Merge branch 'development' into development-restricted
* development:
Updated ChangeLog with credit
Fix a fairly common typo in comments
Make config check include for configs examples more consistent
diff --git a/ChangeLog b/ChangeLog
index 68b1255..7310f3e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -2,7 +2,13 @@
= mbed TLS 2.1.2 released 2015-10-xx
+Security
+ * Added fix for CVE-2015-xxxxx to prevent heap corruption due to buffer
+ overflow of the hostname or session ticket.
+
Changes
+ * Added checking of hostname length in mbedtls_ssl_set_hostname() to ensure
+ domain names are compliant with RFC 1035.
* Fixed paths for check_config.h in example config files. (Found by bachp)
(#291)
diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
index d23b1be..a017ec0 100644
--- a/include/mbedtls/ssl.h
+++ b/include/mbedtls/ssl.h
@@ -139,6 +139,8 @@
#define MBEDTLS_SSL_TRANSPORT_STREAM 0 /*!< TLS */
#define MBEDTLS_SSL_TRANSPORT_DATAGRAM 1 /*!< DTLS */
+#define MBEDTLS_SSL_MAX_HOST_NAME_LEN 255 /*!< Maximum host name defined in RFC 1035 */
+
/* RFC 6066 section 4, see also mfl_code_to_length in ssl_tls.c
* NONE must be zero so that memset()ing structure to zero works */
#define MBEDTLS_SSL_MAX_FRAG_LEN_NONE 0 /*!< don't use this extension */
diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index c82e2e7..32eae0f 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -60,6 +60,7 @@
size_t *olen )
{
unsigned char *p = buf;
+ const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN;
size_t hostname_len;
*olen = 0;
@@ -72,6 +73,12 @@
hostname_len = strlen( ssl->hostname );
+ if( end < p || (size_t)( end - p ) < hostname_len + 9 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
+ return;
+ }
+
/*
* struct {
* NameType name_type;
@@ -115,6 +122,7 @@
size_t *olen )
{
unsigned char *p = buf;
+ const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN;
*olen = 0;
@@ -123,6 +131,12 @@
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding renegotiation extension" ) );
+ if( end < p || (size_t)( end - p ) < 5 + ssl->verify_data_len )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
+ return;
+ }
+
/*
* Secure renegotiation
*/
@@ -149,6 +163,7 @@
size_t *olen )
{
unsigned char *p = buf;
+ const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN;
size_t sig_alg_len = 0;
const int *md;
#if defined(MBEDTLS_RSA_C) || defined(MBEDTLS_ECDSA_C)
@@ -162,9 +177,27 @@
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding signature_algorithms extension" ) );
+ for( md = ssl->conf->sig_hashes; *md != MBEDTLS_MD_NONE; md++ )
+ {
+#if defined(MBEDTLS_ECDSA_C)
+ sig_alg_len += 2;
+#endif
+#if defined(MBEDTLS_RSA_C)
+ sig_alg_len += 2;
+#endif
+ }
+
+ if( end < p || (size_t)( end - p ) < sig_alg_len + 6 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
+ return;
+ }
+
/*
* Prepare signature_algorithms extension (TLS 1.2)
*/
+ sig_alg_len = 0;
+
for( md = ssl->conf->sig_hashes; *md != MBEDTLS_MD_NONE; md++ )
{
#if defined(MBEDTLS_ECDSA_C)
@@ -214,6 +247,7 @@
size_t *olen )
{
unsigned char *p = buf;
+ const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN;
unsigned char *elliptic_curve_list = p + 6;
size_t elliptic_curve_len = 0;
const mbedtls_ecp_curve_info *info;
@@ -235,6 +269,25 @@
for( info = mbedtls_ecp_curve_list(); info->grp_id != MBEDTLS_ECP_DP_NONE; info++ )
{
#endif
+ elliptic_curve_len += 2;
+ }
+
+ if( end < p || (size_t)( end - p ) < 6 + elliptic_curve_len )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
+ return;
+ }
+
+ elliptic_curve_len = 0;
+
+#if defined(MBEDTLS_ECP_C)
+ for( grp_id = ssl->conf->curve_list; *grp_id != MBEDTLS_ECP_DP_NONE; grp_id++ )
+ {
+ info = mbedtls_ecp_curve_info_from_grp_id( *grp_id );
+#else
+ for( info = mbedtls_ecp_curve_list(); info->grp_id != MBEDTLS_ECP_DP_NONE; info++ )
+ {
+#endif
elliptic_curve_list[elliptic_curve_len++] = info->tls_id >> 8;
elliptic_curve_list[elliptic_curve_len++] = info->tls_id & 0xFF;
@@ -260,12 +313,18 @@
size_t *olen )
{
unsigned char *p = buf;
- ((void) ssl);
+ const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN;
*olen = 0;
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding supported_point_formats extension" ) );
+ if( end < p || (size_t)( end - p ) < 6 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
+ return;
+ }
+
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS ) & 0xFF );
@@ -285,14 +344,22 @@
size_t *olen )
{
unsigned char *p = buf;
+ const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN;
+
+ *olen = 0;
if( ssl->conf->mfl_code == MBEDTLS_SSL_MAX_FRAG_LEN_NONE ) {
