mirror of
https://github.com/cuberite/polarssl.git
synced 2025-11-03 20:22:59 -05:00
Rename & move ticket functions to ticket module
This commit is contained in:
Manuel Pégourié-Gonnard
parent
fd6d8978f9
commit
a4a473516e
@ -30,6 +30,13 @@
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extern "C" {
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#endif
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/* Temporary, WIP */
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int mbedtls_ssl_ticket_write( mbedtls_ssl_context *ssl, size_t *tlen );
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/* Temporary, WIP */
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int mbedtls_ssl_ticket_parse( mbedtls_ssl_context *ssl,
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unsigned char *buf,
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size_t len );
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#ifdef __cplusplus
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}
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@ -50,314 +50,9 @@
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#endif
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#if defined(MBEDTLS_SSL_SESSION_TICKETS)
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/* Implementation that should never be optimized out by the compiler */
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static void mbedtls_zeroize( void *v, size_t n ) {
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volatile unsigned char *p = v; while( n-- ) *p++ = 0;
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}
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/*
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* Serialize a session in the following format:
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* 0 . n-1 session structure, n = sizeof(mbedtls_ssl_session)
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* n . n+2 peer_cert length = m (0 if no certificate)
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* n+3 . n+2+m peer cert ASN.1
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*
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* Assumes ticket is NULL (always true on server side).
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*/
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static int ssl_save_session( const mbedtls_ssl_session *session,
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unsigned char *buf, size_t buf_len,
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size_t *olen )
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{
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unsigned char *p = buf;
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size_t left = buf_len;
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#if defined(MBEDTLS_X509_CRT_PARSE_C)
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size_t cert_len;
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#endif /* MBEDTLS_X509_CRT_PARSE_C */
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if( left < sizeof( mbedtls_ssl_session ) )
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return( -1 );
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memcpy( p, session, sizeof( mbedtls_ssl_session ) );
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p += sizeof( mbedtls_ssl_session );
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left -= sizeof( mbedtls_ssl_session );
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#if defined(MBEDTLS_X509_CRT_PARSE_C)
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if( session->peer_cert == NULL )
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cert_len = 0;
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else
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cert_len = session->peer_cert->raw.len;
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if( left < 3 + cert_len )
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return( -1 );
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*p++ = (unsigned char)( cert_len >> 16 & 0xFF );
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*p++ = (unsigned char)( cert_len >> 8 & 0xFF );
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*p++ = (unsigned char)( cert_len & 0xFF );
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if( session->peer_cert != NULL )
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memcpy( p, session->peer_cert->raw.p, cert_len );
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p += cert_len;
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#endif /* MBEDTLS_X509_CRT_PARSE_C */
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*olen = p - buf;
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return( 0 );
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}
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/*
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* Unserialise session, see ssl_save_session()
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*/
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static int ssl_load_session( mbedtls_ssl_session *session,
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const unsigned char *buf, size_t len )
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{
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const unsigned char *p = buf;
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const unsigned char * const end = buf + len;
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#if defined(MBEDTLS_X509_CRT_PARSE_C)
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size_t cert_len;
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#endif /* MBEDTLS_X509_CRT_PARSE_C */
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if( p + sizeof( mbedtls_ssl_session ) > end )
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return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
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memcpy( session, p, sizeof( mbedtls_ssl_session ) );
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p += sizeof( mbedtls_ssl_session );
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#if defined(MBEDTLS_X509_CRT_PARSE_C)
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if( p + 3 > end )
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return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
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cert_len = ( p[0] << 16 ) | ( p[1] << 8 ) | p[2];
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p += 3;
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if( cert_len == 0 )
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{
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session->peer_cert = NULL;
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}
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else
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{
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int ret;
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if( p + cert_len > end )
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return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
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session->peer_cert = mbedtls_malloc( sizeof( mbedtls_x509_crt ) );
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if( session->peer_cert == NULL )
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return( MBEDTLS_ERR_SSL_MALLOC_FAILED );
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mbedtls_x509_crt_init( session->peer_cert );
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if( ( ret = mbedtls_x509_crt_parse_der( session->peer_cert,
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p, cert_len ) ) != 0 )
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{
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mbedtls_x509_crt_free( session->peer_cert );
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mbedtls_free( session->peer_cert );
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session->peer_cert = NULL;
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return( ret );
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}
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p += cert_len;
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}
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#endif /* MBEDTLS_X509_CRT_PARSE_C */
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if( p != end )
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return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
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return( 0 );
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}
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/*
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* Create session ticket, secured as recommended in RFC 5077 section 4:
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*
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* struct {
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* opaque key_name[16];
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* opaque iv[16];
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* opaque encrypted_state<0..2^16-1>;
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* opaque mac[32];
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* } ticket;
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*
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* (the internal state structure differs, however).
