Merge remote-tracking branch 'restricted/mbedtls-2.28-restricted' int…

…o mbedtls-2.28.1rc0-pr

ChangeLog.d/bignum-0-mod-2.txt

@@ -0,0 +1,4 @@
+Bugfix
+ * Fix a null pointer dereference when performing some operations on zero
+ represented with 0 limbs (specifically mbedtls_mpi_mod_int() dividing
+ by 2, and mbedtls_mpi_write_string() in base 2).

ChangeLog.d/buf-overread-use-psa-static-ecdh.txt

@@ -0,0 +1,6 @@
+Security
+ * Fix a potential heap buffer overread in TLS 1.2 server-side when
+ MBEDTLS_USE_PSA_CRYPTO is enabled, an opaque key (created with
+ mbedtls_pk_setup_opaque()) is provisioned, and a static ECDH ciphersuite
+ is selected. This may result in an application crash or potentially an
+ information leak.

ChangeLog.d/cookie_parsing_bug.txt

@@ -0,0 +1,9 @@
+Security
+ * Fix a buffer overread in DTLS ClientHello parsing in servers with
+ MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE enabled. An unauthenticated client
+ or a man-in-the-middle could cause a DTLS server to read up to 255 bytes
+ after the end of the SSL input buffer. The buffer overread only happens
+ when MBEDTLS_SSL_IN_CONTENT_LEN is less than a threshold that depends on
+ the exact configuration: 258 bytes if using mbedtls_ssl_cookie_check(),
+ and possibly up to 571 bytes with a custom cookie check function.
+ Reported by the Cybeats PSI Team.

ChangeLog.d/fix_tls_record_size_check.txt

@@ -0,0 +1,4 @@
+Bugfix
+ * Fix record sizes larger than 16384 being sometimes accepted despite being
+ non-compliant. This could not lead to a buffer overflow. In particular,
+ application data size was already checked correctly.

include/mbedtls/pk.h

@@ -217,32 +217,6 @@ typedef struct
 typedef void mbedtls_pk_restart_ctx;
 #endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
 
-#if defined(MBEDTLS_RSA_C)
-/**
- * Quick access to an RSA context inside a PK context.
- *
- * \warning You must make sure the PK context actually holds an RSA context
- * before using this function!
- */
-static inline mbedtls_rsa_context *mbedtls_pk_rsa( const mbedtls_pk_context pk )
-{
- return( (mbedtls_rsa_context *) (pk).pk_ctx );
-}
-#endif /* MBEDTLS_RSA_C */
-
-#if defined(MBEDTLS_ECP_C)
-/**
- * Quick access to an EC context inside a PK context.
- *
- * \warning You must make sure the PK context actually holds an EC context
- * before using this function!
- */
-static inline mbedtls_ecp_keypair *mbedtls_pk_ec( const mbedtls_pk_context pk )
-{
- return( (mbedtls_ecp_keypair *) (pk).pk_ctx );
-}
-#endif /* MBEDTLS_ECP_C */
-
 #if defined(MBEDTLS_PK_RSA_ALT_SUPPORT)
 /**
  * \brief Types for RSA-alt abstraction
@@ -656,6 +630,55 @@ const char * mbedtls_pk_get_name( const mbedtls_pk_context *ctx );
  */
 mbedtls_pk_type_t mbedtls_pk_get_type( const mbedtls_pk_context *ctx );
 
+#if defined(MBEDTLS_RSA_C)
+/**
+ * Quick access to an RSA context inside a PK context.
+ *
+ * \warning This function can only be used when the type of the context, as
+ * returned by mbedtls_pk_get_type(), is #MBEDTLS_PK_RSA.
+ * Ensuring that is the caller's responsibility.
+ * Alternatively, you can check whether this function returns NULL.
+ *
+ * \return The internal RSA context held by the PK context, or NULL.
+ */
+static inline mbedtls_rsa_context *mbedtls_pk_rsa( const mbedtls_pk_context pk )
+{
+ switch( mbedtls_pk_get_type( &pk ) )
+ {
+ case MBEDTLS_PK_RSA:
+ return( (mbedtls_rsa_context *) (pk).pk_ctx );
+ default:
+ return( NULL );
+ }
+}
+#endif /* MBEDTLS_RSA_C */
+
+#if defined(MBEDTLS_ECP_C)
+/**
+ * Quick access to an EC context inside a PK context.
+ *
+ * \warning This function can only be used when the type of the context, as
+ * returned by mbedtls_pk_get_type(), is #MBEDTLS_PK_ECKEY,
+ * #MBEDTLS_PK_ECKEY_DH, or #MBEDTLS_PK_ECDSA.
+ * Ensuring that is the caller's responsibility.
+ * Alternatively, you can check whether this function returns NULL.
+ *
+ * \return The internal EC context held by the PK context, or NULL.
+ */
+static inline mbedtls_ecp_keypair *mbedtls_pk_ec( const mbedtls_pk_context pk )
+{
+ switch( mbedtls_pk_get_type( &pk ) )
+ {
+ case MBEDTLS_PK_ECKEY:
+ case MBEDTLS_PK_ECKEY_DH:
+ case MBEDTLS_PK_ECDSA:
+ return( (mbedtls_ecp_keypair *) (pk).pk_ctx );
+ default:
+ return( NULL );
+ }
+}
+#endif /* MBEDTLS_ECP_C */
+
 #if defined(MBEDTLS_PK_PARSE_C)
 /** \ingroup pk_module */
 /**

