commit 2c99d289fd018311514573447f87b792611aefde
author David Benjamin <davidben@chromium.org> Tue Sep 01 10:23:00 2015 -0400
committer Adam Langley <agl@google.com> Tue Sep 01 20:18:21 2015 +0000
tree e06dbb290926b15a38f9a1f8227e1a9cfb1589c3
parent 43c4d17230af10222e09380661308e3a8c72cfbc

Fix buffer size computation.

The maximum buffer size computation wasn't quite done right in
ssl_buffer.c, so we were failing with BUFFER_TOO_SMALL for sufficiently
large records. Fix this and, as penance, add 103 tests.

(Test that we can receive maximum-size records in all cipher suites.
Also test SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER while I'm here.)

BUG=526998

Change-Id: I714c16dda2ed13f49d8e6cd1b48adc5a8491f43c
Reviewed-on: https://boringssl-review.googlesource.com/5785
Reviewed-by: Adam Langley <agl@google.com>

ssl/ssl_buffer.c

diff --git a/ssl/ssl_buffer.c b/ssl/ssl_buffer.c
index 37f27be..63dcd80 100644
--- a/ssl/ssl_buffer.c
+++ b/ssl/ssl_buffer.c
@@ -84,7 +84,12 @@
   }
 
   size_t header_len = ssl_record_prefix_len(ssl);
-  size_t cap = SSL3_RT_HEADER_LENGTH + SSL3_RT_MAX_PLAIN_LENGTH;
+  size_t cap = SSL3_RT_MAX_ENCRYPTED_LENGTH;
+  if (SSL_IS_DTLS(ssl)) {
+    cap += DTLS1_RT_HEADER_LENGTH;
+  } else {
+    cap += SSL3_RT_HEADER_LENGTH;
+  }
   if (ssl->options & SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER) {
     cap += SSL3_RT_MAX_EXTRA;
   }
@@ -234,10 +239,14 @@
 
   /* TODO(davidben): This matches the original behavior in keeping the malloc
    * size consistent. Does this matter? |cap| could just be |max_len|. */
-  size_t cap = SSL3_RT_HEADER_LENGTH + SSL3_RT_MAX_PLAIN_LENGTH +
-               SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD;
-  if (!SSL_IS_DTLS(ssl) && (ssl->mode & SSL_MODE_CBC_RECORD_SPLITTING)) {
-    cap += SSL3_RT_HEADER_LENGTH + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD;
+  size_t cap = SSL3_RT_MAX_PLAIN_LENGTH + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD;
+  if (SSL_IS_DTLS(ssl)) {
+    cap += DTLS1_RT_HEADER_LENGTH;
+  } else {
+    cap += SSL3_RT_HEADER_LENGTH;
+    if (ssl->mode & SSL_MODE_CBC_RECORD_SPLITTING) {
+      cap += SSL3_RT_HEADER_LENGTH + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD;
+    }
   }
 
   if (max_len > cap) {