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- /*
- * QEMU Crypto cipher libgcrypt algorithms
- *
- * Copyright (c) 2015 Red Hat, Inc.
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, see <http://www.gnu.org/licenses/>.
- *
- */
- #ifdef CONFIG_QEMU_PRIVATE_XTS
- #include "crypto/xts.h"
- #endif
- #include <gcrypt.h>
- bool qcrypto_cipher_supports(QCryptoCipherAlgorithm alg,
- QCryptoCipherMode mode)
- {
- switch (alg) {
- case QCRYPTO_CIPHER_ALG_DES_RFB:
- case QCRYPTO_CIPHER_ALG_3DES:
- case QCRYPTO_CIPHER_ALG_AES_128:
- case QCRYPTO_CIPHER_ALG_AES_192:
- case QCRYPTO_CIPHER_ALG_AES_256:
- case QCRYPTO_CIPHER_ALG_CAST5_128:
- case QCRYPTO_CIPHER_ALG_SERPENT_128:
- case QCRYPTO_CIPHER_ALG_SERPENT_192:
- case QCRYPTO_CIPHER_ALG_SERPENT_256:
- case QCRYPTO_CIPHER_ALG_TWOFISH_128:
- case QCRYPTO_CIPHER_ALG_TWOFISH_256:
- break;
- default:
- return false;
- }
- switch (mode) {
- case QCRYPTO_CIPHER_MODE_ECB:
- case QCRYPTO_CIPHER_MODE_CBC:
- case QCRYPTO_CIPHER_MODE_XTS:
- case QCRYPTO_CIPHER_MODE_CTR:
- return true;
- default:
- return false;
- }
- }
- typedef struct QCryptoCipherGcrypt {
- QCryptoCipher base;
- gcry_cipher_hd_t handle;
- size_t blocksize;
- #ifdef CONFIG_QEMU_PRIVATE_XTS
- gcry_cipher_hd_t tweakhandle;
- uint8_t iv[XTS_BLOCK_SIZE];
- #endif
- } QCryptoCipherGcrypt;
- static void qcrypto_gcrypt_ctx_free(QCryptoCipher *cipher)
- {
- QCryptoCipherGcrypt *ctx = container_of(cipher, QCryptoCipherGcrypt, base);
- gcry_cipher_close(ctx->handle);
- g_free(ctx);
- }
- static int qcrypto_gcrypt_encrypt(QCryptoCipher *cipher, const void *in,
- void *out, size_t len, Error **errp)
- {
- QCryptoCipherGcrypt *ctx = container_of(cipher, QCryptoCipherGcrypt, base);
- gcry_error_t err;
- if (len & (ctx->blocksize - 1)) {
- error_setg(errp, "Length %zu must be a multiple of block size %zu",
- len, ctx->blocksize);
- return -1;
- }
- err = gcry_cipher_encrypt(ctx->handle, out, len, in, len);
- if (err != 0) {
- error_setg(errp, "Cannot encrypt data: %s", gcry_strerror(err));
- return -1;
- }
- return 0;
- }
- static int qcrypto_gcrypt_decrypt(QCryptoCipher *cipher, const void *in,
- void *out, size_t len, Error **errp)
- {
- QCryptoCipherGcrypt *ctx = container_of(cipher, QCryptoCipherGcrypt, base);
- gcry_error_t err;
- if (len & (ctx->blocksize - 1)) {
- error_setg(errp, "Length %zu must be a multiple of block size %zu",
- len, ctx->blocksize);
- return -1;
- }
- err = gcry_cipher_decrypt(ctx->handle, out, len, in, len);
- if (err != 0) {
- error_setg(errp, "Cannot decrypt data: %s",
- gcry_strerror(err));
- return -1;
- }
- return 0;
- }
- static int qcrypto_gcrypt_setiv(QCryptoCipher *cipher,
- const uint8_t *iv, size_t niv,
- Error **errp)
- {
- QCryptoCipherGcrypt *ctx = container_of(cipher, QCryptoCipherGcrypt, base);
- gcry_error_t err;
- if (niv != ctx->blocksize) {
- error_setg(errp, "Expected IV size %zu not %zu",
- ctx->blocksize, niv);
- return -1;
- }
- gcry_cipher_reset(ctx->handle);
- err = gcry_cipher_setiv(ctx->handle, iv, niv);
- if (err != 0) {
- error_setg(errp, "Cannot set IV: %s", gcry_strerror(err));
- return -1;
- }
- return 0;
- }
- static int qcrypto_gcrypt_ctr_setiv(QCryptoCipher *cipher,
- const uint8_t *iv, size_t niv,
- Error **errp)
- {
- QCryptoCipherGcrypt *ctx = container_of(cipher, QCryptoCipherGcrypt, base);
- gcry_error_t err;
- if (niv != ctx->blocksize) {
- error_setg(errp, "Expected IV size %zu not %zu",
