bugfix: if the len of iv is not 96-bit, y0 can be calculated incorrectly
An initialization vector IV can have any number of bits between 1 and
2^64. So it should be filled to the lower 64-bit in the last step
when computing ghash.
Signed-off-by: openluopworld <luopengxq@gmail.com>
diff --git a/library/gcm.c b/library/gcm.c
index 0810fd2..e1c1c7d 100644
--- a/library/gcm.c
+++ b/library/gcm.c
@@ -278,8 +278,7 @@
else
{
memset( work_buf, 0x00, 16 );
- MBEDTLS_PUT_UINT32_BE( iv_len >> 29, work_buf, 8 );
- MBEDTLS_PUT_UINT32_BE( iv_len << 3, work_buf, 12 );
+ MBEDTLS_PUT_UINT64_BE( iv_len * 8, work_buf, 8 );
p = iv;
while( iv_len > 0 )