Add peer CRT digest to session tickets
This commit changes the format of session tickets to include
the digest of the peer's CRT if MBEDTLS_SSL_KEEP_PEER_CERTIFICATE
is disabled.
This commit does not yet remove the peer CRT itself.
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index c682166..5e39579 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -9023,6 +9023,12 @@
#define SSL_SERIALIZED_SESSION_CONFIG_TICKET 0
#endif /* MBEDTLS_SSL_SESSION_TICKETS */
+#if defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
+#define SSL_SERIALIZED_SESSION_CONFIG_KEEP_CRT 1
+#else
+#define SSL_SERIALIZED_SESSION_CONFIG_KEEP_CRT 0
+#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
+
#define SSL_SERIALIZED_SESSION_CONFIG_TIME_BIT 0
#define SSL_SERIALIZED_SESSION_CONFIG_CRT_BIT 1
#define SSL_SERIALIZED_SESSION_CONFIG_CLIENT_TICKET_BIT 2
@@ -9030,6 +9036,7 @@
#define SSL_SERIALIZED_SESSION_CONFIG_TRUNC_HMAC_BIT 4
#define SSL_SERIALIZED_SESSION_CONFIG_ETM_BIT 5
#define SSL_SERIALIZED_SESSION_CONFIG_TICKET_BIT 6
+#define SSL_SERIALIZED_SESSION_CONFIG_KEEP_CRT_BIT 7
#define SSL_SERIALIZED_SESSION_CONFIG_BITFLAG \
( (uint16_t) ( \
@@ -9039,7 +9046,8 @@
( SSL_SERIALIZED_SESSION_CONFIG_MFL << SSL_SERIALIZED_SESSION_CONFIG_MFL_BIT ) | \
( SSL_SERIALIZED_SESSION_CONFIG_TRUNC_HMAC << SSL_SERIALIZED_SESSION_CONFIG_TRUNC_HMAC_BIT ) | \
( SSL_SERIALIZED_SESSION_CONFIG_ETM << SSL_SERIALIZED_SESSION_CONFIG_ETM_BIT ) | \
- ( SSL_SERIALIZED_SESSION_CONFIG_TICKET << SSL_SERIALIZED_SESSION_CONFIG_TICKET_BIT ) ) )
+ ( SSL_SERIALIZED_SESSION_CONFIG_TICKET << SSL_SERIALIZED_SESSION_CONFIG_TICKET_BIT ) | \
+ ( SSL_SERIALIZED_SESSION_CONFIG_KEEP_CRT << SSL_SERIALIZED_SESSION_CONFIG_KEEP_CRT_BIT ) ) )
static unsigned char ssl_serialized_session_header[] = {
MBEDTLS_VERSION_MAJOR,
@@ -9073,6 +9081,8 @@
* opaque master[48]; // fixed length in the standard
* uint32 verify_result;
* opaque peer_cert<0..2^24-1>; // length 0 means no peer cert
+ * uint8_t peer_cert_digest_type;
+ * opaque peer_cert_digest<0..2^8-1>;
* opaque ticket<0..2^24-1>; // length 0 means no ticket
* uint32 ticket_lifetime;
* uint8 mfl_code; // up to 255 according to standard
@@ -9184,6 +9194,31 @@
p += cert_len;
}
}
+
+ /* Digest of peer certificate */
+#if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
+ if( session->peer_cert_digest != NULL )
+ {
+ used += 1 /* type */ + 1 /* length */ + session->peer_cert_digest_len;
+ if( used <= buf_len )
+ {
+ *p++ = (unsigned char) session->peer_cert_digest_type;
+ *p++ = (unsigned char) session->peer_cert_digest_len;
+ memcpy( p, session->peer_cert_digest,
+ session->peer_cert_digest_len );
+ p += session->peer_cert_digest_len;
+ }
+ }
+ else
+ {
+ used += 2;
+ if( used <= buf_len )
+ {
+ *p++ = (unsigned char) MBEDTLS_MD_NONE;
+ *p++ = 0;
+ }
+ }
+#endif /* !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
#endif /* MBEDTLS_X509_CRT_PARSE_C */
/*
@@ -9325,6 +9360,9 @@
* we exit early before we replaced them with valid ones. */
#if defined(MBEDTLS_X509_CRT_PARSE_C)
session->peer_cert = NULL;
+#if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
+ session->peer_cert_digest = NULL;
+#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
#endif
#if defined(MBEDTLS_SSL_SESSION_TICKETS) && defined(MBEDTLS_SSL_CLI_C)
session->ticket = NULL;
@@ -9369,6 +9407,30 @@
p += cert_len;
}
+
+#if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
+ /* Deserialize CRT digest from the end of the ticket. */
+ if( 2 > (size_t)( end - p ) )
+ return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
+
+ session->peer_cert_digest_type = (mbedtls_md_type_t) *p++;
+ session->peer_cert_digest_len = (size_t) *p++;
+
+ if( session->peer_cert_digest_len != 0 )
+ {
+ if( session->peer_cert_digest_len > (size_t)( end - p ) )
+ return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
+
+ session->peer_cert_digest =
+ mbedtls_calloc( 1, session->peer_cert_digest_len );
+ if( session->peer_cert_digest == NULL )
+ return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
+
+ memcpy( session->peer_cert_digest, p,
+ session->peer_cert_digest_len );
+ p += session->peer_cert_digest_len;
+ }
+#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
#endif /* MBEDTLS_X509_CRT_PARSE_C */
/*