Merge pull request #5859 from paul-elliott-arm/fix_ct_uninit_memory_access_2.28

Backport 2.28: Fix uninitialised memory access in constant time functions
diff --git a/ChangeLog.d/fix-x25519-program.txt b/ChangeLog.d/fix-x25519-program.txt
new file mode 100644
index 0000000..af60465
--- /dev/null
+++ b/ChangeLog.d/fix-x25519-program.txt
@@ -0,0 +1,4 @@
+Bugfix
+   * Fix a bug in x25519 example program where the removal of
+     MBEDTLS_ECDH_LEGACY_CONTEXT caused the program not to run. Fixes #4901 and
+     #3191.
diff --git a/include/mbedtls/aes.h b/include/mbedtls/aes.h
index e280dbb..401ac39 100644
--- a/include/mbedtls/aes.h
+++ b/include/mbedtls/aes.h
@@ -564,7 +564,7 @@
  *             for example, with 96-bit random nonces, you should not encrypt
  *             more than 2**32 messages with the same key.
  *
- *             Note that for both stategies, sizes are measured in blocks and
+ *             Note that for both strategies, sizes are measured in blocks and
  *             that an AES block is 16 bytes.
  *
  * \warning    Upon return, \p stream_block contains sensitive data. Its
diff --git a/include/mbedtls/aria.h b/include/mbedtls/aria.h
index 6e47272..d294c47 100644
--- a/include/mbedtls/aria.h
+++ b/include/mbedtls/aria.h
@@ -321,7 +321,7 @@
  *             for example, with 96-bit random nonces, you should not encrypt
  *             more than 2**32 messages with the same key.
  *
- *             Note that for both stategies, sizes are measured in blocks and
+ *             Note that for both strategies, sizes are measured in blocks and
  *             that an ARIA block is 16 bytes.
  *
  * \warning    Upon return, \p stream_block contains sensitive data. Its
diff --git a/include/mbedtls/bignum.h b/include/mbedtls/bignum.h
index 9d2cff3..dd594c5 100644
--- a/include/mbedtls/bignum.h
+++ b/include/mbedtls/bignum.h
@@ -989,7 +989,7 @@
  *                 generate yourself and that are supposed to be prime, then
  *                 \p rounds should be at least the half of the security
  *                 strength of the cryptographic algorithm. On the other hand,
- *                 if \p X is chosen uniformly or non-adversially (as is the
+ *                 if \p X is chosen uniformly or non-adversarially (as is the
  *                 case when mbedtls_mpi_gen_prime calls this function), then
  *                 \p rounds can be much lower.
  *
diff --git a/include/mbedtls/blowfish.h b/include/mbedtls/blowfish.h
index 15a49c5..d5f8099 100644
--- a/include/mbedtls/blowfish.h
+++ b/include/mbedtls/blowfish.h
@@ -246,7 +246,7 @@
  *             The recommended way to ensure uniqueness is to use a message
  *             counter.
  *
- *             Note that for both stategies, sizes are measured in blocks and
+ *             Note that for both strategies, sizes are measured in blocks and
  *             that a Blowfish block is 8 bytes.
  *
  * \warning    Upon return, \p stream_block contains sensitive data. Its
diff --git a/include/mbedtls/camellia.h b/include/mbedtls/camellia.h
index 925a623..d39d932 100644
--- a/include/mbedtls/camellia.h
+++ b/include/mbedtls/camellia.h
@@ -273,7 +273,7 @@
  *             encrypted: for example, with 96-bit random nonces, you should
  *             not encrypt more than 2**32 messages with the same key.
  *
- *             Note that for both stategies, sizes are measured in blocks and
+ *             Note that for both strategies, sizes are measured in blocks and
  *             that a CAMELLIA block is \c 16 Bytes.
  *
  * \warning    Upon return, \p stream_block contains sensitive data. Its
diff --git a/include/mbedtls/chachapoly.h b/include/mbedtls/chachapoly.h
index c4ec7b5..ed568bc 100644
--- a/include/mbedtls/chachapoly.h
+++ b/include/mbedtls/chachapoly.h
@@ -161,7 +161,7 @@
  * \param ctx       The ChaCha20-Poly1305 context. This must be initialized
  *                  and bound to a key.
  * \param nonce     The nonce/IV to use for the message.
- *                  This must be a redable buffer of length \c 12 Bytes.
+ *                  This must be a readable buffer of length \c 12 Bytes.
  * \param mode      The operation to perform: #MBEDTLS_CHACHAPOLY_ENCRYPT or
  *                  #MBEDTLS_CHACHAPOLY_DECRYPT (discouraged, see warning).
  *
diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h
index 6acd9b1..1cd6eb6 100644
--- a/include/mbedtls/config.h
+++ b/include/mbedtls/config.h
@@ -2918,7 +2918,7 @@
  *
  * Requires: MBEDTLS_MD_C
  *
- * Uncomment to enable the HMAC_DRBG random number geerator.
+ * Uncomment to enable the HMAC_DRBG random number generator.
  */
 #define MBEDTLS_HMAC_DRBG_C
 
