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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/utils_crypt.c | |
parent | Initial commit. (diff) | |
download | cryptsetup-upstream.tar.xz cryptsetup-upstream.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 '')
-rw-r--r-- | lib/utils_crypt.c | 347 |
1 files changed, 347 insertions, 0 deletions
diff --git a/lib/utils_crypt.c b/lib/utils_crypt.c new file mode 100644 index 0000000..0b7dc37 --- /dev/null +++ b/lib/utils_crypt.c @@ -0,0 +1,347 @@ +/* + * utils_crypt - cipher utilities for cryptsetup + * + * Copyright (C) 2004-2007 Clemens Fruhwirth <clemens@endorphin.org> + * Copyright (C) 2009-2023 Red Hat, Inc. All rights reserved. + * Copyright (C) 2009-2023 Milan Broz + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <strings.h> +#include <unistd.h> +#include <ctype.h> +#include <errno.h> + +#include "libcryptsetup.h" +#include "utils_crypt.h" + +#define MAX_CAPI_LEN_STR "143" /* for sscanf of crypto API string + 16 + \0 */ + +int crypt_parse_name_and_mode(const char *s, char *cipher, int *key_nums, + char *cipher_mode) +{ + if (!s || !cipher || !cipher_mode) + return -EINVAL; + + if (sscanf(s, "%" MAX_CIPHER_LEN_STR "[^-]-%" MAX_CIPHER_LEN_STR "s", + cipher, cipher_mode) == 2) { + if (!strcmp(cipher_mode, "plain")) + strcpy(cipher_mode, "cbc-plain"); + if (key_nums) { + char *tmp = strchr(cipher, ':'); + *key_nums = tmp ? atoi(++tmp) : 1; + if (!*key_nums) + return -EINVAL; + } + + return 0; + } + + /* Short version for "empty" cipher */ + if (!strcmp(s, "null") || !strcmp(s, "cipher_null")) { + strcpy(cipher, "cipher_null"); + strcpy(cipher_mode, "ecb"); + if (key_nums) + *key_nums = 0; + return 0; + } + + if (sscanf(s, "%" MAX_CIPHER_LEN_STR "[^-]", cipher) == 1) { + strcpy(cipher_mode, "cbc-plain"); + if (key_nums) + *key_nums = 1; + return 0; + } + + return -EINVAL; +} + +int crypt_parse_hash_integrity_mode(const char *s, char *integrity) +{ + char mode[MAX_CIPHER_LEN], hash[MAX_CIPHER_LEN]; + int r; + + if (!s || !integrity || strchr(s, '(') || strchr(s, ')')) + return -EINVAL; + + r = sscanf(s, "%" MAX_CIPHER_LEN_STR "[^-]-%" MAX_CIPHER_LEN_STR "s", mode, hash); + if (r == 2 && !isdigit(hash[0])) + r = snprintf(integrity, MAX_CIPHER_LEN, "%s(%s)", mode, hash); + else if (r == 2) + r = snprintf(integrity, MAX_CIPHER_LEN, "%s-%s", mode, hash); + else if (r == 1) + r = snprintf(integrity, MAX_CIPHER_LEN, "%s", mode); + else + return -EINVAL; + + if (r < 0 || r >= MAX_CIPHER_LEN) + return -EINVAL; + + return 0; +} + +int crypt_parse_integrity_mode(const char *s, char *integrity, + int *integrity_key_size) +{ + int ks = 0, r = 0; + + if (!s || !integrity) + return -EINVAL; + + /* AEAD modes */ + if (!strcmp(s, "aead") || + !strcmp(s, "poly1305") || + !strcmp(s, "none")) { + strncpy(integrity, s, MAX_CIPHER_LEN); + ks = 0; + } else if (!strcmp(s, "hmac-sha1")) { + strncpy(integrity, "hmac(sha1)", MAX_CIPHER_LEN); + ks = 20; + } else if (!strcmp(s, "hmac-sha256")) { + strncpy(integrity, "hmac(sha256)", MAX_CIPHER_LEN); + ks = 32; + } else if (!strcmp(s, "hmac-sha512")) { + ks = 64; + strncpy(integrity, "hmac(sha512)", MAX_CIPHER_LEN); + } else if (!strcmp(s, "cmac-aes")) { + ks = 16; + strncpy(integrity, "cmac(aes)", MAX_CIPHER_LEN); + } else + r = -EINVAL; + + if (integrity_key_size) + *integrity_key_size = ks; + + return r; +} + +int crypt_parse_pbkdf(const char *s, const char **pbkdf) +{ + const char *tmp = NULL; + + if (!s) + return -EINVAL; + + if (!strcasecmp(s, CRYPT_KDF_PBKDF2)) + tmp = CRYPT_KDF_PBKDF2; + else if (!strcasecmp(s, CRYPT_KDF_ARGON2I)) + tmp = CRYPT_KDF_ARGON2I; + else if (!strcasecmp(s, CRYPT_KDF_ARGON2ID)) + tmp = CRYPT_KDF_ARGON2ID; + + if (!tmp) + return -EINVAL; + + if (pbkdf) + *pbkdf = tmp; + + return 0; +} + +/* + * Thanks Mikulas Patocka for these two char converting functions. + * + * This function is used to load cryptographic keys, so it is coded in such a + * way that there are no conditions or memory accesses that depend on data. + * + * Explanation of the logic: + * (ch - '9' - 1) is negative if ch <= '9' + * ('0' - 1 - ch) is negative if ch >= '0' + * we "and" these two values, so the result is negative if ch is in the range + * '0' ... '9' + * we are only interested in the sign, so we do a shift ">> 8"; note that right + * shift of a negative value is implementation-defined, so we cast the + * value to (unsigned) before the shift --- we have 0xffffff if ch is in + * the range '0' ... '9', 0 otherwise + * we "and" this value with (ch - '0' + 1) --- we have a value 1 ... 10 if ch is + * in the range '0' ... '9', 0 otherwise + * we add this value to -1 --- we have a value 0 ... 9 if ch is in the range '0' + * ... '9', -1 otherwise + * the next line is similar to the previous one, but we need to decode both + * uppercase and lowercase letters, so we use (ch & 0xdf), which converts + * lowercase to uppercase + */ +static int hex_to_bin(unsigned char ch) +{ + unsigned char cu = ch & 0xdf; + return -1 + + ((ch - '0' + 1) & (unsigned)((ch - '9' - 1) & ('0' - 1 - ch)) >> 8) + + ((cu - 'A' + 11) & (unsigned)((cu - 'F' - 1) & ('A' - 1 - cu)) >> 8); +} + +static char hex2asc(unsigned char c) +{ + return c + '0' + ((unsigned)(9 - c) >> 4 & 0x27); +} + +ssize_t crypt_hex_to_bytes(const char *hex, char **result, int safe_alloc) +{ + char *bytes; + size_t i, len; + int bl, bh; + + if (!hex || !result) + return -EINVAL; + + len = strlen(hex); + if (len % 2) + return -EINVAL; + len /= 2; + + bytes = safe_alloc ? crypt_safe_alloc(len) : malloc(len); + if (!bytes) + return -ENOMEM; + + for (i = 0; i < len; i++) { + bh = hex_to_bin(hex[i * 2]); + bl = hex_to_bin(hex[i * 2 + 1]); + if (bh == -1 || bl == -1) { + safe_alloc ? crypt_safe_free(bytes) : free(bytes); + return -EINVAL; + } + bytes[i] = (bh << 4) | bl; + } + *result = bytes; + return i; +} + +char *crypt_bytes_to_hex(size_t size, const char *bytes) +{ + unsigned i; + char *hex; + + if (size && !bytes) + return NULL; + + /* Alloc adds trailing \0 */ + if (size == 0) + hex = crypt_safe_alloc(2); + else + hex = crypt_safe_alloc(size * 2 + 1); + if (!hex) + return NULL; + + if (size == 0) + hex[0] = '-'; + else for (i = 0; i < size; i++) { + hex[i * 2] = hex2asc((const unsigned char)bytes[i] >> 4); + hex[i * 2 + 1] = hex2asc((const unsigned char)bytes[i] & 0xf); + } + + return hex; +} + +void crypt_log_hex(struct crypt_device *cd, + const char *bytes, size_t size, + const char *sep, int numwrap, const char *wrapsep) +{ + unsigned i; + + for (i = 0; i < size; i++) { + if (wrapsep && numwrap && i && !(i % numwrap)) + crypt_logf(cd, CRYPT_LOG_NORMAL, wrapsep); + crypt_logf(cd, CRYPT_LOG_NORMAL, "%c%c%s", + hex2asc((const unsigned char)bytes[i] >> 4), + hex2asc((const unsigned char)bytes[i] & 0xf), sep); + } +} + +bool crypt_is_cipher_null(const char *cipher_spec) +{ + if (!cipher_spec) + return false; + return (strstr(cipher_spec, "cipher_null") || !strcmp(cipher_spec, "null")); +} + +int crypt_capi_to_cipher(char **org_c, char **org_i, const char *c_dm, const char *i_dm) +{ + char cipher[MAX_CAPI_ONE_LEN], mode[MAX_CAPI_ONE_LEN], iv[MAX_CAPI_ONE_LEN], + auth[MAX_CAPI_ONE_LEN], tmp[MAX_CAPI_LEN], dmcrypt_tmp[MAX_CAPI_LEN*2], + capi[MAX_CAPI_LEN+1]; + size_t len; + int i; + + if (!c_dm) + return -EINVAL; + + /* legacy mode */ + if (strncmp(c_dm, "capi:", 4)) { + if (!(*org_c = strdup(c_dm))) + return -ENOMEM; + if (i_dm) { + if (!(*org_i = strdup(i_dm))) { + free(*org_c); + *org_c = NULL; + return -ENOMEM; + } + } else + *org_i = NULL; + return 0; + } + + /* modes with capi: prefix */ + i = sscanf(c_dm, "capi:%" MAX_CAPI_LEN_STR "[^-]-%" MAX_CAPI_ONE_LEN_STR "s", tmp, iv); + if (i != 2) + return -EINVAL; + + len = strlen(tmp); + if (len < 2) + return -EINVAL; + + if (tmp[len-1] == ')') + tmp[len-1] = '\0'; + + if (sscanf(tmp, "rfc4309(%" MAX_CAPI_LEN_STR "s", capi) == 1) { + if (!(*org_i = strdup("aead"))) + return -ENOMEM; + } else if (sscanf(tmp, "rfc7539(%" MAX_CAPI_LEN_STR "[^,],%" MAX_CAPI_ONE_LEN_STR "s", capi, auth) == 2) { + if (!(*org_i = strdup(auth))) + return -ENOMEM; + } else if (sscanf(tmp, "authenc(%" MAX_CAPI_ONE_LEN_STR "[^,],%" MAX_CAPI_LEN_STR "s", auth, capi) == 2) { + if (!(*org_i = strdup(auth))) + return -ENOMEM; + } else { + if (i_dm) { + if (!(*org_i = strdup(i_dm))) + return -ENOMEM; + } else + *org_i = NULL; + memset(capi, 0, sizeof(capi)); + strncpy(capi, tmp, sizeof(capi)-1); + } + + i = sscanf(capi, "%" MAX_CAPI_ONE_LEN_STR "[^(](%" MAX_CAPI_ONE_LEN_STR "[^)])", mode, cipher); + if (i == 2) + i = snprintf(dmcrypt_tmp, sizeof(dmcrypt_tmp), "%s-%s-%s", cipher, mode, iv); + else + i = snprintf(dmcrypt_tmp, sizeof(dmcrypt_tmp), "%s-%s", capi, iv); + if (i < 0 || (size_t)i >= sizeof(dmcrypt_tmp)) { + free(*org_i); + *org_i = NULL; + return -EINVAL; + } + + if (!(*org_c = strdup(dmcrypt_tmp))) { + free(*org_i); + *org_i = NULL; + return -ENOMEM; + } + + return 0; +} |