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*/
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static int ssl_write_ticket( mbedtls_ssl_context *ssl, size_t *tlen )
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{
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int ret;
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unsigned char * const start = ssl->out_msg + 10;
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unsigned char *p = start;
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unsigned char *state;
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unsigned char iv[16];
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size_t clear_len, enc_len, pad_len, i;
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*tlen = 0;
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if( ssl->conf->ticket_keys == NULL )
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return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
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/* Write key name */
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memcpy( p, ssl->conf->ticket_keys->key_name, 16 );
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p += 16;
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/* Generate and write IV (with a copy for aes_crypt) */
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if( ( ret = ssl->conf->f_rng( ssl->conf->p_rng, p, 16 ) ) != 0 )
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return( ret );
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memcpy( iv, p, 16 );
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p += 16;
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/*
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* Dump session state
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*
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* After the session state itself, we still need room for 16 bytes of
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* padding and 32 bytes of MAC, so there's only so much room left
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*/
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state = p + 2;
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if( ssl_save_session( ssl->session_negotiate, state,
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MBEDTLS_SSL_MAX_CONTENT_LEN - ( state - ssl->out_msg ) - 48,
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&clear_len ) != 0 )
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{
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return( MBEDTLS_ERR_SSL_CERTIFICATE_TOO_LARGE );
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}
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MBEDTLS_SSL_DEBUG_BUF( 3, "session ticket cleartext", state, clear_len );
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/* Apply PKCS padding */
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pad_len = 16 - clear_len % 16;
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enc_len = clear_len + pad_len;
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for( i = clear_len; i < enc_len; i++ )
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state[i] = (unsigned char) pad_len;
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/* Encrypt */
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if( ( ret = mbedtls_aes_crypt_cbc( &ssl->conf->ticket_keys->enc, MBEDTLS_AES_ENCRYPT,
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enc_len, iv, state, state ) ) != 0 )
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{
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return( ret );
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}
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/* Write length */
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*p++ = (unsigned char)( ( enc_len >> 8 ) & 0xFF );
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*p++ = (unsigned char)( ( enc_len ) & 0xFF );
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p = state + enc_len;
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/* Compute and write MAC( key_name + iv + enc_state_len + enc_state ) */
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if( ( ret = mbedtls_md_hmac( mbedtls_md_info_from_type( MBEDTLS_MD_SHA256 ),
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ssl->conf->ticket_keys->mac_key, 16,
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start, p - start, p ) ) != 0 )
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{
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return( ret );
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}
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p += 32;
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*tlen = p - start;
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MBEDTLS_SSL_DEBUG_BUF( 3, "session ticket structure", start, *tlen );
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return( 0 );
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}
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/*
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* Load session ticket (see ssl_write_ticket for structure)
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*/
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static int ssl_parse_ticket( mbedtls_ssl_context *ssl,
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unsigned char *buf,
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size_t len )
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{
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int ret;
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mbedtls_ssl_session session;
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unsigned char *key_name = buf;
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unsigned char *iv = buf + 16;
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unsigned char *enc_len_p = iv + 16;
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unsigned char *ticket = enc_len_p + 2;
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unsigned char *mac;
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unsigned char computed_mac[32];
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size_t enc_len, clear_len, i;
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unsigned char pad_len, diff;
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MBEDTLS_SSL_DEBUG_BUF( 3, "session ticket structure", buf, len );
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if( len < 34 || ssl->conf->ticket_keys == NULL )
