Adapt prototypes of ticket handling functions

This is an intermediate step. The ssl_config argument will be replace by a
ticket context next.
parent a4a47351
......@@ -31,12 +31,17 @@ extern "C" {
#endif
/* Temporary, WIP */
int mbedtls_ssl_ticket_write( mbedtls_ssl_context *ssl, size_t *tlen );
int mbedtls_ssl_ticket_write( const mbedtls_ssl_config *conf,
const mbedtls_ssl_session *session,
unsigned char *start,
const unsigned char *end,
size_t *tlen );
/* Temporary, WIP */
int mbedtls_ssl_ticket_parse( mbedtls_ssl_context *ssl,
unsigned char *buf,
size_t len );
int mbedtls_ssl_ticket_parse( const mbedtls_ssl_config *conf,
mbedtls_ssl_session *session,
unsigned char *buf,
size_t len );
#ifdef __cplusplus
}
......
......@@ -51,6 +51,11 @@
#if defined(MBEDTLS_SSL_SESSION_TICKETS)
#include "mbedtls/ssl_ticket.h"
/* Implementation that should never be optimized out by the compiler */
static void mbedtls_zeroize( void *v, size_t n ) {
volatile unsigned char *p = v; while( n-- ) *p++ = 0;
}
#endif
#if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY)
......@@ -406,6 +411,7 @@ static int ssl_parse_session_ticket_ext( mbedtls_ssl_context *ssl,
size_t len )
{
int ret;
mbedtls_ssl_session session;
if( ssl->conf->session_tickets == MBEDTLS_SSL_SESSION_TICKETS_DISABLED )
return( 0 );
......@@ -429,12 +435,27 @@ static int ssl_parse_session_ticket_ext( mbedtls_ssl_context *ssl,
/*
* Failures are ok: just ignore the ticket and proceed.
*/
if( ( ret = mbedtls_ssl_ticket_parse( ssl, buf, len ) ) != 0 )
if( ( ret = mbedtls_ssl_ticket_parse( ssl->conf, &session,
buf, len ) ) != 0 )
{
mbedtls_ssl_session_free( &session );
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_ticket_parse", ret );
return( 0 );
}
/*
* Keep the session ID sent by the client, since we MUST send it back to
* inform them 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 ) );
MBEDTLS_SSL_DEBUG_MSG( 3, ( "session successfully restored from ticket" ) );
ssl->handshake->resume = 1;
......@@ -3509,7 +3530,11 @@ static int ssl_write_new_session_ticket( mbedtls_ssl_context *ssl )
ssl->out_msg[6] = ( lifetime >> 8 ) & 0xFF;
ssl->out_msg[7] = ( lifetime ) & 0xFF;
if( ( ret = mbedtls_ssl_ticket_write( ssl, &tlen ) ) != 0 )
if( ( ret = mbedtls_ssl_ticket_write( ssl->conf,
ssl->session_negotiate,
ssl->out_msg + 10,
ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN,
&tlen ) ) != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_ticket_write", ret );
tlen = 0;
......
......@@ -39,11 +39,6 @@
#include <string.h>
/* Implementation that should never be optimized out by the compiler */
static void mbedtls_zeroize( void *v, size_t n ) {
volatile unsigned char *p = v; while( n-- ) *p++ = 0;
}
/*
* Serialize a session in the following format:
* 0 . n-1 session structure, n = sizeof(mbedtls_ssl_session)
......@@ -167,10 +162,13 @@ static int ssl_load_session( mbedtls_ssl_session *session,
*
* (the internal state structure differs, however).
