AuroraMiddleware/mbedtls
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Merge branch 'truncated-hmac' into development

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This commit is contained in:
Paul Bakker 2013-07-19 14:52:07 +02:00
commit 872c29b705
5 changed files with 157 additions and 0 deletions
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21
include/polarssl/ssl.h
View File

@ -148,6 +148,10 @@
#define SSL_LEGACY_ALLOW_RENEGOTIATION 1
#define SSL_LEGACY_BREAK_HANDSHAKE 2
#define SSL_TRUNC_HMAC_DISABLED 0
#define SSL_TRUNC_HMAC_ENABLED 1
#define SSL_TRUNCATED_HMAC_LEN 10 /* 80 bits, rfc 6066 section 7 */
/*
* Size of the input / output buffer.
* Note: the RFC defines the default size of SSL / TLS messages. If you
@ -251,6 +255,8 @@
#define TLS_EXT_MAX_FRAGMENT_LENGTH 1
#define TLS_EXT_TRUNCATED_HMAC 4
#define TLS_EXT_SUPPORTED_ELLIPTIC_CURVES 10
#define TLS_EXT_SUPPORTED_POINT_FORMATS 11
@ -333,6 +339,7 @@ struct _ssl_session
#endif /* POLARSSL_X509_PARSE_C */
unsigned char mfl_code; /*!< MaxFragmentLength negotiated by peer */
int trunc_hmac; /*!< flag for truncated hmac activation */
};
/*
@ -540,6 +547,7 @@ struct _ssl_context
int disable_renegotiation; /*!< enable/disable renegotiation */
int allow_legacy_renegotiation; /*!< allow legacy renegotiation */
const int *ciphersuite_list[4]; /*!< allowed ciphersuites / version */
int trunc_hmac; /*!< negotiate truncated hmac? */
#if defined(POLARSSL_DHM_C)
mpi dhm_P; /*!< prime modulus for DHM */
@ -976,6 +984,19 @@ void ssl_set_min_version( ssl_context *ssl, int major, int minor );
*/
int ssl_set_max_frag_len( ssl_context *ssl, unsigned char mfl_code );
/**
* \brief Activate negotiation of truncated HMAC (Client only)
* (Default: SSL_TRUNC_HMAC_ENABLED)
*
* \param ssl SSL context
* \param truncate Enable or disable (SSL_TRUNC_HMAC_ENABLED or
* SSL_TRUNC_HMAC_DISABLED)
*
* \return O if successful,
* POLARSSL_ERR_SSL_BAD_INPUT_DATA if used server-side
*/
int ssl_set_truncated_hmac( ssl_context *ssl, int truncate );
/**
* \brief Enable / Disable renegotiation support for connection when
* initiated by peer

54
library/ssl_cli.c
View File

@ -293,6 +293,28 @@ static void ssl_write_max_fragment_length_ext( ssl_context *ssl,
*olen = 5;
}
static void ssl_write_truncated_hmac_ext( ssl_context *ssl,
unsigned char *buf, size_t *olen )
{
unsigned char *p = buf;
if( ssl->trunc_hmac == SSL_TRUNC_HMAC_DISABLED )
{
*olen = 0;
return;
}
SSL_DEBUG_MSG( 3, ( "client hello, adding truncated_hmac extension" ) );
*p++ = (unsigned char)( ( TLS_EXT_TRUNCATED_HMAC >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( TLS_EXT_TRUNCATED_HMAC ) & 0xFF );
*p++ = 0x00;
*p++ = 0x00;
*olen = 4;
}
static int ssl_write_client_hello( ssl_context *ssl )
{
int ret;
@ -463,6 +485,9 @@ static int ssl_write_client_hello( ssl_context *ssl )
ssl_write_max_fragment_length_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
ssl_write_truncated_hmac_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
SSL_DEBUG_MSG( 3, ( "client hello, total extension length: %d",
ext_len ) );
@ -526,6 +551,7 @@ static int ssl_parse_renegotiation_info( ssl_context *ssl,
return( 0 );
}
static int ssl_parse_max_fragment_length_ext( ssl_context *ssl,
const unsigned char *buf,
size_t len )
@ -544,6 +570,23 @@ static int ssl_parse_max_fragment_length_ext( ssl_context *ssl,
return( 0 );
}
static int ssl_parse_truncated_hmac_ext( ssl_context *ssl,
const unsigned char *buf,
size_t len )
{
if( ssl->trunc_hmac == SSL_TRUNC_HMAC_DISABLED ||
len != 0 )
{
return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO );
}
((void) buf);
ssl->session_negotiate->trunc_hmac = SSL_TRUNC_HMAC_ENABLED;
return( 0 );
}
static int ssl_parse_server_hello( ssl_context *ssl )
{
uint32_t t;
@ -771,6 +814,17 @@ static int ssl_parse_server_hello( ssl_context *ssl )
break;
case TLS_EXT_TRUNCATED_HMAC:
SSL_DEBUG_MSG( 3, ( "found truncated_hmac extension" ) );
if( ( ret = ssl_parse_truncated_hmac_ext( ssl,
ext + 4, ext_size ) ) != 0 )
{
return( ret );
}
break;
default:
SSL_DEBUG_MSG( 3, ( "unknown extension found: %d (ignoring)",
ext_id ) );

