* utils_crypt - cipher utilities for cryptsetup
*
* Copyright (C) 2004-2007 Clemens Fruhwirth <clemens@endorphin.org>
- * Copyright (C) 2009-2020 Red Hat, Inc. All rights reserved.
- * Copyright (C) 2009-2020 Milan Broz
+ * 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
#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)
{
return -EINVAL;
r = sscanf(s, "%" MAX_CIPHER_LEN_STR "[^-]-%" MAX_CIPHER_LEN_STR "s", mode, hash);
- if (r == 2)
+ 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)
+ if (r < 0 || r >= MAX_CIPHER_LEN)
return -EINVAL;
return 0;
if (!s || !integrity)
return -EINVAL;
- // FIXME: do not hardcode it here
-
/* AEAD modes */
if (!strcmp(s, "aead") ||
!strcmp(s, "poly1305") ||
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 buf[3] = "xx\0", *endp, *bytes;
+ char *bytes;
size_t i, len;
+ int bl, bh;
+
+ if (!hex || !result)
+ return -EINVAL;
len = strlen(hex);
if (len % 2)
return -ENOMEM;
for (i = 0; i < len; i++) {
- memcpy(buf, &hex[i * 2], 2);
- bytes[i] = strtoul(buf, &endp, 16);
- if (endp != &buf[2]) {
+ 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;
+}
projects / platform / upstream / cryptsetup.git / blobdiff