA_ALG_HKDF_GET_HASH( alg );
+        size_t hash_size = PSA_HASH_SIZE( hash_alg );
+        if( hash_size == 0 )
+            return( PSA_ERROR_NOT_SUPPORTED );
+        if( capacity > 255 * hash_size )
+            return( PSA_ERROR_INVALID_ARGUMENT );
+        status = psa_generator_hkdf_setup( &generator->ctx.hkdf,
+                                           slot,
+                                           hash_alg,
+                                           salt, salt_length,
+                                           label, label_length );
+    }
+    else
+#endif
+    {
+        return( PSA_ERROR_NOT_SUPPORTED );
+    }
+
+    /* Set generator->alg even on failure so that abort knows what to do. */
+    generator->alg = alg;
+    if( status == PSA_SUCCESS )
+        generator->capacity = capacity;
+    else
+        psa_generator_abort( generator );
+    return( status );
+}
+
+
+
+/****************************************************************/
+/* Random generation */
+/****************************************************************/
+
+psa_status_t psa_generate_random( uint8_t *output,
+                                  size_t output_size )
+{
+    int ret = mbedcrypto_ctr_drbg_random( &global_data.ctr_drbg,
+                                       output, output_size );
+    return( mbedcrypto_to_psa_error( ret ) );
+}
+
+psa_status_t psa_generate_key( psa_key_slot_t key,
+                               psa_key_type_t type,
+                               size_t bits,
+                               const void *extra,
+                               size_t extra_size )
+{
+    key_slot_t *slot;
+    psa_status_t status;
+
+    if( extra == NULL && extra_size != 0 )
+        return( PSA_ERROR_INVALID_ARGUMENT );
+
+    status = psa_get_empty_key_slot( key, &slot );
+    if( status != PSA_SUCCESS )
+        return( status );
+
+    if( key_type_is_raw_bytes( type ) )
+    {
+        status = prepare_raw_data_slot( type, bits, &slot->data.raw );
+        if( status != PSA_SUCCESS )
+            return( status );
+        status = psa_generate_random( slot->data.raw.data,
+                                      slot->data.raw.bytes );
+        if( status != PSA_SUCCESS )
+        {
+            mbedcrypto_free( slot->data.raw.data );
+            return( status );
+        }
+#if defined(MBEDCRYPTO_DES_C)
+        if( type == PSA_KEY_TYPE_DES )
+            psa_des_set_key_parity( slot->data.raw.data,
+                                    slot->data.raw.bytes );
+#endif /* MBEDCRYPTO_DES_C */
+    }
+    else
+
+#if defined(MBEDCRYPTO_RSA_C) && defined(MBEDCRYPTO_GENPRIME)
+    if ( type == PSA_KEY_TYPE_RSA_KEYPAIR )
+    {
+        mbedcrypto_rsa_context *rsa;
+        int ret;
+        int exponent = 65537;
+        if( bits > PSA_VENDOR_RSA_MAX_KEY_BITS )
+            return( PSA_ERROR_NOT_SUPPORTED );
+        if( extra != NULL )
+        {
+            const psa_generate_key_extra_rsa *p = extra;
+            if( extra_size != sizeof( *p ) )
+                return( PSA_ERROR_INVALID_ARGUMENT );
+#if INT_MAX < 0xffffffff
+            /* Check that the uint32_t value passed by the caller fits
+             * in the range supported by this implementation. */
+            if( p->e > INT_MAX )
+                return( PSA_ERROR_NOT_SUPPORTED );
+#endif
+            exponent = p->e;
+        }
+        rsa = mbedcrypto_calloc( 1, sizeof( *rsa ) );
+        if( rsa == NULL )
