Avoid out-of-bounds write in SSL_get_shared_ciphers

PR: 3317

diff --git a/ssl/ssl_lib.c b/ssl/ssl_lib.c
index cfe40b2fa4311284b012c9cd2696440c0e56229f..4f2a2715def854b976d1fdda6ce3db740d3e2fd8 100644 (file)
--- a/ssl/ssl_lib.c
+++ b/ssl/ssl_lib.c
@@ -1320,6 +1320,9 @@ char *SSL_get_shared_ciphers(const SSL *s,char *buf,int len)
                (len < 2))
                return(NULL);
 
+       if (sk_SSL_CIPHER_num(sk) == 0)
+               return NULL;
+
        p=buf;
        sk=s->session->ciphers;
        for (i=0; i<sk_SSL_CIPHER_num(sk); i++)