/* * Copyright 2008-2021 The OpenSSL Project Authors. All Rights Reserved. * * Licensed under the Apache License 2.0 (the "License"). You may not use * this file except in compliance with the License. You can obtain a copy * in the file LICENSE in the source distribution or at * https://www.openssl.org/source/license.html */ #include <string.h> #include <openssl/crypto.h> #include "crypto/modes.h" #if defined(__GNUC__) && !defined(STRICT_ALIGNMENT) typedef size_t size_t_aX __attribute((__aligned__(1))); #else typedef size_t size_t_aX; #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; if (*num < 0) { /* There is no good way to signal an error return from here */ *num = -1; return; } n = *num; #if !defined(OPENSSL_SMALL_FOOTPRINT) if (16 % sizeof(size_t) == 0) { /* always true actually */ do { 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 < 16; n += sizeof(size_t)) *(size_t_aX *)(out + n) = *(size_t_aX *)(in + n) ^ *(size_t_aX *)(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; } |