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zkey-cryptsetup: Add new 'convert' command

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The 'convert' command converts a LUKS2 volume that uses a clear volume key
and the 'aes' cipher to use a secure volume key and the 'paes' cipher.

Optionally, the volume can use the integrity option with LUKS2 using a
clear key integrity key.

Signed-off-by: Ingo Franzki <ifranzki@linux.ibm.com>
Reviewed-by: Jorg Schmidbauer <jschmidb@de.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
This commit is contained in:
Ingo Franzki
2025-02-14 10:00:40 +01:00
committed by Jan Höppner
parent c80a0c8af0
commit efdd34a56c
4 changed files with 441 additions and 19 deletions
Download Patch File Download Diff File Expand all files Collapse all files
zkey/zkey-cryptsetup.c
+320 -14
View File
@@ -82,7 +82,7 @@ static const struct util_prg prg = {
{
.owner = "IBM Corp.",
.pub_first = 2018,
.pub_last = 2024,
.pub_last = 2025,
},
UTIL_PRG_COPYRIGHT_END
}
@@ -125,6 +125,7 @@ static struct zkey_cryptsetup_globals {
#define COMMAND_VALIDATE "validate"
#define COMMAND_SETVP "setvp"
#define COMMAND_SETKEY "setkey"
#define COMMAND_CONVERT "convert"
#define ZKEY_CRYPTSETUP_COMMAND_MAX_LEN 10
@@ -251,6 +252,33 @@ static struct util_opt opt_vec[] = {
.desc = "Suppresses all confirmation questions. Use with care!",
.command = COMMAND_SETKEY,
},
/***********************************************************/
{
.flags = UTIL_OPT_FLAG_SECTION,
.desc = "OPTIONS",
.command = COMMAND_CONVERT,
},
{
.option = {"volume-key-file", required_argument, NULL, 'm'},
.argument = "FILE-NAME",
.desc = "Specifies the name of a file containing the secure "
"AES key that is set as new volume key",
.command = COMMAND_CONVERT,
},
{
.option = {"master-key-file", required_argument, NULL, 'm'},
.argument = "FILE-NAME",
.desc = "Alias for the '--volume-key-file'|'-m' option",
.command = COMMAND_CONVERT,
.flags = UTIL_OPT_FLAG_NOSHORT,
},
OPT_PASSPHRASE_ENTRY(COMMAND_CONVERT),
{
.option = {"batch-mode", 0, NULL, 'q'},
.desc = "Suppresses all confirmation questions. Use with care!",
.command = COMMAND_CONVERT,
},
/***********************************************************/
{
.flags = UTIL_OPT_FLAG_SECTION,
@@ -288,12 +316,14 @@ struct zkey_cryptsetup_command {
int has_options;
char *pos_arg;
int open_device;
const char *expected_cipher;
};
static int command_reencipher(void);
static int command_validate(void);
static int command_setvp(void);
static int command_setkey(void);
static int command_convert(void);
static struct zkey_cryptsetup_command zkey_cryptsetup_commands[] = {
{
@@ -308,6 +338,7 @@ static struct zkey_cryptsetup_command zkey_cryptsetup_commands[] = {
.has_options = 1,
.pos_arg = "DEVICE",
.open_device = 1,
.expected_cipher = "paes",
},
{
.command = COMMAND_VALIDATE,
@@ -320,6 +351,7 @@ static struct zkey_cryptsetup_command zkey_cryptsetup_commands[] = {
.has_options = 1,
.pos_arg = "DEVICE",
.open_device = 1,
.expected_cipher = "paes",
},
{
.command = COMMAND_SETVP,
@@ -334,6 +366,7 @@ static struct zkey_cryptsetup_command zkey_cryptsetup_commands[] = {
.has_options = 1,
.pos_arg = "DEVICE",
.open_device = 1,
.expected_cipher = "paes",
},
{
.command = COMMAND_SETKEY,
@@ -346,6 +379,22 @@ static struct zkey_cryptsetup_command zkey_cryptsetup_commands[] = {
.has_options = 1,
.pos_arg = "DEVICE",
.open_device = 1,
.expected_cipher = "paes",
},
{
