diff options
Diffstat (limited to 'src/cryptenroll/cryptenroll.c')
-rw-r--r-- | src/cryptenroll/cryptenroll.c | 201 |
1 files changed, 162 insertions, 39 deletions
diff --git a/src/cryptenroll/cryptenroll.c b/src/cryptenroll/cryptenroll.c index 1cb6652..04352bf 100644 --- a/src/cryptenroll/cryptenroll.c +++ b/src/cryptenroll/cryptenroll.c @@ -1,8 +1,10 @@ /* SPDX-License-Identifier: LGPL-2.1-or-later */ #include <getopt.h> +#include <sys/mman.h> #include "ask-password-api.h" +#include "blockdev-util.h" #include "build.h" #include "cryptenroll-fido2.h" #include "cryptenroll-list.h" @@ -13,6 +15,7 @@ #include "cryptenroll-wipe.h" #include "cryptenroll.h" #include "cryptsetup-util.h" +#include "devnum-util.h" #include "env-util.h" #include "escape.h" #include "fileio.h" @@ -33,6 +36,7 @@ static EnrollType arg_enroll_type = _ENROLL_TYPE_INVALID; static char *arg_unlock_keyfile = NULL; static UnlockType arg_unlock_type = UNLOCK_PASSWORD; static char *arg_unlock_fido2_device = NULL; +static char *arg_unlock_tpm2_device = NULL; static char *arg_pkcs11_token_uri = NULL; static char *arg_fido2_device = NULL; static char *arg_tpm2_device = NULL; @@ -42,6 +46,7 @@ static Tpm2PCRValue *arg_tpm2_hash_pcr_values = NULL; static size_t arg_tpm2_n_hash_pcr_values = 0; static bool arg_tpm2_pin = false; static char *arg_tpm2_public_key = NULL; +static bool arg_tpm2_load_public_key = true; static uint32_t arg_tpm2_public_key_pcr_mask = 0; static char *arg_tpm2_signature = NULL; static char *arg_tpm2_pcrlock = NULL; @@ -61,6 +66,7 @@ assert_cc(sizeof(arg_wipe_slots_mask) * 8 >= _ENROLL_TYPE_MAX); STATIC_DESTRUCTOR_REGISTER(arg_unlock_keyfile, freep); STATIC_DESTRUCTOR_REGISTER(arg_unlock_fido2_device, freep); +STATIC_DESTRUCTOR_REGISTER(arg_unlock_tpm2_device, freep); STATIC_DESTRUCTOR_REGISTER(arg_pkcs11_token_uri, freep); STATIC_DESTRUCTOR_REGISTER(arg_fido2_device, freep); STATIC_DESTRUCTOR_REGISTER(arg_tpm2_device, freep); @@ -98,6 +104,66 @@ static const char *const luks2_token_type_table[_ENROLL_TYPE_MAX] = { DEFINE_STRING_TABLE_LOOKUP(luks2_token_type, EnrollType); +static int determine_default_node(void) { + int r; + + /* If no device is specified we'll default to the backing device of /var/. + * + * Why /var/ and not just / you ask? + * + * On most systems /var/ is going to be on the root fs, hence the outcome is usually the same. + * + * However, on systems where / and /var/ are separate it makes more sense to default to /var/ because + * that's where the persistent and variable data is placed (i.e. where LUKS should be used) while / + * doesn't really have to be variable and could as well be immutable or ephemeral. Hence /var/ should + * be a better default. + * + * Or to say this differently: it makes sense to support well systems with /var/ being on /. It also + * makes sense to support well systems with them being separate, and /var/ being variable and + * persistent. But any other kind of system appears much less interesting to support, and in that + * case people should just specify the device name explicitly. */ + + dev_t devno; + r = get_block_device("/var", &devno); + if (r < 0) + return