svn commit: r346649 - head/sys/opencrypto

[John Baldwin]

Author: jhb
Date: Wed Apr 24 23:27:39 2019
New Revision: 346649
URL: https://svnweb.freebsd.org/changeset/base/346649

Log:
  Don't panic for empty CCM requests.
  
  A request to encrypt an empty payload without any AAD is unusual, but
  it is defined behavior.  Removing this assertion removes a panic and
  instead returns the correct tag for an empty buffer.
  
  Reviewed by:	cem, sef
  MFC after:	2 weeks
  Sponsored by:	Chelsio Communications
  Differential Revision:	https://reviews.freebsd.org/D20043

Modified:
  head/sys/opencrypto/cbc_mac.c

Modified: head/sys/opencrypto/cbc_mac.c
==============================================================================
--- head/sys/opencrypto/cbc_mac.c	Wed Apr 24 23:18:10 2019	(r346648)
+++ head/sys/opencrypto/cbc_mac.c	Wed Apr 24 23:27:39 2019	(r346649)
@@ -82,9 +82,6 @@ AES_CBC_MAC_Reinit(struct aes_cbc_mac_ctx *ctx, const 
 	uint8_t *bp = b0, flags = 0;
 	uint8_t L = 0;
 	uint64_t dataLength = ctx->cryptDataLength;
-	
-	KASSERT(ctx->authDataLength != 0 || ctx->cryptDataLength != 0,
-	    ("Auth Data and Data lengths cannot both be 0"));
 
 	KASSERT(nonceLen >= 7 && nonceLen <= 13,
 	    ("nonceLen must be between 7 and 13 bytes"));