mbedtls_ssl_(read|write)_version using tls_version

remove use of MBEDTLS_SSL_MINOR_VERSION_*
remove use of MBEDTLS_SSL_MAJOR_VERSION_*
(only remaining use is in tests/suites/test_suite_ssl.data)

Signed-off-by: Glenn Strauss <gstrauss@gluelogic.com>
diff --git a/library/ssl_client.c b/library/ssl_client.c
index f173097..731b44f 100644
--- a/library/ssl_client.c
+++ b/library/ssl_client.c
@@ -602,9 +602,8 @@
      * In all cases this is the TLS 1.2 version.
      */
     MBEDTLS_SSL_CHK_BUF_PTR( p, end, 2 );
-    mbedtls_ssl_write_version( MBEDTLS_SSL_MAJOR_VERSION_3,
-                               MBEDTLS_SSL_MINOR_VERSION_3,
-                               ssl->conf->transport, p );
+    mbedtls_ssl_write_version( p, ssl->conf->transport,
+                               MBEDTLS_SSL_VERSION_TLS1_2 );
     p += 2;
 
     /* ...
diff --git a/library/ssl_misc.h b/library/ssl_misc.h
index 9202300..672659d 100644
--- a/library/ssl_misc.h
+++ b/library/ssl_misc.h
@@ -59,35 +59,6 @@
 #define inline __inline
 #endif
 
-/* Legacy minor version numbers as defined by:
- * - RFC 2246: ProtocolVersion version = { 3, 1 };     // TLS v1.0
- * - RFC 4346: ProtocolVersion version = { 3, 2 };     // TLS v1.1
- *
- * We no longer support these versions, but some code still references those
- * constants as part of negotiating with the peer, so keep them available
- * internally.
- */
-#define MBEDTLS_SSL_MINOR_VERSION_1             1
-#define MBEDTLS_SSL_MINOR_VERSION_2             2
-
-/* Determine minimum supported version */
-#define MBEDTLS_SSL_MIN_MAJOR_VERSION           MBEDTLS_SSL_MAJOR_VERSION_3
-
-#if defined(MBEDTLS_SSL_PROTO_TLS1_2)
-#define MBEDTLS_SSL_MIN_MINOR_VERSION           MBEDTLS_SSL_MINOR_VERSION_3
-#elif defined(MBEDTLS_SSL_PROTO_TLS1_3)
-#define MBEDTLS_SSL_MIN_MINOR_VERSION           MBEDTLS_SSL_MINOR_VERSION_4
-#endif /* MBEDTLS_SSL_PROTO_TLS1_3 */
-
-/* Determine maximum supported version */
-#define MBEDTLS_SSL_MAX_MAJOR_VERSION           MBEDTLS_SSL_MAJOR_VERSION_3
-
-#if defined(MBEDTLS_SSL_PROTO_TLS1_3)
-#define MBEDTLS_SSL_MAX_MINOR_VERSION           MBEDTLS_SSL_MINOR_VERSION_4
-#elif defined(MBEDTLS_SSL_PROTO_TLS1_2)
-#define MBEDTLS_SSL_MAX_MINOR_VERSION           MBEDTLS_SSL_MINOR_VERSION_3
-#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
-
 /* Shorthand for restartable ECC */
 #if defined(MBEDTLS_ECP_RESTARTABLE) && \
     defined(MBEDTLS_SSL_CLI_C) && \
@@ -1457,10 +1428,10 @@
                           uint32_t *flags );
 #endif /* MBEDTLS_X509_CRT_PARSE_C */
 
