--- /dev/null
+/* ====================================================================
+ * 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/crypto.h>
+#include "modes_lcl.h"
+#include <string.h>
+
+#ifndef MODES_DEBUG
+# ifndef NDEBUG
+# define NDEBUG
+# endif
+#endif
+#include <assert.h>
+
+/* The input and output encrypted as though 128bit cfb mode is being
+ * used. The extra state information to record how much of the
+ * 128bit block we have used is contained in *num;
+ */
+void CRYPTO_cfb128_encrypt(const unsigned char *in, unsigned char *out,
+ size_t len, const void *key,
+ unsigned char ivec[16], int *num,
+ int enc, block128_f block)
+{
+ unsigned int n;
+ size_t l = 0;
+
+ assert(in && out && key && ivec && num);
+
+ n = *num;
+
+ if (enc) {
+#if !defined(OPENSSL_SMALL_FOOTPRINT)
+ if (16%sizeof(size_t) == 0) do { /* always true actually */
+ while (n && len) {
+ *(out++) = ivec[n] ^= *(in++);
+ --len;
+ n = (n+1) % 16;
+ }
+#if defined(STRICT_ALIGNMENT)
+ if (((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0)
+ break;
+#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;
+ } while (0);
+ /* the rest would be commonly eliminated by x86* compiler */
+#endif
+ while (l<len) {
+ if (n == 0) {
+ (*block)(ivec, ivec, key);
+ }
+ out[l] = ivec[n] ^= in[l];
+ ++l;
+ n = (n+1) % 16;
+ }
+ *num = n;
+ } else {
+#if !defined(OPENSSL_SMALL_FOOTPRINT)
+ if (16%sizeof(size_t) == 0) do { /* always true actually */
+ while (n && len) {
+ unsigned char c;
+ *(out++) = ivec[n] ^ (c = *(in++)); ivec[n] = c;
+ --len;
+ n = (n+1) % 16;
+ }
+#if defined(STRICT_ALIGNMENT)
+ if (((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0)
+ break;
+#endif
+ 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--) {
+ unsigned char c;
+ out[n] = ivec[n] ^ (c = in[n]); ivec[n] = c;
+ ++n;
+ }
+ }
+ *num = n;
+ return;
+ } while (0);
+ /* the rest would be commonly eliminated by x86* compiler */
+#endif
+ 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;
+ }
+}
+
+/* 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 unsigned char *in,unsigned char *out,
+ int nbits,const void *key,
+ unsigned char ivec[16],int enc,
+ block128_f block)
+{
+ int n,rem,num;
+ unsigned char 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 unsigned char *in, unsigned char *out,
+ size_t bits, const void *key,
+ unsigned char ivec[16], int *num,
+ int enc, block128_f block)
+{
+ size_t n;
+ unsigned char 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);
+}
+
projects / cassiopeia.git / blobdiff