/* SPDX-License-Identifier: LGPL-2.1-or-later */ #include "alloc-util.h" #include "cryptsetup-util.h" #include "dlfcn-util.h" #include "log.h" #include "parse-util.h" #if HAVE_LIBCRYPTSETUP static void *cryptsetup_dl = NULL; int (*sym_crypt_activate_by_passphrase)(struct crypt_device *cd, const char *name, int keyslot, const char *passphrase, size_t passphrase_size, uint32_t flags); #if HAVE_CRYPT_ACTIVATE_BY_SIGNED_KEY int (*sym_crypt_activate_by_signed_key)(struct crypt_device *cd, const char *name, const char *volume_key, size_t volume_key_size, const char *signature, size_t signature_size, uint32_t flags); #endif int (*sym_crypt_activate_by_volume_key)(struct crypt_device *cd, const char *name, const char *volume_key, size_t volume_key_size, uint32_t flags); int (*sym_crypt_deactivate_by_name)(struct crypt_device *cd, const char *name, uint32_t flags); int (*sym_crypt_format)(struct crypt_device *cd, const char *type, const char *cipher, const char *cipher_mode, const char *uuid, const char *volume_key, size_t volume_key_size, void *params); void (*sym_crypt_free)(struct crypt_device *cd); const char *(*sym_crypt_get_cipher)(struct crypt_device *cd); const char *(*sym_crypt_get_cipher_mode)(struct crypt_device *cd); uint64_t (*sym_crypt_get_data_offset)(struct crypt_device *cd); const char *(*sym_crypt_get_device_name)(struct crypt_device *cd); const char *(*sym_crypt_get_dir)(void); const char *(*sym_crypt_get_type)(struct crypt_device *cd); const char *(*sym_crypt_get_uuid)(struct crypt_device *cd); int (*sym_crypt_get_verity_info)(struct crypt_device *cd, struct crypt_params_verity *vp); int (*sym_crypt_get_volume_key_size)(struct crypt_device *cd); int (*sym_crypt_init)(struct crypt_device **cd, const char *device); int (*sym_crypt_init_by_name)(struct crypt_device **cd, const char *name); int (*sym_crypt_keyslot_add_by_volume_key)(struct crypt_device *cd, int keyslot, const char *volume_key, size_t volume_key_size, const char *passphrase, size_t passphrase_size); int (*sym_crypt_keyslot_destroy)(struct crypt_device *cd, int keyslot); int (*sym_crypt_keyslot_max)(const char *type); int (*sym_crypt_load)(struct crypt_device *cd, const char *requested_type, void *params); int (*sym_crypt_resize)(struct crypt_device *cd, const char *name, uint64_t new_size); int (*sym_crypt_resume_by_passphrase)(struct crypt_device *cd, const char *name, int keyslot, const char *passphrase, size_t passphrase_size); int (*sym_crypt_set_data_device)(struct crypt_device *cd, const char *device); void (*sym_crypt_set_debug_level)(int level); void (*sym_crypt_set_log_callback)(struct crypt_device *cd, void (*log)(int level, const char *msg, void *usrptr), void *usrptr); #if HAVE_CRYPT_SET_METADATA_SIZE int (*sym_crypt_set_metadata_size)(struct crypt_device *cd, uint64_t metadata_size, uint64_t keyslots_size); #endif int (*sym_crypt_set_pbkdf_type)(struct crypt_device *cd, const struct crypt_pbkdf_type *pbkdf); int (*sym_crypt_suspend)(struct crypt_device *cd, const char *name); int (*sym_crypt_token_json_get)(struct crypt_device *cd, int token, const char **json); int (*sym_crypt_token_json_set)(struct crypt_device *cd, int token, const char *json); #if HAVE_CRYPT_TOKEN_MAX int (*sym_crypt_token_max)(const char *type); #endif crypt_token_info (*sym_crypt_token_status)(struct crypt_device *cd, int token, const char **type); int (*sym_crypt_volume_key_get)(struct crypt_device *cd, int keyslot, char *volume_key, size_t *volume_key_size, const char *passphrase, size_t passphrase_size); #if HAVE_CRYPT_REENCRYPT_INIT_BY_PASSPHRASE int (*sym_crypt_reencrypt_init_by_passphrase)(struct crypt_device *cd, const char *name, const char *passphrase, size_t passphrase_size, int keyslot_old, int keyslot_new, const char *cipher, const char *cipher_mode, const struct crypt_params_reencrypt *params); #endif #if HAVE_CRYPT_REENCRYPT int (*sym_crypt_reencrypt)(struct crypt_device *cd, int (*progress)(uint64_t size, uint64_t offset, void *usrptr)); #endif int (*sym_crypt_metadata_locking)(struct crypt_device *cd, int enable); #if HAVE_CRYPT_SET_DATA_OFFSET int (*sym_crypt_set_data_offset)(struct crypt_device *cd, uint64_t data_offset); #endif int (*sym_crypt_header_restore)(struct crypt_device *cd, const char *requested_type, const char *backup_file); int (*sym_crypt_volume_key_keyring)(struct crypt_device *cd, int enable); /* Unfortunately libcryptsetup provides neither an environment variable to redirect where to look for token * modules, nor does it have an API to change the token lookup path at runtime. The maintainers suggest using * ELF interposition instead (see https://gitlab.com/cryptsetup/cryptsetup/-/issues/846). Hence let's do * that: let's interpose libcryptsetup's crypt_token_external_path() function with our own, that *does* * honour an environment variable where to look for tokens. This is tremendously useful for debugging * libcryptsetup tokens: set the environment variable to your build dir and you can easily test token modules * without jumping through various hoops. */ /* Do this only on new enough compilers that actually support the "symver" attribute. Given this is a debug * feature, let's simply not bother on older compilers */ #if BUILD_MODE_DEVELOPER && defined(__has_attribute) && __has_attribute(symver) const char *my_crypt_token_external_path(void); /* prototype for our own implementation */ /* We use the "symver" attribute to mark this implementation as the default implementation, and drop the * SD_SHARED namespace we by default attach to our symbols via a version script. */ __attribute__((symver("crypt_token_external_path@@"))) _public_ const char *my_crypt_token_external_path(void) { const char *e; e = secure_getenv("SYSTEMD_CRYPTSETUP_TOKEN_PATH"); if (e) return e; /* Now chain invoke the original implementation. */ if (cryptsetup_dl) { typeof(crypt_token_external_path) *func; func = (typeof(crypt_token_external_path)*) dlsym(cryptsetup_dl, "crypt_token_external_path"); if (func) return func(); } return NULL; } #endif static void cryptsetup_log_glue(int level, const char *msg, void *usrptr) { switch (level) { case CRYPT_LOG_NORMAL: level = LOG_NOTICE; break; case CRYPT_LOG_ERROR: level = LOG_ERR; break; case CRYPT_LOG_VERBOSE: level = LOG_INFO; break; case CRYPT_LOG_DEBUG: level = LOG_DEBUG; break; default: log_error("Unknown libcryptsetup log level: %d", level); level = LOG_ERR; } log_full(level, "%s", msg); } void cryptsetup_enable_logging(struct crypt_device *cd) { /* It's OK to call this with a NULL parameter, in which case libcryptsetup will set the default log * function. * * Note that this is also called from dlopen_cryptsetup(), which we call here too. Sounds like an * endless loop, but isn't because we break it via the check for 'cryptsetup_dl' early in * dlopen_cryptsetup(). */ if (dlopen_cryptsetup() < 0) return; /* If this fails, let's gracefully ignore the issue, this is just debug logging after * all, and if this failed we already generated a debug log message that should help * to track things down. */ sym_crypt_set_log_callback(cd, cryptsetup_log_glue, NULL); sym_crypt_set_debug_level(DEBUG_LOGGING ? CRYPT_DEBUG_ALL : CRYPT_DEBUG_NONE); } int cryptsetup_set_minimal_pbkdf(struct crypt_device *cd) { /* With CRYPT_PBKDF_NO_BENCHMARK flag set .time_ms member is ignored * while .iterations must be set at least to recommended minimum value. */ static const struct crypt_pbkdf_type minimal_pbkdf = { .hash = "sha512", .type = CRYPT_KDF_PBKDF2, .iterations = 1000, /* recommended minimum count for pbkdf2 * according to NIST SP 800-132, ch. 5.2 */ .flags = CRYPT_PBKDF_NO_BENCHMARK }; int r; /* Sets a minimal PKBDF in case we already have a high entropy key. */ r = dlopen_cryptsetup(); if (r < 0) return r; r = sym_crypt_set_pbkdf_type(cd, &minimal_pbkdf); if (r < 0) return r; return 0; } int cryptsetup_get_token_as_json( struct crypt_device *cd, int idx, const char *verify_type, JsonVariant **ret) { _cleanup_(json_variant_unrefp) JsonVariant *v = NULL; const char *text; int r; assert(cd); /* Extracts and parses the LUKS2 JSON token data from a LUKS2 device. Optionally verifies the type of * the token. Returns: * * -EINVAL → token index out of range or "type" field missing * -ENOENT → token doesn't exist * -EMEDIUMTYPE → "verify_type" specified and doesn't match token's type */ r = dlopen_cryptsetup(); if (r < 0) return r; r = sym_crypt_token_json_get(cd, idx, &text); if (r < 0) return r; r = json_parse(text, 