.command = COMMAND_CONVERT,
.abbrev_len = 4,
.function = command_convert,
.need_pkey_device = 1,
.short_desc = "Convert a clear-key LUKS2 volume to use a "
"secure volume key",
.long_desc = "Convert a LUKS2 volume that uses a clear volume "
"key and the 'aes' cipher to use a secure volume "
"key and the 'paes' cipher",
.has_options = 1,
.pos_arg = "DEVICE",
.open_device = 1,
.expected_cipher = "aes",
},
{ .command = NULL }
};
@@ -1149,7 +1198,8 @@ static int put_vp_token(struct crypt_device *cd, int token,
/*
* Open the LUKS2 device
*/
static int open_device(const char *device, struct crypt_device **cd)
static int open_device(const char *device, struct crypt_device **cd,
const char *expected_cipher)
{
const struct crypt_pbkdf_type pbkdf2 = {
.type = CRYPT_KDF_PBKDF2,
@@ -1180,9 +1230,9 @@ static int open_device(const char *device, struct crypt_device **cd)
goto out;
}
if (strcmp(crypt_get_cipher(cdev), "paes") != 0) {
warnx("Device '%s' is not encrypted using the 'paes' cipher",
device);
if (strcmp(crypt_get_cipher(cdev), expected_cipher) != 0) {
warnx("Device '%s' is not encrypted using the '%s' cipher",
device, expected_cipher);
rc = -EINVAL;
goto out;
}
@@ -1386,7 +1436,7 @@ static int check_keysize_and_cipher_mode(const u8 *key, size_t keysize)
static int open_keyslot(int keyslot, char **key, size_t *keysize,
size_t *integrity_keysize,
char **password, size_t *password_len,
const char *prompt)
const char *prompt, bool no_keysize_check)
{
struct crypt_params_integrity ip = { 0 };
#ifdef HAVE_CRYPT_KEYSLOT_GET_PBKDF
@@ -1414,10 +1464,13 @@ static int open_keyslot(int keyslot, char **key, size_t *keysize,
pr_verbose("Integrity key size: %u", ip.integrity_key_size);
}
rc = check_keysize_and_cipher_mode(NULL,
vkeysize - ip.integrity_key_size);
if (rc != 0)
return rc;
if (!no_keysize_check) {
rc = check_keysize_and_cipher_mode(NULL,
vkeysize -
ip.integrity_key_size);
if (rc != 0)
return rc;
}
vkey = malloc(vkeysize);
if (vkey == NULL) {
@@ -1528,7 +1581,7 @@ static int validate_keyslot(int keyslot, char **key, size_t *keysize,
int rc, is_old;
rc = open_keyslot(keyslot, &vkey, &vkeysize, &ikeysize,
password, password_len, prompt);
password, password_len, prompt, false);
if (rc < 0)
return rc;
@@ -1570,6 +1623,27 @@ out:
return rc;
}
/*
* Return the number of active key slots in a LUKS2 volume.
*/
static int count_active_keyslots(struct crypt_device *cd)
{
crypt_keyslot_info info;
int i, n;
for (i = 0, n = 0; ; i++) {
info = crypt_keyslot_status(cd, i);
if (info == CRYPT_SLOT_INVALID)
break;
if (info < CRYPT_SLOT_ACTIVE || info > CRYPT_SLOT_ACTIVE_LAST)
continue;
n++;
}
return n;
}
/*
* Prepares for a re-enciphering of a secure volume key. Dependent on the
* options specified by the user and the state of the volume key, it starts
@@ -2002,7 +2076,7 @@ static int command_validate(void)
util_asprintf(&prompt, "Enter passphrase for '%s': ", g.pos_arg);
rc = open_keyslot(CRYPT_ANY_SLOT, &key, &keysize, &integrity_keysize,
NULL, NULL, prompt);
NULL, NULL, prompt, false);
free(prompt);
if (rc < 0)
goto out;
@@ -2228,7 +2302,7 @@ static int command_setkey(void)
util_asprintf(&prompt, "Enter passphrase for '%s': ", g.pos_arg);
rc = open_keyslot(CRYPT_ANY_SLOT, &key, &keysize, &integrity_keysize,
&password, &password_len, prompt);
&password, &password_len, prompt, false);
free(prompt);
if (rc < 0)
goto out;
@@ -2337,6 +2411,238 @@ out:
}
/*
* Command handler for 'convert'.