diff --git a/include/mbedtls/ecp.h b/include/mbedtls/ecp.h
index 9effa44..64a0bcc 100644
--- a/include/mbedtls/ecp.h
+++ b/include/mbedtls/ecp.h
@@ -315,7 +315,7 @@
 #if !defined(MBEDTLS_ECP_WINDOW_SIZE)
 /*
  * Maximum "window" size used for point multiplication.
- * Default: a point where higher memory usage yields disminishing performance
+ * Default: a point where higher memory usage yields diminishing performance
  *          returns.
  * Minimum value: 2. Maximum value: 7.
  *
diff --git a/include/mbedtls/oid.h b/include/mbedtls/oid.h
index 1c39186..0186217 100644
--- a/include/mbedtls/oid.h
+++ b/include/mbedtls/oid.h
@@ -143,7 +143,7 @@
 #define MBEDTLS_OID_AT_GIVEN_NAME               MBEDTLS_OID_AT "\x2A" /**< id-at-givenName AttributeType:= {id-at 42} */
 #define MBEDTLS_OID_AT_INITIALS                 MBEDTLS_OID_AT "\x2B" /**< id-at-initials AttributeType:= {id-at 43} */
 #define MBEDTLS_OID_AT_GENERATION_QUALIFIER     MBEDTLS_OID_AT "\x2C" /**< id-at-generationQualifier AttributeType:= {id-at 44} */
-#define MBEDTLS_OID_AT_UNIQUE_IDENTIFIER        MBEDTLS_OID_AT "\x2D" /**< id-at-uniqueIdentifier AttributType:= {id-at 45} */
+#define MBEDTLS_OID_AT_UNIQUE_IDENTIFIER        MBEDTLS_OID_AT "\x2D" /**< id-at-uniqueIdentifier AttributeType:= {id-at 45} */
 #define MBEDTLS_OID_AT_DN_QUALIFIER             MBEDTLS_OID_AT "\x2E" /**< id-at-dnQualifier AttributeType:= {id-at 46} */
 #define MBEDTLS_OID_AT_PSEUDONYM                MBEDTLS_OID_AT "\x41" /**< id-at-pseudonym AttributeType:= {id-at 65} */
 
