X-Git-Url: https://pd.if.org/git/?p=zpackage;a=blobdiff_plain;f=libtomcrypt%2Fsrc%2Fmodes%2Fxts%2Fxts_decrypt.c;fp=libtomcrypt%2Fsrc%2Fmodes%2Fxts%2Fxts_decrypt.c;h=0000000000000000000000000000000000000000;hp=458099150860360a7c5f96e7a2b8f5f9a27534d2;hb=d6319f7ea0a76de91bc01d9734d235b494c40198;hpb=5299b2ad7c4ba7a82ee1bcb1953663f63e8e9a14

diff --git a/libtomcrypt/src/modes/xts/xts_decrypt.c b/libtomcrypt/src/modes/xts/xts_decrypt.c
deleted file mode 100644
index 4580991..0000000
--- a/libtomcrypt/src/modes/xts/xts_decrypt.c
+++ /dev/null
@@ -1,156 +0,0 @@
-/* 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.
- */
-#include "tomcrypt.h"
-
-/**
- Source donated by Elliptic Semiconductor Inc (www.ellipticsemi.com) to the LibTom Projects
- */
-
-#ifdef LTC_XTS_MODE
-
-static int _tweak_uncrypt(const unsigned char *C, unsigned char *P, unsigned char *T, symmetric_xts *xts)
-{
-   unsigned long x;
-   int err;
-
-   /* tweak encrypt block i */
-#ifdef LTC_FAST
-   for (x = 0; x < 16; x += sizeof(LTC_FAST_TYPE)) {
-      *(LTC_FAST_TYPE_PTR_CAST(&P[x])) = *(LTC_FAST_TYPE_PTR_CAST(&C[x])) ^ *(LTC_FAST_TYPE_PTR_CAST(&T[x]));
-   }
-#else
-   for (x = 0; x < 16; x++) {
-      P[x] = C[x] ^ T[x];
-   }
-#endif
-
-   err = cipher_descriptor[xts->cipher].ecb_decrypt(P, P, &xts->key1);
-
-#ifdef LTC_FAST
-   for (x = 0; x < 16; x += sizeof(LTC_FAST_TYPE)) {
-      *(LTC_FAST_TYPE_PTR_CAST(&P[x])) ^= *(LTC_FAST_TYPE_PTR_CAST(&T[x]));
-   }
-#else
-   for (x = 0; x < 16; x++) {
-      P[x] = P[x] ^ T[x];
-   }
-#endif
-
-   /* LFSR the tweak */
-   xts_mult_x(T);
-
-   return err;
-}
-
-/** XTS Decryption
- @param ct     [in] Ciphertext
- @param ptlen  Length of plaintext (and ciphertext)
- @param pt     [out]  Plaintext
- @param tweak  [in] The 128--bit encryption tweak (e.g. sector number)
- @param xts    The XTS structure
- Returns CRYPT_OK upon success
- */
-int xts_decrypt(const unsigned char *ct, unsigned long ptlen, unsigned char *pt, unsigned char *tweak,
-                symmetric_xts *xts)
-{
-   unsigned char PP[16], CC[16], T[16];
-   unsigned long i, m, mo, lim;
-   int err;
-
-   /* check inputs */
-   LTC_ARGCHK(pt != NULL);
-   LTC_ARGCHK(ct != NULL);
-   LTC_ARGCHK(tweak != NULL);
-   LTC_ARGCHK(xts != NULL);
-
-   /* check if valid */
-   if ((err = cipher_is_valid(xts->cipher)) != CRYPT_OK) {
-      return err;
-   }
-
-   /* get number of blocks */
-   m = ptlen >> 4;
-   mo = ptlen & 15;
-
-   /* must have at least one full block */
-   if (m == 0) {
-      return CRYPT_INVALID_ARG;
-   }
-
-   if (mo == 0) {
-      lim = m;
-   } else {
-      lim = m - 1;
-   }
-
-   if (cipher_descriptor[xts->cipher].accel_xts_decrypt && lim > 0) {
-
-      /* use accelerated decryption for whole blocks */
-      if ((err = cipher_descriptor[xts->cipher].accel_xts_decrypt(ct, pt, lim, tweak, &xts->key1, &xts->key2)) !=
-                 CRYPT_OK) {
-         return err;
-      }
-      ct += lim * 16;
-      pt += lim * 16;
-
-      /* tweak is encrypted on output */
-      XMEMCPY(T, tweak, sizeof(T));
-   } else {
-      /* encrypt the tweak */
-      if ((err = cipher_descriptor[xts->cipher].ecb_encrypt(tweak, T, &xts->key2)) != CRYPT_OK) {
-         return err;
-      }
-
-      for (i = 0; i < lim; i++) {
-         if ((err = _tweak_uncrypt(ct, pt, T, xts)) != CRYPT_OK) {
-            return err;
-         }
-         ct += 16;
-         pt += 16;
-      }
-   }
-
-   /* if ptlen not divide 16 then */
-   if (mo > 0) {
-      XMEMCPY(CC, T, 16);
-      xts_mult_x(CC);
-
-      /* PP = tweak decrypt block m-1 */
-      if ((err = _tweak_uncrypt(ct, PP, CC, xts)) != CRYPT_OK) {
-         return err;
-      }
-
-      /* Pm = first ptlen % 16 bytes of PP */
-      for (i = 0; i < mo; i++) {
-         CC[i] = ct[16 + i];
-         pt[16 + i] = PP[i];
-      }
-      for (; i < 16; i++) {
-         CC[i] = PP[i];
-      }
-
-      /* Pm-1 = Tweak uncrypt CC */
-      if ((err = _tweak_uncrypt(CC, pt, T, xts)) != CRYPT_OK) {
-         return err;
-      }
-   }
-
-   /* Decrypt the tweak back */
-   if ((err = cipher_descriptor[xts->cipher].ecb_decrypt(T, tweak, &xts->key2)) != CRYPT_OK) {
-      return err;
-   }
-
-   return CRYPT_OK;
-}
-
-#endif
-
-/* ref:         $Format:%D$ */
-/* git commit:  $Format:%H$ */
-/* commit time: $Format:%ai$ */