Fix length checking of various ClientKeyExchange's
diff --git a/library/ecdh.c b/library/ecdh.c
index cd65690..e35602d 100644
--- a/library/ecdh.c
+++ b/library/ecdh.c
@@ -218,10 +218,19 @@
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 );
}
/*
diff --git a/library/ssl_srv.c b/library/ssl_srv.c
index 0241b43..16fb264 100644
--- a/library/ssl_srv.c
+++ b/library/ssl_srv.c
@@ -2394,19 +2394,20 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
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 @@
{
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 );
}
}