1 files changed, 230 insertions, 0 deletions
diff --git a/src/crypto/modes/cfb.c b/src/crypto/modes/cfb.c
new file mode 100644
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+++ b/src/crypto/modes/cfb.c
@@ -0,0 +1,230 @@
+/* ====================================================================
+ * Copyright (c) 2008 The OpenSSL Project.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. All advertising materials mentioning features or use of this
+ *    software must display the following acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
+ *
+ * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
+ *    endorse or promote products derived from this software without
+ *    prior written permission. For written permission, please contact
+ *    openssl-core@openssl.org.
+ *
+ * 5. Products derived from this software may not be called "OpenSSL"
+ *    nor may "OpenSSL" appear in their names without prior written
+ *    permission of the OpenSSL Project.
+ *
+ * 6. Redistributions of any form whatsoever must retain the following
+ *    acknowledgment:
+ *    "This product includes software developed by the OpenSSL Project
+ *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
+ * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ * ==================================================================== */
+
+#include <openssl/modes.h>
+
+#include <assert.h>
+#include <string.h>
+
+#include "internal.h"
+
+
+void CRYPTO_cfb128_encrypt(const uint8_t *in, uint8_t *out, size_t len,
+                           const void *key, uint8_t ivec[16], int *num, int enc,
+                           block128_f block) {
+  unsigned int n;
+  size_t l = 0;
+
+  assert(in && out && key && ivec && num);
+  assert((16 % sizeof(size_t)) == 0);
+
+  n = *num;
+
+  if (enc) {
+    while (n && len) {
+      *(out++) = ivec[n] ^= *(in++);
+      --len;
+      n = (n + 1) % 16;
+    }
+#if STRICT_ALIGNMENT
+    if (((size_t)in | (size_t)out | (size_t)ivec) % sizeof(size_t) != 0) {
+      while (l < len) {
+        if (n == 0) {
+          (*block)(ivec, ivec, key);
+        }
+        out[l] = ivec[n] ^= in[l];
+        ++l;
+        n = (n + 1) % 16;
+      }
+      *num = n;
+      return;
+    }
+#endif
+    while (len >= 16) {
+      (*block)(ivec, ivec, key);
+      for (; n < 16; n += sizeof(size_t)) {
+        *(size_t *)(out + n) = *(size_t *)(ivec + n) ^= *(size_t *)(in + n);
+      }
+      len -= 16;
+      out += 16;
+      in += 16;
+      n = 0;
+    }
+    if (len) {
+      (*block)(ivec, ivec, key);
+      while (len--) {
+        out[n] = ivec[n] ^= in[n];
+        ++n;
+      }
+    }
+    *num = n;
+    return;
+  } else {
+    while (n && len) {
+      uint8_t c;
+      *(out++) = ivec[n] ^ (c = *(in++));
+      ivec[n] = c;
+      --len;
+      n = (n + 1) % 16;
+    }
+    if (STRICT_ALIGNMENT && ((size_t)in | (size_t)out | (size_t)ivec) % sizeof(size_t) != 0) {
+      while (l < len) {
+        unsigned char c;
+        if (n == 0) {
+          (*block)(ivec, ivec, key);
+        }
+        out[l] = ivec[n] ^ (c = in[l]);
+        ivec[n] = c;
+        ++l;
+        n = (n + 1) % 16;
+      }
+      *num = n;
+      return;
+    }
+    while (len >= 16) {
+      (*block)(ivec, ivec, key);
+      for (; n < 16; n += sizeof(size_t)) {
+        size_t t = *(size_t *)(in + n);
+        *(size_t *)(out + n) = *(size_t *)(ivec + n) ^ t;
+        *(size_t *)(ivec + n) = t;
+      }
+      len -= 16;
+      out += 16;
+      in += 16;
+      n = 0;
+    }
+    if (len) {
+      (*block)(ivec, ivec, key);
+      while (len--) {
+        uint8_t c;
+        out[n] = ivec[n] ^ (c = in[n]);
+        ivec[n] = c;
+        ++n;
+      }
+    }
+    *num = n;
+    return;
+  }
+}
+
+
+/* This expects a single block of size nbits for both in and out. Note that
+   it corrupts any extra bits in the last byte of out */
+static void cfbr_encrypt_block(const uint8_t *in, uint8_t *out, unsigned nbits,
+                               const void *key, uint8_t ivec[16], int enc,
+                               block128_f block) {
+  int n, rem, num;
+  uint8_t ovec[16 * 2 + 1]; /* +1 because we dererefence (but don't use) one
+                               byte off the end */
+
+  if (nbits <= 0 || nbits > 128) {
+    return;
+  }
+
+  /* fill in the first half of the new IV with the current IV */
+  memcpy(ovec, ivec, 16);
+  /* construct the new IV */
+  (*block)(ivec, ivec, key);
+  num = (nbits + 7) / 8;
+  if (enc) {
+    /* encrypt the input */
+    for (n = 0; n < num; ++n) {
+      out[n] = (ovec[16 + n] = in[n] ^ ivec[n]);
+    }
+  } else {
+    /* decrypt the input */
+    for (n = 0; n < num; ++n) {
+      out[n] = (ovec[16 + n] = in[n]) ^ ivec[n];
+    }
+  }
+  /* shift ovec left... */
+  rem = nbits % 8;
+  num = nbits / 8;
+  if (rem == 0) {
+    memcpy(ivec, ovec + num, 16);
+  } else {
+    for (n = 0; n < 16; ++n) {
+      ivec[n] = ovec[n + num] << rem | ovec[n + num + 1] >> (8 - rem);
+    }
+  }
+
+  /* it is not necessary to cleanse ovec, since the IV is not secret */
+}
+
+/* N.B. This expects the input to be packed, MS bit first */
+void CRYPTO_cfb128_1_encrypt(const uint8_t *in, uint8_t *out, size_t bits,
+                             const void *key, uint8_t ivec[16], int *num,
+                             int enc, block128_f block) {
+  size_t n;
+  uint8_t c[1], d[1];
+
+  assert(in && out && key && ivec && num);
+  assert(*num == 0);
+
+  for (n = 0; n < bits; ++n) {
+    c[0] = (in[n / 8] & (1 << (7 - n % 8))) ? 0x80 : 0;
+    cfbr_encrypt_block(c, d, 1, key, ivec, enc, block);
+    out[n / 8] = (out[n / 8] & ~(1 << (unsigned int)(7 - n % 8))) |
+                 ((d[0] & 0x80) >> (unsigned int)(n % 8));
+  }
+}
+
+void CRYPTO_cfb128_8_encrypt(const unsigned char *in, unsigned char *out,
+                             size_t length, const void *key,
+                             unsigned char ivec[16], int *num, int enc,
+                             block128_f block) {
+  size_t n;
+
+  assert(in && out && key && ivec && num);
+  assert(*num == 0);
+
+  for (n = 0; n < length; ++n) {
+    cfbr_encrypt_block(&in[n], &out[n], 8, key, ivec, enc, block);
+  }
+}
+