Prohibit RC4 in DTLS.

ssl/d1_lib.c

@@ -167,3 +167,23 @@ void dtls1_clear(SSL *s)
 	ssl3_clear(s);
 	s->version=DTLS1_VERSION;
 	}
+
+/*
+ * As it's impossible to use stream ciphers in "datagram" mode, this
+ * simple filter is designed to disengage them in DTLS. Unfortunately
+ * there is no universal way to identify stream SSL_CIPHER, so we have
+ * to explicitly list their SSL_* codes. Currently RC4 is the only one
+ * available, but if new ones emerge, they will have to be added...
+ */
+SSL_CIPHER *dtls1_get_cipher(unsigned int u)
+	{
+	SSL_CIPHER *ciph = ssl3_get_cipher(u);
+
+	if (ciph != NULL)
+		{
+		if (ciph->algorithm_enc == SSL_RC4)
+			return NULL;
+		}
+
+	return ciph;
+	}

ssl/ssl_locl.h

@@ -746,7 +746,7 @@ const SSL_METHOD *func_name(void)  \
 		ssl3_put_cipher_by_char, \
 		ssl3_pending, \
 		ssl3_num_ciphers, \
-		ssl3_get_cipher, \
+		dtls1_get_cipher, \
 		s_get_meth, \
 		dtls1_default_timeout, \
 		&DTLSv1_enc_data, \
@@ -915,6 +915,7 @@ void dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
 void dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr);
 void dtls1_reset_seq_numbers(SSL *s, int rw);
 long dtls1_default_timeout(void);
+SSL_CIPHER *dtls1_get_cipher(unsigned int u);
 
 
 /* some client-only functions */