log_error_errno(r, "Failed to determine block device backing /var/: %m"); + if (r == 0) + return log_error_errno(SYNTHETIC_ERRNO(ENXIO), + "File system /var/ is on not backed by a (single) whole block device."); + + _cleanup_(sd_device_unrefp) sd_device *dev = NULL; + r = sd_device_new_from_devnum(&dev, 'b', devno); + if (r < 0) + return log_error_errno(r, "Unable to access backing block device for /var/: %m"); + + const char *dm_uuid; + r = sd_device_get_property_value(dev, "DM_UUID", &dm_uuid); + if (r == -ENOENT) + return log_error_errno(r, "Backing block device of /var/ is not a DM device: %m"); + if (r < 0) + return log_error_errno(r, "Unable to query DM_UUID udev property of backing block device for /var/: %m"); + + if (!startswith(dm_uuid, "CRYPT-LUKS2-")) + return log_error_errno(SYNTHETIC_ERRNO(ENXIO), "Block device backing /var/ is not a LUKS2 device."); + + _cleanup_(sd_device_unrefp) sd_device *origin = NULL; + r = block_device_get_originating(dev, &origin); + if (r < 0) + return log_error_errno(r, "Failed to get originating device of LUKS2 device backing /var/: %m"); + + const char *dp; + r = sd_device_get_devname(origin, &dp); + if (r < 0) + return log_error_errno(r, "Failed to get device path for LUKS2 device backing /var/: %m"); + + r = free_and_strdup_warn(&arg_node, dp); + if (r < 0) + return r; + + log_info("No device specified, defaulting to '%s'.", arg_node); + return 0; +} + static int help(void) { _cleanup_free_ char *link = NULL; int r; @@ -106,7 +172,7 @@ static int help(void) { if (r < 0) return log_oom(); - printf("%1$s [OPTIONS...] BLOCK-DEVICE\n\n" + printf("%1$s [OPTIONS...] [BLOCK-DEVICE]\n\n" "%5$sEnroll a security token or authentication credential to a LUKS volume.%6$s\n\n" " -h --help Show this help\n" " --version Show package version\n" @@ -117,6 +183,8 @@ static int help(void) { " Use a file to unlock the volume\n" " --unlock-fido2-device=PATH\n" " Use a FIDO2 device to unlock the volume\n" + " --unlock-tpm2-device=PATH\n" + " Use a TPM2 device to unlock the volume\n" "\n%3$sSimple Enrollment:%4$s\n" " --password Enroll a user-supplied password\n" " --recovery-key Enroll a recovery key\n" @@ -172,6 +240,7 @@ static int parse_argv(int argc, char *argv[]) { ARG_RECOVERY_KEY, ARG_UNLOCK_KEYFILE, ARG_UNLOCK_FIDO2_DEVICE, + ARG_UNLOCK_TPM2_DEVICE, ARG_PKCS11_TOKEN_URI, ARG_FIDO2_DEVICE, ARG_TPM2_DEVICE, @@ -197,6 +266,7 @@ static int parse_argv(int argc, char *argv[]) { { "recovery-key", no_argument, NULL, ARG_RECOVERY_KEY }, { "unlock-key-file", required_argument, NULL, ARG_UNLOCK_KEYFILE }, { "unlock-fido2-device", required_argument, NULL, ARG_UNLOCK_FIDO2_DEVICE }, + { "unlock-tpm2-device", required_argument, NULL, ARG_UNLOCK_TPM2_DEVICE }, { "pkcs11-token-uri", required_argument, NULL, ARG_PKCS11_TOKEN_URI }, { "fido2-credential-algorithm", required_argument, NULL, ARG_FIDO2_CRED_ALG }, { "fido2-device", required_argument, NULL, ARG_FIDO2_DEVICE }, @@ -304,6 +374,26 @@ static int parse_argv(int argc, char *argv[]) { break; } + case ARG_UNLOCK_TPM2_DEVICE: { + _cleanup_free_ char *device = NULL; + + if (arg_unlock_type != UNLOCK_PASSWORD) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "Multiple unlock methods specified at once, refusing."); + + assert(!arg_unlock_tpm2_device); + + if (!streq(optarg, "auto")) { + device = strdup(optarg); + if (!device) + return log_oom(); + } + + arg_unlock_type = UNLOCK_TPM2; + arg_unlock_tpm2_device = TAKE_PTR(device); + break; + } + case ARG_PKCS11_TOKEN_URI: { _cleanup_free_ char *uri = NULL; @@ -409,9 +499,17 @@ static int parse_argv(int argc, char *argv[]) { break; case ARG_TPM2_PUBLIC_KEY: + /* an empty argument disables loading a public key */ + if (isempty(optarg)) { + arg_tpm2_load_public_key = false; + arg_tpm2_public_key = mfree(arg_tpm2_public_key); + break; + } + r = parse_path_argument(optarg, /* suppress_root= */ false, &arg_tpm2_public_key); if (r < 0) return r; + arg_tpm2_load_public_key = true; break; @@ -507,17 +605,23 @@ static int parse_argv(int argc, char *argv[]) { } } - if (optind >= argc) - return log_error_errno(SYNTHETIC_ERRNO(EINVAL), - "No block device node specified, refusing."); - if (argc > optind+1) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Too many arguments, refusing."); - r = parse_path_argument(argv[optind], false, &arg_node); - if (r < 0) - return r; + if (optind < argc) { + r = parse_path_argument(argv[optind], false, &arg_node); + if (r < 0) + return r; + } else { + if (wipe_requested()) + return log_error_errno(SYNTHETIC_ERRNO(EINVAL), + "Wiping requested and no block device node specified, refusing."); + + r = determine_default_node(); + if (r < 0) + return r; + } if (arg_enroll_type == ENROLL_FIDO2) { @@ -533,31 +637,33 @@ static int parse_argv(int argc, char *argv[]) { } } - if (auto_pcrlock) { - assert(!arg_tpm2_pcrlock); + if (arg_enroll_type == ENROLL_TPM2) { + if (auto_pcrlock) { + assert(!arg_tpm2_pcrlock); - r = tpm2_pcrlock_search_file(NULL, NULL, &arg_tpm2_pcrlock); - if (r < 0) { - if (r != -ENOENT) - log_warning_errno(r, "Search for pcrlock.json failed, assuming it does not exist: %m"); - } else - log_info("Automatically using pcrlock policy '%s'.", arg_tpm2_pcrlock); - } + r = tpm2_pcrlock_search_file(NULL, NULL, &arg_tpm2_pcrlock); + if (r < 0) { + if (r != -ENOENT) + log_warning_errno(r, "Search for pcrlock.json failed, assuming it does not exist: %m"); + } else + log_info("Automatically using pcrlock policy '%s'.", arg_tpm2_pcrlock); + } - if (auto_public_key_pcr_mask) { - assert(arg_tpm2_public_key_pcr_mask == 0); - arg_tpm2_public_key_pcr_mask = INDEX_TO_MASK(uint32_t, TPM2_PCR_KERNEL_BOOT); - } + if (auto_public_key_pcr_mask) { + assert(arg_tpm2_public_key_pcr_mask == 0); + arg_tpm2_public_key_pcr_mask = INDEX_TO_MASK(uint32_t, TPM2_PCR_KERNEL_BOOT); + } - if (auto_hash_pcr_values && !arg_tpm2_pcrlock) { /* Only lock to PCR 7 by default if no pcrlock policy is around (which is a better replacement) */ - assert(arg_tpm2_n_hash_pcr_values == 0); + if (auto_hash_pcr_values && !arg_tpm2_pcrlock) { /* Only lock to PCR 7 by default if no pcrlock policy is around (which is a better replacement) */ + assert(arg_tpm2_n_hash_pcr_values == 0); - if (!GREEDY_REALLOC_APPEND( - arg_tpm2_hash_pcr_values, - arg_tpm2_n_hash_pcr_values, - &TPM2_PCR_VALUE_MAKE(TPM2_PCR_INDEX_DEFAULT, /* hash= */ 0, /* value= */ {}), - 1)) - return log_oom(); + if (!GREEDY_REALLOC_APPEND( + arg_tpm2_hash_pcr_values, + arg_tpm2_n_hash_pcr_values, + &TPM2_PCR_VALUE_MAKE(TPM2_PCR_INDEX_DEFAULT, /* hash= */ 0, /* value= */ {}), + 1)) + return log_oom(); + } } return 1; @@ -571,7 +677,7 @@ static int check_for_homed(struct crypt_device *cd) { /* Politely refuse operating on homed volumes. The enrolled tokens for the user record and the LUKS2 * volume should not get out of sync. */ - for (int token = 0; token < crypt_token_max(CRYPT_LUKS2); token ++) { + for (int token = 0; token < crypt_token_max(CRYPT_LUKS2); token++) { r = cryptsetup_get_token_as_json(cd, token, "systemd-homed", NULL); if (IN_SET(r, -ENOENT, -EINVAL, -EMEDIUMTYPE)) continue; @@ -644,7 +750,7 @@ static int prepare_luks( r = crypt_load(cd, CRYPT_LUKS2, NULL); if (r < 0) - return log_error_errno(r, "Failed to load LUKS2 superblock: %m"); + return log_error_errno(r, "Failed to load LUKS2 superblock of %s: %m", arg_node); r = check_for_homed(cd); if (r < 0) @@ -666,6 +772,10 @@ static int prepare_luks( switch (arg_unlock_type) { + case UNLOCK_PASSWORD: + r = load_volume_key_password(cd, arg_node, vk, &vks); + break; + case UNLOCK_KEYFILE: r = load_volume_key_keyfile(cd, vk, &vks); break; @@ -674,8 +784,8 @@ static int prepare_luks( r = load_volume_key_fido2(cd, arg_node, arg_unlock_fido2_device, vk, &vks); break; - case UNLOCK_PASSWORD: - r = load_volume_key_password(cd, arg_node, vk, &vks); + case UNLOCK_TPM2: + r = load_volume_key_tpm2(cd, arg_node, arg_unlock_tpm2_device, vk, &vks); break; default: @@ -696,16 +806,17 @@ static int run(int argc, char *argv[]) { _cleanup_(crypt_freep) struct crypt_device *cd = NULL; _cleanup_(erase_and_freep) void *vk = NULL; size_t vks; - int slot, r; + int slot, slot_to_wipe, r; - log_show_color(true); - log_parse_environment(); - log_open(); + log_setup(); r = parse_argv(argc, argv); if (r <= 0) return r; + /* A delicious drop of snake oil */ + (void) mlockall(MCL_FUTURE); + cryptsetup_enable_logging(NULL); if (arg_enroll_type < 0) @@ -734,9 +845,21 @@ static int run(int argc, char *argv[]) { break; case ENROLL_TPM2: - slot = enroll_tpm2(cd, vk, vks, arg_tpm2_device, arg_tpm2_seal_key_handle, arg_tpm2_device_key, arg_tpm2_hash_pcr_values, arg_tpm2_n_hash_pcr_values, arg_tpm2_public_key, arg_tpm2_public_key_pcr_mask, arg_tpm2_signature, arg_tpm2_pin, arg_tpm2_pcrlock); + slot = enroll_tpm2(cd, vk, vks, arg_tpm2_device, arg_tpm2_seal_key_handle, arg_tpm2_device_key, arg_tpm2_hash_pcr_values, arg_tpm2_n_hash_pcr_values, arg_tpm2_public_key, arg_tpm2_load_public_key, arg_tpm2_public_key_pcr_mask, arg_tpm2_signature, arg_tpm2_pin, arg_tpm2_pcrlock, &slot_to_wipe); + + if (slot >= 0 && slot_to_wipe >= 0) { + /* Updating PIN on an existing enrollment */ + r = wipe_slots( + cd, + &slot_to_wipe, + /* n_explicit_slots= */ 1, + WIPE_EXPLICIT, + /* by_mask= */ 0, + /* except_slot= */ -1); + if (r < 0) + return r; + } break; - case _ENROLL_TYPE_INVALID: /* List enrolled slots if we are called without anything to enroll or wipe */ if (!wipe_requested()) |