--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hmac_file.c	Mon May 31 18:21:40 2004 +0000
@@ -0,0 +1,96 @@
+/* LibTomCrypt, modular cryptographic library -- Tom St Denis
+ *
+ * LibTomCrypt is a library that provides various cryptographic
+ * algorithms in a highly modular and flexible manner.
+ *
+ * The library is free for all purposes without any express
+ * guarantee it works.
+ *
+ * Tom St Denis, [email protected], http://libtomcrypt.org
+ */
+/* Submited by Dobes Vandermeer  ([email protected]) */
+
+#include "mycrypt.h"
+
+/*
+    (1) append zeros to the end of K to create a B byte string
+        (e.g., if K is of length 20 bytes and B=64, then K will be
+         appended with 44 zero bytes 0x00)
+    (2) XOR (bitwise exclusive-OR) the B byte string computed in step
+        (1) with ipad (ipad = the byte 0x36 repeated B times)
+    (3) append the stream of data 'text' to the B byte string resulting
+        from step (2)
+    (4) apply H to the stream generated in step (3)
+    (5) XOR (bitwise exclusive-OR) the B byte string computed in
+        step (1) with opad (opad = the byte 0x5C repeated B times.)
+    (6) append the H result from step (4) to the B byte string
+        resulting from step (5)
+    (7) apply H to the stream generated in step (6) and output
+        the result
+*/
+
+#ifdef HMAC
+
+#define HMAC_BLOCKSIZE hash_descriptor[hash].blocksize
+
+/* hmac_file added by Tom St Denis */
+int hmac_file(int hash, const char *fname, 
+              const unsigned char *key, unsigned long keylen, 
+                    unsigned char *dst, unsigned long *dstlen)
+{
+#ifdef NO_FILE
+    return CRYPT_NOP;
+#else
+   hmac_state hmac;
+   FILE *in;
+   unsigned char buf[512];
+   size_t x;
+   int err;
+
+   _ARGCHK(fname  != NULL);
+   _ARGCHK(key    != NULL);
+   _ARGCHK(dst    != NULL);
+   _ARGCHK(dstlen != NULL);
+   
+   if((err = hash_is_valid(hash)) != CRYPT_OK) {
+       return err;
+   }
+
+   if ((err = hmac_init(&hmac, hash, key, keylen)) != CRYPT_OK) {
+       return err;
+   }
+
+   in = fopen(fname, "rb");
+   if (in == NULL) {
+      return CRYPT_FILE_NOTFOUND;
+   }
+
+   /* process the file contents */
+   do {
+      x = fread(buf, 1, sizeof(buf), in);
+      if ((err = hmac_process(&hmac, buf, (unsigned long)x)) != CRYPT_OK) {
+         /* we don't trap this error since we're already returning an error! */
+         fclose(in);
+         return err;
+      }
+   } while (x == sizeof(buf));
+
+   if (fclose(in) != 0) {
+      return CRYPT_ERROR;
+   }
+
+   /* get final hmac */
+   if ((err = hmac_done(&hmac, dst, dstlen)) != CRYPT_OK) {
+      return err;
+   }
+
+#ifdef CLEAN_STACK
+   /* clear memory */
+   zeromem(buf, sizeof(buf));
+#endif   
+   return CRYPT_OK;
+#endif
+}
+
+#endif
+