Index: openssl/crypto/modes/ctr128.c |
=================================================================== |
--- openssl/crypto/modes/ctr128.c (revision 0) |
+++ openssl/crypto/modes/ctr128.c (revision 0) |
@@ -0,0 +1,184 @@ |
+/* ==================================================================== |
+ * 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 "modes.h" |
+#include <string.h> |
+ |
+#ifndef MODES_DEBUG |
+# ifndef NDEBUG |
+# define NDEBUG |
+# endif |
+#endif |
+#include <assert.h> |
+ |
+typedef unsigned int u32; |
+typedef unsigned char u8; |
+ |
+#define STRICT_ALIGNMENT |
+#if defined(__i386) || defined(__i386__) || \ |
+ defined(__x86_64) || defined(__x86_64__) || \ |
+ defined(_M_IX86) || defined(_M_AMD64) || defined(_M_X64) || \ |
+ defined(__s390__) || defined(__s390x__) |
+# undef STRICT_ALIGNMENT |
+#endif |
+ |
+/* NOTE: the IV/counter CTR mode is big-endian. The code itself |
+ * is endian-neutral. */ |
+ |
+/* increment counter (128-bit int) by 1 */ |
+static void ctr128_inc(unsigned char *counter) { |
+ u32 n=16; |
+ u8 c; |
+ |
+ do { |
+ --n; |
+ c = counter[n]; |
+ ++c; |
+ counter[n] = c; |
+ if (c) return; |
+ } while (n); |
+} |
+ |
+#if !defined(OPENSSL_SMALL_FOOTPRINT) |
+static void ctr128_inc_aligned(unsigned char *counter) { |
+ size_t *data,c,n; |
+ const union { long one; char little; } is_endian = {1}; |
+ |
+ if (is_endian.little) { |
+ ctr128_inc(counter); |
+ return; |
+ } |
+ |
+ data = (size_t *)counter; |
+ n = 16/sizeof(size_t); |
+ do { |
+ --n; |
+ c = data[n]; |
+ ++c; |
+ data[n] = c; |
+ if (c) return; |
+ } while (n); |
+} |
+#endif |
+ |
+/* The input encrypted as though 128bit counter mode is being |
+ * used. The extra state information to record how much of the |
+ * 128bit block we have used is contained in *num, and the |
+ * encrypted counter is kept in ecount_buf. Both *num and |
+ * ecount_buf must be initialised with zeros before the first |
+ * call to CRYPTO_ctr128_encrypt(). |
+ * |
+ * This algorithm assumes that the counter is in the x lower bits |
+ * of the IV (ivec), and that the application has full control over |
+ * overflow and the rest of the IV. This implementation takes NO |
+ * responsability for checking that the counter doesn't overflow |
+ * into the rest of the IV when incremented. |
+ */ |
+void CRYPTO_ctr128_encrypt(const unsigned char *in, unsigned char *out, |
+ size_t len, const void *key, |
+ unsigned char ivec[16], unsigned char ecount_buf[16], |
+ unsigned int *num, block128_f block) |
+{ |
+ unsigned int n; |
+ size_t l=0; |
+ |
+ assert(in && out && key && ecount_buf && num); |
+ assert(*num < 16); |
+ |
+ n = *num; |
+ |
+#if !defined(OPENSSL_SMALL_FOOTPRINT) |
+ if (16%sizeof(size_t) == 0) do { /* always true actually */ |
+ while (n && len) { |
+ *(out++) = *(in++) ^ ecount_buf[n]; |
+ --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, ecount_buf, key); |
+ ctr128_inc_aligned(ivec); |
+ for (; n<16; n+=sizeof(size_t)) |
+ *(size_t *)(out+n) = |
+ *(size_t *)(in+n) ^ *(size_t *)(ecount_buf+n); |
+ len -= 16; |
+ out += 16; |
+ in += 16; |
+ n = 0; |
+ } |
+ if (len) { |
+ (*block)(ivec, ecount_buf, key); |
+ ctr128_inc_aligned(ivec); |
+ while (len--) { |
+ out[n] = in[n] ^ ecount_buf[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, ecount_buf, key); |
+ ctr128_inc(ivec); |
+ } |
+ out[l] = in[l] ^ ecount_buf[n]; |
+ ++l; |
+ n = (n+1) % 16; |
+ } |
+ |
+ *num=n; |
+} |