Add new ABI-independent format for serialization
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index db09bf8..4a886ae 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -9846,14 +9846,23 @@
* Serialize a session in the following format:
* (in the presentation language of TLS, RFC 8446 section 3)
*
- * opaque session_struct[n]; // n = sizeof(mbedtls_ssl_session)
- * select (MBEDTLS_SSL_KEEP_PEER_CERTIFICATE) {
- * case enabled: opaque peer_cert<0..2^24-1>; // length 0 means no cert
- * case disabled: opaque peer_cert_digest<0..2^8-1>;
- * }
- * opaque ticket<0..2^24-1>; // 0 means no ticket
+ * uint64 start_time;
+ * uint8 ciphersuite[2]; // defined by the standard
+ * uint8 compression; // 0 or 1
+ * uint8 session_id_len; // at most 32
+ * opaque session_id[32];
+ * opaque master[48]; // fixed length in the standard
+ * uint32 verify_result;
+ * opaque peer_cert<0..2^24-1>; // length 0 means no peer cert
+ * opaque ticket<0..2^24-1>; // length 0 means no ticket
+ * uint32 ticket_lifetime;
+ * uint8 mfl_code; // up to 255 according to standard
+ * uint8 trunc_hmac; // 0 or 1
+ * uint8 encrypt_then_mac; // 0 or 1
*
- * Only the peer's certificate is saved, not the whole chain.
+ * The order is the same as in the definition of the structure, except
+ * verify_result is put before peer_cert so that all mandatory fields come
+ * together in one block.
*/
int mbedtls_ssl_session_save( const mbedtls_ssl_session *session,
unsigned char *buf,
@@ -9862,30 +9871,69 @@
{
unsigned char *p = buf;
size_t used = 0;
+#if defined(MBEDTLS_HAVE_TIME)
+ uint64_t start;
+#endif
#if defined(MBEDTLS_X509_CRT_PARSE_C)
#if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
size_t cert_len;
-#else
- size_t cert_digest_len;
#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
#endif /* MBEDTLS_X509_CRT_PARSE_C */
- /*
- * Shallow copy of the session structure
- */
- used += sizeof( mbedtls_ssl_session );
- /* This also copies the values of pointer fields in the
- * session to be serialized, but they'll be ignored when
- * loading the session through ssl_load_session(). */
+ /*
+ * Time
+ */
+#if defined(MBEDTLS_HAVE_TIME)
+ used += 8;
+
if( used <= buf_len )
{
- memcpy( p, session, sizeof( mbedtls_ssl_session ) );
- p += sizeof( mbedtls_ssl_session );
+ start = (uint64_t) session->start;
+
+ *p++ = (unsigned char)( ( start >> 56 ) & 0xFF );
+ *p++ = (unsigned char)( ( start >> 48 ) & 0xFF );
+ *p++ = (unsigned char)( ( start >> 40 ) & 0xFF );
+ *p++ = (unsigned char)( ( start >> 32 ) & 0xFF );
+ *p++ = (unsigned char)( ( start >> 24 ) & 0xFF );
+ *p++ = (unsigned char)( ( start >> 16 ) & 0xFF );
+ *p++ = (unsigned char)( ( start >> 8 ) & 0xFF );
+ *p++ = (unsigned char)( ( start ) & 0xFF );
+ }
+#endif /* MBEDTLS_HAVE_TIME */
+
+ /*
+ * Basic mandatory fields
+ */
+ used += 2 /* ciphersuite */
+ + 1 /* compression */
+ + 1 /* id_len */
+ + sizeof( session->id )
+ + sizeof( session->master )
+ + 4; /* verify_result */
+
+ if( used <= buf_len )
+ {
+ *p++ = (unsigned char)( ( session->ciphersuite >> 8 ) & 0xFF );
+ *p++ = (unsigned char)( ( session->ciphersuite ) & 0xFF );
+
+ *p++ = (unsigned char)( session->compression & 0xFF );
