Sanity check the return from final_finish_mac

The return value is checked for 0. This is currently safe but we should
really check for <= 0 since -1 is frequently used for error conditions.
Thanks to Kevin Wojtysiak (Int3 Solutions) and Paramjot Oberoi (Int3
Solutions) for reporting this issue.

Reviewed-by: Andy Polyakov <appro@openssl.org>

diff --git a/ssl/s3_both.c b/ssl/s3_both.c
index d0cb763b8d57279eb2b2fdd4344e4dbbf51a1c4a..bf5e8c7c2da42c27478ab80f79ea166a3c9b2dc8 100644 (file)
--- a/ssl/s3_both.c
+++ b/ssl/s3_both.c
@@ -168,7 +168,7 @@ int ssl3_send_finished(SSL *s, int a, int b, const char *sender, int slen)
         i = s->method->ssl3_enc->final_finish_mac(s,
                                                   sender, slen,
                                                   s->s3->tmp.finish_md);
-        if (i == 0)
+        if (i <= 0)
             return 0;
         s->s3->tmp.finish_md_len = i;
         memcpy(p, s->s3->tmp.finish_md, i);

diff --git a/ssl/ssl_locl.h b/ssl/ssl_locl.h
index 8b4c6150efdc5db923131f49d5cc83d966f2613d..9ae1a0711b180126e47897db9e2280d5f0fb4b07 100644 (file)
--- a/ssl/ssl_locl.h
+++ b/ssl/ssl_locl.h
@@ -2073,7 +2073,6 @@ void dtls1_set_message_header(SSL *s,
 __owur int dtls1_write_app_data_bytes(SSL *s, int type, const void *buf, int len);
 
 __owur int dtls1_send_change_cipher_spec(SSL *s, int a, int b);
-__owur int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen);
 __owur int dtls1_read_failed(SSL *s, int code);
 __owur int dtls1_buffer_message(SSL *s, int ccs);
 __owur int dtls1_retransmit_message(SSL *s, unsigned short seq,