include/mbedtls/ssl_internal.h

@@ -934,16 +934,22 @@ void mbedtls_ssl_transform_free( mbedtls_ssl_transform *transform );
  */
 void mbedtls_ssl_handshake_free( mbedtls_ssl_context *ssl );
 
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_handshake_client_step( mbedtls_ssl_context *ssl );
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_handshake_server_step( mbedtls_ssl_context *ssl );
 void mbedtls_ssl_handshake_wrapup( mbedtls_ssl_context *ssl );
 
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_send_fatal_handshake_failure( mbedtls_ssl_context *ssl );
 
 void mbedtls_ssl_reset_checksum( mbedtls_ssl_context *ssl );
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_derive_keys( mbedtls_ssl_context *ssl );
 
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_handle_message_type( mbedtls_ssl_context *ssl );
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_prepare_handshake_record( mbedtls_ssl_context *ssl );
 void mbedtls_ssl_update_handshake_status( mbedtls_ssl_context *ssl );
 
@@ -1023,27 +1029,39 @@ void mbedtls_ssl_update_handshake_status( mbedtls_ssl_context *ssl );
  * following the above definition.
  *
  */
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_read_record( mbedtls_ssl_context *ssl,
  unsigned update_hs_digest );
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_fetch_input( mbedtls_ssl_context *ssl, size_t nb_want );
 
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_write_handshake_msg( mbedtls_ssl_context *ssl );
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_write_record( mbedtls_ssl_context *ssl, uint8_t force_flush );
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_flush_output( mbedtls_ssl_context *ssl );
 
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_parse_certificate( mbedtls_ssl_context *ssl );
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_write_certificate( mbedtls_ssl_context *ssl );
 
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_parse_change_cipher_spec( mbedtls_ssl_context *ssl );
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_write_change_cipher_spec( mbedtls_ssl_context *ssl );
 
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_parse_finished( mbedtls_ssl_context *ssl );
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_write_finished( mbedtls_ssl_context *ssl );
 
 void mbedtls_ssl_optimize_checksum( mbedtls_ssl_context *ssl,
  const mbedtls_ssl_ciphersuite_t *ciphersuite_info );
 
 #if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED)
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_psk_derive_premaster( mbedtls_ssl_context *ssl, mbedtls_key_exchange_type_t key_ex );
 
 /**
@@ -1108,14 +1126,18 @@ mbedtls_pk_type_t mbedtls_ssl_pk_alg_from_sig( unsigned char sig );
 
 mbedtls_md_type_t mbedtls_ssl_md_alg_from_hash( unsigned char hash );
 unsigned char mbedtls_ssl_hash_from_md_alg( int md );
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_set_calc_verify_md( mbedtls_ssl_context *ssl, int md );
 
 #if defined(MBEDTLS_ECP_C)
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_check_curve( const mbedtls_ssl_context *ssl, mbedtls_ecp_group_id grp_id );
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_check_curve_tls_id( const mbedtls_ssl_context *ssl, uint16_t tls_id );
 #endif
 
 #if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_check_sig_hash( const mbedtls_ssl_context *ssl,
  mbedtls_md_type_t md );
 #endif
@@ -1171,6 +1193,7 @@ static inline mbedtls_x509_crt *mbedtls_ssl_own_cert( mbedtls_ssl_context *ssl )
  *
  * Return 0 if everything is OK, -1 if not.
  */
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_check_cert_usage( const mbedtls_x509_crt *cert,
  const mbedtls_ssl_ciphersuite_t *ciphersuite,
  int cert_endpoint,
@@ -1219,21 +1242,26 @@ static inline size_t mbedtls_ssl_hs_hdr_len( const mbedtls_ssl_context *ssl )
 #if defined(MBEDTLS_SSL_PROTO_DTLS)
 void mbedtls_ssl_send_flight_completed( mbedtls_ssl_context *ssl );
 void mbedtls_ssl_recv_flight_completed( mbedtls_ssl_context *ssl );
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_resend( mbedtls_ssl_context *ssl );
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_flight_transmit( mbedtls_ssl_context *ssl );
 #endif
 
 /* Visible for testing purposes only */
 #if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_dtls_replay_check( mbedtls_ssl_context const *ssl );
 void mbedtls_ssl_dtls_replay_update( mbedtls_ssl_context *ssl );
 #endif
 
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_session_copy( mbedtls_ssl_session *dst,
  const mbedtls_ssl_session *src );
 
 #if defined(MBEDTLS_SSL_PROTO_SSL3) || defined(MBEDTLS_SSL_PROTO_TLS1) || \
  defined(MBEDTLS_SSL_PROTO_TLS1_1)
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_get_key_exchange_md_ssl_tls( mbedtls_ssl_context *ssl,
  unsigned char *output,
  unsigned char *data, size_t data_len );
@@ -1243,6 +1271,7 @@ int mbedtls_ssl_get_key_exchange_md_ssl_tls( mbedtls_ssl_context *ssl,
 #if defined(MBEDTLS_SSL_PROTO_TLS1) || defined(MBEDTLS_SSL_PROTO_TLS1_1) || \
  defined(MBEDTLS_SSL_PROTO_TLS1_2)
 /* The hash buffer must have at least MBEDTLS_MD_MAX_SIZE bytes of length. */
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_get_key_exchange_md_tls1_2( mbedtls_ssl_context *ssl,
  unsigned char *hash, size_t *hashlen,
  unsigned char *data, size_t data_len,
@@ -1255,11 +1284,13 @@ int mbedtls_ssl_get_key_exchange_md_tls1_2( mbedtls_ssl_context *ssl,
 #endif
 
 void mbedtls_ssl_transform_init( mbedtls_ssl_transform *transform );
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_encrypt_buf( mbedtls_ssl_context *ssl,
  mbedtls_ssl_transform *transform,
  mbedtls_record *rec,
  int (*f_rng)(void *, unsigned char *, size_t),
  void *p_rng );
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_decrypt_buf( mbedtls_ssl_context const *ssl,
  mbedtls_ssl_transform *transform,
  mbedtls_record *rec );
@@ -1277,17 +1308,20 @@ static inline size_t mbedtls_ssl_ep_len( const mbedtls_ssl_context *ssl )
 }
 
 #if defined(MBEDTLS_SSL_PROTO_DTLS)
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_resend_hello_request( mbedtls_ssl_context *ssl );
 #endif /* MBEDTLS_SSL_PROTO_DTLS */
 
 void mbedtls_ssl_set_timer( mbedtls_ssl_context *ssl, uint32_t millisecs );
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_check_timer( mbedtls_ssl_context *ssl );
 
 void mbedtls_ssl_reset_in_out_pointers( mbedtls_ssl_context *ssl );
 void mbedtls_ssl_update_out_pointers( mbedtls_ssl_context *ssl,
  mbedtls_ssl_transform *transform );
 void mbedtls_ssl_update_in_pointers( mbedtls_ssl_context *ssl );
 
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_session_reset_int( mbedtls_ssl_context *ssl, int partial );
 
 #if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
@@ -1297,6 +1331,7 @@ void mbedtls_ssl_dtls_replay_reset( mbedtls_ssl_context *ssl );
 void mbedtls_ssl_handshake_wrapup_free_hs_transform( mbedtls_ssl_context *ssl );
 
 #if defined(MBEDTLS_SSL_RENEGOTIATION)
+MBEDTLS_CHECK_RETURN_CRITICAL
 int mbedtls_ssl_start_renegotiation( mbedtls_ssl_context *ssl );
 #endif /* MBEDTLS_SSL_RENEGOTIATION */
 
@@ -1306,4 +1341,12 @@ void mbedtls_ssl_buffering_free( mbedtls_ssl_context *ssl );
 void mbedtls_ssl_flight_free( mbedtls_ssl_flight_item *flight );
 #endif /* MBEDTLS_SSL_PROTO_DTLS */
 
+#if defined(MBEDTLS_TEST_HOOKS)
+int mbedtls_ssl_check_dtls_clihlo_cookie(
+ mbedtls_ssl_context *ssl,
+ const unsigned char *cli_id, size_t cli_id_len,
+ const unsigned char *in, size_t in_len,
+ unsigned char *obuf, size_t buf_len, size_t *olen );
+#endif
+
 #endif /* ssl_internal.h */

library/bignum.c

@@ -1829,7 +1829,7 @@ int mbedtls_mpi_mod_int( mbedtls_mpi_uint *r, const mbedtls_mpi *A, mbedtls_mpi_
  /*
  * handle trivial cases
  */
- if( b == 1 )
+ if( b == 1 || A->n == 0 )
  {
  *r = 0;
  return( 0 );

library/ssl_ciphersuites.c

@@ -2181,6 +2181,7 @@ const int *mbedtls_ssl_list_ciphersuites( void )
 static int supported_ciphersuites[MAX_CIPHERSUITES];
 static int supported_init = 0;
 
+MBEDTLS_CHECK_RETURN_CRITICAL
 static int ciphersuite_is_removed( const mbedtls_ssl_ciphersuite_t *cs_info )
 {
  (void)cs_info;