http://git.openssl.org/gitweb/?p=openssl.git;a=commitdiff;h=2016265dfbab162ec30718b5e7480add42598158

Don't know the full story, but it looks like a "can't do random
perfectly, so do it god awful" problem was found in 2013, and
replaced with "only do it badly if a flag is set".  New flags
(SSL_MODE_SEND_SERVERHELLO_TIME and SSL_MODE_SEND_SERVERHELLO_TIME)
were added [Ben Laurie?] to support the old scheme of "use time_t
for first 4 bytes of the random buffer".

Nothing uses these flags [ecosystem scan by sthen]

Fully discourage use of these flags in the future by removing
support & definition of them.  The buflen < 4 check is also interesting,
because no entropy would be returned.  No callers passed such small
buffers.
ok miod sthen

7 files changed, 6 insertions, 43 deletions

diff --git a/lib/libssl/d1_clnt.c b/lib/libssl/d1_clnt.c
index 8ff4d8e3694..976b753a87f 100644
--- a/lib/libssl/d1_clnt.c
+++ b/lib/libssl/d1_clnt.c
@@ -791,8 +791,7 @@ dtls1_client_hello(SSL *s)
 		for (i = 0; p[i]=='\0' && i < sizeof(s->s3->client_random); i++)
 			;
 		if (i == sizeof(s->s3->client_random))
-			ssl_fill_hello_random(s, 0, p,
-			    sizeof(s->s3->client_random));
+			RAND_pseudo_bytes(p, sizeof(s->s3->client_random));
 
 		/* Do the message type and length last */
 		d = p = &(buf[DTLS1_HM_HEADER_LENGTH]);
diff --git a/lib/libssl/d1_srvr.c b/lib/libssl/d1_srvr.c
index 24f0a2e86ea..a118e8e82f8 100644
--- a/lib/libssl/d1_srvr.c
+++ b/lib/libssl/d1_srvr.c
@@ -909,7 +909,8 @@ dtls1_send_server_hello(SSL *s)
 	if (s->state == SSL3_ST_SW_SRVR_HELLO_A) {
 		buf = (unsigned char *)s->init_buf->data;
 		p = s->s3->server_random;
-		ssl_fill_hello_random(s, 1, p, SSL3_RANDOM_SIZE);
+		RAND_pseudo_bytes(p, SSL3_RANDOM_SIZE);
+
 		/* Do the message type and length last */
 		d = p= &(buf[DTLS1_HM_HEADER_LENGTH]);
 
diff --git a/lib/libssl/s23_clnt.c b/lib/libssl/s23_clnt.c
index 16c30c083ab..1bc582364bd 100644
--- a/lib/libssl/s23_clnt.c
+++ b/lib/libssl/s23_clnt.c
@@ -285,30 +285,6 @@ end:
 	return (ret);
 }
 
-/*
- * Fill a ClientRandom or ServerRandom field of length len. Returns <= 0
- * on failure, 1 on success.
- */
-int
-ssl_fill_hello_random(SSL *s, int server, unsigned char *result, int len)
-{
-	int send_time = 0;
-
-	if (len < 4)
-		return 0;
-	if (server)
-		send_time = (s->mode & SSL_MODE_SEND_SERVERHELLO_TIME) != 0;
-	else
-		send_time = (s->mode & SSL_MODE_SEND_CLIENTHELLO_TIME) != 0;
-	if (send_time) {
-		unsigned long Time = (unsigned long)time(NULL);
-		unsigned char *p = result;
-		l2n(Time, p);
-		return RAND_pseudo_bytes(p, len - 4);
-	} else
-		return RAND_pseudo_bytes(result, len);
-}
-
 static int
 ssl23_client_hello(SSL *s)
 {
@@ -352,8 +328,7 @@ ssl23_client_hello(SSL *s)
 	buf = (unsigned char *)s->init_buf->data;
 	if (s->state == SSL23_ST_CW_CLNT_HELLO_A) {
 		p = s->s3->client_random;
-		if (ssl_fill_hello_random(s, 0, p, SSL3_RANDOM_SIZE) <= 0)
-			return -1;
+		RAND_pseudo_bytes(p, SSL3_RANDOM_SIZE);
 
 		if (version == TLS1_2_VERSION) {
 			version_major = TLS1_2_VERSION_MAJOR;
diff --git a/lib/libssl/s3_clnt.c b/lib/libssl/s3_clnt.c
index f2c7dd24421..45dfb64f927 100644
--- a/lib/libssl/s3_clnt.c
+++ b/lib/libssl/s3_clnt.c
@@ -674,9 +674,7 @@ ssl3_client_hello(SSL *s)
 		/* else use the pre-loaded session */
 
 		p = s->s3->client_random;
-
-		if (ssl_fill_hello_random(s, 0, p, SSL3_RANDOM_SIZE) <= 0)
-			goto err;
+		RAND_pseudo_bytes(p, SSL3_RANDOM_SIZE);
 
 		/* Do the message type and length last */
 		d = p = &(buf[4]);
diff --git a/lib/libssl/s3_srvr.c b/lib/libssl/s3_srvr.c
index bd22569ef0a..c948045ae40 100644
--- a/lib/libssl/s3_srvr.c
+++ b/lib/libssl/s3_srvr.c
@@ -1130,10 +1130,7 @@ ssl3_get_client_hello(SSL *s)
 	{
 		unsigned char *pos;
 		pos = s->s3->server_random;
-		if (ssl_fill_hello_random(s, 1, pos, SSL3_RANDOM_SIZE) <= 0) {
-			al = SSL_AD_INTERNAL_ERROR;
-			goto f_err;
-		}
+		RAND_pseudo_bytes(pos, SSL3_RANDOM_SIZE);
 	}
 
 	if (!s->hit && s->version >= TLS1_VERSION && s->tls_session_secret_cb) {
diff --git a/lib/libssl/ssl.h b/lib/libssl/ssl.h
index fd01ac98064..0c5d76bc238 100644
--- a/lib/libssl/ssl.h
+++ b/lib/libssl/ssl.h
@@ -611,12 +611,6 @@ struct ssl_session_st {
  * TLS only.)  "Released" buffers are put onto a free-list in the context
  * or just freed (depending on the context's setting for freelist_max_len). */
 #define SSL_MODE_RELEASE_BUFFERS 0x00000010L
-/* Send the current time in the Random fields of the ClientHello and
- * ServerHello records for compatibility with hypothetical implementations
- * that require it.
- */
-#define SSL_MODE_SEND_CLIENTHELLO_TIME 0x00000020L
-#define SSL_MODE_SEND_SERVERHELLO_TIME 0x00000040L
 
 /* Note: SSL[_CTX]_set_{options,mode} use |= op on the previous value,
  * they cannot be used to clear bits. */
diff --git a/lib/libssl/ssl_locl.h b/lib/libssl/ssl_locl.h
index 4aa2911da70..a96402ec5cd 100644
--- a/lib/libssl/ssl_locl.h
+++ b/lib/libssl/ssl_locl.h
@@ -621,7 +621,6 @@ void ssl_set_cert_masks(CERT *c, const SSL_CIPHER *cipher);
 STACK_OF(SSL_CIPHER) *ssl_get_ciphers_by_id(SSL *s);
 int ssl_verify_alarm_type(long type);
 void ssl_load_ciphers(void);
-int ssl_fill_hello_random(SSL *s, int server, unsigned char *field, int len);
 
 const SSL_CIPHER *ssl3_get_cipher_by_char(const unsigned char *p);
 int ssl3_put_cipher_by_char(const SSL_CIPHER *c, unsigned char *p);