diff --git a/include/mbedtls/platform_util.h b/include/mbedtls/platform_util.h
index f3af3ac..cd112ab 100644
--- a/include/mbedtls/platform_util.h
+++ b/include/mbedtls/platform_util.h
@@ -198,7 +198,7 @@
  *
  * This macro has an empty expansion. It exists for documentation purposes:
  * a #MBEDTLS_CHECK_RETURN_OPTIONAL annotation indicates that the function
- * has been analyzed for return-check usefuless, whereas the lack of
+ * has been analyzed for return-check usefulness, whereas the lack of
  * an annotation indicates that the function has not been analyzed and its
  * return-check usefulness is unknown.
  */
diff --git a/include/mbedtls/rsa.h b/include/mbedtls/rsa.h
index ca0c6e1..062df73 100644
--- a/include/mbedtls/rsa.h
+++ b/include/mbedtls/rsa.h
@@ -687,7 +687,7 @@
  *                   mode being set to #MBEDTLS_RSA_PRIVATE and might instead
  *                   return #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED.
  *
- * \param ctx        The initnialized RSA context to use.
+ * \param ctx        The initialized RSA context to use.
  * \param f_rng      The RNG function to use. This is needed for padding
  *                   generation and must be provided.
  * \param p_rng      The RNG context to be passed to \p f_rng. This may
diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
index 8c2d8f8..5064ec5 100644
--- a/include/mbedtls/ssl.h
+++ b/include/mbedtls/ssl.h
@@ -1152,7 +1152,7 @@
 #endif
 
 #if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY) && defined(MBEDTLS_SSL_SRV_C)
-    /** Callback to create & write a cookie for ClientHello veirifcation    */
+    /** Callback to create & write a cookie for ClientHello verification    */
     int (*f_cookie_write)( void *, unsigned char **, unsigned char *,
                            const unsigned char *, size_t );
     /** Callback to verify validity of a ClientHello cookie                 */
@@ -2498,7 +2498,7 @@
  *                 successfully cached, return 1 otherwise.
  *
  * \param conf           SSL configuration
- * \param p_cache        parmater (context) for both callbacks
+ * \param p_cache        parameter (context) for both callbacks
  * \param f_get_cache    session get callback
  * \param f_set_cache    session set callback
  */
@@ -2529,7 +2529,7 @@
 /**
  * \brief          Load serialized session data into a session structure.
  *                 On client, this can be used for loading saved sessions
- *                 before resuming them with mbedstls_ssl_set_session().
+ *                 before resuming them with mbedtls_ssl_set_session().
  *                 On server, this can be used for alternative implementations
  *                 of session cache or session tickets.
  *
@@ -3508,7 +3508,7 @@
  *                 \c mbedtls_ssl_get_record_expansion().
  *
  * \note           For DTLS, it is also possible to set a limit for the total
- *                 size of daragrams passed to the transport layer, including
+ *                 size of datagrams passed to the transport layer, including
  *                 record overhead, see \c mbedtls_ssl_set_mtu().
  *
  * \param conf     SSL configuration
diff --git a/include/mbedtls/x509_crt.h b/include/mbedtls/x509_crt.h
index 70a4e4d..0f2885a 100644
--- a/include/mbedtls/x509_crt.h
+++ b/include/mbedtls/x509_crt.h
@@ -107,7 +107,7 @@
 typedef struct mbedtls_x509_san_other_name
 {
     /**
-     * The type_id is an OID as deifned in RFC 5280.
+     * The type_id is an OID as defined in RFC 5280.
      * To check the value of the type id, you should use
      * \p MBEDTLS_OID_CMP with a known OID mbedtls_x509_buf.
      */
@@ -979,7 +979,7 @@
  * \param is_ca     is this a CA certificate
  * \param max_pathlen   maximum length of certificate chains below this
  *                      certificate (only for CA certificates, -1 is
- *                      inlimited)
+ *                      unlimited)
  *
  * \return          0 if successful, or a MBEDTLS_ERR_X509_ALLOC_FAILED
  */
diff --git a/include/psa/crypto_config.h b/include/psa/crypto_config.h
index 9019ca9..f261e01 100644
--- a/include/psa/crypto_config.h
+++ b/include/psa/crypto_config.h
@@ -60,7 +60,6 @@
 #define PSA_WANT_ALG_CMAC                       1
 #define PSA_WANT_ALG_CFB                        1
 #define PSA_WANT_ALG_CHACHA20_POLY1305          1
-#define PSA_WANT_ALG_CMAC                       1
 #define PSA_WANT_ALG_CTR                        1
 #define PSA_WANT_ALG_DETERMINISTIC_ECDSA        1
 #define PSA_WANT_ALG_ECB_NO_PADDING             1
diff --git a/programs/pkey/ecdh_curve25519.c b/programs/pkey/ecdh_curve25519.c
index 67f1363..65b206a 100644
--- a/programs/pkey/ecdh_curve25519.c
+++ b/programs/pkey/ecdh_curve25519.c
@@ -34,12 +34,12 @@
 #define MBEDTLS_EXIT_FAILURE    EXIT_FAILURE
 #endif /* MBEDTLS_PLATFORM_C */
 
