Fix wrong length limit in GCM
See for example page 8 of
http://csrc.nist.gov/publications/nistpubs/800-38D/SP-800-38D.pdf
The previous constant probably came from a typo as it was 2^26 - 2^5 instead
of 2^36 - 2^5. Clearly the intention was to allow for a constant bigger than
2^32 as the ull suffix and cast to uint64_t show.
fixes #362
diff --git a/ChangeLog b/ChangeLog
index 8a736f9..4526254 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
mbed TLS ChangeLog (Sorted per branch, date)
+= mbed TLS 2.2.1 released 2015-12-xx
+
+Bugfix
+ * Fix over-restricive length limit in GCM. Found by Andreas-N. #362
+
= mbed TLS 2.2.0 released 2015-11-04
Security
diff --git a/library/gcm.c b/library/gcm.c
index 4298254..aaacf97 100644
--- a/library/gcm.c
+++ b/library/gcm.c
@@ -362,7 +362,7 @@
/* Total length is restricted to 2^39 - 256 bits, ie 2^36 - 2^5 bytes
* Also check for possible overflow */
if( ctx->len + length < ctx->len ||
- (uint64_t) ctx->len + length > 0x03FFFFE0ull )
+ (uint64_t) ctx->len + length > 0xFFFFFFFE0ull )
{
return( MBEDTLS_ERR_GCM_BAD_INPUT );
}