Add callbacks supporting generation and retrieval of supplemental data entries, facilitating RFC 5878 (TLS auth extensions)
Removed prior audit proof logic - audit proof support was implemented using the generic TLS extension API
Tests exercising the new supplemental data registration and callback api can be found in ssltest.c.
Implemented changes to s_server and s_client to exercise supplemental data callbacks via the -auth argument, as well as additional flags to exercise supplemental data being sent only during renegotiation.
diff --git a/apps/s_client.c b/apps/s_client.c
index 2f13503..e38f16e 100644
--- a/apps/s_client.c
+++ b/apps/s_client.c
@@ -203,7 +203,6 @@
#ifndef OPENSSL_NO_TLSEXT
static int c_tlsextdebug=0;
static int c_status_req=0;
-static int c_proof_debug=0;
#endif
static int c_msg=0;
static int c_showcerts=0;
@@ -215,7 +214,8 @@
static void print_stuff(BIO *berr,SSL *con,int full);
#ifndef OPENSSL_NO_TLSEXT
static int ocsp_resp_cb(SSL *s, void *arg);
-static int audit_proof_cb(SSL *s, void *arg);
+static int c_auth = 0;
+static int c_auth_require_reneg = 0;
#endif
static BIO *bio_c_out=NULL;
static BIO *bio_c_msg=NULL;
@@ -223,6 +223,35 @@
static int c_ign_eof=0;
static int c_brief=0;
+#ifndef OPENSSL_NO_TLSEXT
+
+static const unsigned char *most_recent_supplemental_data;
+static size_t most_recent_supplemental_data_length;
+
+static int server_provided_server_authz = 0;
+static int server_provided_client_authz = 0;
+
+static const unsigned char auth_ext_data[]={TLSEXT_AUTHZDATAFORMAT_dtcp};
+
+static int suppdata_cb(SSL *s, unsigned short supp_data_type,
+ const unsigned char *in,
+ unsigned short inlen, int *al,
+ void *arg);
+
+static int auth_suppdata_generate_cb(SSL *s, unsigned short supp_data_type,
+ const unsigned char **out,
+ unsigned short *outlen, void *arg);
+
+static int authz_tlsext_generate_cb(SSL *s, unsigned short ext_type,
+ const unsigned char **out, unsigned short *outlen,
+ void *arg);
+
+static int authz_tlsext_cb(SSL *s, unsigned short ext_type,
+ const unsigned char *in,
+ unsigned short inlen, int *al,
+ void *arg);
+#endif
+
#ifndef OPENSSL_NO_PSK
/* Default PSK identity and key */
static char *psk_identity="Client_identity";
@@ -362,14 +391,13 @@
BIO_printf(bio_err," -tlsextdebug - hex dump of all TLS extensions received\n");
BIO_printf(bio_err," -status - request certificate status from server\n");
BIO_printf(bio_err," -no_ticket - disable use of RFC4507bis session tickets\n");
- BIO_printf(bio_err," -proof_debug - request an audit proof and print its hex dump\n");
+ BIO_printf(bio_err," -serverinfo types - send empty ClientHello extensions (comma-separated numbers)\n");
+ BIO_printf(bio_err," -auth - send and receive RFC 5878 TLS auth extensions and supplemental data\n");
+ BIO_printf(bio_err," -auth_require_reneg - Do not send TLS auth extensions until renegotiation\n");
# ifndef OPENSSL_NO_NEXTPROTONEG
BIO_printf(bio_err," -nextprotoneg arg - enable NPN extension, considering named protocols supported (comma-separated list)\n");
BIO_printf(bio_err," -alpn arg - enable ALPN extension, considering named protocols supported (comma-separated list)\n");
# endif
-#ifndef OPENSSL_NO_TLSEXT
- BIO_printf(bio_err," -serverinfo types - send empty ClientHello extensions (comma-separated numbers)\n");
