r16410@catbus: nickm | 2007-11-05 10:54:29 -0500

 Code to remember client_random and server_random values, and to compute hmac using TLS master secret.


svn:r12381

2 files changed, 44 insertions, 0 deletions

diff --git a/src/common/tortls.c b/src/common/tortls.c
index 162c9d740b..ce5b702a2b 100644
--- a/src/common/tortls.c
+++ b/src/common/tortls.c
@@ -20,6 +20,7 @@ const char tortls_c_id[] =
 
 #include <assert.h>
 #include <openssl/ssl.h>
+#include <openssl/ssl3.h>
 #include <openssl/err.h>
 #include <openssl/tls1.h>
 #include <openssl/asn1.h>
@@ -896,3 +897,39 @@ tor_tls_used_v1_handshake(tor_tls_t *tls)
   return 1;
 }
 
+#if SSL3_RANDOM_SIZE != TOR_TLS_RANDOM_LEN
+#error "The TOR_TLS_RANDOM_LEN macro is defined incorrectly.  That's a bug."
+#endif
+
+/** DOCDOC */
+int
+tor_tls_get_random_values(tor_tls_t *tls, char *client_random_out,
+                          char *server_random_out)
+{
+  tor_assert(tls && tls->ssl);
+  if (!tls->ssl->s3)
+    return -1;
+  memcpy(client_random_out, tls->ssl->s3->client_random, SSL3_RANDOM_SIZE);
+  memcpy(server_random_out, tls->ssl->s3->server_random, SSL3_RANDOM_SIZE);
+  return 0;
+}
+
+/** DOCDOC */
+int
+tor_tls_hmac_with_master_secret(tor_tls_t *tls, char *hmac_out,
+                                const char *data, size_t data_len)
+{
+  SSL_SESSION *s;
+  tor_assert(tls && tls->ssl);
+  if (!(s = SSL_get_session(tls->ssl)))
+    return -1;
+  if (s->master_key_length < 0)
+    return -1;
+  crypto_hmac_sha1(hmac_out,
+                   (const char*)s->master_key,
+                   (size_t)s->master_key_length,
+                   data, data_len);
+  return 0;
+}
+
+
diff --git a/src/common/tortls.h b/src/common/tortls.h
index 89cbe3be58..eac337b921 100644
--- a/src/common/tortls.h
+++ b/src/common/tortls.h
@@ -41,6 +41,9 @@ typedef struct tor_tls_t tor_tls_t;
   case TOR_TLS_ERROR_NO_ROUTE:                  \
   case TOR_TLS_ERROR_TIMEOUT
 
+/**DOCDOC*/
+#define TOR_TLS_RANDOM_LEN 32
+
 #define TOR_TLS_IS_ERROR(rv) ((rv) < TOR_TLS_CLOSE)
 
 void tor_tls_free_all(void);
@@ -65,6 +68,10 @@ void tor_tls_get_n_raw_bytes(tor_tls_t *tls,
                              size_t *n_read, size_t *n_written);
 
 int tor_tls_used_v1_handshake(tor_tls_t *tls);
+int tor_tls_get_random_values(tor_tls_t *tls, char *client_random_out,
+                              char *server_random_out);
+int tor_tls_hmac_with_master_secret(tor_tls_t *tls, char *hmac_out,
+                                    const char *data, size_t data_len);
 
 /* Log and abort if there are unhandled TLS errors in OpenSSL's error stack.
  */