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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 08:06:26 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 08:06:26 +0000 |
commit | 1660d4b7a65d9ad2ce0deaa19d35579ca4084ac5 (patch) | |
tree | 6cf8220b628ebd2ccfc1375dd6516c6996e9abcc /lib/crypto_backend/crypto_cipher_kernel.c | |
parent | Initial commit. (diff) | |
download | cryptsetup-1660d4b7a65d9ad2ce0deaa19d35579ca4084ac5.tar.xz cryptsetup-1660d4b7a65d9ad2ce0deaa19d35579ca4084ac5.zip |
Adding upstream version 2:2.6.1.upstream/2%2.6.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/crypto_backend/crypto_cipher_kernel.c')
-rw-r--r-- | lib/crypto_backend/crypto_cipher_kernel.c | 351 |
1 files changed, 351 insertions, 0 deletions
diff --git a/lib/crypto_backend/crypto_cipher_kernel.c b/lib/crypto_backend/crypto_cipher_kernel.c new file mode 100644 index 0000000..3460717 --- /dev/null +++ b/lib/crypto_backend/crypto_cipher_kernel.c @@ -0,0 +1,351 @@ +/* + * Linux kernel userspace API crypto backend implementation (skcipher) + * + * Copyright (C) 2012-2023 Red Hat, Inc. All rights reserved. + * Copyright (C) 2012-2023 Milan Broz + * + * This file 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 file 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 file; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include <string.h> +#include <stdlib.h> +#include <stdio.h> +#include <stdbool.h> +#include <errno.h> +#include <unistd.h> +#include <sys/socket.h> +#include <sys/stat.h> +#include "crypto_backend_internal.h" + +#ifdef ENABLE_AF_ALG + +#include <linux/if_alg.h> + +#ifndef AF_ALG +#define AF_ALG 38 +#endif +#ifndef SOL_ALG +#define SOL_ALG 279 +#endif + +#ifndef ALG_SET_AEAD_AUTHSIZE +#define ALG_SET_AEAD_AUTHSIZE 5 +#endif + +/* + * ciphers + * + * ENOENT - algorithm not available + * ENOTSUP - AF_ALG family not available + * (but cannot check specifically for skcipher API) + */ +static int _crypt_cipher_init(struct crypt_cipher_kernel *ctx, + const void *key, size_t key_length, + size_t tag_length, struct sockaddr_alg *sa) +{ + if (!ctx) + return -EINVAL; + + ctx->opfd = -1; + ctx->tfmfd = socket(AF_ALG, SOCK_SEQPACKET, 0); + if (ctx->tfmfd < 0) { + crypt_cipher_destroy_kernel(ctx); + return -ENOTSUP; + } + + if (bind(ctx->tfmfd, (struct sockaddr *)sa, sizeof(*sa)) < 0) { + crypt_cipher_destroy_kernel(ctx); + return -ENOENT; + } + + if (setsockopt(ctx->tfmfd, SOL_ALG, ALG_SET_KEY, key, key_length) < 0) { + crypt_cipher_destroy_kernel(ctx); + return -EINVAL; + } + + if (tag_length && setsockopt(ctx->tfmfd, SOL_ALG, ALG_SET_AEAD_AUTHSIZE, NULL, tag_length) < 0) { + crypt_cipher_destroy_kernel(ctx); + return -EINVAL; + } + + ctx->opfd = accept(ctx->tfmfd, NULL, 0); + if (ctx->opfd < 0) { + crypt_cipher_destroy_kernel(ctx); + return -EINVAL; + } + + return 0; +} + +int crypt_cipher_init_kernel(struct crypt_cipher_kernel *ctx, const char *name, + const char *mode, const void *key, size_t key_length) +{ + struct sockaddr_alg sa = { + .salg_family = AF_ALG, + .salg_type = "skcipher", + }; + int r; + + if (!strcmp(name, "cipher_null")) + key_length = 0; + + r = snprintf((char *)sa.salg_name, sizeof(sa.salg_name), "%s(%s)", mode, name); + if (r < 0 || (size_t)r >= sizeof(sa.salg_name)) + return -EINVAL; + + return _crypt_cipher_init(ctx, key, key_length, 0, &sa); +} + +/* The in/out should be aligned to page boundary */ +static int _crypt_cipher_crypt(struct crypt_cipher_kernel *ctx, + const char *in, size_t in_length, + char *out, size_t out_length, + const char *iv, size_t iv_length, + uint32_t direction) +{ + int r = 0; + ssize_t len; + struct af_alg_iv *alg_iv; + struct cmsghdr *header; + uint32_t *type; + struct iovec iov = { + .iov_base = (void*)(uintptr_t)in, + .iov_len = in_length, + }; + int iv_msg_size = iv ? CMSG_SPACE(sizeof(*alg_iv) + iv_length) : 0; + char buffer[CMSG_SPACE(sizeof(*type)) + iv_msg_size]; + struct msghdr msg = { + .msg_control = buffer, + .msg_controllen = sizeof(buffer), + .msg_iov = &iov, + .msg_iovlen = 1, + }; + + if (!in || !out || !in_length) + return -EINVAL; + + if ((!iv && iv_length) || (iv && !iv_length)) + return -EINVAL; + + memset(buffer, 0, sizeof(buffer)); + + /* Set encrypt/decrypt operation */ + header = CMSG_FIRSTHDR(&msg); + if (!header) + return -EINVAL; + + header->cmsg_level = SOL_ALG; + header->cmsg_type = ALG_SET_OP; + header->cmsg_len = CMSG_LEN(sizeof(*type)); + type = (void*)CMSG_DATA(header); + *type = direction; + + /* Set IV */ + if (iv) { + header = CMSG_NXTHDR(&msg, header); + if (!header) + return -EINVAL; + + header->cmsg_level = SOL_ALG; + header->cmsg_type = ALG_SET_IV; + header->cmsg_len = iv_msg_size; + alg_iv = (void*)CMSG_DATA(header); + alg_iv->ivlen = iv_length; + memcpy(alg_iv->iv, iv, iv_length); + } + + len = sendmsg(ctx->opfd, &msg, 0); + if (len != (ssize_t)(in_length)) + r = -EIO; + else { + len = read(ctx->opfd, out, out_length); + if (len != (ssize_t)out_length) + r = -EIO; + } + + crypt_backend_memzero(buffer, sizeof(buffer)); + return r; +} + +int crypt_cipher_encrypt_kernel(struct crypt_cipher_kernel *ctx, + const char *in, char *out, size_t length, + const char *iv, size_t iv_length) +{ + return _crypt_cipher_crypt(ctx, in, length, out, length, + iv, iv_length, ALG_OP_ENCRYPT); +} + +int crypt_cipher_decrypt_kernel(struct crypt_cipher_kernel *ctx, + const char *in, char *out, size_t length, + const char *iv, size_t iv_length) +{ + return _crypt_cipher_crypt(ctx, in, length, out, length, + iv, iv_length, ALG_OP_DECRYPT); +} + +void crypt_cipher_destroy_kernel(struct crypt_cipher_kernel *ctx) +{ + if (ctx->tfmfd >= 0) + close(ctx->tfmfd); + if (ctx->opfd >= 0) + close(ctx->opfd); + + ctx->tfmfd = -1; + ctx->opfd = -1; +} + +int crypt_cipher_check_kernel(const char *name, const char *mode, + const char *integrity, size_t key_length) +{ + struct crypt_cipher_kernel c; + char mode_name[64], tmp_salg_name[180], *real_mode = NULL, *cipher_iv = NULL, *key; + const char *salg_type; + bool aead; + int r; + struct sockaddr_alg sa = { + .salg_family = AF_ALG, + }; + + aead = integrity && strcmp(integrity, "none"); + + /* Remove IV if present */ + if (mode) { + strncpy(mode_name, mode, sizeof(mode_name)); + mode_name[sizeof(mode_name) - 1] = 0; + cipher_iv = strchr(mode_name, '-'); + if (cipher_iv) { + *cipher_iv = '\0'; + real_mode = mode_name; + } + } + + salg_type = aead ? "aead" : "skcipher"; + r = snprintf((char *)sa.salg_type, sizeof(sa.salg_type), "%s", salg_type); + if (r < 0 || (size_t)r >= sizeof(sa.salg_name)) + return -EINVAL; + + memset(tmp_salg_name, 0, sizeof(tmp_salg_name)); + + /* FIXME: this is duplicating a part of devmapper backend */ + if (aead && !strcmp(integrity, "poly1305")) + r = snprintf(tmp_salg_name, sizeof(tmp_salg_name), "rfc7539(%s,%s)", name, integrity); + else if (!real_mode) + r = snprintf(tmp_salg_name, sizeof(tmp_salg_name), "%s", name); + else if (aead && !strcmp(real_mode, "ccm")) + r = snprintf(tmp_salg_name, sizeof(tmp_salg_name), "rfc4309(%s(%s))", real_mode, name); + else + r = snprintf(tmp_salg_name, sizeof(tmp_salg_name), "%s(%s)", real_mode, name); + + if (r < 0 || (size_t)r >= sizeof(tmp_salg_name)) + return -EINVAL; + + memcpy(sa.salg_name, tmp_salg_name, sizeof(sa.salg_name)); + + key = malloc(key_length); + if (!key) + return -ENOMEM; + + /* We cannot use RNG yet, any key works here, tweak the first part if it is split key (XTS). */ + memset(key, 0xab, key_length); + *key = 0xef; + + r = _crypt_cipher_init(&c, key, key_length, 0, &sa); + crypt_cipher_destroy_kernel(&c); + free(key); + + return r; +} + +int crypt_bitlk_decrypt_key_kernel(const void *key, size_t key_length, + const char *in, char *out, size_t length, + const char *iv, size_t iv_length, + const char *tag, size_t tag_length) +{ + struct crypt_cipher_kernel c; + struct sockaddr_alg sa = { + .salg_family = AF_ALG, + .salg_type = "aead", + .salg_name = "ccm(aes)", + }; + int r; + char buffer[128], ccm_iv[16]; + + if (length + tag_length > sizeof(buffer)) + return -EINVAL; + + if (iv_length > sizeof(ccm_iv) - 2) + return -EINVAL; + + r = _crypt_cipher_init(&c, key, key_length, tag_length, &sa); + if (r < 0) + return r; + + memcpy(buffer, in, length); + memcpy(buffer + length, tag, tag_length); + + /* CCM IV - RFC3610 */ + memset(ccm_iv, 0, sizeof(ccm_iv)); + ccm_iv[0] = 15 - iv_length - 1; + memcpy(ccm_iv + 1, iv, iv_length); + memset(ccm_iv + 1 + iv_length, 0, ccm_iv[0] + 1); + iv_length = sizeof(ccm_iv); + + r = _crypt_cipher_crypt(&c, buffer, length + tag_length, out, length, + ccm_iv, iv_length, ALG_OP_DECRYPT); + + crypt_cipher_destroy_kernel(&c); + crypt_backend_memzero(buffer, sizeof(buffer)); + + return r; +} + +#else /* ENABLE_AF_ALG */ +int crypt_cipher_init_kernel(struct crypt_cipher_kernel *ctx, const char *name, + const char *mode, const void *key, size_t key_length) +{ + return -ENOTSUP; +} + +void crypt_cipher_destroy_kernel(struct crypt_cipher_kernel *ctx) +{ + return; +} + +int crypt_cipher_encrypt_kernel(struct crypt_cipher_kernel *ctx, + const char *in, char *out, size_t length, + const char *iv, size_t iv_length) +{ + return -EINVAL; +} +int crypt_cipher_decrypt_kernel(struct crypt_cipher_kernel *ctx, + const char *in, char *out, size_t length, + const char *iv, size_t iv_length) +{ + return -EINVAL; +} +int crypt_cipher_check_kernel(const char *name, const char *mode, + const char *integrity, size_t key_length) +{ + /* Cannot check, expect success. */ + return 0; +} +int crypt_bitlk_decrypt_key_kernel(const void *key, size_t key_length, + const char *in, char *out, size_t length, + const char *iv, size_t iv_length, + const char *tag, size_t tag_length) +{ + return -ENOTSUP; +} +#endif |