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-rw-r--r--src/decrepit/xts/xts.c295
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diff --git a/src/decrepit/xts/xts.c b/src/decrepit/xts/xts.c
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+/* ====================================================================
+ * Copyright (c) 2011 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/evp.h>
+
+#include <string.h>
+
+#include <openssl/aes.h>
+#include <openssl/cipher.h>
+#include <openssl/modes.h>
+
+
+#if defined(OPENSSL_X86_64) || defined(OPENSSL_X86) || defined(OPENSSL_AARCH64)
+#define STRICT_ALIGNMENT 0
+#else
+#define STRICT_ALIGNMENT 1
+#endif
+
+typedef struct xts128_context {
+ void *key1, *key2;
+ block128_f block1, block2;
+} XTS128_CONTEXT;
+
+static size_t CRYPTO_xts128_encrypt(const XTS128_CONTEXT *ctx,
+ const uint8_t iv[16], const uint8_t *inp,
+ uint8_t *out, size_t len, int enc) {
+ const union {
+ long one;
+ char little;
+ } is_endian = {1};
+ union {
+ uint64_t u[2];
+ uint32_t d[4];
+ uint8_t c[16];
+ } tweak, scratch;
+ unsigned int i;
+
+ if (len < 16) return 0;
+
+ memcpy(tweak.c, iv, 16);
+
+ (*ctx->block2)(tweak.c, tweak.c, ctx->key2);
+
+ if (!enc && (len % 16)) len -= 16;
+
+ while (len >= 16) {
+#if defined(STRICT_ALIGNMENT)
+ memcpy(scratch.c, inp, 16);
+ scratch.u[0] ^= tweak.u[0];
+ scratch.u[1] ^= tweak.u[1];
+#else
+ scratch.u[0] = ((unint64_t *)inp)[0] ^ tweak.u[0];
+ scratch.u[1] = ((unint64_t *)inp)[1] ^ tweak.u[1];
+#endif
+ (*ctx->block1)(scratch.c, scratch.c, ctx->key1);
+#if defined(STRICT_ALIGNMENT)
+ scratch.u[0] ^= tweak.u[0];
+ scratch.u[1] ^= tweak.u[1];
+ memcpy(out, scratch.c, 16);
+#else
+ ((unint64_t *)out)[0] = scratch.u[0] ^= tweak.u[0];
+ ((unint64_t *)out)[1] = scratch.u[1] ^= tweak.u[1];
+#endif
+ inp += 16;
+ out += 16;
+ len -= 16;
+
+ if (len == 0) return 1;
+
+ if (is_endian.little) {
+ unsigned int carry, res;
+
+ res = 0x87 & (((int)tweak.d[3]) >> 31);
+ carry = (unsigned int)(tweak.u[0] >> 63);
+ tweak.u[0] = (tweak.u[0] << 1) ^ res;
+ tweak.u[1] = (tweak.u[1] << 1) | carry;
+ } else {
+ size_t c;
+
+ for (c = 0, i = 0; i < 16; ++i) {
+ /*
+ * + substitutes for |, because c is 1 bit
+ */
+ c += ((size_t)tweak.c[i]) << 1;
+ tweak.c[i] = (uint8_t)c;
+ c = c >> 8;
+ }
+ tweak.c[0] ^= (uint8_t)(0x87 & (0 - c));
+ }
+ }
+ if (enc) {
+ for (i = 0; i < len; ++i) {
+ uint8_t c = inp[i];
+ out[i] = scratch.c[i];
+ scratch.c[i] = c;
+ }
+ scratch.u[0] ^= tweak.u[0];
+ scratch.u[1] ^= tweak.u[1];
+ (*ctx->block1)(scratch.c, scratch.c, ctx->key1);
+ scratch.u[0] ^= tweak.u[0];
+ scratch.u[1] ^= tweak.u[1];
+ memcpy(out - 16, scratch.c, 16);
+ } else {
+ union {
+ uint64_t u[2];
+ uint8_t c[16];
+ } tweak1;
+
+ if (is_endian.little) {
+ unsigned int carry, res;
+
+ res = 0x87 & (((int)tweak.d[3]) >> 31);
+ carry = (unsigned int)(tweak.u[0] >> 63);
+ tweak1.u[0] = (tweak.u[0] << 1) ^ res;
+ tweak1.u[1] = (tweak.u[1] << 1) | carry;
+ } else {
+ size_t c;
+
+ for (c = 0, i = 0; i < 16; ++i) {
+ /*
+ * + substitutes for |, because c is 1 bit
+ */
+ c += ((size_t)tweak.c[i]) << 1;
+ tweak1.c[i] = (uint8_t)c;
+ c = c >> 8;
+ }
+ tweak1.c[0] ^= (uint8_t)(0x87 & (0 - c));
+ }