-void mbedtls_ssl_write_version( int major, int minor, int transport,
-                        unsigned char ver[2] );
-void mbedtls_ssl_read_version( int *major, int *minor, int transport,
-                       const unsigned char ver[2] );
+void mbedtls_ssl_write_version( unsigned char version[2], int transport,
+                                mbedtls_ssl_protocol_version tls_version );
+uint16_t mbedtls_ssl_read_version( const unsigned char version[2],
+                                   int transport );
 
 static inline size_t mbedtls_ssl_in_hdr_len( const mbedtls_ssl_context *ssl )
 {
diff --git a/library/ssl_msg.c b/library/ssl_msg.c
index 0112951..f1e852e 100644
--- a/library/ssl_msg.c
+++ b/library/ssl_msg.c
@@ -2682,8 +2682,8 @@
         if( tls_ver == MBEDTLS_SSL_VERSION_TLS1_3 )
             tls_ver = MBEDTLS_SSL_VERSION_TLS1_2;
 #endif /* MBEDTLS_SSL_PROTO_TLS1_3 */
-        mbedtls_ssl_write_version( tls_ver >> 8, tls_ver & 0xFF,
-                                   ssl->conf->transport, ssl->out_hdr + 1 );
+        mbedtls_ssl_write_version( ssl->out_hdr + 1, ssl->conf->transport,
+                                   tls_ver );
 
         memcpy( ssl->out_ctr, ssl->cur_out_ctr, MBEDTLS_SSL_SEQUENCE_NUMBER_LEN );
         MBEDTLS_PUT_UINT16_BE( len, ssl->out_len, 0);
@@ -2698,8 +2698,7 @@
             rec.data_offset = ssl->out_msg - rec.buf;
 
             memcpy( &rec.ctr[0], ssl->out_ctr, sizeof( rec.ctr ) );
-            mbedtls_ssl_write_version( tls_ver >> 8, tls_ver & 0xFF,
-                                       ssl->conf->transport, rec.ver );
+            mbedtls_ssl_write_version( rec.ver, ssl->conf->transport, tls_ver );
             rec.type = ssl->out_msgtype;
 
 #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
@@ -3421,7 +3420,7 @@
                                     size_t len,
                                     mbedtls_record *rec )
 {
-    int major_ver, minor_ver;
+    mbedtls_ssl_protocol_version tls_version;
 
     size_t const rec_hdr_type_offset    = 0;
     size_t const rec_hdr_type_len       = 1;
@@ -3531,11 +3530,10 @@
 
     rec->ver[0] = buf[ rec_hdr_version_offset + 0 ];
     rec->ver[1] = buf[ rec_hdr_version_offset + 1 ];
-    mbedtls_ssl_read_version( &major_ver, &minor_ver,
-                              ssl->conf->transport,
-                              &rec->ver[0] );
+    tls_version = mbedtls_ssl_read_version( buf + rec_hdr_version_offset,
+                                            ssl->conf->transport );
 
-    if( ( ( major_ver << 8 ) | minor_ver ) > ssl->conf->max_tls_version )
+    if( tls_version > ssl->conf->max_tls_version )
     {
         MBEDTLS_SSL_DEBUG_MSG( 1, ( "TLS version mismatch" ) );
         return( MBEDTLS_ERR_SSL_INVALID_RECORD );
@@ -3569,9 +3567,8 @@
     MBEDTLS_SSL_DEBUG_BUF( 4, "input record header", buf, rec->data_offset );
 
     MBEDTLS_SSL_DEBUG_MSG( 3, ( "input record: msgtype = %u, "
-                                "version = [%d:%d], msglen = %" MBEDTLS_PRINTF_SIZET,
-                                rec->type,
-                                major_ver, minor_ver, rec->data_len ) );
+                                "version = [0x%x], msglen = %" MBEDTLS_PRINTF_SIZET,
+                                rec->type, (unsigned)tls_version, rec->data_len ) );
 
