128-bit block cipher modes consolidation. As consolidated functions

rely on indirect call to block functions, they are not as fast as
non-consolidated routines. However, performance loss(*) is within
measurement error and consolidation advantages are considered to
outweigh it.

(*) actually one can observe performance *improvement* on e.g.
    CBC benchmarks thanks to optimization, which also becomes
    shared among ciphers.

crypto/modes/ofb128.c

@@ -0,0 +1,130 @@
+/* ====================================================================
+ * 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 <stddef.h>
+#include <string.h>
+
+#ifndef MODES_DEBUG
+# ifndef NDEBUG
+#  define NDEBUG
+# endif
+#endif
+#include <assert.h>
+
+#include "modes.h"
+
+#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
+
+/* 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,
+			block_f block)
+{
+	unsigned int n;
+	size_t l=0;
+
+	assert(in && out && key && ivec && num);
+
+	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;
+		}
+#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=0; 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;
+}