diff options
| -rw-r--r-- | src/libtls/tls.h | 6 | ||||
| -rw-r--r-- | src/libtls/tls_eap.c | 9 | ||||
| -rw-r--r-- | src/libtls/tls_fragmentation.c | 27 |
3 files changed, 23 insertions, 19 deletions
diff --git a/src/libtls/tls.h b/src/libtls/tls.h index e22b0facc..6b4876f73 100644 --- a/src/libtls/tls.h +++ b/src/libtls/tls.h @@ -26,6 +26,12 @@ #ifndef TLS_H_ #define TLS_H_ +/** + * Maximum size of a TLS fragment + * as defined by section 6.2.1. "Fragmentation" of RFC 5246 TLS 1.2 + */ +#define TLS_MAX_FRAGMENT_LEN 16384 + typedef enum tls_version_t tls_version_t; typedef enum tls_content_type_t tls_content_type_t; typedef enum tls_handshake_type_t tls_handshake_type_t; diff --git a/src/libtls/tls_eap.c b/src/libtls/tls_eap.c index 613431822..e84da7061 100644 --- a/src/libtls/tls_eap.c +++ b/src/libtls/tls_eap.c @@ -21,8 +21,11 @@ #include <debug.h> #include <library.h> -/** Size limit for a single TLS message */ -#define MAX_TLS_MESSAGE_LEN 65536 +/** + * Size limit for a TLS message allowing for worst-case protection overhead + * according to section 6.2.3. "Payload Protection" of RFC 5246 TLS 1.2 + */ +#define TLS_MAX_MESSAGE_LEN 4 * (TLS_MAX_FRAGMENT_LEN + 2048) typedef struct private_tls_eap_t private_tls_eap_t; @@ -165,7 +168,7 @@ static status_t process_pkt(private_tls_eap_t *this, eap_tls_packet_t *pkt) } msg_len = untoh32(pkt + 1); if (msg_len < pkt_len - sizeof(eap_tls_packet_t) - sizeof(msg_len) || - msg_len > MAX_TLS_MESSAGE_LEN) + msg_len > TLS_MAX_MESSAGE_LEN) { DBG1(DBG_TLS, "invalid %N packet length (%u bytes)", eap_type_names, this->type, msg_len); diff --git a/src/libtls/tls_fragmentation.c b/src/libtls/tls_fragmentation.c index 62e36aaec..eb9976884 100644 --- a/src/libtls/tls_fragmentation.c +++ b/src/libtls/tls_fragmentation.c @@ -18,6 +18,11 @@ #include <bio/bio_reader.h> #include <debug.h> +/** + * Maximum size of a TLS handshake message we accept + */ +#define TLS_MAX_HANDSHAKE_LEN 65536 + typedef struct private_tls_fragmentation_t private_tls_fragmentation_t; /** @@ -94,16 +99,6 @@ struct private_tls_fragmentation_t { }; /** - * Maximum size of a TLS fragment - */ -#define MAX_TLS_FRAGMENT_LEN 16384 - -/** - * Maximum size of a TLS handshake message we accept - */ -#define MAX_TLS_HANDSHAKE_LEN 65536 - -/** * Process a TLS alert */ static status_t process_alert(private_tls_fragmentation_t *this, @@ -134,7 +129,7 @@ static status_t process_handshake(private_tls_fragmentation_t *this, status_t status; chunk_t data; - if (reader->remaining(reader) > MAX_TLS_FRAGMENT_LEN) + if (reader->remaining(reader) > TLS_MAX_FRAGMENT_LEN) { DBG1(DBG_TLS, "TLS fragment has invalid length"); this->alert->add(this->alert, TLS_FATAL, TLS_DECODE_ERROR); @@ -151,7 +146,7 @@ static status_t process_handshake(private_tls_fragmentation_t *this, return NEED_MORE; } this->type = type; - if (len > MAX_TLS_HANDSHAKE_LEN) + if (len > TLS_MAX_HANDSHAKE_LEN) { DBG1(DBG_TLS, "TLS handshake exceeds maximum length"); this->alert->add(this->alert, TLS_FATAL, TLS_DECODE_ERROR); @@ -207,7 +202,7 @@ static status_t process_application(private_tls_fragmentation_t *this, status_t status; chunk_t data; - if (reader->remaining(reader) > MAX_TLS_FRAGMENT_LEN) + if (reader->remaining(reader) > TLS_MAX_FRAGMENT_LEN) { DBG1(DBG_TLS, "TLS fragment has invalid length"); this->alert->add(this->alert, TLS_FATAL, TLS_DECODE_ERROR); @@ -427,14 +422,14 @@ METHOD(tls_fragmentation_t, build, status_t, if (this->output.len) { *type = this->output_type; - if (this->output.len <= MAX_TLS_FRAGMENT_LEN) + if (this->output.len <= TLS_MAX_FRAGMENT_LEN) { *data = this->output; this->output = chunk_empty; return NEED_MORE; } - *data = chunk_create(this->output.ptr, MAX_TLS_FRAGMENT_LEN); - this->output = chunk_clone(chunk_skip(this->output, MAX_TLS_FRAGMENT_LEN)); + *data = chunk_create(this->output.ptr, TLS_MAX_FRAGMENT_LEN); + this->output = chunk_clone(chunk_skip(this->output, TLS_MAX_FRAGMENT_LEN)); return NEED_MORE; } return status; |