*
* Convert a LUKS2 volume that uses a clear volume key and the 'aes' cipher
* to use a secure volume key and the 'paes' cipher.
*/
static int command_convert(void)
{
struct crypt_params_integrity ip_new = { 0 };
struct crypt_params_integrity ip = { 0 };
struct crypt_params_luks2 luks2 = { 0 };
char new_vp[VERIFICATION_PATTERN_LEN];
struct crypt_device *new_cd = NULL;
char vp[VERIFICATION_PATTERN_LEN];
struct vp_token vp_tok = { 0 };
size_t integrity_keysize = 0;
size_t password_len = 0;
size_t newekey_size = 0;
size_t newkey_size = 0;
char *password = NULL;
size_t ekeysize = 0;
size_t keysize = 0;
u8 *newkey = NULL;
int num_keyslots;
u8 *key = NULL;
int is_old_mk;
char *prompt;
int is_xts;
char *msg;
int rc;
/* Check preconditions */
if (strcmp(crypt_get_cipher_mode(g.cd), "xts-plain64") != 0 &&
strcmp(crypt_get_cipher_mode(g.cd), "cbc-plain64") != 0) {
warnx("The volume uses cipher mode '%s' and thus can not be "
"converted to use the 'paes' cipher",
crypt_get_cipher_mode(g.cd));
return EXIT_FAILURE;
}
is_xts = (strncmp(crypt_get_cipher_mode(g.cd), "xts-", 4) == 0);
/* Read new volume key and validate it */
if (g.volume_key_file == NULL) {
misc_print_required_parm("--volume-key-file/-m");
return EXIT_FAILURE;
}
newkey = read_secure_key(g.volume_key_file, &newkey_size, g.verbose);
if (newkey == NULL)
return EXIT_FAILURE;
rc = crypt_get_integrity_info(g.cd, &ip);
if (rc == 0)
integrity_keysize = ip.integrity_key_size;
newekey_size = newkey_size - integrity_keysize;
rc = check_keysize_and_cipher_mode(newkey, newekey_size);
if (rc != 0)
goto out;
rc = validate_secure_key(g.pkey_fd, newkey, newekey_size, NULL,
&is_old_mk, NULL, g.verbose);
if (rc != 0) {
warnx("The secure key in file '%s' is not valid",
g.volume_key_file);
goto out;
}
if (is_secure_key(newkey, newekey_size) &&
is_old_mk) {
util_asprintf(&msg, "The secure key in file '%s' is "
"enciphered with the master key in the OLD "
"master key register. Do you want to set this "
"key as the new volume key anyway [y/N]?",
g.volume_key_file);
util_print_indented(msg, 0);
free(msg);
if (!_prompt_for_yes()) {
warnx("Device '%s' is left unchanged", g.pos_arg);
rc = -EINVAL;
goto out;
}
}
rc = generate_key_verification_pattern(newkey, newekey_size,
new_vp, sizeof(new_vp),
g.verbose);
if (rc != 0) {
warnx("Failed to generate the verification pattern: %s",
strerror(-rc));
warnx("Make sure that kernel module 'paes_s390' is loaded and "
"that the 'paes' cipher is available");
goto out;
}
/* Get current (clear) volume key from LUKS2 header */
util_asprintf(&prompt, "Enter passphrase for '%s': ", g.pos_arg);
rc = open_keyslot(CRYPT_ANY_SLOT, (char **)&key, &keysize, NULL,
&password, &password_len, prompt, true);
free(prompt);
if (rc < 0)
goto out;
ekeysize = keysize - integrity_keysize;
if (integrity_keysize > 0 &&
memcmp(newkey + newekey_size, key + ekeysize,
integrity_keysize) != 0) {
warnx("The secure key in file '%s' contains a different "
"integrity key (i.e. the last %lu bytes of the key) than "
"the current volume key.", g.volume_key_file,
integrity_keysize);
rc = -EINVAL;
goto out;
}
rc = generate_aes_key_verification_pattern(key, ekeysize,
vp, sizeof(vp),
is_xts ?
