X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=libtomcrypt%2Fsrc%2Fmodes%2Flrw%2Flrw_process.c;fp=libtomcrypt%2Fsrc%2Fmodes%2Flrw%2Flrw_process.c;h=0896bc6413284440ac4dbbdb3e1268d6c27df747;hb=66bc25938679f1d6a1d1200f329093d82a5e99b4;hp=0000000000000000000000000000000000000000;hpb=a52ee0733f420ca20224049260d6fc5cf7d8f621;p=zpackage

diff --git a/libtomcrypt/src/modes/lrw/lrw_process.c b/libtomcrypt/src/modes/lrw/lrw_process.c
new file mode 100644
index 0000000..0896bc6
--- /dev/null
+++ b/libtomcrypt/src/modes/lrw/lrw_process.c
@@ -0,0 +1,118 @@
+/* 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"
+
+/**
+   @file lrw_process.c
+   LRW_MODE implementation, Encrypt/decrypt blocks, Tom St Denis
+*/
+
+#ifdef LTC_LRW_MODE
+
+/**
+  Process blocks with LRW, since decrypt/encrypt are largely the same they share this code.
+  @param pt        The "input" data
+  @param ct        [out] The "output" data
+  @param len       The length of the input, must be a multiple of 128-bits (16 octets)
+  @param mode      LRW_ENCRYPT or LRW_DECRYPT
+  @param lrw       The LRW state
+  @return  CRYPT_OK if successful
+*/
+int lrw_process(const unsigned char *pt, unsigned char *ct, unsigned long len, int mode, symmetric_LRW *lrw)
+{
+   unsigned char prod[16];
+   int           x, err;
+#ifdef LTC_LRW_TABLES
+   int           y;
+#endif
+
+   LTC_ARGCHK(pt  != NULL);
+   LTC_ARGCHK(ct  != NULL);
+   LTC_ARGCHK(lrw != NULL);
+
+   if (len & 15) {
+      return CRYPT_INVALID_ARG;
+   }
+
+   while (len) {
+      /* copy pad */
+      XMEMCPY(prod, lrw->pad, 16);
+
+      /* increment IV */
+      for (x = 15; x >= 0; x--) {
+          lrw->IV[x] = (lrw->IV[x] + 1) & 255;
+          if (lrw->IV[x]) {
+              break;
+          }
+      }
+
+      /* update pad */
+#ifdef LTC_LRW_TABLES
+      /* for each byte changed we undo it's affect on the pad then add the new product */
+      for (; x < 16; x++) {
+#ifdef LTC_FAST
+          for (y = 0; y < 16; y += sizeof(LTC_FAST_TYPE)) {
+              *(LTC_FAST_TYPE_PTR_CAST(lrw->pad + y)) ^= *(LTC_FAST_TYPE_PTR_CAST(&lrw->PC[x][lrw->IV[x]][y])) ^ *(LTC_FAST_TYPE_PTR_CAST(&lrw->PC[x][(lrw->IV[x]-1)&255][y]));
+          }
+#else
+          for (y = 0; y < 16; y++) {
+              lrw->pad[y] ^= lrw->PC[x][lrw->IV[x]][y] ^ lrw->PC[x][(lrw->IV[x]-1)&255][y];
+          }
+#endif
+      }
+#else
+      gcm_gf_mult(lrw->tweak, lrw->IV, lrw->pad);
+#endif
+
+      /* xor prod */
+#ifdef LTC_FAST
+      for (x = 0; x < 16; x += sizeof(LTC_FAST_TYPE)) {
+           *(LTC_FAST_TYPE_PTR_CAST(ct + x)) = *(LTC_FAST_TYPE_PTR_CAST(pt + x)) ^ *(LTC_FAST_TYPE_PTR_CAST(prod + x));
+      }
+#else
+      for (x = 0; x < 16; x++) {
+         ct[x] = pt[x] ^ prod[x];
+      }
+#endif
+
+      /* send through cipher */
+      if (mode == LRW_ENCRYPT) {
+         if ((err = cipher_descriptor[lrw->cipher].ecb_encrypt(ct, ct, &lrw->key)) != CRYPT_OK) {
+            return err;
+         }
+      } else {
+         if ((err = cipher_descriptor[lrw->cipher].ecb_decrypt(ct, ct, &lrw->key)) != CRYPT_OK) {
+            return err;
+         }
+      }
+
+      /* xor prod */
+#ifdef LTC_FAST
+      for (x = 0; x < 16; x += sizeof(LTC_FAST_TYPE)) {
+           *(LTC_FAST_TYPE_PTR_CAST(ct + x)) = *(LTC_FAST_TYPE_PTR_CAST(ct + x)) ^ *(LTC_FAST_TYPE_PTR_CAST(prod + x));
+      }
+#else
+      for (x = 0; x < 16; x++) {
+         ct[x] = ct[x] ^ prod[x];
+      }
+#endif
+
+      /* move to next */
+      pt  += 16;
+      ct  += 16;
+      len -= 16;
+   }
+
+   return CRYPT_OK;
+}
+
+#endif
+/* ref:         $Format:%D$ */
+/* git commit:  $Format:%H$ */
+/* commit time: $Format:%ai$ */