- ctx->blocksize, niv);
- return -1;
- }
- err = gcry_cipher_setctr(ctx->handle, iv, niv);
- if (err != 0) {
- error_setg(errp, "Cannot set Counter: %s", gcry_strerror(err));
- return -1;
- }
- return 0;
- }
- static const struct QCryptoCipherDriver qcrypto_gcrypt_driver = {
- .cipher_encrypt = qcrypto_gcrypt_encrypt,
- .cipher_decrypt = qcrypto_gcrypt_decrypt,
- .cipher_setiv = qcrypto_gcrypt_setiv,
- .cipher_free = qcrypto_gcrypt_ctx_free,
- };
- static const struct QCryptoCipherDriver qcrypto_gcrypt_ctr_driver = {
- .cipher_encrypt = qcrypto_gcrypt_encrypt,
- .cipher_decrypt = qcrypto_gcrypt_decrypt,
- .cipher_setiv = qcrypto_gcrypt_ctr_setiv,
- .cipher_free = qcrypto_gcrypt_ctx_free,
- };
- #ifdef CONFIG_QEMU_PRIVATE_XTS
- static void qcrypto_gcrypt_xts_ctx_free(QCryptoCipher *cipher)
- {
- QCryptoCipherGcrypt *ctx = container_of(cipher, QCryptoCipherGcrypt, base);
- gcry_cipher_close(ctx->tweakhandle);
- qcrypto_gcrypt_ctx_free(cipher);
- }
- static void qcrypto_gcrypt_xts_wrape(const void *ctx, size_t length,
- uint8_t *dst, const uint8_t *src)
- {
- gcry_error_t err;
- err = gcry_cipher_encrypt((gcry_cipher_hd_t)ctx, dst, length, src, length);
- g_assert(err == 0);
- }
- static void qcrypto_gcrypt_xts_wrapd(const void *ctx, size_t length,
- uint8_t *dst, const uint8_t *src)
- {
- gcry_error_t err;
- err = gcry_cipher_decrypt((gcry_cipher_hd_t)ctx, dst, length, src, length);
- g_assert(err == 0);
- }
- static int qcrypto_gcrypt_xts_encrypt(QCryptoCipher *cipher, const void *in,
- void *out, size_t len, Error **errp)
- {
- QCryptoCipherGcrypt *ctx = container_of(cipher, QCryptoCipherGcrypt, base);
- if (len & (ctx->blocksize - 1)) {
- error_setg(errp, "Length %zu must be a multiple of block size %zu",
- len, ctx->blocksize);
- return -1;
- }
- xts_encrypt(ctx->handle, ctx->tweakhandle,
- qcrypto_gcrypt_xts_wrape, qcrypto_gcrypt_xts_wrapd,
- ctx->iv, len, out, in);
- return 0;
- }
- static int qcrypto_gcrypt_xts_decrypt(QCryptoCipher *cipher, const void *in,
- void *out, size_t len, Error **errp)
- {
- QCryptoCipherGcrypt *ctx = container_of(cipher, QCryptoCipherGcrypt, base);
- if (len & (ctx->blocksize - 1)) {
- error_setg(errp, "Length %zu must be a multiple of block size %zu",
- len, ctx->blocksize);
- return -1;
- }
- xts_decrypt(ctx->handle, ctx->tweakhandle,
- qcrypto_gcrypt_xts_wrape, qcrypto_gcrypt_xts_wrapd,
- ctx->iv, len, out, in);
- return 0;
- }
- static int qcrypto_gcrypt_xts_setiv(QCryptoCipher *cipher,
- const uint8_t *iv, size_t niv,
- Error **errp)
- {
- QCryptoCipherGcrypt *ctx = container_of(cipher, QCryptoCipherGcrypt, base);
- if (niv != ctx->blocksize) {
- error_setg(errp, "Expected IV size %zu not %zu",
- ctx->blocksize, niv);
- return -1;
- }
- memcpy(ctx->iv, iv, niv);
- return 0;
- }
- static const struct QCryptoCipherDriver qcrypto_gcrypt_xts_driver = {
- .cipher_encrypt = qcrypto_gcrypt_xts_encrypt,
- .cipher_decrypt = qcrypto_gcrypt_xts_decrypt,
- .cipher_setiv = qcrypto_gcrypt_xts_setiv,
- .cipher_free = qcrypto_gcrypt_xts_ctx_free,
- };
- #endif /* CONFIG_QEMU_PRIVATE_XTS */
- static QCryptoCipher *qcrypto_cipher_ctx_new(QCryptoCipherAlgorithm alg,
- QCryptoCipherMode mode,
- const uint8_t *key,
- size_t nkey,
- Error **errp)
- {
- QCryptoCipherGcrypt *ctx;
- const QCryptoCipherDriver *drv;
- gcry_error_t err;
- int gcryalg, gcrymode;
- if (!qcrypto_cipher_validate_key_length(alg, mode, nkey, errp)) {
