Add support for MS "fast SGC".

CHANGES

@@ -4,6 +4,21 @@
 
  Changes between 0.9.4 and 0.9.5  [xx XXX 1999]
 
+  *) Add support for MS "fast SGC". This is arguably a violation of the
+     SSL3/TLS protocol. Netscape SGC does two handshakes: the first with
+     weak crypto and after checking the certificate is SGC a second one
+     with strong crypto. MS SGC stops the first handshake after receiving
+     the server certificate message and sends a second client hello. Since
+     a server will typically do all the time consuming operations before
+     expecting any further messages from the client (server key exchange
+     is the most expensive) there is little difference between the two.
+
+     To get OpenSSL to support MS SGC we have to permit a second client
+     hello message after we have sent server done. In addition we have to
+     reset the MAC if we do get this second client hello and include the
+     data just received.
+     [Steve Henson]
+
   *) Add a function 'd2i_AutoPrivateKey()' this will automatically decide
      if a DER encoded private key is RSA or DSA traditional format. Changed
      d2i_PrivateKey_bio() to use it. This is only needed for the "traditional"

crypto/crypto.h

@@ -200,11 +200,12 @@ typedef struct crypto_ex_data_func_st
 #define CRYPTO_EX_INDEX_X509_STORE_CTX	5
 
 
-#if 0 /* unnecessary, it's the default and cannot be changed back later anyway */
-/* This is the default callbacks, but we can have others as well */
+/* This is the default callbacks, but we can have others as well:
+ * this is needed in Win32 where the application malloc and the
+ * library malloc may not be the same.
+ */
 #define CRYPTO_malloc_init()	CRYPTO_set_mem_functions(\
 	malloc, realloc, free)
-#endif
 
 #if defined CRYPTO_MDEBUG_ALL || defined CRYPTO_MDEBUG_TIME || defined CRYPTO_MDEBUG_THREAD
 # ifndef CRYPTO_MDEBUG /* avoid duplicate #define */

ssl/s3_both.c

@@ -293,6 +293,18 @@ long ssl3_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
 			SSLerr(SSL_F_SSL3_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
 			goto f_err;
 			}
+		if((mt < 0) && (*p == SSL3_MT_CLIENT_HELLO) &&
+					(st1 == SSL3_ST_SR_CERT_A) &&
+					(stn == SSL3_ST_SR_CERT_B))
+			{
+			/* At this point we have got an MS SGC second client
+			 * hello. We need to restart the mac and mac the data
+			 * currently received.
+			 */
+			ssl3_init_finished_mac(s);
+			ssl3_finish_mac(s, p + s->init_num, i);
+			}
+			
 		s->s3->tmp.message_type= *(p++);
 
 		n2l3(p,l);

ssl/s3_srvr.c

@@ -70,6 +70,7 @@
 
 static SSL_METHOD *ssl3_get_server_method(int ver);
 static int ssl3_get_client_hello(SSL *s);
+static int ssl3_check_client_hello(SSL *s);
 static int ssl3_send_server_hello(SSL *s);
 static int ssl3_send_server_key_exchange(SSL *s);
 static int ssl3_send_certificate_request(SSL *s);
@@ -141,6 +142,7 @@ int ssl3_accept(SSL *s)
 			s->new_session=1;
 			/* s->state=SSL_ST_ACCEPT; */
 
+		case SSL3_ST_SR_MS_SGC:
 		case SSL_ST_BEFORE:
 		case SSL_ST_ACCEPT:
 		case SSL_ST_BEFORE|SSL_ST_ACCEPT:
@@ -184,8 +186,8 @@ int ssl3_accept(SSL *s)
 
 			if (s->state != SSL_ST_RENEGOTIATE)
 				{
+				if(s->state != SSL3_ST_SR_MS_SGC) ssl3_init_finished_mac(s);
 				s->state=SSL3_ST_SR_CLNT_HELLO_A;
-				ssl3_init_finished_mac(s);
 				s->ctx->stats.sess_accept++;
 				}
 			else
@@ -341,12 +343,18 @@ int ssl3_accept(SSL *s)
 
 		case SSL3_ST_SR_CERT_A:
 		case SSL3_ST_SR_CERT_B:
-			/* could be sent for a DH cert, even if we
-			 * have not asked for it :-) */
-			ret=ssl3_get_client_certificate(s);
-			if (ret <= 0) goto end;
-			s->init_num=0;
-			s->state=SSL3_ST_SR_KEY_EXCH_A;
+			/* Check for second client hello if MS SGC */
+			ret = ssl3_check_client_hello(s);
+			if(ret <= 0) goto end;
+			if(ret == 2) s->state = SSL3_ST_SR_MS_SGC;
+			else {
+				/* could be sent for a DH cert, even if we
+				 * have not asked for it :-) */
+				ret=ssl3_get_client_certificate(s);
+				if (ret <= 0) goto end;
+				s->init_num=0;
+				s->state=SSL3_ST_SR_KEY_EXCH_A;
+			}
 			break;
 
 		case SSL3_ST_SR_KEY_EXCH_A:
@@ -510,6 +518,23 @@ static int ssl3_send_hello_request(SSL *s)
 	return(ssl3_do_write(s,SSL3_RT_HANDSHAKE));
 	}
 
+static int ssl3_check_client_hello(SSL *s)
+	{
+	int ok;
+	long n;
+
+	n=ssl3_get_message(s,
+		SSL3_ST_SR_CERT_A,
+		SSL3_ST_SR_CERT_B,
+		-1,
+		SSL3_RT_MAX_PLAIN_LENGTH,
+		&ok);
+	if (!ok) return((int)n);
+	s->s3->tmp.reuse_message = 1;
+	if(s->s3->tmp.message_type == SSL3_MT_CLIENT_HELLO) return 2;
+	return 1;
+}
+
 static int ssl3_get_client_hello(SSL *s)
 	{
 	int i,j,ok,al,ret= -1;

ssl/ssl3.h

@@ -398,6 +398,7 @@ typedef struct ssl3_ctx_st
 #define SSL3_ST_SR_CLNT_HELLO_A		(0x110|SSL_ST_ACCEPT)
 #define SSL3_ST_SR_CLNT_HELLO_B		(0x111|SSL_ST_ACCEPT)
 #define SSL3_ST_SR_CLNT_HELLO_C		(0x112|SSL_ST_ACCEPT)
+#define SSL3_ST_SR_MS_SGC			(0x113|SSL_ST_ACCEPT)
 /* write to client */
 #define SSL3_ST_SW_HELLO_REQ_A		(0x120|SSL_ST_ACCEPT)
 #define SSL3_ST_SW_HELLO_REQ_B		(0x121|SSL_ST_ACCEPT)

ssl/ssl_stat.c

@@ -161,6 +161,7 @@ case SSL3_ST_SW_FLUSH:		str="SSLv3 flush data"; break;
 case SSL3_ST_SR_CLNT_HELLO_A:	str="SSLv3 read client hello A"; break;
 case SSL3_ST_SR_CLNT_HELLO_B:	str="SSLv3 read client hello B"; break;
 case SSL3_ST_SR_CLNT_HELLO_C:	str="SSLv3 read client hello C"; break;
+case SSL3_ST_SR_MS_SGC:		str="SSLv3 read second client hello (MS SGC)"; break;
 case SSL3_ST_SW_HELLO_REQ_A:	str="SSLv3 write hello request A"; break;
 case SSL3_ST_SW_HELLO_REQ_B:	str="SSLv3 write hello request B"; break;
 case SSL3_ST_SW_HELLO_REQ_C:	str="SSLv3 write hello request C"; break;