-#if !defined(MBEDTLS_ECDH_C) || !defined(MBEDTLS_ECDH_LEGACY_CONTEXT) || \
+#if !defined(MBEDTLS_ECDH_C) || \
     !defined(MBEDTLS_ECP_DP_CURVE25519_ENABLED) || \
     !defined(MBEDTLS_ENTROPY_C) || !defined(MBEDTLS_CTR_DRBG_C)
 int main( void )
 {
-    mbedtls_printf( "MBEDTLS_ECDH_C and/or MBEDTLS_ECDH_LEGACY_CONTEXT and/or "
+    mbedtls_printf( "MBEDTLS_ECDH_C and/or "
                     "MBEDTLS_ECP_DP_CURVE25519_ENABLED and/or "
                     "MBEDTLS_ENTROPY_C and/or MBEDTLS_CTR_DRBG_C "
                     "not defined\n" );
@@ -51,6 +51,8 @@
 #include "mbedtls/ctr_drbg.h"
 #include "mbedtls/ecdh.h"
 
+#include <string.h>
+
 
 int main( int argc, char *argv[] )
 {
@@ -59,8 +61,15 @@
     mbedtls_ecdh_context ctx_cli, ctx_srv;
     mbedtls_entropy_context entropy;
     mbedtls_ctr_drbg_context ctr_drbg;
-    unsigned char cli_to_srv[32], srv_to_cli[32];
+    unsigned char cli_to_srv[36], srv_to_cli[33];
     const char pers[] = "ecdh";
+
+    size_t srv_olen;
+    size_t cli_olen;
+    unsigned char secret_cli[32] = { 0 };
+    unsigned char secret_srv[32] = { 0 };
+    const unsigned char *p_cli_to_srv = cli_to_srv;
+
     ((void) argc);
     ((void) argv);
 
@@ -71,15 +80,17 @@
     /*
      * Initialize random number generation
      */
-    mbedtls_printf( "  . Seeding the random number generator..." );
+    mbedtls_printf( "  . Seed the random number generator..." );
     fflush( stdout );
 
     mbedtls_entropy_init( &entropy );
-    if( ( ret = mbedtls_ctr_drbg_seed( &ctr_drbg, mbedtls_entropy_func, &entropy,
-                               (const unsigned char *) pers,
-                               sizeof pers ) ) != 0 )
+    if( ( ret = mbedtls_ctr_drbg_seed( &ctr_drbg, mbedtls_entropy_func,
+                                       &entropy,
+                                       (const unsigned char *) pers,
+                                       sizeof pers ) ) != 0 )
     {
-        mbedtls_printf( " failed\n  ! mbedtls_ctr_drbg_seed returned %d\n", ret );
+        mbedtls_printf( " failed\n  ! mbedtls_ctr_drbg_seed returned %d\n",
+                        ret );
         goto exit;
     }
 
@@ -88,28 +99,23 @@
     /*
      * Client: initialize context and generate keypair
      */
-    mbedtls_printf( "  . Setting up client context..." );
+    mbedtls_printf( "  . Set up client context, generate EC key pair..." );
     fflush( stdout );
 