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return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
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enc_len = ( enc_len_p[0] << 8 ) | enc_len_p[1];
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mac = ticket + enc_len;
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if( len != enc_len + 66 )
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return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
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/* Check name, in constant time though it's not a big secret */
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diff = 0;
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for( i = 0; i < 16; i++ )
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diff |= key_name[i] ^ ssl->conf->ticket_keys->key_name[i];
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/* don't return yet, check the MAC anyway */
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/* Check mac, with constant-time buffer comparison */
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if( ( ret = mbedtls_md_hmac( mbedtls_md_info_from_type( MBEDTLS_MD_SHA256 ),
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ssl->conf->ticket_keys->mac_key, 16,
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buf, len - 32, computed_mac ) ) != 0 )
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{
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return( ret );
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}
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for( i = 0; i < 32; i++ )
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diff |= mac[i] ^ computed_mac[i];
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/* Now return if ticket is not authentic, since we want to avoid
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* decrypting arbitrary attacker-chosen data */
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if( diff != 0 )
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return( MBEDTLS_ERR_SSL_INVALID_MAC );
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/* Decrypt */
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if( ( ret = mbedtls_aes_crypt_cbc( &ssl->conf->ticket_keys->dec, MBEDTLS_AES_DECRYPT,
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enc_len, iv, ticket, ticket ) ) != 0 )
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{
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return( ret );
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}
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/* Check PKCS padding */
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pad_len = ticket[enc_len - 1];
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ret = 0;
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for( i = 2; i < pad_len; i++ )
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if( ticket[enc_len - i] != pad_len )
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ret = MBEDTLS_ERR_SSL_BAD_INPUT_DATA;
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if( ret != 0 )
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return( ret );
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clear_len = enc_len - pad_len;
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MBEDTLS_SSL_DEBUG_BUF( 3, "session ticket cleartext", ticket, clear_len );
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/* Actually load session */
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if( ( ret = ssl_load_session( &session, ticket, clear_len ) ) != 0 )
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{
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MBEDTLS_SSL_DEBUG_MSG( 1, ( "failed to parse ticket content" ) );
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mbedtls_ssl_session_free( &session );
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return( ret );
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}
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#if defined(MBEDTLS_HAVE_TIME)
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/* Check if still valid */
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if( (int) ( time( NULL) - session.start ) > ssl->conf->ticket_lifetime )
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{
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MBEDTLS_SSL_DEBUG_MSG( 1, ( "session ticket expired" ) );
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mbedtls_ssl_session_free( &session );
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return( MBEDTLS_ERR_SSL_SESSION_TICKET_EXPIRED );
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}
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#include "mbedtls/ssl_ticket.h"
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#endif
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/*
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* Keep the session ID sent by the client, since we MUST send it back to
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* inform him we're accepting the ticket (RFC 5077 section 3.4)
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*/
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session.length = ssl->session_negotiate->length;
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memcpy( &session.id, ssl->session_negotiate->id, session.length );
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mbedtls_ssl_session_free( ssl->session_negotiate );
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memcpy( ssl->session_negotiate, &session, sizeof( mbedtls_ssl_session ) );
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/* Zeroize instead of free as we copied the content */
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mbedtls_zeroize( &session, sizeof( mbedtls_ssl_session ) );
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return( 0 );
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}
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#endif /* MBEDTLS_SSL_SESSION_TICKETS */
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#if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY)
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int mbedtls_ssl_set_client_transport_id( mbedtls_ssl_context *ssl,
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const unsigned char *info,
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@ -734,9 +429,9 @@ static int ssl_parse_session_ticket_ext( mbedtls_ssl_context *ssl,
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/*
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* Failures are ok: just ignore the ticket and proceed.
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*/
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if( ( ret = ssl_parse_ticket( ssl, buf, len ) ) != 0 )
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if( ( ret = mbedtls_ssl_ticket_parse( ssl, buf, len ) ) != 0 )
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{
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MBEDTLS_SSL_DEBUG_RET( 1, "ssl_parse_ticket", ret );
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MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_ticket_parse", ret );
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return( 0 );
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}
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@ -3814,9 +3509,9 @@ static int ssl_write_new_session_ticket( mbedtls_ssl_context *ssl )
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ssl->out_msg[6] = ( lifetime >> 8 ) & 0xFF;
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ssl->out_msg[7] = ( lifetime ) & 0xFF;
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if( ( ret = ssl_write_ticket( ssl, &tlen ) ) != 0 )
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if( ( ret = mbedtls_ssl_ticket_write( ssl, &tlen ) ) != 0 )
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{
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MBEDTLS_SSL_DEBUG_RET( 1, "ssl_write_ticket", ret );
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MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_ticket_write", ret );
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tlen = 0;
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}
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@ -39,4 +39,302 @@
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#include <string.h>
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/* Implementation that should never be optimized out by the compiler */
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static void mbedtls_zeroize( void *v, size_t n ) {
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volatile unsigned char *p = v; while( n-- ) *p++ = 0;
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}
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/*
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* Serialize a session in the following format:
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* 0 . n-1 session structure, n = sizeof(mbedtls_ssl_session)
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* n . n+2 peer_cert length = m (0 if no certificate)
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* n+3 . n+2+m peer cert ASN.1
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*
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* Assumes ticket is NULL (always true on server side).
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*/
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static int ssl_save_session( const mbedtls_ssl_session *session,
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unsigned char *buf, size_t buf_len,
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size_t *olen )
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{
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unsigned char *p = buf;
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size_t left = buf_len;
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#if defined(MBEDTLS_X509_CRT_PARSE_C)
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size_t cert_len;
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#endif /* MBEDTLS_X509_CRT_PARSE_C */
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if( left < sizeof( mbedtls_ssl_session ) )
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return( -1 );
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memcpy( p, session, sizeof( mbedtls_ssl_session ) );
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p += sizeof( mbedtls_ssl_session );
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left -= sizeof( mbedtls_ssl_session );
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#if defined(MBEDTLS_X509_CRT_PARSE_C)
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if( session->peer_cert == NULL )
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cert_len = 0;
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else
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cert_len = session->peer_cert->raw.len;
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if( left < 3 + cert_len )
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return( -1 );
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*p++ = (unsigned char)( cert_len >> 16 & 0xFF );
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*p++ = (unsigned char)( cert_len >> 8 & 0xFF );
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*p++ = (unsigned char)( cert_len & 0xFF );
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if( session->peer_cert != NULL )
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memcpy( p, session->peer_cert->raw.p, cert_len );
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p += cert_len;
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#endif /* MBEDTLS_X509_CRT_PARSE_C */
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*olen = p - buf;
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return( 0 );
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}
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/*
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* Unserialise session, see ssl_save_session()
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*/
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static int ssl_load_session( mbedtls_ssl_session *session,
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const unsigned char *buf, size_t len )
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{
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const unsigned char *p = buf;
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const unsigned char * const end = buf + len;
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#if defined(MBEDTLS_X509_CRT_PARSE_C)
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size_t cert_len;
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#endif /* MBEDTLS_X509_CRT_PARSE_C */
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if( p + sizeof( mbedtls_ssl_session ) > end )
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return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
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memcpy( session, p, sizeof( mbedtls_ssl_session ) );
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p += sizeof( mbedtls_ssl_session );
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#if defined(MBEDTLS_X509_CRT_PARSE_C)
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if( p + 3 > end )
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return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
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cert_len = ( p[0] << 16 ) | ( p[1] << 8 ) | p[2];
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p += 3;
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if( cert_len == 0 )
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{
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session->peer_cert = NULL;
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}
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else
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{
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int ret;
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if( p + cert_len > end )
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return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
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session->peer_cert = mbedtls_malloc( sizeof( mbedtls_x509_crt ) );
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if( session->peer_cert == NULL )
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return( MBEDTLS_ERR_SSL_MALLOC_FAILED );
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mbedtls_x509_crt_init( session->peer_cert );
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if( ( ret = mbedtls_x509_crt_parse_der( session->peer_cert,
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p, cert_len ) ) != 0 )
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{
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mbedtls_x509_crt_free( session->peer_cert );
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mbedtls_free( session->peer_cert );
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session->peer_cert = NULL;
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return( ret );
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}
|
||||
|
||||
p += cert_len;
|
||||
}
|
||||
#endif /* MBEDTLS_X509_CRT_PARSE_C */
|
||||
|
||||
if( p != end )
|
||||
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
|
||||
|
||||
return( 0 );
|
||||
}
|
||||
|
||||
/*
|
||||
* Create session ticket, secured as recommended in RFC 5077 section 4:
|
||||
*
|
||||
* struct {
|
||||
* opaque key_name[16];
|
||||
* opaque iv[16];
|
||||
* opaque encrypted_state<0..2^16-1>;
|
||||
* opaque mac[32];
|
||||
* } ticket;
|
||||
*
|
||||
* (the internal state structure differs, however).
|
||||
*/
|
||||
int mbedtls_ssl_ticket_write( mbedtls_ssl_context *ssl, size_t *tlen )
|
||||
{
|
||||
int ret;
|
||||
unsigned char * const start = ssl->out_msg + 10;
|
||||
unsigned char *p = start;
|
||||
unsigned char *state;
|
||||
unsigned char iv[16];
|
||||
size_t clear_len, enc_len, pad_len, i;
|
||||
|
||||
*tlen = 0;
|
||||
|
||||
if( ssl->conf->ticket_keys == NULL )
|
||||
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
|
||||
|
||||
/* Write key name */
|
||||
memcpy( p, ssl->conf->ticket_keys->key_name, 16 );
|
||||
p += 16;
|
||||
|
||||
/* Generate and write IV (with a copy for aes_crypt) */
|
||||
if( ( ret = ssl->conf->f_rng( ssl->conf->p_rng, p, 16 ) ) != 0 )
|
||||
return( ret );
|
||||
memcpy( iv, p, 16 );
|
||||
p += 16;
|
||||
|
||||
/*
|
||||
* Dump session state
|
||||
*
|
||||
* After the session state itself, we still need room for 16 bytes of
|
||||
* padding and 32 bytes of MAC, so there's only so much room left
|
||||
*/
|
||||
state = p + 2;
|
||||
if( ssl_save_session( ssl->session_negotiate, state,
|
||||
MBEDTLS_SSL_MAX_CONTENT_LEN - ( state - ssl->out_msg ) - 48,
|
||||
&clear_len ) != 0 )
|
||||
{
|
||||
return( MBEDTLS_ERR_SSL_CERTIFICATE_TOO_LARGE );
|
||||
}
|
||||
|
||||
/* Apply PKCS padding */
|
||||
pad_len = 16 - clear_len % 16;
|
||||
enc_len = clear_len + pad_len;
|
||||
for( i = clear_len; i < enc_len; i++ )
|
||||
state[i] = (unsigned char) pad_len;
|
||||
|
||||
/* Encrypt */
|
||||
if( ( ret = mbedtls_aes_crypt_cbc( &ssl->conf->ticket_keys->enc, MBEDTLS_AES_ENCRYPT,
|
||||
enc_len, iv, state, state ) ) != 0 )
|
||||
{
|
||||
return( ret );
|
||||
}
|
||||
|
||||
/* Write length */
|
||||
*p++ = (unsigned char)( ( enc_len >> 8 ) & 0xFF );
|
||||
*p++ = (unsigned char)( ( enc_len ) & 0xFF );
|
||||
p = state + enc_len;
|
||||
|
||||
/* Compute and write MAC( key_name + iv + enc_state_len + enc_state ) */
|
||||
if( ( ret = mbedtls_md_hmac( mbedtls_md_info_from_type( MBEDTLS_MD_SHA256 ),
|
||||
ssl->conf->ticket_keys->mac_key, 16,
|
||||
start, p - start, p ) ) != 0 )
|
||||
{
|
||||
return( ret );
|
||||
}
|
||||
p += 32;
|
||||
|
||||
*tlen = p - start;
|
||||
|
||||
return( 0 );
|
||||
}
|
||||
|
||||
/*
|
||||
* Load session ticket (see mbedtls_ssl_ticket_write for structure)
|
||||
*/
|
||||
int mbedtls_ssl_ticket_parse( mbedtls_ssl_context *ssl,
|
||||
unsigned char *buf,
|
||||
size_t len )
|
||||
{
|
||||
int ret;
|
||||
mbedtls_ssl_session session;
|
||||
unsigned char *key_name = buf;
|
||||
unsigned char *iv = buf + 16;
|
||||
unsigned char *enc_len_p = iv + 16;
|
||||
unsigned char *ticket = enc_len_p + 2;
|
||||
unsigned char *mac;
|
||||
unsigned char computed_mac[32];
|
||||
size_t enc_len, clear_len, i;
|
||||
unsigned char pad_len, diff;
|
||||
|
||||
if( len < 34 || ssl->conf->ticket_keys == NULL )
