check in v3.8.2 source

crypto/modes/ofb128.c

@@ -0,0 +1,124 @@
+/* $OpenBSD: ofb128.c,v 1.7 2023/07/08 14:56:54 beck Exp $ */
+/* ====================================================================
+ * 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_local.h"
+#include <string.h>
+
+#ifndef MODES_DEBUG
+# ifndef NDEBUG
+#  define NDEBUG
+# endif
+#endif
+
+/* The input and output encrypted as though 128bit ofb 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_ofb128_encrypt(const unsigned char *in, unsigned char *out,
+    size_t len, const void *key,
+    unsigned char ivec[16], int *num,
+    block128_f block)
+{
+	unsigned int n;
+	size_t l = 0;
+
+	n = *num;
+
+#if !defined(OPENSSL_SMALL_FOOTPRINT)
+	if (16 % sizeof(size_t) == 0)
+		do { /* always true actually */
+			while (n && len) {
+				*(out++) = *(in++) ^ ivec[n];
+				--len;
+				n = (n + 1) % 16;
+			}
+#ifdef __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 *)(in + n) ^ *(size_t *)(ivec +
+					    n);
+				len -= 16;
+				out += 16;
+				in += 16;
+				n = 0;
+			}
+			if (len) {
+				(*block)(ivec, ivec, key);
+				while (len--) {
+					out[n] = in[n] ^ ivec[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] = in[l] ^ ivec[n];
+		++l;
+		n = (n + 1) % 16;
+	}
+
+	*num = n;
+}
+LCRYPTO_ALIAS(CRYPTO_ofb128_encrypt);