des_cbc_encrypt / des_ncbc_encrypt issue.

CHANGES

@@ -14,10 +14,9 @@
   *) DES CBC did not update the IV. Weird.
      [Ben Laurie]
 #else
-     Look at des.c, cbc3_enc.c etc.: Those rely on that bevaviour of
-     des_cbc_encrypt and copy IVs themselves when they have to.
-     Either all those have to be changed too, or things must stay as they
-     are.
+     des_cbc_encrypt does not update the IV, but des_ncbc_encrypt does.
+     Changing the behaviour of the former might break existing programs --
+     where IV updating is needed, des_ncbc_encrypt can be used.
 #endif
 
   *) When bntest is run from "make test" it drives bc to check its

crypto/des/des.h

@@ -151,6 +151,7 @@ void des_ecb3_encrypt(const_des_cblock *input, des_cblock *output,
 DES_LONG des_cbc_cksum(const unsigned char *input,des_cblock *output,
 		       long length,des_key_schedule schedule,
 		       const_des_cblock *ivec);
+/* des_cbc_encrypt does not update the IV!  Use des_ncbc_encrypt instead. */
 void des_cbc_encrypt(const unsigned char *input,unsigned char *output,
 		     long length,des_key_schedule schedule,des_cblock *ivec,
 		     int enc);