|
||||
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
|
||||
|
||||
enc_len = ( enc_len_p[0] << 8 ) | enc_len_p[1];
|
||||
mac = ticket + enc_len;
|
||||
|
||||
if( len != enc_len + 66 )
|
||||
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
|
||||
|
||||
/* Check name, in constant time though it's not a big secret */
|
||||
diff = 0;
|
||||
for( i = 0; i < 16; i++ )
|
||||
diff |= key_name[i] ^ ssl->conf->ticket_keys->key_name[i];
|
||||
/* don't return yet, check the MAC anyway */
|
||||
|
||||
/* Check mac, with constant-time buffer comparison */
|
||||
if( ( ret = mbedtls_md_hmac( mbedtls_md_info_from_type( MBEDTLS_MD_SHA256 ),
|
||||
ssl->conf->ticket_keys->mac_key, 16,
|
||||
buf, len - 32, computed_mac ) ) != 0 )
|
||||
{
|
||||
return( ret );
|
||||
}
|
||||
|
||||
for( i = 0; i < 32; i++ )
|
||||
diff |= mac[i] ^ computed_mac[i];
|
||||
|
||||
/* Now return if ticket is not authentic, since we want to avoid
|
||||
* decrypting arbitrary attacker-chosen data */
|
||||
if( diff != 0 )
|
||||
return( MBEDTLS_ERR_SSL_INVALID_MAC );
|
||||
|
||||
/* Decrypt */
|
||||
if( ( ret = mbedtls_aes_crypt_cbc( &ssl->conf->ticket_keys->dec, MBEDTLS_AES_DECRYPT,
|
||||
enc_len, iv, ticket, ticket ) ) != 0 )
|
||||
{
|
||||
return( ret );
|
||||
}
|
||||
|
||||
/* Check PKCS padding */
|
||||
pad_len = ticket[enc_len - 1];
|
||||
|
||||
ret = 0;
|
||||
for( i = 2; i < pad_len; i++ )
|
||||
if( ticket[enc_len - i] != pad_len )
|
||||
ret = MBEDTLS_ERR_SSL_BAD_INPUT_DATA;
|
||||
if( ret != 0 )
|
||||
return( ret );
|
||||
|
||||
clear_len = enc_len - pad_len;
|
||||
|
||||
/* Actually load session */
|
||||
if( ( ret = ssl_load_session( &session, ticket, clear_len ) ) != 0 )
|
||||
{
|
||||
mbedtls_ssl_session_free( &session );
|
||||
return( ret );
|
||||
}
|
||||
|
||||
#if defined(MBEDTLS_HAVE_TIME)
|
||||
/* Check if still valid */
|
||||
if( (int) ( time( NULL) - session.start ) > ssl->conf->ticket_lifetime )
|
||||
{
|
||||
mbedtls_ssl_session_free( &session );
|
||||
return( MBEDTLS_ERR_SSL_SESSION_TICKET_EXPIRED );
|
||||
}
|
||||
#endif
|
||||
|
||||
/*
|
||||
* Keep the session ID sent by the client, since we MUST send it back to
|
||||
* inform him we're accepting the ticket (RFC 5077 section 3.4)
|
||||
*/
|
||||
session.length = ssl->session_negotiate->length;
|
||||
memcpy( &session.id, ssl->session_negotiate->id, session.length );
|
||||
|
||||
mbedtls_ssl_session_free( ssl->session_negotiate );
|
||||
memcpy( ssl->session_negotiate, &session, sizeof( mbedtls_ssl_session ) );
|
||||
|
||||
/* Zeroize instead of free as we copied the content */
|
||||
mbedtls_zeroize( &session, sizeof( mbedtls_ssl_session ) );
|
||||
|
||||
return( 0 );
|
||||
}
|
||||
|
||||
#endif /* MBEDTLS_SSL_TICKET_C */
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user