0, &v, NULL, NULL); if (r < 0) return r; if (verify_type) { JsonVariant *w; w = json_variant_by_key(v, "type"); if (!w) return -EINVAL; if (!streq_ptr(json_variant_string(w), verify_type)) return -EMEDIUMTYPE; } if (ret) *ret = TAKE_PTR(v); return 0; } int cryptsetup_add_token_json(struct crypt_device *cd, JsonVariant *v) { _cleanup_free_ char *text = NULL; int r; r = dlopen_cryptsetup(); if (r < 0) return r; r = json_variant_format(v, 0, &text); if (r < 0) return log_debug_errno(r, "Failed to format token data for LUKS: %m"); log_debug("Adding token text <%s>", text); r = sym_crypt_token_json_set(cd, CRYPT_ANY_TOKEN, text); if (r < 0) return log_debug_errno(r, "Failed to write token data to LUKS: %m"); return 0; } #endif int dlopen_cryptsetup(void) { #if HAVE_LIBCRYPTSETUP int r; /* libcryptsetup added crypt_reencrypt() in 2.2.0, and marked it obsolete in 2.4.0, replacing it with * crypt_reencrypt_run(), which takes one extra argument but is otherwise identical. The old call is * still available though, and given we want to support 2.2.0 for a while longer, we'll stick to the * old symbol. However, the old symbols now has a GCC deprecation decorator, hence let's turn off * warnings about this for now. */ DISABLE_WARNING_DEPRECATED_DECLARATIONS; r = dlopen_many_sym_or_warn( &cryptsetup_dl, "libcryptsetup.so.12", LOG_DEBUG, DLSYM_ARG(crypt_activate_by_passphrase), #if HAVE_CRYPT_ACTIVATE_BY_SIGNED_KEY DLSYM_ARG(crypt_activate_by_signed_key), #endif DLSYM_ARG(crypt_activate_by_volume_key), DLSYM_ARG(crypt_deactivate_by_name), DLSYM_ARG(crypt_format), DLSYM_ARG(crypt_free), DLSYM_ARG(crypt_get_cipher), DLSYM_ARG(crypt_get_cipher_mode), DLSYM_ARG(crypt_get_data_offset), DLSYM_ARG(crypt_get_device_name), DLSYM_ARG(crypt_get_dir), DLSYM_ARG(crypt_get_type), DLSYM_ARG(crypt_get_uuid), DLSYM_ARG(crypt_get_verity_info), DLSYM_ARG(crypt_get_volume_key_size), DLSYM_ARG(crypt_init), DLSYM_ARG(crypt_init_by_name), DLSYM_ARG(crypt_keyslot_add_by_volume_key), DLSYM_ARG(crypt_keyslot_destroy), DLSYM_ARG(crypt_keyslot_max), DLSYM_ARG(crypt_load), DLSYM_ARG(crypt_resize), DLSYM_ARG(crypt_resume_by_passphrase), DLSYM_ARG(crypt_set_data_device), DLSYM_ARG(crypt_set_debug_level), DLSYM_ARG(crypt_set_log_callback), #if HAVE_CRYPT_SET_METADATA_SIZE DLSYM_ARG(crypt_set_metadata_size), #endif DLSYM_ARG(crypt_set_pbkdf_type), DLSYM_ARG(crypt_suspend), DLSYM_ARG(crypt_token_json_get), DLSYM_ARG(crypt_token_json_set), #if HAVE_CRYPT_TOKEN_MAX DLSYM_ARG(crypt_token_max), #endif DLSYM_ARG(crypt_token_status), DLSYM_ARG(crypt_volume_key_get), #if HAVE_CRYPT_REENCRYPT_INIT_BY_PASSPHRASE DLSYM_ARG(crypt_reencrypt_init_by_passphrase), #endif #if HAVE_CRYPT_REENCRYPT DLSYM_ARG(crypt_reencrypt), #endif DLSYM_ARG(crypt_metadata_locking), #if HAVE_CRYPT_SET_DATA_OFFSET DLSYM_ARG(crypt_set_data_offset), #endif DLSYM_ARG(crypt_header_restore), DLSYM_ARG(crypt_volume_key_keyring)); if (r <= 0) return r; REENABLE_WARNING; /* Redirect the default logging calls of libcryptsetup to our own logging infra. (Note that * libcryptsetup also maintains per-"struct crypt_device" log functions, which we'll also set * whenever allocating a "struct crypt_device" context. Why set both? To be defensive: maybe some * other code loaded into this process also changes the global log functions of libcryptsetup, who * knows? And if so, we still want our own objects to log via our own infra, at the very least.) */ cryptsetup_enable_logging(NULL); return 1; #else return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "cryptsetup support is not compiled in."); #endif } int cryptsetup_get_keyslot_from_token(JsonVariant *v) { int keyslot, r; JsonVariant *w; /* Parses the "keyslots" field of a LUKS2 token object. The field can be an array, but here we assume * that it contains a single element only, since that's the only way we ever generate it * ourselves. */ w = json_variant_by_key(v, "keyslots"); if (!w) return -ENOENT; if (!json_variant_is_array(w) || json_variant_elements(w) != 1) return -EMEDIUMTYPE; w = json_variant_by_index(w, 0); if (!w) return -ENOENT; if (!json_variant_is_string(w)) return -EMEDIUMTYPE; r = safe_atoi(json_variant_string(w), &keyslot); if (r < 0) return r; if (keyslot < 0) return -EINVAL; return keyslot; }