"xts(aes)" : "cbc(aes)",
g.verbose);
if (rc != 0) {
warnx("Failed to generate the verification pattern: %s",
strerror(-rc));
goto out;
}
if (strcmp(vp, new_vp) != 0) {
warnx("The verification patterns of the new and old "
"volume keys do not match");
rc = -EINVAL;
goto out;
}
num_keyslots = count_active_keyslots(g.cd);
pr_verbose("Number of keyslots before conversion: %d", num_keyslots);
util_print_indented("WARNING: It is strongly recommended to take a "
"LUKS header backup using 'cryptsetup "
"luksHeaderBackup' before continuing. The volume "
"might not be recoverable after a failing "
"conversion, if you don't have a LUKS header "
"backup.", 0);
util_asprintf(&msg, "Do you really want to convert device '%s' to "
"use a secure volume key? [y/N]?", g.pos_arg);
util_print_indented(msg, 0);
free(msg);
if (!_prompt_for_yes()) {
warnx("Device '%s' is left unchanged", g.pos_arg);
rc = -EINVAL;
goto out;
}
/* Open the device freshly for crypt_format */
rc = crypt_init(&new_cd, g.pos_arg);
if (rc != 0) {
warnx("Failed to open device '%s': %s", g.pos_arg,
strerror(-rc));
goto out;
}
crypt_set_log_callback(new_cd, cryptsetup_log, NULL);
/* Re-format the device with the same settings, but using 'paes' */
#ifdef CRYPT_ACTIVATE_ERROR_AS_CORRUPTION /* Indicates libcryptsetup > 2.7.5 */
ip_new.integrity_key_size = integrity_keysize;
#endif
luks2.pbkdf = crypt_get_pbkdf_type(g.cd);
luks2.integrity = integrity_keysize > 0 ? ip.integrity : NULL;
luks2.integrity_params = integrity_keysize > 0 ? &ip_new : NULL;
luks2.data_alignment = 0;
luks2.data_device = NULL;
luks2.sector_size = crypt_get_sector_size(g.cd);
luks2.label = crypt_get_label(g.cd);
luks2.subsystem = crypt_get_subsystem(g.cd);
rc = crypt_set_data_offset(new_cd, crypt_get_data_offset(g.cd));
if (rc != 0) {
warnx("Failed to set data size: %s", strerror(-rc));
goto out;
}
rc = crypt_format(new_cd, CRYPT_LUKS2, "paes",
crypt_get_cipher_mode(g.cd), crypt_get_uuid(g.cd),
(char *)newkey, newkey_size, &luks2);
if (rc != 0) {
warnx("Failed to reformat the LUKS header: %s",
strerror(-rc));
goto out;
}
/* Add a key slot with the current password */
rc = crypt_keyslot_add_by_volume_key(new_cd, CRYPT_ANY_SLOT, NULL, 0,
password, password_len);
if (rc != 0) {
warnx("Failed to add a key slotr: %s", strerror(-rc));
goto out;
}
/* Add the verification pattern token */
memcpy(vp_tok.verification_pattern, new_vp,
sizeof(vp_tok.verification_pattern));
rc = put_vp_token(new_cd, -1, &vp_tok);
if (rc < 0)
goto out;
printf("The device '%s' has been successfully converted\n", g.pos_arg);
if (num_keyslots > 1) {
util_print_indented("\nWARNING: Before converting, the "
"volume's LUKS header had multiple active "
"key slots with the same key, but "
"different passwords. Use 'cryptsetup "
"luksAddKey' if you need more than one key "
"slot.", 0);
}
out:
secure_free(password, password_len);
secure_free(newkey, newkey_size);
secure_free(key, keysize);
if (new_cd != NULL)
crypt_free(new_cd);
return rc < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
}
static bool is_command(struct zkey_cryptsetup_command *command, const char *str)
{
char command_str[ZKEY_CRYPTSETUP_COMMAND_STR_LEN];
@@ -2535,7 +2841,7 @@ int main(int argc, char *argv[])
goto out;
}
rc = open_device(g.pos_arg, &g.cd);
rc = open_device(g.pos_arg, &g.cd, command->expected_cipher);
if (rc != 0) {
g.cd = NULL;
rc = EXIT_FAILURE;