     rec->buf     = buf;
     rec->buf_len = rec->data_offset + rec->data_len;
@@ -5810,51 +5807,35 @@
  * and, for DTLS, to/from TLS equivalent.
  *
  * For TLS this is the identity.
- * For DTLS, use 1's complement (v -> 255 - v, and then map as follows:
+ * For DTLS, map as follows, then use 1's complement (v -> ~v):
  * 1.x <-> 3.x+1    for x != 0 (DTLS 1.2 based on TLS 1.2)
+ *                  DTLS 1.0 is stored as TLS 1.1 internally
  */
-void mbedtls_ssl_write_version( int major, int minor, int transport,
-                        unsigned char ver[2] )
+void mbedtls_ssl_write_version( unsigned char version[2], int transport,
+                                mbedtls_ssl_protocol_version tls_version )
 {
 #if defined(MBEDTLS_SSL_PROTO_DTLS)
     if( transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
-    {
-        if( minor == MBEDTLS_SSL_MINOR_VERSION_2 )
-            --minor; /* DTLS 1.0 stored as TLS 1.1 internally */
-
-        ver[0] = (unsigned char)( 255 - ( major - 2 ) );
-        ver[1] = (unsigned char)( 255 - ( minor - 1 ) );
-    }
-    else
+        tls_version =
+          ~( tls_version - ( tls_version == 0x0302 ? 0x0202 : 0x0201 ) );
 #else
     ((void) transport);
 #endif
-    {
-        ver[0] = (unsigned char) major;
-        ver[1] = (unsigned char) minor;
-    }
+    MBEDTLS_PUT_UINT16_BE( tls_version, version, 0 );
 }
 
-void mbedtls_ssl_read_version( int *major, int *minor, int transport,
-                       const unsigned char ver[2] )
+uint16_t mbedtls_ssl_read_version( const unsigned char version[2],
+                                   int transport )
 {
+    uint16_t tls_version = MBEDTLS_GET_UINT16_BE( version, 0 );
 #if defined(MBEDTLS_SSL_PROTO_DTLS)
     if( transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
-    {
-        *major = 255 - ver[0] + 2;
-        *minor = 255 - ver[1] + 1;
-
-        if( *minor == MBEDTLS_SSL_MINOR_VERSION_1 )
-            ++*minor; /* DTLS 1.0 stored as TLS 1.1 internally */
-    }
-    else
+        tls_version =
+          ~( tls_version - ( tls_version == 0xfeff ? 0x0202 : 0x0201 ) );
 #else
     ((void) transport);
 #endif
-    {
-        *major = ver[0];
-        *minor = ver[1];
-    }
+    return tls_version;
 }
 
 /*
diff --git a/library/ssl_tls12_client.c b/library/ssl_tls12_client.c
index 451d871..8f5ab9b 100644
--- a/library/ssl_tls12_client.c
+++ b/library/ssl_tls12_client.c
@@ -1121,7 +1121,7 @@
 static int ssl_parse_hello_verify_request( mbedtls_ssl_context *ssl )
 {
     const unsigned char *p = ssl->in_msg + mbedtls_ssl_hs_hdr_len( ssl );
-    int major_ver, minor_ver;
+    mbedtls_ssl_protocol_version tls_version;
     unsigned char cookie_len;
 
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse hello verify request" ) );
@@ -1146,16 +1146,15 @@
      * } HelloVerifyRequest;
      */
     MBEDTLS_SSL_DEBUG_BUF( 3, "server version", p, 2 );
-    mbedtls_ssl_read_version( &major_ver, &minor_ver, ssl->conf->transport, p );
+    tls_version = mbedtls_ssl_read_version( p, ssl->conf->transport );
     p += 2;
 
     /*
      * Since the RFC is not clear on this point, accept DTLS 1.0 (TLS 1.1)
-     * even is lower than our min version.
+     * even if lower than our min version.
      */
-    if( major_ver < MBEDTLS_SSL_MAJOR_VERSION_3 ||
-        minor_ver < MBEDTLS_SSL_MINOR_VERSION_2 ||
-        ( ( major_ver << 8 ) | minor_ver ) > ssl->conf->max_tls_version )
+    if( tls_version < 0x0302 || /* TLSv1.1 */
+        tls_version > ssl->conf->max_tls_version )
     {
         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad server version" ) );
 