+
+ *p++ = (unsigned char)( session->id_len & 0xFF );
+ memcpy( p, session->id, 32 );
+ p += 32;
+
+ memcpy( p, session->master, 48 );
+ p += 48;
+
+ *p++ = (unsigned char)( ( session->verify_result >> 24 ) & 0xFF );
+ *p++ = (unsigned char)( ( session->verify_result >> 16 ) & 0xFF );
+ *p++ = (unsigned char)( ( session->verify_result >> 8 ) & 0xFF );
+ *p++ = (unsigned char)( ( session->verify_result ) & 0xFF );
}
/*
- * Copy of the peer's end-entity certificate
+ * Peer's end-entity certificate
*/
#if defined(MBEDTLS_X509_CRT_PARSE_C)
#if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
@@ -9909,30 +9957,35 @@
}
}
#else /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
- if( session->peer_cert_digest == NULL )
- cert_digest_len = 0;
- else
- cert_digest_len = session->peer_cert_digest_len;
-
- used += 1 + cert_digest_len;
-
- if( used <= buf_len )
+ if( session->peer_cert_digest != NULL )
{
- *p++ = (unsigned char) cert_digest_len;
-
- if( session->peer_cert_digest != NULL )
- memcpy( p, session->peer_cert_digest, cert_digest_len );
-
- p += cert_digest_len;
+ used += 1 /* type */ + 1 /* length */ + session->peer_cert_digest_len;
+ if( used <= buf_len )
+ {
+ *p++ = (unsigned char) session->peer_cert_digest_type;
+ *p++ = (unsigned char) session->peer_cert_digest_len;
+ memcpy( p, session->peer_cert_digest,
+ session->peer_cert_digest_len );
+ p += session->peer_cert_digest_len;
+ }
+ }
+ else
+ {
+ used += 2;
+ if( used <= buf_len )
+ {
+ *p++ = (unsigned char) MBEDTLS_MD_NONE;
+ *p++ = 0;
+ }
}
#endif /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
#endif /* MBEDTLS_X509_CRT_PARSE_C */
/*
- * Copy of the session ticket if any
+ * Session ticket if any, plus associated data
*/
#if defined(MBEDTLS_SSL_SESSION_TICKETS) && defined(MBEDTLS_SSL_CLI_C)
- used += 3 + session->ticket_len;
+ used += 3 + session->ticket_len + 4; /* len + ticket + lifetime */
if( used <= buf_len )
{
@@ -9945,9 +9998,38 @@
memcpy( p, session->ticket, session->ticket_len );
p += session->ticket_len;
}
+
+ *p++ = (unsigned char)( ( session->ticket_lifetime >> 24 ) & 0xFF );
+ *p++ = (unsigned char)( ( session->ticket_lifetime >> 16 ) & 0xFF );
+ *p++ = (unsigned char)( ( session->ticket_lifetime >> 8 ) & 0xFF );
+ *p++ = (unsigned char)( ( session->ticket_lifetime ) & 0xFF );
}
#endif /* MBEDTLS_SSL_SESSION_TICKETS && MBEDTLS_SSL_CLI_C */
+ /*
+ * Misc extension-related info
+ */
+#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
+ used += 1;
+
+ if( used <= buf_len )
+ *p++ = session->mfl_code;
+#endif
+
+#if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
+ used += 1;
+
+ if( used <= buf_len )
+ *p++ = (unsigned char)( ( session->trunc_hmac ) & 0xFF );
+#endif
+
+#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
+ used += 1;
+
+ if( used <= buf_len )
+ *p++ = (unsigned char)( ( session->encrypt_then_mac ) & 0xFF );
+#endif
+
/* Done */
*olen = used;
@@ -9958,7 +10040,7 @@
}
/*
- * Unserialize session, see mbedtls_ssl_session_save().
+ * Unserialize session, see mbedtls_ssl_session_save() for format.
*
* This internal version is wrapped by a public function that cleans up in
* case of error.
