Fix length checking of various ClientKeyExchange's

parent 96d52653
PolarSSL ChangeLog (Sorted per branch, date)
= PolarSSL 1.3 branch
Bugfix
* The length of various ClientKeyExchange messages was not properly checked.
= PolarSSL 1.3.5 released on 2014-03-26
Features
* HMAC-DRBG as a separate module
......
......@@ -218,10 +218,19 @@ int ecdh_make_public( ecdh_context *ctx, size_t *olen,
int ecdh_read_public( ecdh_context *ctx,
const unsigned char *buf, size_t blen )
{
int ret;
const unsigned char *p = buf;
if( ctx == NULL )
return( POLARSSL_ERR_ECP_BAD_INPUT_DATA );
return ecp_tls_read_point( &ctx->grp, &ctx->Qp, &buf, blen );
if( ( ret = ecp_tls_read_point( &ctx->grp, &ctx->Qp, &p, blen ) ) != 0 )
return( ret );
if( (size_t)( p - buf ) != blen )
return( POLARSSL_ERR_ECP_BAD_INPUT_DATA );
return( 0 );
}
/*
......
......@@ -2394,19 +2394,20 @@ static int ssl_parse_client_dh_public( ssl_context *ssl, unsigned char **p,
n = ( (*p)[0] << 8 ) | (*p)[1];
*p += 2;
if( n < 1 || n > ssl->handshake->dhm_ctx.len || *p + n > end )
if( *p + n > end )
{
SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
}
if( ( ret = dhm_read_public( &ssl->handshake->dhm_ctx,
*p, n ) ) != 0 )
if( ( ret = dhm_read_public( &ssl->handshake->dhm_ctx, *p, n ) ) != 0 )
{
SSL_DEBUG_RET( 1, "dhm_read_public", ret );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE_RP );
}
*p += n;
SSL_DEBUG_MPI( 3, "DHM: GY", &ssl->handshake->dhm_ctx.GY );
return( ret );
......@@ -2583,7 +2584,7 @@ static int ssl_parse_client_key_exchange( ssl_context *ssl )
if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_RSA )
{
unsigned char *p = ssl->in_msg + 4;
unsigned char *end = ssl->in_msg + ssl->in_msglen;
unsigned char *end = ssl->in_msg + ssl->in_hslen;
if( ( ret = ssl_parse_client_dh_public( ssl, &p, end ) ) != 0 )
{
......@@ -2591,6 +2592,12 @@ static int ssl_parse_client_key_exchange( ssl_context *ssl )
return( ret );
}
if( p != end )
{
SSL_DEBUG_MSG( 1, ( "bad client key exchange" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
}
ssl->handshake->pmslen = ssl->handshake->dhm_ctx.len;
if( ( ret = dhm_calc_secret( &ssl->handshake->dhm_ctx,
......@@ -2615,17 +2622,8 @@ static int ssl_parse_client_key_exchange( ssl_context *ssl )
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDH_RSA ||
ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDH_ECDSA )
{
size_t n = ssl->in_msg[3];
if( n < 1 || n > mpi_size( &ssl->handshake->ecdh_ctx.grp.P ) * 2 + 2 ||
n + 4 != ssl->in_hslen )
{
SSL_DEBUG_MSG( 1, ( "bad client key exchange message" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
}
if( ( ret = ecdh_read_public( &ssl->handshake->ecdh_ctx,
ssl->in_msg + 4, n ) ) != 0 )
ssl->in_msg + 4, ssl->in_hslen - 4 ) ) != 0 )
{
SSL_DEBUG_RET( 1, "ecdh_read_public", ret );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE_RP );
......@@ -2654,7 +2652,7 @@ static int ssl_parse_client_key_exchange( ssl_context *ssl )
if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_PSK )
{
unsigned char *p = ssl->in_msg + 4;
unsigned char *end = ssl->in_msg + ssl->in_msglen;
unsigned char *end = ssl->in_msg + ssl->in_hslen;
if( ( ret = ssl_parse_client_psk_identity( ssl, &p, end ) ) != 0 )
{
......@@ -2662,6 +2660,12 @@ static int ssl_parse_client_key_exchange( ssl_context *ssl )
return( ret );
}
if( p != end )
{
SSL_DEBUG_MSG( 1, ( "bad client key exchange" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
}
if( ( ret = ssl_psk_derive_premaster( ssl,
ciphersuite_info->key_exchange ) ) != 0 )
{
......@@ -2675,7 +2679,7 @@ static int ssl_parse_client_key_exchange( ssl_context *ssl )
if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_RSA_PSK )
{
unsigned char *p = ssl->in_msg + 4;
unsigned char *end = ssl->in_msg + ssl->in_msglen;
unsigned char *end = ssl->in_msg + ssl->in_hslen;
if( ( ret = ssl_parse_client_psk_identity( ssl, &p, end ) ) != 0 )
{
......@@ -2702,7 +2706,7 @@ static int ssl_parse_client_key_exchange( ssl_context *ssl )
if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_DHE_PSK )
{
unsigned char *p = ssl->in_msg + 4;
unsigned char *end = ssl->in_msg + ssl->in_msglen;
unsigned char *end = ssl->in_msg + ssl->in_hslen;
if( ( ret = ssl_parse_client_psk_identity( ssl, &p, end ) ) != 0 )
{
......@@ -2715,6 +2719,12 @@ static int ssl_parse_client_key_exchange( ssl_context *ssl )
return( ret );
}
if( p != end )
{
SSL_DEBUG_MSG( 1, ( "bad client key exchange" ) );
return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE );
}
if( ( ret = ssl_psk_derive_premaster( ssl,
ciphersuite_info->key_exchange ) ) != 0 )
{
......@@ -2728,7 +2738,7 @@ static int ssl_parse_client_key_exchange( ssl_context *ssl )
if( ciphersuite_info->key_exchange == POLARSSL_KEY_EXCHANGE_ECDHE_PSK )
{
unsigned char *p = ssl->in_msg + 4;
unsigned char *end = ssl->in_msg + ssl->in_msglen;
unsigned char *end = ssl->in_msg + ssl->in_hslen;
if( ( ret = ssl_parse_client_psk_identity( ssl, &p, end ) ) != 0 )
{
......@@ -2759,10 +2769,10 @@ static int ssl_parse_client_key_exchange( ssl_context *ssl )
{
if( ( ret = ssl_parse_encrypted_pms( ssl,
ssl->in_msg + 4,
ssl->in_msg + ssl->in_msglen,
ssl->in_msg + ssl->in_hslen,
0 ) ) != 0 )
{
SSL_DEBUG_RET( 1, ( "ssl_parse_parse_ecrypted_pms_secret" ), ret );
SSL_DEBUG_RET( 1, ( "ssl_parse_parse_encrypted_pms_secret" ), ret );
return( ret );
}
}
......
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