@@ -1212,7 +1211,6 @@
 #endif
     int handshake_failure = 0;
     const mbedtls_ssl_ciphersuite_t *suite_info;
-    int major_ver, minor_ver;
 
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse server hello" ) );
 
@@ -1297,10 +1295,8 @@
      */
     buf += mbedtls_ssl_hs_hdr_len( ssl );
 
-    MBEDTLS_SSL_DEBUG_BUF( 3, "server hello, version", buf + 0, 2 );
-    mbedtls_ssl_read_version( &major_ver, &minor_ver,
-                      ssl->conf->transport, buf + 0 );
-    ssl->tls_version = ( major_ver << 8 ) | minor_ver;
+    MBEDTLS_SSL_DEBUG_BUF( 3, "server hello, version", buf, 2 );
+    ssl->tls_version = mbedtls_ssl_read_version( buf, ssl->conf->transport );
     ssl->session_negotiate->tls_version = ssl->tls_version;
 
     if( ssl->tls_version < ssl->conf->min_tls_version ||
@@ -1988,9 +1984,8 @@
      *      opaque random[46];
      *  } PreMasterSecret;
      */
-    mbedtls_ssl_write_version( MBEDTLS_SSL_MAJOR_VERSION_3,
-                               MBEDTLS_SSL_MINOR_VERSION_3,
-                               ssl->conf->transport, p );
+    mbedtls_ssl_write_version( p, ssl->conf->transport,
+                               MBEDTLS_SSL_VERSION_TLS1_2 );
 
     if( ( ret = ssl->conf->f_rng( ssl->conf->p_rng, p + 2, 46 ) ) != 0 )
     {
diff --git a/library/ssl_tls12_server.c b/library/ssl_tls12_server.c
index 3ce7fb2..49cda3f 100644
--- a/library/ssl_tls12_server.c
+++ b/library/ssl_tls12_server.c
@@ -1147,7 +1147,6 @@
     int handshake_failure = 0;
     const int *ciphersuites;
     const mbedtls_ssl_ciphersuite_t *ciphersuite_info;
-    int major, minor;
 
     /* If there is no signature-algorithm extension present,
      * we need to fall back to the default values for allowed
@@ -1206,13 +1205,11 @@
     MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, protocol version: [%d:%d]",
                    buf[1], buf[2] ) );
 
-    mbedtls_ssl_read_version( &major, &minor, ssl->conf->transport, buf + 1 );
-
     /* According to RFC 5246 Appendix E.1, the version here is typically
      * "{03,00}, the lowest version number supported by the client, [or] the
      * value of ClientHello.client_version", so the only meaningful check here
      * is the major version shouldn't be less than 3 */
-    if( major < MBEDTLS_SSL_MAJOR_VERSION_3 )
+    if( mbedtls_ssl_read_version( buf + 1, ssl->conf->transport ) < 0x0300 )
     {
         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
         return( MBEDTLS_ERR_SSL_BAD_PROTOCOL_VERSION );
@@ -1405,8 +1402,7 @@
      */
     MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, version", buf, 2 );
 
-    mbedtls_ssl_read_version( &major, &minor, ssl->conf->transport, buf );
-    ssl->tls_version = ( major << 8 ) | minor;
+    ssl->tls_version = mbedtls_ssl_read_version( buf, ssl->conf->transport );
     ssl->session_negotiate->tls_version = ssl->tls_version;
 
     if( ssl->tls_version != MBEDTLS_SSL_VERSION_TLS1_2 )
@@ -2354,8 +2350,7 @@
 
     /* The RFC is not clear on this point, but sending the actual negotiated
      * version looks like the most interoperable thing to do. */
-    mbedtls_ssl_write_version( ssl->tls_version >> 8, ssl->tls_version & 0xFF,
-                               ssl->conf->transport, p );
+    mbedtls_ssl_write_version( p, ssl->conf->transport, ssl->tls_version );
     MBEDTLS_SSL_DEBUG_BUF( 3, "server version", p, 2 );
     p += 2;
 