+            return( PSA_ERROR_INSUFFICIENT_MEMORY );
+        mbedcrypto_rsa_init( rsa, MBEDCRYPTO_RSA_PKCS_V15, MBEDCRYPTO_MD_NONE );
+        ret = mbedcrypto_rsa_gen_key( rsa,
+                                   mbedcrypto_ctr_drbg_random,
+                                   &global_data.ctr_drbg,
+                                   (unsigned int) bits,
+                                   exponent );
+        if( ret != 0 )
+        {
+            mbedcrypto_rsa_free( rsa );
+            mbedcrypto_free( rsa );
+            return( mbedcrypto_to_psa_error( ret ) );
+        }
+        slot->data.rsa = rsa;
+    }
+    else
+#endif /* MBEDCRYPTO_RSA_C && MBEDCRYPTO_GENPRIME */
+
+#if defined(MBEDCRYPTO_ECP_C)
+    if ( PSA_KEY_TYPE_IS_ECC( type ) && PSA_KEY_TYPE_IS_KEYPAIR( type ) )
+    {
+        psa_ecc_curve_t curve = PSA_KEY_TYPE_GET_CURVE( type );
+        mbedcrypto_ecp_group_id grp_id = mbedcrypto_ecc_group_of_psa( curve );
+        const mbedcrypto_ecp_curve_info *curve_info =
+            mbedcrypto_ecp_curve_info_from_grp_id( grp_id );
+        mbedcrypto_ecp_keypair *ecp;
+        int ret;
+        if( extra != NULL )
+            return( PSA_ERROR_NOT_SUPPORTED );
+        if( grp_id == MBEDCRYPTO_ECP_DP_NONE || curve_info == NULL )
+            return( PSA_ERROR_NOT_SUPPORTED );
+        if( curve_info->bit_size != bits )
+            return( PSA_ERROR_INVALID_ARGUMENT );
+        ecp = mbedcrypto_calloc( 1, sizeof( *ecp ) );
+        if( ecp == NULL )
+            return( PSA_ERROR_INSUFFICIENT_MEMORY );
+        mbedcrypto_ecp_keypair_init( ecp );
+        ret = mbedcrypto_ecp_gen_key( grp_id, ecp,
+                                   mbedcrypto_ctr_drbg_random,
+                                   &global_data.ctr_drbg );
+        if( ret != 0 )
+        {
+            mbedcrypto_ecp_keypair_free( ecp );
+            mbedcrypto_free( ecp );
+            return( mbedcrypto_to_psa_error( ret ) );
+        }
+        slot->data.ecp = ecp;
+    }
+    else
+#endif /* MBEDCRYPTO_ECP_C */
+
+        return( PSA_ERROR_NOT_SUPPORTED );
+
+    slot->type = type;
+    return( PSA_SUCCESS );
+}
+
+
+/****************************************************************/
+/* Module setup */
+/****************************************************************/
+
+void mbedcrypto_psa_crypto_free( void )
+{
+    psa_key_slot_t key;
+    for( key = 1; key <= PSA_KEY_SLOT_COUNT; key++ )
+        psa_destroy_key( key );
+    mbedcrypto_ctr_drbg_free( &global_data.ctr_drbg );
+    mbedcrypto_entropy_free( &global_data.entropy );
+    mbedcrypto_zeroize( &global_data, sizeof( global_data ) );
+}
+
+psa_status_t psa_crypto_init( void )
+{
+    int ret;
+    const unsigned char drbg_seed[] = "PSA";
+
+    if( global_data.initialized != 0 )
+        return( PSA_SUCCESS );
+
+    mbedcrypto_zeroize( &global_data, sizeof( global_data ) );
+    mbedcrypto_entropy_init( &global_data.entropy );
+    mbedcrypto_ctr_drbg_init( &global_data.ctr_drbg );
+
+    ret = mbedcrypto_ctr_drbg_seed( &global_data.ctr_drbg,
+                                 mbedcrypto_entropy_func,
+                                 &global_data.entropy,
+                                 drbg_seed, sizeof( drbg_seed ) - 1 );
+    if( ret != 0 )
+        goto exit;
+
+    global_data.initialized = 1;
+
+exit:
+    if( ret != 0 )
+        mbedcrypto_psa_crypto_free( );
+    return( mbedcrypto_to_psa_error( ret ) );
+}
+
+#endif /* MBEDCRYPTO_PSA_CRYPTO_C */