+#if defined(STRICT_ALIGNMENT)
+ memcpy(scratch.c, inp, 16);
+ scratch.u[0] ^= tweak1.u[0];
+ scratch.u[1] ^= tweak1.u[1];
+#else
+ scratch.u[0] = ((unint64_t *)inp)[0] ^ tweak1.u[0];
+ scratch.u[1] = ((unint64_t *)inp)[1] ^ tweak1.u[1];
+#endif
+ (*ctx->block1)(scratch.c, scratch.c, ctx->key1);
+ scratch.u[0] ^= tweak1.u[0];
+ scratch.u[1] ^= tweak1.u[1];
+
+ for (i = 0; i < len; ++i) {
+ uint8_t c = inp[16 + i];
+ out[16 + i] = scratch.c[i];
+ scratch.c[i] = c;
+ }
+ scratch.u[0] ^= tweak.u[0];
+ scratch.u[1] ^= tweak.u[1];
+ (*ctx->block1)(scratch.c, scratch.c, ctx->key1);
+#if defined(STRICT_ALIGNMENT)
+ scratch.u[0] ^= tweak.u[0];
+ scratch.u[1] ^= tweak.u[1];
+ memcpy(out, scratch.c, 16);
+#else
+ ((unint64_t *)out)[0] = scratch.u[0] ^ tweak.u[0];
+ ((unint64_t *)out)[1] = scratch.u[1] ^ tweak.u[1];
+#endif
+ }
+
+ return 1;
+}
+
+typedef struct {
+ union {
+ double align;
+ AES_KEY ks;
+ } ks1, ks2; /* AES key schedules to use */
+ XTS128_CONTEXT xts;
+} EVP_AES_XTS_CTX;
+
+static int aes_xts_init_key(EVP_CIPHER_CTX *ctx, const uint8_t *key,
+ const uint8_t *iv, int enc) {
+ EVP_AES_XTS_CTX *xctx = ctx->cipher_data;
+ if (!iv && !key) {
+ return 1;
+ }
+
+ if (key) {
+ /* key_len is two AES keys */
+ if (enc) {
+ AES_set_encrypt_key(key, ctx->key_len * 4, &xctx->ks1.ks);
+ xctx->xts.block1 = (block128_f) AES_encrypt;
+ } else {
+ AES_set_decrypt_key(key, ctx->key_len * 4, &xctx->ks1.ks);
+ xctx->xts.block1 = (block128_f) AES_decrypt;
+ }
+
+ AES_set_encrypt_key(key + ctx->key_len / 2,
+ ctx->key_len * 4, &xctx->ks2.ks);
+ xctx->xts.block2 = (block128_f) AES_encrypt;
+ xctx->xts.key1 = &xctx->ks1;
+ }
+
+ if (iv) {
+ xctx->xts.key2 = &xctx->ks2;
+ memcpy(ctx->iv, iv, 16);
+ }
+
+ return 1;
+}
+
+static int aes_xts_cipher(EVP_CIPHER_CTX *ctx, uint8_t *out,
+ const uint8_t *in, size_t len) {
+ EVP_AES_XTS_CTX *xctx = ctx->cipher_data;
+ if (!xctx->xts.key1 ||
+ !xctx->xts.key2 ||
+ !out ||
+ !in ||
+ len < AES_BLOCK_SIZE ||
+ !CRYPTO_xts128_encrypt(&xctx->xts, ctx->iv, in, out, len, ctx->encrypt)) {
+ return 0;
+ }
+ return 1;
+}
+
+static int aes_xts_ctrl(EVP_CIPHER_CTX *c, int type, int arg, void *ptr) {
+ EVP_AES_XTS_CTX *xctx = c->cipher_data;
+ if (type == EVP_CTRL_COPY) {
+ EVP_CIPHER_CTX *out = ptr;
+ EVP_AES_XTS_CTX *xctx_out = out->cipher_data;
+ if (xctx->xts.key1) {
+ if (xctx->xts.key1 != &xctx->ks1) {
+ return 0;
+ }
+ xctx_out->xts.key1 = &xctx_out->ks1;
+ }
+ if (xctx->xts.key2) {
+ if (xctx->xts.key2 != &xctx->ks2) {
+ return 0;
+ }
+ xctx_out->xts.key2 = &xctx_out->ks2;
+ }
+ return 1;
+ } else if (type != EVP_CTRL_INIT) {
+ return -1;
+ }
+ /* key1 and key2 are used as an indicator both key and IV are set */
+ xctx->xts.key1 = NULL;
+ xctx->xts.key2 = NULL;
+ return 1;
+}
+
+static const EVP_CIPHER aes_256_xts = {
+ NID_aes_256_xts, 1 /* block_size */, 32 /* key_size */,
+ 16 /* iv_len */, sizeof(EVP_AES_XTS_CTX),
+ EVP_CIPH_XTS_MODE | EVP_CIPH_CUSTOM_IV | EVP_CIPH_ALWAYS_CALL_INIT |
+ EVP_CIPH_CTRL_INIT | EVP_CIPH_CUSTOM_COPY,
+ NULL /* app_data */, aes_xts_init_key, aes_xts_cipher,
+ NULL /* cleanup */, aes_xts_ctrl};
+
+const EVP_CIPHER *EVP_aes_256_xts(void) { return &aes_256_xts; }
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