@@ -2494,8 +2489,7 @@
     buf = ssl->out_msg;
     p = buf + 4;
 
-    mbedtls_ssl_write_version( ssl->tls_version >> 8, ssl->tls_version & 0xFF,
-                               ssl->conf->transport, p );
+    mbedtls_ssl_write_version( p, ssl->conf->transport, ssl->tls_version );
     p += 2;
 
     MBEDTLS_SSL_DEBUG_MSG( 3, ( "server hello, chosen version: [%d:%d]",
@@ -3734,9 +3728,8 @@
         return( ret );
 #endif /* MBEDTLS_SSL_ASYNC_PRIVATE */
 
-    mbedtls_ssl_write_version( MBEDTLS_SSL_MAJOR_VERSION_3,
-                               MBEDTLS_SSL_MINOR_VERSION_3,
-                               ssl->conf->transport, ver );
+    mbedtls_ssl_write_version( ver, ssl->conf->transport,
+                               ssl->session_negotiate->tls_version );
 
     /* Avoid data-dependent branches while checking for invalid
      * padding, to protect against timing-based Bleichenbacher-type
diff --git a/library/ssl_tls13_client.c b/library/ssl_tls13_client.c
index d7748b7..acb4865 100644
--- a/library/ssl_tls13_client.c
+++ b/library/ssl_tls13_client.c
@@ -75,17 +75,15 @@
      * They are defined by the configuration.
      * Currently, we advertise only TLS 1.3 or both TLS 1.3 and TLS 1.2.
      */
-    mbedtls_ssl_write_version( MBEDTLS_SSL_MAJOR_VERSION_3,
-                               MBEDTLS_SSL_MINOR_VERSION_4,
-                               MBEDTLS_SSL_TRANSPORT_STREAM, p );
+    mbedtls_ssl_write_version( p, MBEDTLS_SSL_TRANSPORT_STREAM,
+                               MBEDTLS_SSL_VERSION_TLS1_3 );
     MBEDTLS_SSL_DEBUG_MSG( 3, ( "supported version: [3:4]" ) );
 
 
     if( ssl->handshake->min_minor_ver <= MBEDTLS_SSL_MINOR_VERSION_3 )
     {
-        mbedtls_ssl_write_version( MBEDTLS_SSL_MAJOR_VERSION_3,
-                                   MBEDTLS_SSL_MINOR_VERSION_3,
-                                   MBEDTLS_SSL_TRANSPORT_STREAM, p + 2 );
+        mbedtls_ssl_write_version( p + 2, MBEDTLS_SSL_TRANSPORT_STREAM,
+                                   MBEDTLS_SSL_VERSION_TLS1_2 );
         MBEDTLS_SSL_DEBUG_MSG( 3, ( "supported version: [3:3]" ) );
     }
 
@@ -101,8 +99,8 @@
     ((void) ssl);
 
     MBEDTLS_SSL_CHK_BUF_READ_PTR( buf, end, 2 );
-    if( buf[0] != MBEDTLS_SSL_MAJOR_VERSION_3 ||
-        buf[1] != MBEDTLS_SSL_MINOR_VERSION_4 )
+    if( mbedtls_ssl_read_version( buf, ssl->conf->transport ) !=
+          MBEDTLS_SSL_VERSION_TLS1_3 )
     {
         MBEDTLS_SSL_DEBUG_MSG( 1, ( "unexpected version" ) );
 
@@ -1026,8 +1024,8 @@
      * with ProtocolVersion defined as:
      * uint16 ProtocolVersion;
      */
-    if( !( p[0] == MBEDTLS_SSL_MAJOR_VERSION_3 &&
-           p[1] == MBEDTLS_SSL_MINOR_VERSION_3 ) )
+    if( mbedtls_ssl_read_version( p, ssl->conf->transport ) !=
+          MBEDTLS_SSL_VERSION_TLS1_2 )
     {
         MBEDTLS_SSL_DEBUG_MSG( 1, ( "Unsupported version of TLS." ) );
         MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION,