The branch master has been updated
via c96ce52ce293785b54a42d119c457aef739cc2ce (commit)
from 284d19c2ced0264bd46de61718aa4a60efa8d175 (commit)
- Log -----------------------------------------------------------------
commit c96ce52ce293785b54a42d119c457aef739cc2ce
Author: Matt Caswell <m...@openssl.org>
Date: Fri Mar 1 15:40:20 2019 +0000
Don't write the tick_identity to the session
Sessions must be immutable once they can be shared with multiple threads.
We were breaking that rule by writing the ticket index into it during the
handshake. This can lead to incorrect behaviour, including failed
connections in multi-threaded environments.
Reported by David Benjamin.
Reviewed-by: Paul Dale <paul.d...@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/8383)
-----------------------------------------------------------------------
Summary of changes:
ssl/ssl_locl.h | 11 +++++++----
ssl/statem/extensions.c | 2 --
ssl/statem/extensions_clnt.c | 36 +++++++++++++++++++++++-------------
ssl/statem/extensions_srvr.c | 4 ++--
ssl/statem/statem_clnt.c | 5 +----
5 files changed, 33 insertions(+), 25 deletions(-)
diff --git a/ssl/ssl_locl.h b/ssl/ssl_locl.h
index ae6417b..a51cc6c 100644
--- a/ssl/ssl_locl.h
+++ b/ssl/ssl_locl.h
@@ -578,7 +578,6 @@ struct ssl_session_st {
/* Session lifetime hint in seconds */
unsigned long tick_lifetime_hint;
uint32_t tick_age_add;
- int tick_identity;
/* Max number of bytes that can be sent as early data */
uint32_t max_early_data;
/* The ALPN protocol selected for this session */
@@ -1364,6 +1363,13 @@ struct ssl_st {
* as this extension is optional on server side.
*/
uint8_t max_fragment_len_mode;
+
+ /*
+ * On the client side the number of ticket identities we sent in the
+ * ClientHello. On the server side the identity of the ticket we
+ * selected.
+ */
+ int tick_identity;
} ext;
/*
@@ -2064,9 +2070,6 @@ typedef enum downgrade_en {
#define TLSEXT_KEX_MODE_FLAG_KE 1
#define TLSEXT_KEX_MODE_FLAG_KE_DHE 2
-/* An invalid index into the TLSv1.3 PSK identities */
-#define TLSEXT_PSK_BAD_IDENTITY -1
-
#define SSL_USE_PSS(s) (s->s3->tmp.peer_sigalg != NULL && \
s->s3->tmp.peer_sigalg->sig == EVP_PKEY_RSA_PSS)
diff --git a/ssl/statem/extensions.c b/ssl/statem/extensions.c
index 60d4da0..dcf2bfe 100644
--- a/ssl/statem/extensions.c
+++ b/ssl/statem/extensions.c
@@ -989,7 +989,6 @@ static int final_server_name(SSL *s, unsigned int context,
int sent)
ss->ext.ticklen = 0;
ss->ext.tick_lifetime_hint = 0;
ss->ext.tick_age_add = 0;
- ss->ext.tick_identity = 0;
if (!ssl_generate_session_id(s, ss)) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_FINAL_SERVER_NAME,
ERR_R_INTERNAL_ERROR);
@@ -1645,7 +1644,6 @@ static int final_early_data(SSL *s, unsigned int context,
int sent)
if (s->max_early_data == 0
|| !s->hit
- || s->session->ext.tick_identity != 0
|| s->early_data_state != SSL_EARLY_DATA_ACCEPTING
|| !s->ext.early_data_ok
|| s->hello_retry_request != SSL_HRR_NONE
diff --git a/ssl/statem/extensions_clnt.c b/ssl/statem/extensions_clnt.c
index f01e9ee..9d7a4f8 100644
--- a/ssl/statem/extensions_clnt.c
+++ b/ssl/statem/extensions_clnt.c
@@ -996,7 +996,7 @@ EXT_RETURN tls_construct_ctos_psk(SSL *s, WPACKET *pkt,
unsigned int context,
const EVP_MD *handmd = NULL, *mdres = NULL, *mdpsk = NULL;
int dores = 0;
- s->session->ext.tick_identity = TLSEXT_PSK_BAD_IDENTITY;
+ s->ext.tick_identity = 0;
/*
* Note: At this stage of the code we only support adding a single
@@ -1086,6 +1086,7 @@ EXT_RETURN tls_construct_ctos_psk(SSL *s, WPACKET *pkt,
unsigned int context,
agems += s->session->ext.tick_age_add;
reshashsize = EVP_MD_size(mdres);
+ s->ext.tick_identity++;
dores = 1;
}
@@ -1145,6 +1146,7 @@ EXT_RETURN tls_construct_ctos_psk(SSL *s, WPACKET *pkt,
unsigned int context,
ERR_R_INTERNAL_ERROR);
return EXT_RETURN_FAIL;
}
+ s->ext.tick_identity++;
}
if (!WPACKET_close(pkt)
@@ -1183,11 +1185,6 @@ EXT_RETURN tls_construct_ctos_psk(SSL *s, WPACKET *pkt,
unsigned int context,
return EXT_RETURN_FAIL;
}
- if (dores)
- s->session->ext.tick_identity = 0;
- if (s->psksession != NULL)
- s->psksession->ext.tick_identity = (dores ? 1 : 0);
-
return EXT_RETURN_SENT;
#else
return EXT_RETURN_NOT_SENT;
@@ -1932,8 +1929,7 @@ int tls_parse_stoc_early_data(SSL *s, PACKET *pkt,
unsigned int context,
}
if (!s->ext.early_data_ok
- || !s->hit
- || s->session->ext.tick_identity != 0) {
+ || !s->hit) {
/*
* If we get here then we didn't send early data, or we didn't resume
* using the first identity, or the SNI/ALPN is not consistent so the
@@ -1961,17 +1957,28 @@ int tls_parse_stoc_psk(SSL *s, PACKET *pkt, unsigned
int context, X509 *x,
return 0;
}
- if (s->session->ext.tick_identity == (int)identity) {
+ if (identity >= (unsigned int)s->ext.tick_identity) {
+ SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PARSE_STOC_PSK,
+ SSL_R_BAD_PSK_IDENTITY);
+ return 0;
+ }
+
+ /*
+ * Session resumption tickets are always sent before PSK tickets. If the
+ * ticket index is 0 then it must be for a session resumption ticket if we
+ * sent two tickets, or if we didn't send a PSK ticket.
+ */
+ if (identity == 0 && (s->psksession == NULL || s->ext.tick_identity == 2))
{
s->hit = 1;
SSL_SESSION_free(s->psksession);
s->psksession = NULL;
return 1;
}
- if (s->psksession == NULL
- || s->psksession->ext.tick_identity != (int)identity) {
- SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PARSE_STOC_PSK,
- SSL_R_BAD_PSK_IDENTITY);
+ if (s->psksession == NULL) {
+ /* Should never happen */
+ SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PARSE_STOC_PSK,
+ ERR_R_INTERNAL_ERROR);
return 0;
}
@@ -1990,6 +1997,9 @@ int tls_parse_stoc_psk(SSL *s, PACKET *pkt, unsigned int
context, X509 *x,
s->session = s->psksession;
s->psksession = NULL;
s->hit = 1;
+ /* Early data is only allowed if we used the first ticket */
+ if (identity != 0)
+ s->ext.early_data_ok = 0;
#endif
return 1;
diff --git a/ssl/statem/extensions_srvr.c b/ssl/statem/extensions_srvr.c
index 73ceadc..7b1c5c9 100644
--- a/ssl/statem/extensions_srvr.c
+++ b/ssl/statem/extensions_srvr.c
@@ -1277,7 +1277,7 @@ int tls_parse_ctos_psk(SSL *s, PACKET *pkt, unsigned int
context, X509 *x,
goto err;
}
- sess->ext.tick_identity = id;
+ s->ext.tick_identity = id;
SSL_SESSION_free(s->session);
s->session = sess;
@@ -1951,7 +1951,7 @@ EXT_RETURN tls_construct_stoc_psk(SSL *s, WPACKET *pkt,
unsigned int context,
if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_psk)
|| !WPACKET_start_sub_packet_u16(pkt)
- || !WPACKET_put_bytes_u16(pkt, s->session->ext.tick_identity)
+ || !WPACKET_put_bytes_u16(pkt, s->ext.tick_identity)
|| !WPACKET_close(pkt)) {
SSLfatal(s, SSL_AD_INTERNAL_ERROR,
SSL_F_TLS_CONSTRUCT_STOC_PSK, ERR_R_INTERNAL_ERROR);
diff --git a/ssl/statem/statem_clnt.c b/ssl/statem/statem_clnt.c
index 1f55113..2a9b737 100644
--- a/ssl/statem/statem_clnt.c
+++ b/ssl/statem/statem_clnt.c
@@ -1613,10 +1613,7 @@ MSG_PROCESS_RETURN tls_process_server_hello(SSL *s,
PACKET *pkt)
* so the PAC-based session secret is always preserved. It'll be
* overwritten if the server refuses resumption.
*/
- if (s->session->session_id_length > 0
- || (SSL_IS_TLS13(s)
- && s->session->ext.tick_identity
- != TLSEXT_PSK_BAD_IDENTITY)) {
+ if (s->session->session_id_length > 0) {
tsan_counter(&s->session_ctx->stats.sess_miss);
if (!ssl_get_new_session(s, 0)) {
/* SSLfatal() already called */
