Here's a backport version of the session ticket override patch against
OpenSSL 0.9.8i. This provides the same API that was committed into 0.9.9
tree and it can be used with the current development snapshot of
wpa_supplicant/hostapd 0.6.x for EAP-FAST.
--
Jouni Malinen PGP id EFC895FA
This patch adds support for TLS SessionTicket extension (RFC 5077) for
the parts used by EAP-FAST (RFC 4851).
This is based on the patch from Alexey Kobozev <[EMAIL PROTECTED]>
(sent to openssl-dev mailing list on Tue, 07 Jun 2005 15:40:58 +0300).
OpenSSL 0.9.8i does not enable TLS extension support by default, so it
will need to be enabled by adding enable-tlsext to config script
command line.
Index: openssl-0.9.8i/ssl/s3_clnt.c
===================================================================
--- openssl-0.9.8i.orig/ssl/s3_clnt.c 2008-06-16 19:56:41.000000000 +0300
+++ openssl-0.9.8i/ssl/s3_clnt.c 2008-11-23 20:39:40.000000000 +0200
@@ -759,6 +759,21 @@
goto f_err;
}
+#ifndef OPENSSL_NO_TLSEXT
+ /* check if we want to resume the session based on external pre-shared
secret */
+ if (s->version >= TLS1_VERSION && s->tls_session_secret_cb)
+ {
+ SSL_CIPHER *pref_cipher=NULL;
+ s->session->master_key_length=sizeof(s->session->master_key);
+ if (s->tls_session_secret_cb(s, s->session->master_key,
&s->session->master_key_length,
+ NULL, &pref_cipher, s->tls_session_secret_cb_arg))
+ {
+ s->session->cipher=pref_cipher ?
+ pref_cipher : ssl_get_cipher_by_char(s,p+j);
+ }
+ }
+#endif /* OPENSSL_NO_TLSEXT */
+
if (j != 0 && j == s->session->session_id_length
&& memcmp(p,s->session->session_id,j) == 0)
{
@@ -2701,11 +2716,8 @@
{
int ok;
long n;
- /* If we have no ticket or session ID is non-zero length (a match of
- * a non-zero session length would never reach here) it cannot be a
- * resumed session.
- */
- if (!s->session->tlsext_tick || s->session->session_id_length)
+ /* If we have no ticket it cannot be a resumed session. */
+ if (!s->session->tlsext_tick)
return 1;
/* this function is called when we really expect a Certificate
* message, so permit appropriate message length */
Index: openssl-0.9.8i/ssl/s3_srvr.c
===================================================================
--- openssl-0.9.8i.orig/ssl/s3_srvr.c 2008-09-14 21:16:09.000000000 +0300
+++ openssl-0.9.8i/ssl/s3_srvr.c 2008-11-23 20:37:40.000000000 +0200
@@ -959,6 +959,59 @@
SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO,SSL_R_CLIENTHELLO_TLSEXT);
goto err;
}
+
+ /* Check if we want to use external pre-shared secret for this
+ * handshake for not reused session only. We need to generate
+ * server_random before calling tls_session_secret_cb in order to allow
+ * SessionTicket processing to use it in key derivation. */
+ {
+ unsigned long Time;
+ unsigned char *pos;
+ Time=(unsigned long)time(NULL); /* Time */
+ pos=s->s3->server_random;
+ l2n(Time,pos);
+ if (RAND_pseudo_bytes(pos,SSL3_RANDOM_SIZE-4) <= 0)
+ {
+ al=SSL_AD_INTERNAL_ERROR;
+ goto f_err;
+ }
+ }
+
+ if (!s->hit && s->version >= TLS1_VERSION && s->tls_session_secret_cb)
+ {
+ SSL_CIPHER *pref_cipher=NULL;
+
+ s->session->master_key_length=sizeof(s->session->master_key);
+ if(s->tls_session_secret_cb(s, s->session->master_key,
&s->session->master_key_length,
+ ciphers, &pref_cipher, s->tls_session_secret_cb_arg))
+ {
+ s->hit=1;
+ s->session->ciphers=ciphers;
+ s->session->verify_result=X509_V_OK;
+
+ ciphers=NULL;
+
+ /* check if some cipher was preferred by call back */
+ pref_cipher=pref_cipher ? pref_cipher :
ssl3_choose_cipher(s, s->session->ciphers, SSL_get_ciphers(s));
+ if (pref_cipher == NULL)
+ {
+ al=SSL_AD_HANDSHAKE_FAILURE;
+
SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO,SSL_R_NO_SHARED_CIPHER);
+ goto f_err;
+ }
+
+ s->session->cipher=pref_cipher;
+
+ if (s->cipher_list)
+ sk_SSL_CIPHER_free(s->cipher_list);
+
+ if (s->cipher_list_by_id)
+ sk_SSL_CIPHER_free(s->cipher_list_by_id);
+
+ s->cipher_list = sk_SSL_CIPHER_dup(s->session->ciphers);
+ s->cipher_list_by_id =
sk_SSL_CIPHER_dup(s->session->ciphers);
+ }
+ }
#endif
/* Worst case, we will use the NULL compression, but if we have other
* options, we will now look for them. We have i-1 compression
@@ -1097,16 +1150,22 @@
unsigned char *buf;
unsigned char *p,*d;
int i,sl;
- unsigned long l,Time;
+ unsigned long l;
+#ifdef OPENSSL_NO_TLSEXT
+ unsigned long Time;
+#endif
if (s->state == SSL3_ST_SW_SRVR_HELLO_A)
{
buf=(unsigned char *)s->init_buf->data;
+#ifdef OPENSSL_NO_TLSEXT
p=s->s3->server_random;
+ /* Generate server_random if it was not needed previously */
Time=(unsigned long)time(NULL); /* Time */
l2n(Time,p);
if (RAND_pseudo_bytes(p,SSL3_RANDOM_SIZE-4) <= 0)
return -1;
+#endif
/* Do the message type and length last */
d=p= &(buf[4]);
Index: openssl-0.9.8i/ssl/ssl_err.c
===================================================================
--- openssl-0.9.8i.orig/ssl/ssl_err.c 2008-08-13 22:44:44.000000000 +0300
+++ openssl-0.9.8i/ssl/ssl_err.c 2008-11-23 20:33:43.000000000 +0200
@@ -253,6 +253,7 @@
{ERR_FUNC(SSL_F_TLS1_ENC), "TLS1_ENC"},
{ERR_FUNC(SSL_F_TLS1_SETUP_KEY_BLOCK), "TLS1_SETUP_KEY_BLOCK"},
{ERR_FUNC(SSL_F_WRITE_PENDING), "WRITE_PENDING"},
+{ERR_FUNC(SSL_F_SSL_SET_SESSION_TICKET_EXT), "SSL_set_session_ticket_ext"},
{0,NULL}
};
Index: openssl-0.9.8i/ssl/ssl.h
===================================================================
--- openssl-0.9.8i.orig/ssl/ssl.h 2008-08-13 22:44:44.000000000 +0300
+++ openssl-0.9.8i/ssl/ssl.h 2008-11-23 20:35:41.000000000 +0200
@@ -344,6 +344,7 @@
* 'struct ssl_st *' function parameters used to prototype callbacks
* in SSL_CTX. */
typedef struct ssl_st *ssl_crock_st;
+typedef struct tls_session_ticket_ext_st TLS_SESSION_TICKET_EXT;
/* used to hold info on the particular ciphers used */
typedef struct ssl_cipher_st
@@ -362,6 +363,9 @@
DECLARE_STACK_OF(SSL_CIPHER)
+typedef int (*tls_session_ticket_ext_cb_fn)(SSL *s, const unsigned char *data,
int len, void *arg);
+typedef int (*tls_session_secret_cb_fn)(SSL *s, void *secret, int *secret_len,
STACK_OF(SSL_CIPHER) *peer_ciphers, SSL_CIPHER **cipher, void *arg);
+
/* Used to hold functions for SSLv2 or SSLv3/TLSv1 functions */
typedef struct ssl_method_st
{
@@ -1034,6 +1038,18 @@
/* RFC4507 session ticket expected to be received or sent */
int tlsext_ticket_expected;
+
+ /* TLS Session Ticket extension override */
+ TLS_SESSION_TICKET_EXT *tlsext_session_ticket;
+
+ /* TLS Session Ticket extension callback */
+ tls_session_ticket_ext_cb_fn tls_session_ticket_ext_cb;
+ void *tls_session_ticket_ext_cb_arg;
+
+ /* TLS pre-shared secret session resumption */
+ tls_session_secret_cb_fn tls_session_secret_cb;
+ void *tls_session_secret_cb_arg;
+
SSL_CTX * initial_ctx; /* initial ctx, used to store sessions */
#define session_ctx initial_ctx
#else
@@ -1632,6 +1648,15 @@
int SSL_COMP_add_compression_method(int id,void *cm);
#endif
+/* TLS extensions functions */
+int SSL_set_session_ticket_ext(SSL *s, void *ext_data, int ext_len);
+
+int SSL_set_session_ticket_ext_cb(SSL *s, tls_session_ticket_ext_cb_fn cb,
+ void *arg);
+
+/* Pre-shared secret session resumption functions */
+int SSL_set_session_secret_cb(SSL *s, tls_session_secret_cb_fn
tls_session_secret_cb, void *arg);
+
/* BEGIN ERROR CODES */
/* The following lines are auto generated by the script mkerr.pl. Any changes
* made after this point may be overwritten when the script is next run.
@@ -1824,6 +1849,7 @@
#define SSL_F_TLS1_ENC 210
#define SSL_F_TLS1_SETUP_KEY_BLOCK 211
#define SSL_F_WRITE_PENDING 212
+#define SSL_F_SSL_SET_SESSION_TICKET_EXT 213
/* Reason codes. */
#define SSL_R_APP_DATA_IN_HANDSHAKE 100
Index: openssl-0.9.8i/ssl/ssl_sess.c
===================================================================
--- openssl-0.9.8i.orig/ssl/ssl_sess.c 2008-06-04 21:35:27.000000000 +0300
+++ openssl-0.9.8i/ssl/ssl_sess.c 2008-11-23 20:32:24.000000000 +0200
@@ -707,6 +707,61 @@
return(s->session_timeout);
}
+#ifndef OPENSSL_NO_TLSEXT
+int SSL_set_session_secret_cb(SSL *s, int (*tls_session_secret_cb)(SSL *s,
void *secret, int *secret_len,
+ STACK_OF(SSL_CIPHER) *peer_ciphers, SSL_CIPHER **cipher, void *arg),
void *arg)
+ {
+ if (s == NULL) return(0);
+ s->tls_session_secret_cb = tls_session_secret_cb;
+ s->tls_session_secret_cb_arg = arg;
+ return(1);
+ }
+
+int SSL_set_session_ticket_ext_cb(SSL *s, tls_session_ticket_ext_cb_fn cb,
+ void *arg)
+ {
+ if (s == NULL) return(0);
+ s->tls_session_ticket_ext_cb = cb;
+ s->tls_session_ticket_ext_cb_arg = arg;
+ return(1);
+ }
+
+int SSL_set_session_ticket_ext(SSL *s, void *ext_data, int ext_len)
+ {
+ if (s->version >= TLS1_VERSION)
+ {
+ if (s->tlsext_session_ticket)
+ {
+ OPENSSL_free(s->tlsext_session_ticket);
+ s->tlsext_session_ticket = NULL;
+ }
+
+ s->tlsext_session_ticket =
OPENSSL_malloc(sizeof(TLS_SESSION_TICKET_EXT) + ext_len);
+ if (!s->tlsext_session_ticket)
+ {
+ SSLerr(SSL_F_SSL_SET_SESSION_TICKET_EXT,
ERR_R_MALLOC_FAILURE);
+ return 0;
+ }
+
+ if (ext_data)
+ {
+ s->tlsext_session_ticket->length = ext_len;
+ s->tlsext_session_ticket->data =
s->tlsext_session_ticket + 1;
+ memcpy(s->tlsext_session_ticket->data, ext_data,
ext_len);
+ }
+ else
+ {
+ s->tlsext_session_ticket->length = 0;
+ s->tlsext_session_ticket->data = NULL;
+ }
+
+ return 1;
+ }
+
+ return 0;
+ }
+#endif /* OPENSSL_NO_TLSEXT */
+
typedef struct timeout_param_st
{
SSL_CTX *ctx;
Index: openssl-0.9.8i/ssl/t1_lib.c
===================================================================
--- openssl-0.9.8i.orig/ssl/t1_lib.c 2008-09-04 01:13:04.000000000 +0300
+++ openssl-0.9.8i/ssl/t1_lib.c 2008-11-23 20:31:20.000000000 +0200
@@ -106,6 +106,12 @@
void tls1_free(SSL *s)
{
+#ifndef OPENSSL_NO_TLSEXT
+ if (s->tlsext_session_ticket)
+ {
+ OPENSSL_free(s->tlsext_session_ticket);
+ }
+#endif
ssl3_free(s);
}
@@ -175,8 +181,23 @@
int ticklen;
if (s->session && s->session->tlsext_tick)
ticklen = s->session->tlsext_ticklen;
+ else if (s->session && s->tlsext_session_ticket &&
+ s->tlsext_session_ticket->data)
+ {
+ ticklen = s->tlsext_session_ticket->length;
+ s->session->tlsext_tick = OPENSSL_malloc(ticklen);
+ if (!s->session->tlsext_tick)
+ return NULL;
+ memcpy(s->session->tlsext_tick,
+ s->tlsext_session_ticket->data,
+ ticklen);
+ s->session->tlsext_ticklen = ticklen;
+ }
else
ticklen = 0;
+ if (ticklen == 0 && s->tlsext_session_ticket &&
+ s->tlsext_session_ticket->data == NULL)
+ goto skip_ext;
/* Check for enough room 2 for extension type, 2 for len
* rest for ticket
*/
@@ -190,6 +211,7 @@
ret += ticklen;
}
}
+ skip_ext:
if (s->tlsext_status_type == TLSEXT_STATUSTYPE_ocsp)
{
@@ -407,6 +429,15 @@
}
}
+ else if (type == TLSEXT_TYPE_session_ticket)
+ {
+ if (s->tls_session_ticket_ext_cb &&
+ !s->tls_session_ticket_ext_cb(s, data, size,
s->tls_session_ticket_ext_cb_arg))
+ {
+ *al = TLS1_AD_INTERNAL_ERROR;
+ return 0;
+ }
+ }
else if (type == TLSEXT_TYPE_status_request
&& s->ctx->tlsext_status_cb)
{
@@ -553,6 +584,12 @@
}
else if (type == TLSEXT_TYPE_session_ticket)
{
+ if (s->tls_session_ticket_ext_cb &&
+ !s->tls_session_ticket_ext_cb(s, data, size,
s->tls_session_ticket_ext_cb_arg))
+ {
+ *al = TLS1_AD_INTERNAL_ERROR;
+ return 0;
+ }
if ((SSL_get_options(s) & SSL_OP_NO_TICKET)
|| (size > 0))
{
@@ -776,6 +813,15 @@
s->tlsext_ticket_expected = 1;
return 0; /* Cache miss */
}
+ if (s->tls_session_secret_cb)
+ {
+ /* Indicate cache miss here and instead of
+ * generating the session from ticket now,
+ * trigger abbreviated handshake based on
+ * external mechanism to calculate the master
+ * secret later. */
+ return 0;
+ }
return tls_decrypt_ticket(s, p, size, session_id, len,
ret);
}
Index: openssl-0.9.8i/ssl/tls1.h
===================================================================
--- openssl-0.9.8i.orig/ssl/tls1.h 2008-04-30 19:11:33.000000000 +0300
+++ openssl-0.9.8i/ssl/tls1.h 2008-11-23 20:22:38.000000000 +0200
@@ -398,6 +398,13 @@
#define TLS_MD_MASTER_SECRET_CONST
"\x6d\x61\x73\x74\x65\x72\x20\x73\x65\x63\x72\x65\x74" /*master secret*/
#endif
+/* TLS extension struct */
+struct tls_session_ticket_ext_st
+ {
+ unsigned short length;
+ void *data;
+ };
+
#ifdef __cplusplus
}
#endif
Index: openssl-0.9.8i/util/ssleay.num
===================================================================
--- openssl-0.9.8i.orig/util/ssleay.num 2008-06-05 13:57:21.000000000 +0300
+++ openssl-0.9.8i/util/ssleay.num 2008-11-23 20:22:05.000000000 +0200
@@ -242,3 +242,5 @@
SSL_get_servername 291 EXIST::FUNCTION:TLSEXT
SSL_get_servername_type 292 EXIST::FUNCTION:TLSEXT
SSL_CTX_set_client_cert_engine 293 EXIST::FUNCTION:ENGINE
+SSL_set_session_ticket_ext 306 EXIST::FUNCTION:TLSEXT
+SSL_set_session_secret_cb 307 EXIST::FUNCTION:TLSEXT