-    ret = mbedtls_ecp_group_load( &ctx_cli.grp, MBEDTLS_ECP_DP_CURVE25519 );
+    ret = mbedtls_ecdh_setup( &ctx_cli, MBEDTLS_ECP_DP_CURVE25519 );
     if( ret != 0 )
     {
-        mbedtls_printf( " failed\n  ! mbedtls_ecp_group_load returned %d\n", ret );
+        mbedtls_printf( " failed\n  ! mbedtls_ecdh_setup returned %d\n", ret );
         goto exit;
     }
 
-    ret = mbedtls_ecdh_gen_public( &ctx_cli.grp, &ctx_cli.d, &ctx_cli.Q,
-                                   mbedtls_ctr_drbg_random, &ctr_drbg );
+    ret = mbedtls_ecdh_make_params( &ctx_cli, &cli_olen, cli_to_srv,
+                                    sizeof( cli_to_srv ),
+                                    mbedtls_ctr_drbg_random, &ctr_drbg );
     if( ret != 0 )
     {
-        mbedtls_printf( " failed\n  ! mbedtls_ecdh_gen_public returned %d\n", ret );
-        goto exit;
-    }
-
-    ret = mbedtls_mpi_write_binary( &ctx_cli.Q.X, cli_to_srv, 32 );
-    if( ret != 0 )
-    {
-        mbedtls_printf( " failed\n  ! mbedtls_mpi_write_binary returned %d\n", ret );
+        mbedtls_printf( " failed\n  ! mbedtls_ecdh_make_params returned %d\n",
+                        ret );
         goto exit;
     }
 
@@ -118,90 +124,70 @@
     /*
      * Server: initialize context and generate keypair
      */
-    mbedtls_printf( "  . Setting up server context..." );
+    mbedtls_printf( "  . Server: read params, generate public key..." );
     fflush( stdout );
 
-    ret = mbedtls_ecp_group_load( &ctx_srv.grp, MBEDTLS_ECP_DP_CURVE25519 );
+    ret = mbedtls_ecdh_read_params( &ctx_srv, &p_cli_to_srv,
+                                    p_cli_to_srv + sizeof( cli_to_srv ) );
     if( ret != 0 )
     {
-        mbedtls_printf( " failed\n  ! mbedtls_ecp_group_load returned %d\n", ret );
+        mbedtls_printf( " failed\n  ! mbedtls_ecdh_read_params returned %d\n",
+                        ret );
         goto exit;
     }
 
-    ret = mbedtls_ecdh_gen_public( &ctx_srv.grp, &ctx_srv.d, &ctx_srv.Q,
-                                   mbedtls_ctr_drbg_random, &ctr_drbg );
+    ret = mbedtls_ecdh_make_public( &ctx_srv, &srv_olen, srv_to_cli,
+                                    sizeof( srv_to_cli ),
+                                    mbedtls_ctr_drbg_random, &ctr_drbg );
     if( ret != 0 )
     {
-        mbedtls_printf( " failed\n  ! mbedtls_ecdh_gen_public returned %d\n", ret );
-        goto exit;
-    }
-
-    ret = mbedtls_mpi_write_binary( &ctx_srv.Q.X, srv_to_cli, 32 );
-    if( ret != 0 )
-    {
-        mbedtls_printf( " failed\n  ! mbedtls_mpi_write_binary returned %d\n", ret );
+        mbedtls_printf( " failed\n  ! mbedtls_ecdh_make_public returned %d\n",
+                        ret );
         goto exit;
     }
 
     mbedtls_printf( " ok\n" );
 
     /*
-     * Server: read peer's key and generate shared secret
+     * Client: read public key
      */
-    mbedtls_printf( "  . Server reading client key and computing secret..." );
+    mbedtls_printf( "  . Client: read public key..." );
     fflush( stdout );
 