-#endif
#endif
BIO_printf(bio_err," -legacy_renegotiation - enable use of legacy renegotiation (dangerous)\n");
BIO_printf(bio_err," -use_srtp profiles - Offer SRTP key management with a colon-separated profile list\n");
@@ -823,8 +851,10 @@
c_tlsextdebug=1;
else if (strcmp(*argv,"-status") == 0)
c_status_req=1;
- else if (strcmp(*argv,"-proof_debug") == 0)
- c_proof_debug=1;
+ else if (strcmp(*argv,"-auth") == 0)
+ c_auth = 1;
+ else if (strcmp(*argv,"-auth_require_reneg") == 0)
+ c_auth_require_reneg = 1;
#endif
#ifdef WATT32
else if (strcmp(*argv,"-wdebug") == 0)
@@ -1399,9 +1429,12 @@
}
#endif
- if (c_proof_debug)
- SSL_CTX_set_tlsext_authz_server_audit_proof_cb(ctx,
- audit_proof_cb);
+ if (c_auth)
+ {
+ SSL_CTX_set_custom_cli_ext(ctx, TLSEXT_TYPE_client_authz, authz_tlsext_generate_cb, authz_tlsext_cb, bio_err);
+ SSL_CTX_set_custom_cli_ext(ctx, TLSEXT_TYPE_server_authz, authz_tlsext_generate_cb, authz_tlsext_cb, bio_err);
+ SSL_CTX_set_cli_supp_data(ctx, TLSEXT_SUPPLEMENTALDATATYPE_authz_data, suppdata_cb, auth_suppdata_generate_cb, bio_err);
+ }
#endif
con=SSL_new(ctx);
@@ -2395,26 +2428,76 @@
return 1;
}
-static int audit_proof_cb(SSL *s, void *arg)
+static int authz_tlsext_cb(SSL *s, unsigned short ext_type,
+ const unsigned char *in,
+ unsigned short inlen, int *al,
+ void *arg)
{
- const unsigned char *proof;
- size_t proof_len;
- size_t i;
- SSL_SESSION *sess = SSL_get_session(s);
-
- proof = SSL_SESSION_get_tlsext_authz_server_audit_proof(sess,
- &proof_len);
- if (proof != NULL)
+ if (TLSEXT_TYPE_server_authz == ext_type)
{
- BIO_printf(bio_c_out, "Audit proof: ");
- for (i = 0; i < proof_len; ++i)
- BIO_printf(bio_c_out, "%02X", proof[i]);
- BIO_printf(bio_c_out, "\n");
+ server_provided_server_authz = (memchr(in,
+ TLSEXT_AUTHZDATAFORMAT_dtcp,
+ inlen) != NULL);
}
- else
+
+ if (TLSEXT_TYPE_client_authz == ext_type)
{
- BIO_printf(bio_c_out, "No audit proof found.\n");
+ server_provided_client_authz = (memchr(in,
+ TLSEXT_AUTHZDATAFORMAT_dtcp,
+ inlen) != NULL);
+ }
+
+ return 1;
+ }
+
+static int authz_tlsext_generate_cb(SSL *s, unsigned short ext_type,
+ const unsigned char **out, unsigned short *outlen,
+ void *arg)
+ {
+ if (c_auth)
+ {
+ if (!c_auth_require_reneg || (c_auth_require_reneg && SSL_num_renegotiations(s)))
+ {
+ *out = auth_ext_data;
+ *outlen = 1;
+ return 1;
+ }
+ }
+ //no auth extension to send
+ return -1;
+ }
+
+static int suppdata_cb(SSL *s, unsigned short supp_data_type,
+ const unsigned char *in,
+ unsigned short inlen, int *al,
+ void *arg)
+ {
+ if (supp_data_type == TLSEXT_SUPPLEMENTALDATATYPE_authz_data)
+ {
+ most_recent_supplemental_data = in;
+ most_recent_supplemental_data_length = inlen;
}
return 1;
}
+
+static int auth_suppdata_generate_cb(SSL *s, unsigned short supp_data_type,
+ const unsigned char **out,
+ unsigned short *outlen, void *arg)
+ {
+ unsigned char *result;
+ if (c_auth && server_provided_client_authz && server_provided_server_authz)
+ {
+ if (!c_auth_require_reneg || (c_auth_require_reneg && SSL_num_renegotiations(s)))
+ {
+ result = OPENSSL_malloc(10);
+ memcpy(result, "5432154321", 10);
+ *out = result;
+ *outlen = 10;
+ return 1;
+ }
+ }
+ //no supplemental data to send
+ return -1;
+ }
+
#endif