@@ -9969,25 +10051,61 @@
{
const unsigned char *p = buf;
const unsigned char * const end = buf + len;
+#if defined(MBEDTLS_HAVE_TIME)
+ uint64_t start;
+#endif
#if defined(MBEDTLS_X509_CRT_PARSE_C)
#if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
size_t cert_len;
-#else
- size_t cert_digest_len;
#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
#endif /* MBEDTLS_X509_CRT_PARSE_C */
/*
- * Shallow session structure
+ * Time
*/
- if( sizeof( mbedtls_ssl_session ) > (size_t)( end - p ) )
+#if defined(MBEDTLS_HAVE_TIME)
+ if( 8 > (size_t)( end - p ) )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
- memcpy( session, p, sizeof( mbedtls_ssl_session ) );
- p += sizeof( mbedtls_ssl_session );
+ start = ( (uint64_t) p[0] << 56 ) |
+ ( (uint64_t) p[1] << 48 ) |
+ ( (uint64_t) p[2] << 40 ) |
+ ( (uint64_t) p[3] << 32 ) |
+ ( (uint64_t) p[4] << 24 ) |
+ ( (uint64_t) p[5] << 16 ) |
+ ( (uint64_t) p[6] << 8 ) |
+ ( (uint64_t) p[7] );
+ p += 8;
- /* Non-NULL pointer fields of `session` are meaningless
- * and potentially harmful. Zeroize them for safety. */
+ session->start = (time_t) start;
+#endif /* MBEDTLS_HAVE_TIME */
+
+ /*
+ * Basic mandatory fields
+ */
+ if( 2 + 1 + 1 + 32 + 48 + 4 > (size_t)( end - p ) )
+ return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
+
+ session->ciphersuite = ( p[0] << 8 ) | p[1];
+ p += 2;
+
+ session->compression = *p++;
+
+ session->id_len = *p++;
+ memcpy( session->id, p, 32 );
+ p += 32;
+
+ memcpy( session->master, p, 48 );
+ p += 48;
+
+ session->verify_result = ( (uint32_t) p[0] << 24 ) |
+ ( (uint32_t) p[1] << 16 ) |
+ ( (uint32_t) p[2] << 8 ) |
+ ( (uint32_t) p[3] );
+ p += 4;
+
+ /* Immediately clear invalid pointer values that have been read, in case
+ * we exit early before we replaced them with valid ones. */
#if defined(MBEDTLS_X509_CRT_PARSE_C)
#if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
session->peer_cert = NULL;
@@ -10038,32 +10156,38 @@
}
#else /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
/* Deserialize CRT digest from the end of the ticket. */
- if( 1 > (size_t)( end - p ) )
+ if( 2 > (size_t)( end - p ) )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
- cert_digest_len = (size_t) p[0];
- p++;
+ session->peer_cert_digest_type = (mbedtls_md_type_t) *p++;
+ session->peer_cert_digest_len = (size_t) *p++;
- if( cert_digest_len != 0 )
+ if( session->peer_cert_digest_len != 0 )
{
- if( cert_digest_len > (size_t)( end - p ) ||
- cert_digest_len != session->peer_cert_digest_len )
- {
+ const mbedtls_md_info_t *md_info =
+ mbedtls_md_info_from_type( session->peer_cert_digest_type );
+ if( md_info == NULL )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
- }
+ if( session->peer_cert_digest_len != mbedtls_md_get_size( md_info ) )
+ return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
- session->peer_cert_digest = mbedtls_calloc( 1, cert_digest_len );
+ if( session->peer_cert_digest_len > (size_t)( end - p ) )
+ return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
+
+ session->peer_cert_digest =
+ mbedtls_calloc( 1, session->peer_cert_digest_len );
if( session->peer_cert_digest == NULL )
return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
- memcpy( session->peer_cert_digest, p, cert_digest_len );
- p += cert_digest_len;
+ memcpy( session->peer_cert_digest, p,
+ session->peer_cert_digest_len );
+ p += session->peer_cert_digest_len;
}
#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
#endif /* MBEDTLS_X509_CRT_PARSE_C */
/*
- * Session ticket
+ * Session ticket and associated data
*/
#if defined(MBEDTLS_SSL_SESSION_TICKETS) && defined(MBEDTLS_SSL_CLI_C)
if( 3 > (size_t)( end - p ) )
@@ -10084,8 +10208,41 @@
memcpy( session->ticket, p, session->ticket_len );
p += session->ticket_len;
}
+
+ if( 4 > (size_t)( end - p ) )
+ return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
+
+ session->ticket_lifetime = ( (uint32_t) p[0] << 24 ) |
+ ( (uint32_t) p[1] << 16 ) |
+ ( (uint32_t) p[2] << 8 ) |
+ ( (uint32_t) p[3] );
+ p += 4;
#endif /* MBEDTLS_SSL_SESSION_TICKETS && MBEDTLS_SSL_CLI_C */
+ /*
+ * Misc extension-related info
+ */
+#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
+ if( 1 > (size_t)( end - p ) )
+ return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
+
+ session->mfl_code = *p++;
+#endif
+
+#if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
+ if( 1 > (size_t)( end - p ) )
+ return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
+
+ session->trunc_hmac = *p++;
+#endif
+
+#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
+ if( 1 > (size_t)( end - p ) )
+ return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
+
+ session->encrypt_then_mac = *p++;
+#endif
+
/* Done, should have consumed entire buffer */
if( p != end )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );