X-Git-Url: https://git.distorted.org.uk/~mdw/catacomb/blobdiff_plain/0f00dc4c8eb47e67bc0f148c2dd109f73a451e0a..1b420890ac399d1844ab6c4fe0e0e22ba8fbe3ad:/symm/des.h

diff --git a/symm/des.h b/symm/des.h
index 682be6b0..6f5ebbe8 100644
--- a/symm/des.h
+++ b/symm/des.h
@@ -66,6 +66,23 @@ typedef struct des_ctx {
 
 /*----- Functions provided ------------------------------------------------*/
 
+/* --- @des_fixparity@ --- *
+ *
+ * Arguments:	@octet *z@ = output buffer pointer, or null
+ *		@const octet *p@ = input buffer pointer
+ *		@size_t sz@ = size of the buffers
+ *
+ * Returns:	Zero if the input already had correct parity, @-1@ if changes
+ *		were necessary (in constant time).
+ *
+ * Use:		Check the @sz@ bytes at @p@ for odd parity (as used in DES
+ *		keys); if @z@ is not null, then copy a parity-fixed version
+ *		of @p@ to @z@.  The two buffers at @p@ and @z@ may coincide,
+ *		or be disjoint, but not otherwise overlap.
+ */
+
+extern int des_fixparity(octet */*z*/, const octet */*p*/, size_t /*sz*/);
+
 /* --- @des_expand@ --- *
  *
  * Arguments:	@const octet *k@ = pointer to key material