-    ret = mbedtls_mpi_lset( &ctx_srv.Qp.Z, 1 );
+    ret = mbedtls_ecdh_read_public( &ctx_cli, srv_to_cli,
+                                    sizeof( srv_to_cli ) );
     if( ret != 0 )
     {
-        mbedtls_printf( " failed\n  ! mbedtls_mpi_lset returned %d\n", ret );
-        goto exit;
-    }
-
-    ret = mbedtls_mpi_read_binary( &ctx_srv.Qp.X, cli_to_srv, 32 );
-    if( ret != 0 )
-    {
-        mbedtls_printf( " failed\n  ! mbedtls_mpi_read_binary returned %d\n", ret );
-        goto exit;
-    }
-
-    ret = mbedtls_ecdh_compute_shared( &ctx_srv.grp, &ctx_srv.z,
-                                       &ctx_srv.Qp, &ctx_srv.d,
-                                       mbedtls_ctr_drbg_random, &ctr_drbg );
-    if( ret != 0 )
-    {
-        mbedtls_printf( " failed\n  ! mbedtls_ecdh_compute_shared returned %d\n", ret );
+        mbedtls_printf( " failed\n  ! mbedtls_ecdh_read_public returned %d\n",
+                        ret );
         goto exit;
     }
 
     mbedtls_printf( " ok\n" );
 
     /*
-     * Client: read peer's key and generate shared secret
+     * Calculate secrets
      */
-    mbedtls_printf( "  . Client reading server key and computing secret..." );
+    mbedtls_printf( "  . Calculate secrets..." );
     fflush( stdout );
 
-    ret = mbedtls_mpi_lset( &ctx_cli.Qp.Z, 1 );
+    ret = mbedtls_ecdh_calc_secret( &ctx_cli, &cli_olen, secret_cli,
+                                    sizeof( secret_cli ),
+                                    mbedtls_ctr_drbg_random, &ctr_drbg );
     if( ret != 0 )
     {
-        mbedtls_printf( " failed\n  ! mbedtls_mpi_lset returned %d\n", ret );
+        mbedtls_printf( " failed\n  ! mbedtls_ecdh_calc_secret returned %d\n",
+                        ret );
         goto exit;
     }
 
-    ret = mbedtls_mpi_read_binary( &ctx_cli.Qp.X, srv_to_cli, 32 );
+    ret = mbedtls_ecdh_calc_secret( &ctx_srv, &srv_olen, secret_srv,
+                                    sizeof( secret_srv ),
+                                    mbedtls_ctr_drbg_random, &ctr_drbg );
     if( ret != 0 )
     {
-        mbedtls_printf( " failed\n  ! mbedtls_mpi_read_binary returned %d\n", ret );
-        goto exit;
-    }
-
-    ret = mbedtls_ecdh_compute_shared( &ctx_cli.grp, &ctx_cli.z,
-                                       &ctx_cli.Qp, &ctx_cli.d,
-                                       mbedtls_ctr_drbg_random, &ctr_drbg );
-    if( ret != 0 )
-    {
-        mbedtls_printf( " failed\n  ! mbedtls_ecdh_compute_shared returned %d\n", ret );
+        mbedtls_printf( " failed\n  ! mbedtls_ecdh_calc_secret returned %d\n",
+                        ret );
         goto exit;
     }
 
@@ -210,13 +196,13 @@
     /*
      * Verification: are the computed secrets equal?
      */
-    mbedtls_printf( "  . Checking if both computed secrets are equal..." );
+    mbedtls_printf( "  . Check if both calculated secrets are equal..." );
     fflush( stdout );
 
-    ret = mbedtls_mpi_cmp_mpi( &ctx_cli.z, &ctx_srv.z );
-    if( ret != 0 )
+    ret = memcmp( secret_srv, secret_cli, srv_olen );
+    if( ret != 0 || ( cli_olen != srv_olen ) )
     {
-        mbedtls_printf( " failed\n  ! mbedtls_ecdh_compute_shared returned %d\n", ret );
+        mbedtls_printf( " failed\n  ! Shared secrets not equal.\n" );
         goto exit;
     }