- return NULL;
- }
- switch (alg) {
- case QCRYPTO_CIPHER_ALG_DES_RFB:
- gcryalg = GCRY_CIPHER_DES;
- break;
- case QCRYPTO_CIPHER_ALG_3DES:
- gcryalg = GCRY_CIPHER_3DES;
- break;
- case QCRYPTO_CIPHER_ALG_AES_128:
- gcryalg = GCRY_CIPHER_AES128;
- break;
- case QCRYPTO_CIPHER_ALG_AES_192:
- gcryalg = GCRY_CIPHER_AES192;
- break;
- case QCRYPTO_CIPHER_ALG_AES_256:
- gcryalg = GCRY_CIPHER_AES256;
- break;
- case QCRYPTO_CIPHER_ALG_CAST5_128:
- gcryalg = GCRY_CIPHER_CAST5;
- break;
- case QCRYPTO_CIPHER_ALG_SERPENT_128:
- gcryalg = GCRY_CIPHER_SERPENT128;
- break;
- case QCRYPTO_CIPHER_ALG_SERPENT_192:
- gcryalg = GCRY_CIPHER_SERPENT192;
- break;
- case QCRYPTO_CIPHER_ALG_SERPENT_256:
- gcryalg = GCRY_CIPHER_SERPENT256;
- break;
- case QCRYPTO_CIPHER_ALG_TWOFISH_128:
- gcryalg = GCRY_CIPHER_TWOFISH128;
- break;
- case QCRYPTO_CIPHER_ALG_TWOFISH_256:
- gcryalg = GCRY_CIPHER_TWOFISH;
- break;
- default:
- error_setg(errp, "Unsupported cipher algorithm %s",
- QCryptoCipherAlgorithm_str(alg));
- return NULL;
- }
- drv = &qcrypto_gcrypt_driver;
- switch (mode) {
- case QCRYPTO_CIPHER_MODE_ECB:
- gcrymode = GCRY_CIPHER_MODE_ECB;
- break;
- case QCRYPTO_CIPHER_MODE_XTS:
- #ifdef CONFIG_QEMU_PRIVATE_XTS
- drv = &qcrypto_gcrypt_xts_driver;
- gcrymode = GCRY_CIPHER_MODE_ECB;
- #else
- gcrymode = GCRY_CIPHER_MODE_XTS;
- #endif
- break;
- case QCRYPTO_CIPHER_MODE_CBC:
- gcrymode = GCRY_CIPHER_MODE_CBC;
- break;
- case QCRYPTO_CIPHER_MODE_CTR:
- drv = &qcrypto_gcrypt_ctr_driver;
- gcrymode = GCRY_CIPHER_MODE_CTR;
- break;
- default:
- error_setg(errp, "Unsupported cipher mode %s",
- QCryptoCipherMode_str(mode));
- return NULL;
- }
- ctx = g_new0(QCryptoCipherGcrypt, 1);
- ctx->base.driver = drv;
- err = gcry_cipher_open(&ctx->handle, gcryalg, gcrymode, 0);
- if (err != 0) {
- error_setg(errp, "Cannot initialize cipher: %s",
- gcry_strerror(err));
- goto error;
- }
- ctx->blocksize = gcry_cipher_get_algo_blklen(gcryalg);
- #ifdef CONFIG_QEMU_PRIVATE_XTS
- if (mode == QCRYPTO_CIPHER_MODE_XTS) {
- if (ctx->blocksize != XTS_BLOCK_SIZE) {
- error_setg(errp,
- "Cipher block size %zu must equal XTS block size %d",
- ctx->blocksize, XTS_BLOCK_SIZE);
- goto error;
- }
- err = gcry_cipher_open(&ctx->tweakhandle, gcryalg, gcrymode, 0);
- if (err != 0) {
- error_setg(errp, "Cannot initialize cipher: %s",
- gcry_strerror(err));
- goto error;
- }
- }
- #endif
- if (alg == QCRYPTO_CIPHER_ALG_DES_RFB) {
- /* We're using standard DES cipher from gcrypt, so we need
- * to munge the key so that the results are the same as the
- * bizarre RFB variant of DES :-)
- */
- uint8_t *rfbkey = qcrypto_cipher_munge_des_rfb_key(key, nkey);
- err = gcry_cipher_setkey(ctx->handle, rfbkey, nkey);
- g_free(rfbkey);
- } else {
- #ifdef CONFIG_QEMU_PRIVATE_XTS
- if (mode == QCRYPTO_CIPHER_MODE_XTS) {
- nkey /= 2;
- err = gcry_cipher_setkey(ctx->tweakhandle, key + nkey, nkey);
- if (err != 0) {
- error_setg(errp, "Cannot set key: %s", gcry_strerror(err));
- goto error;
- }
- }
- #endif
- err = gcry_cipher_setkey(ctx->handle, key, nkey);
- }
- if (err != 0) {
- error_setg(errp, "Cannot set key: %s", gcry_strerror(err));
- goto error;
- }
- return &ctx->base;
- error:
- #ifdef CONFIG_QEMU_PRIVATE_XTS
- gcry_cipher_close(ctx->tweakhandle);
- #endif
- gcry_cipher_close(ctx->handle);
- g_free(ctx);
- return NULL;
- }
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