diff options
Diffstat (limited to 'crypto/cipher-afalg.c')
| -rw-r--r-- | crypto/cipher-afalg.c | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/crypto/cipher-afalg.c b/crypto/cipher-afalg.c new file mode 100644 index 0000000000..01343b2b7c --- /dev/null +++ b/crypto/cipher-afalg.c @@ -0,0 +1,226 @@ +/* + * QEMU Crypto af_alg-backend cipher support + * + * Copyright (c) 2017 HUAWEI TECHNOLOGIES CO., LTD. + * + * Authors: + * Longpeng(Mike) <longpeng2@huawei.com> + * + * This work is licensed under the terms of the GNU GPL, version 2 or + * (at your option) any later version. See the COPYING file in the + * top-level directory. + */ +#include "qemu/osdep.h" +#include "qemu/sockets.h" +#include "qemu-common.h" +#include "qapi/error.h" +#include "crypto/cipher.h" +#include "cipherpriv.h" + + +static char * +qcrypto_afalg_cipher_format_name(QCryptoCipherAlgorithm alg, + QCryptoCipherMode mode, + Error **errp) +{ + char *name; + const char *alg_name; + const char *mode_name; + + switch (alg) { + case QCRYPTO_CIPHER_ALG_AES_128: + case QCRYPTO_CIPHER_ALG_AES_192: + case QCRYPTO_CIPHER_ALG_AES_256: + alg_name = "aes"; + break; + case QCRYPTO_CIPHER_ALG_CAST5_128: + alg_name = "cast5"; + break; + case QCRYPTO_CIPHER_ALG_SERPENT_128: + case QCRYPTO_CIPHER_ALG_SERPENT_192: + case QCRYPTO_CIPHER_ALG_SERPENT_256: + alg_name = "serpent"; + break; + case QCRYPTO_CIPHER_ALG_TWOFISH_128: + case QCRYPTO_CIPHER_ALG_TWOFISH_192: + case QCRYPTO_CIPHER_ALG_TWOFISH_256: + alg_name = "twofish"; + break; + + default: + error_setg(errp, "Unsupported cipher algorithm %d", alg); + return NULL; + } + + mode_name = QCryptoCipherMode_lookup[mode]; + name = g_strdup_printf("%s(%s)", mode_name, alg_name); + + return name; +} + +QCryptoAFAlg * +qcrypto_afalg_cipher_ctx_new(QCryptoCipherAlgorithm alg, + QCryptoCipherMode mode, + const uint8_t *key, + size_t nkey, Error **errp) +{ + QCryptoAFAlg *afalg; + size_t expect_niv; + char *name; + + name = qcrypto_afalg_cipher_format_name(alg, mode, errp); + if (!name) { + return NULL; + } + + afalg = qcrypto_afalg_comm_alloc(AFALG_TYPE_CIPHER, name, errp); + if (!afalg) { + g_free(name); + return NULL; + } + + g_free(name); + + /* setkey */ + if (qemu_setsockopt(afalg->tfmfd, SOL_ALG, ALG_SET_KEY, key, + nkey) != 0) { + error_setg_errno(errp, errno, "Set key failed"); + qcrypto_afalg_comm_free(afalg); + return NULL; + } + + /* prepare msg header */ + afalg->msg = g_new0(struct msghdr, 1); + afalg->msg->msg_controllen += CMSG_SPACE(ALG_OPTYPE_LEN); + expect_niv = qcrypto_cipher_get_iv_len(alg, mode); + if (expect_niv) { + afalg->msg->msg_controllen += CMSG_SPACE(ALG_MSGIV_LEN(expect_niv)); + } + afalg->msg->msg_control = g_new0(uint8_t, afalg->msg->msg_controllen); + + /* We use 1st msghdr for crypto-info and 2nd msghdr for IV-info */ + afalg->cmsg = CMSG_FIRSTHDR(afalg->msg); + afalg->cmsg->cmsg_type = ALG_SET_OP; + afalg->cmsg->cmsg_len = CMSG_SPACE(ALG_OPTYPE_LEN); + if (expect_niv) { + afalg->cmsg = CMSG_NXTHDR(afalg->msg, afalg->cmsg); + afalg->cmsg->cmsg_type = ALG_SET_IV; + afalg->cmsg->cmsg_len = CMSG_SPACE(ALG_MSGIV_LEN(expect_niv)); + } + afalg->cmsg = CMSG_FIRSTHDR(afalg->msg); + + return afalg; +} + +static int +qcrypto_afalg_cipher_setiv(QCryptoCipher *cipher, + const uint8_t *iv, + size_t niv, Error **errp) +{ + struct af_alg_iv *alg_iv; + size_t expect_niv; + QCryptoAFAlg *afalg = cipher->opaque; + + expect_niv = qcrypto_cipher_get_iv_len(cipher->alg, cipher->mode); + if (niv != expect_niv) { + error_setg(errp, "Set IV len(%zu) not match expected(%zu)", + niv, expect_niv); + return -1; + } + + /* move ->cmsg to next msghdr, for IV-info */ + afalg->cmsg = CMSG_NXTHDR(afalg->msg, afalg->cmsg); + + /* build setiv msg */ + afalg->cmsg->cmsg_level = SOL_ALG; + alg_iv = (struct af_alg_iv *)CMSG_DATA(afalg->cmsg); + alg_iv->ivlen = niv; + memcpy(alg_iv->iv, iv, niv); + + return 0; +} + +static int +qcrypto_afalg_cipher_op(QCryptoAFAlg *afalg, + const void *in, void *out, + size_t len, bool do_encrypt, + Error **errp) +{ + uint32_t *type = NULL; + struct iovec iov; + size_t ret, rlen, done = 0; + uint32_t origin_controllen; + + origin_controllen = afalg->msg->msg_controllen; + /* movev ->cmsg to first header, for crypto-info */ + afalg->cmsg = CMSG_FIRSTHDR(afalg->msg); + + /* build encrypt msg */ + afalg->cmsg->cmsg_level = SOL_ALG; + afalg->msg->msg_iov = &iov; + afalg->msg->msg_iovlen = 1; + type = (uint32_t *)CMSG_DATA(afalg->cmsg); + if (do_encrypt) { + *type = ALG_OP_ENCRYPT; + } else { + *type = ALG_OP_DECRYPT; + } + + do { + iov.iov_base = (void *)in + done; + iov.iov_len = len - done; + + /* send info to AF_ALG core */ + ret = sendmsg(afalg->opfd, afalg->msg, 0); + if (ret == -1) { + error_setg_errno(errp, errno, "Send data to AF_ALG core failed"); + return -1; + } + + /* encrypto && get result */ + rlen = read(afalg->opfd, out, ret); + if (rlen == -1) { + error_setg_errno(errp, errno, "Get result from AF_ALG core failed"); + return -1; + } + assert(rlen == ret); + + /* do not update IV for following chunks */ + afalg->msg->msg_controllen = 0; + done += ret; + } while (done < len); + + afalg->msg->msg_controllen = origin_controllen; + + return 0; +} + +static int +qcrypto_afalg_cipher_encrypt(QCryptoCipher *cipher, + const void *in, void *out, + size_t len, Error **errp) +{ + return qcrypto_afalg_cipher_op(cipher->opaque, in, out, + len, true, errp); +} + +static int +qcrypto_afalg_cipher_decrypt(QCryptoCipher *cipher, + const void *in, void *out, + size_t len, Error **errp) +{ + return qcrypto_afalg_cipher_op(cipher->opaque, in, out, + len, false, errp); +} + +static void qcrypto_afalg_comm_ctx_free(QCryptoCipher *cipher) +{ + qcrypto_afalg_comm_free(cipher->opaque); +} + +struct QCryptoCipherDriver qcrypto_cipher_afalg_driver = { + .cipher_encrypt = qcrypto_afalg_cipher_encrypt, + .cipher_decrypt = qcrypto_afalg_cipher_decrypt, + .cipher_setiv = qcrypto_afalg_cipher_setiv, + .cipher_free = qcrypto_afalg_comm_ctx_free, +}; 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