51
library/ssl_srv.c
View File

@ -306,6 +306,23 @@ static int ssl_parse_max_fragment_length_ext( ssl_context *ssl,
return( 0 );
}
static int ssl_parse_truncated_hmac_ext( ssl_context *ssl,
const unsigned char *buf,
size_t len )
{
if( len != 0 )
{
SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
}
((void) buf);
ssl->session_negotiate->trunc_hmac = SSL_TRUNC_HMAC_ENABLED;
return( 0 );
}
#if defined(POLARSSL_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO)
static int ssl_parse_client_hello_v2( ssl_context *ssl )
{
@ -848,6 +865,14 @@ static int ssl_parse_client_hello( ssl_context *ssl )
return( ret );
break;
case TLS_EXT_TRUNCATED_HMAC:
SSL_DEBUG_MSG( 3, ( "found truncated hmac extension" ) );
ret = ssl_parse_truncated_hmac_ext( ssl, ext + 4, ext_size );
if( ret != 0 )
return( ret );
break;
default:
SSL_DEBUG_MSG( 3, ( "unknown extension found: %d (ignoring)",
ext_id ) );
@ -957,6 +982,29 @@ have_ciphersuite:
return( 0 );
}
static void ssl_write_truncated_hmac_ext( ssl_context *ssl,
unsigned char *buf,
size_t *olen )
{
unsigned char *p = buf;
if( ssl->session_negotiate->trunc_hmac == SSL_TRUNC_HMAC_DISABLED )
{
*olen = 0;
return;
}
SSL_DEBUG_MSG( 3, ( "server hello, adding truncated hmac extension" ) );
*p++ = (unsigned char)( ( TLS_EXT_TRUNCATED_HMAC >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( TLS_EXT_TRUNCATED_HMAC ) & 0xFF );
*p++ = 0x00;
*p++ = 0x00;
*olen = 4;
}
static void ssl_write_renegotiation_ext( ssl_context *ssl,
unsigned char *buf,
size_t *olen )
@ -1128,6 +1176,9 @@ static int ssl_write_server_hello( ssl_context *ssl )
ssl_write_max_fragment_length_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
ssl_write_truncated_hmac_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
SSL_DEBUG_MSG( 3, ( "server hello, total extension length: %d", ext_len ) );
*p++ = (unsigned char)( ( ext_len >> 8 ) & 0xFF );

18
library/ssl_tls.c
View File

@ -475,6 +475,14 @@ int ssl_derive_keys( ssl_context *ssl )
}
transform->maclen = md_get_size( md_info );
/*
* If HMAC is to be truncated, we shall keep the leftmost bytes,
* (rfc 6066 page 13 or rfc 2104 section 4),
* so we only need to adjust the length here.
*/
if( session->trunc_hmac == SSL_TRUNC_HMAC_ENABLED )
transform->maclen = SSL_TRUNCATED_HMAC_LEN;
}
transform->keylen = cipher_info->key_length;
@ -3141,6 +3149,16 @@ int ssl_set_max_frag_len( ssl_context *ssl, unsigned char mfl_code )
return( 0 );
}
int ssl_set_truncated_hmac( ssl_context *ssl, int truncate )
{
if( ssl->endpoint != SSL_IS_CLIENT )
return( POLARSSL_ERR_SSL_BAD_INPUT_DATA );
ssl->trunc_hmac = truncate;
return( 0 );
}
void ssl_set_renegotiation( ssl_context *ssl, int renegotiation )
{
ssl->disable_renegotiation = renegotiation;

13
programs/ssl/ssl_client2.c
View File

@ -58,6 +58,7 @@
#define DFL_MAX_VERSION -1
#define DFL_AUTH_MODE SSL_VERIFY_OPTIONAL
#define DFL_MFL_CODE SSL_MAX_FRAG_LEN_NONE
#define DFL_TRUNC_HMAC 0
#define LONG_HEADER "User-agent: blah-blah-blah-blah-blah-blah-blah-blah-" \
"-01--blah-blah-blah-blah-blah-blah-blah-blah-blah-blah-blah-blah-blah-" \
@ -94,6 +95,7 @@ struct options
int max_version; /* maximum protocol version accepted */
int auth_mode; /* verify mode for connection */
unsigned char mfl_code; /* code for maximum fragment length */
int trunc_hmac; /* negotiate truncated hmac or not */
} opt;
static void my_debug( void *ctx, int level, const char *str )
@ -191,6 +193,7 @@ static int my_verify( void *data, x509_cert *crt, int depth, int *flags )
" options: none, optional, required\n" \
" max_frag_len=%%d default: 16384 (tls default)" \
" options: 512, 1024, 2048, 4096" \
" trunc_hmac=%%d default: 0 (disabled)\n" \
USAGE_PSK \
"\n" \
" force_ciphersuite=<name> default: all enabled\n"\
@ -281,6 +284,7 @@ int main( int argc, char *argv[] )
opt.max_version = DFL_MAX_VERSION;
opt.auth_mode = DFL_AUTH_MODE;
opt.mfl_code = DFL_MFL_CODE;
opt.trunc_hmac = DFL_TRUNC_HMAC;
for( i = 1; i < argc; i++ )
{
@ -416,6 +420,12 @@ int main( int argc, char *argv[] )
else
goto usage;
}
else if( strcmp( p, "trunc_hmac" ) == 0 )
{
opt.trunc_hmac = atoi( q );
if( opt.trunc_hmac < 0 || opt.trunc_hmac > 1 )
goto usage;
}
else
goto usage;
}
@ -623,6 +633,9 @@ int main( int argc, char *argv[] )
ssl_set_max_frag_len( &ssl, opt.mfl_code );
if( opt.trunc_hmac != 0 )
ssl_set_truncated_hmac( &ssl, SSL_TRUNC_HMAC_ENABLED );
ssl_set_rng( &ssl, ctr_drbg_random, &ctr_drbg );
ssl_set_dbg( &ssl, my_debug, stdout );
ssl_set_bio( &ssl, net_recv, &server_fd,