*/
int mbedtls_ssl_ticket_write( mbedtls_ssl_context *ssl, size_t *tlen )
int mbedtls_ssl_ticket_write( const mbedtls_ssl_config *conf,
const mbedtls_ssl_session *session,
unsigned char *start,
const unsigned char *end,
size_t *tlen )
{
int ret;
unsigned char * const start = ssl->out_msg + 10;
unsigned char *p = start;
unsigned char *state;
unsigned char iv[16];
......@@ -178,32 +176,29 @@ int mbedtls_ssl_ticket_write( mbedtls_ssl_context *ssl, size_t *tlen )
*tlen = 0;
if( ssl->conf->ticket_keys == NULL )
if( conf->ticket_keys == NULL )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
/* We need at least 16 bytes for key_name, 16 for IV, 2 for len
* 16 for padding, 32 for MAC, in addition to session itself,
* that will be checked when writing it. */
if( end - start < 16 + 16 + 2 + 16 + 32 )
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
/* Write key name */
memcpy( p, ssl->conf->ticket_keys->key_name, 16 );
memcpy( p, 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 )
if( ( ret = conf->f_rng( 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
*/
/* Dump session state */
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 );
}
if( ssl_save_session( session, state, end - state, &clear_len ) != 0 )
return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );
/* Apply PKCS padding */
pad_len = 16 - clear_len % 16;
......@@ -212,7 +207,7 @@ int mbedtls_ssl_ticket_write( mbedtls_ssl_context *ssl, size_t *tlen )
state[i] = (unsigned char) pad_len;
/* Encrypt */
if( ( ret = mbedtls_aes_crypt_cbc( &ssl->conf->ticket_keys->enc, MBEDTLS_AES_ENCRYPT,
if( ( ret = mbedtls_aes_crypt_cbc( &conf->ticket_keys->enc, MBEDTLS_AES_ENCRYPT,
enc_len, iv, state, state ) ) != 0 )
{
return( ret );
......@@ -225,7 +220,7 @@ int mbedtls_ssl_ticket_write( mbedtls_ssl_context *ssl, size_t *tlen )
/* 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,
conf->ticket_keys->mac_key, 16,
start, p - start, p ) ) != 0 )
{
return( ret );
......@@ -240,12 +235,12 @@ int mbedtls_ssl_ticket_write( mbedtls_ssl_context *ssl, size_t *tlen )
/*
* 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 mbedtls_ssl_ticket_parse( const mbedtls_ssl_config *conf,
mbedtls_ssl_session *session,
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;
......@@ -255,7 +250,7 @@ int mbedtls_ssl_ticket_parse( mbedtls_ssl_context *ssl,
size_t enc_len, clear_len, i;
unsigned char pad_len, diff;
if( len < 34 || ssl->conf->ticket_keys == NULL )
if( len < 34 || conf->ticket_keys == NULL )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
enc_len = ( enc_len_p[0] << 8 ) | enc_len_p[1];
......@@ -267,12 +262,12 @@ int mbedtls_ssl_ticket_parse( mbedtls_ssl_context *ssl,
/* 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];
diff |= key_name[i] ^ 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,
conf->ticket_keys->mac_key, 16,
buf, len - 32, computed_mac ) ) != 0 )
{
return( ret );
......@@ -287,7 +282,7 @@ int mbedtls_ssl_ticket_parse( mbedtls_ssl_context *ssl,
return( MBEDTLS_ERR_SSL_INVALID_MAC );
/* Decrypt */
if( ( ret = mbedtls_aes_crypt_cbc( &ssl->conf->ticket_keys->dec, MBEDTLS_AES_DECRYPT,
if( ( ret = mbedtls_aes_crypt_cbc( &conf->ticket_keys->dec, MBEDTLS_AES_DECRYPT,
enc_len, iv, ticket, ticket ) ) != 0 )
{
return( ret );
......@@ -306,34 +301,15 @@ int mbedtls_ssl_ticket_parse( mbedtls_ssl_context *ssl,
clear_len = enc_len - pad_len;
/* Actually load session */
if( ( ret = ssl_load_session( &session, ticket, clear_len ) ) != 0 )
{
mbedtls_ssl_session_free( &session );
if( ( ret = ssl_load_session( session, ticket, clear_len ) ) != 0 )
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 );
if( (int) ( time( NULL) - session->start ) > conf->ticket_lifetime )
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 );
}
......
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