- *olen = 0;
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding max_fragment_length extension" ) );
+ if( end < p || (size_t)( end - p ) < 5 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
+ return;
+ }
+
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH ) & 0xFF );
@@ -310,15 +377,23 @@
unsigned char *buf, size_t *olen )
{
unsigned char *p = buf;
+ const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN;
+
+ *olen = 0;
if( ssl->conf->trunc_hmac == MBEDTLS_SSL_TRUNC_HMAC_DISABLED )
{
- *olen = 0;
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding truncated_hmac extension" ) );
+ if( end < p || (size_t)( end - p ) < 4 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
+ return;
+ }
+
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_TRUNCATED_HMAC >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_TRUNCATED_HMAC ) & 0xFF );
@@ -334,17 +409,25 @@
unsigned char *buf, size_t *olen )
{
unsigned char *p = buf;
+ const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN;
+
+ *olen = 0;
if( ssl->conf->encrypt_then_mac == MBEDTLS_SSL_ETM_DISABLED ||
ssl->conf->max_minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
{
- *olen = 0;
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding encrypt_then_mac "
"extension" ) );
+ if( end < p || (size_t)( end - p ) < 4 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
+ return;
+ }
+
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC ) & 0xFF );
@@ -360,17 +443,25 @@
unsigned char *buf, size_t *olen )
{
unsigned char *p = buf;
+ const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN;
+
+ *olen = 0;
if( ssl->conf->extended_ms == MBEDTLS_SSL_EXTENDED_MS_DISABLED ||
ssl->conf->max_minor_ver == MBEDTLS_SSL_MINOR_VERSION_0 )
{
- *olen = 0;
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding extended_master_secret "
"extension" ) );
+ if( end < p || (size_t)( end - p ) < 4 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
+ return;
+ }
+
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET ) & 0xFF );
@@ -386,16 +477,24 @@
unsigned char *buf, size_t *olen )
{
unsigned char *p = buf;
+ const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN;
size_t tlen = ssl->session_negotiate->ticket_len;
+ *olen = 0;
+
if( ssl->conf->session_tickets == MBEDTLS_SSL_SESSION_TICKETS_DISABLED )
{
- *olen = 0;
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding session ticket extension" ) );
+ if( end < p || (size_t)( end - p ) < 4 + tlen )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
+ return;
+ }
+
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SESSION_TICKET >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SESSION_TICKET ) & 0xFF );
@@ -404,8 +503,7 @@
*olen = 4;
- if( ssl->session_negotiate->ticket == NULL ||
- ssl->session_negotiate->ticket_len == 0 )
+ if( ssl->session_negotiate->ticket == NULL || tlen == 0 )
{
return;
}
@@ -423,16 +521,28 @@
unsigned char *buf, size_t *olen )
{
unsigned char *p = buf;
+ const unsigned char *end = ssl->out_msg + MBEDTLS_SSL_MAX_CONTENT_LEN;
+ size_t alpnlen = 0;
const char **cur;
+ *olen = 0;
+
if( ssl->conf->alpn_list == NULL )
{
- *olen = 0;
return;
}
MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding alpn extension" ) );
+ for( cur = ssl->conf->alpn_list; *cur != NULL; cur++ )
+ alpnlen += (unsigned char)( strlen( *cur ) & 0xFF ) + 1;
+
+ if( end < p || (size_t)( end - p ) < 6 + alpnlen )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 1, ( "buffer too small" ) );
+ return;
+ }
+
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ALPN >> 8 ) & 0xFF );
*p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_ALPN ) & 0xFF );
@@ -799,13 +909,13 @@
ext_len += olen;
#endif
-#if defined(MBEDTLS_SSL_SESSION_TICKETS)
- ssl_write_session_ticket_ext( ssl, p + 2 + ext_len, &olen );
+#if defined(MBEDTLS_SSL_ALPN)
+ ssl_write_alpn_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
#endif
-#if defined(MBEDTLS_SSL_ALPN)
- ssl_write_alpn_ext( ssl, p + 2 + ext_len, &olen );
+#if defined(MBEDTLS_SSL_SESSION_TICKETS)
+ ssl_write_session_ticket_ext( ssl, p + 2 + ext_len, &olen );
ext_len += olen;
#endif
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 9213290..71c99d3 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -5833,6 +5833,9 @@
if( hostname_len + 1 == 0 )
return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
+ if( hostname_len > MBEDTLS_SSL_MAX_HOST_NAME_LEN )
+ return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
+
ssl->hostname = mbedtls_calloc( 1, hostname_len + 1 );
if( ssl->hostname == NULL )