| /* SPDX-License-Identifier: LGPL-2.1-or-later */ |
| |
| #include "libfido2-util.h" |
| |
| #if HAVE_LIBFIDO2 |
| #include "alloc-util.h" |
| #include "ask-password-api.h" |
| #include "dlfcn-util.h" |
| #include "format-table.h" |
| #include "locale-util.h" |
| #include "log.h" |
| #include "memory-util.h" |
| #include "random-util.h" |
| #include "strv.h" |
| |
| static void *libfido2_dl = NULL; |
| |
| int (*sym_fido_assert_allow_cred)(fido_assert_t *, const unsigned char *, size_t) = NULL; |
| void (*sym_fido_assert_free)(fido_assert_t **) = NULL; |
| size_t (*sym_fido_assert_hmac_secret_len)(const fido_assert_t *, size_t) = NULL; |
| const unsigned char* (*sym_fido_assert_hmac_secret_ptr)(const fido_assert_t *, size_t) = NULL; |
| fido_assert_t* (*sym_fido_assert_new)(void) = NULL; |
| int (*sym_fido_assert_set_clientdata_hash)(fido_assert_t *, const unsigned char *, size_t) = NULL; |
| int (*sym_fido_assert_set_extensions)(fido_assert_t *, int) = NULL; |
| int (*sym_fido_assert_set_hmac_salt)(fido_assert_t *, const unsigned char *, size_t) = NULL; |
| int (*sym_fido_assert_set_rp)(fido_assert_t *, const char *) = NULL; |
| int (*sym_fido_assert_set_up)(fido_assert_t *, fido_opt_t) = NULL; |
| int (*sym_fido_assert_set_uv)(fido_assert_t *, fido_opt_t) = NULL; |
| size_t (*sym_fido_cbor_info_extensions_len)(const fido_cbor_info_t *) = NULL; |
| char **(*sym_fido_cbor_info_extensions_ptr)(const fido_cbor_info_t *) = NULL; |
| void (*sym_fido_cbor_info_free)(fido_cbor_info_t **) = NULL; |
| fido_cbor_info_t* (*sym_fido_cbor_info_new)(void) = NULL; |
| size_t (*sym_fido_cbor_info_options_len)(const fido_cbor_info_t *) = NULL; |
| char** (*sym_fido_cbor_info_options_name_ptr)(const fido_cbor_info_t *) = NULL; |
| const bool* (*sym_fido_cbor_info_options_value_ptr)(const fido_cbor_info_t *) = NULL; |
| void (*sym_fido_cred_free)(fido_cred_t **) = NULL; |
| size_t (*sym_fido_cred_id_len)(const fido_cred_t *) = NULL; |
| const unsigned char* (*sym_fido_cred_id_ptr)(const fido_cred_t *) = NULL; |
| fido_cred_t* (*sym_fido_cred_new)(void) = NULL; |
| int (*sym_fido_cred_set_clientdata_hash)(fido_cred_t *, const unsigned char *, size_t) = NULL; |
| int (*sym_fido_cred_set_extensions)(fido_cred_t *, int) = NULL; |
| int (*sym_fido_cred_set_rk)(fido_cred_t *, fido_opt_t) = NULL; |
| int (*sym_fido_cred_set_rp)(fido_cred_t *, const char *, const char *) = NULL; |
| int (*sym_fido_cred_set_type)(fido_cred_t *, int) = NULL; |
| int (*sym_fido_cred_set_user)(fido_cred_t *, const unsigned char *, size_t, const char *, const char *, const char *) = NULL; |
| int (*sym_fido_cred_set_uv)(fido_cred_t *, fido_opt_t) = NULL; |
| void (*sym_fido_dev_free)(fido_dev_t **) = NULL; |
| int (*sym_fido_dev_get_assert)(fido_dev_t *, fido_assert_t *, const char *) = NULL; |
| int (*sym_fido_dev_get_cbor_info)(fido_dev_t *, fido_cbor_info_t *) = NULL; |
| void (*sym_fido_dev_info_free)(fido_dev_info_t **, size_t) = NULL; |
| int (*sym_fido_dev_info_manifest)(fido_dev_info_t *, size_t, size_t *) = NULL; |
| const char* (*sym_fido_dev_info_manufacturer_string)(const fido_dev_info_t *) = NULL; |
| const char* (*sym_fido_dev_info_product_string)(const fido_dev_info_t *) = NULL; |
| fido_dev_info_t* (*sym_fido_dev_info_new)(size_t) = NULL; |
| const char* (*sym_fido_dev_info_path)(const fido_dev_info_t *) = NULL; |
| const fido_dev_info_t* (*sym_fido_dev_info_ptr)(const fido_dev_info_t *, size_t) = NULL; |
| bool (*sym_fido_dev_is_fido2)(const fido_dev_t *) = NULL; |
| int (*sym_fido_dev_make_cred)(fido_dev_t *, fido_cred_t *, const char *) = NULL; |
| fido_dev_t* (*sym_fido_dev_new)(void) = NULL; |
| int (*sym_fido_dev_open)(fido_dev_t *, const char *) = NULL; |
| int (*sym_fido_dev_close)(fido_dev_t *) = NULL; |
| const char* (*sym_fido_strerr)(int) = NULL; |
| |
| int dlopen_libfido2(void) { |
| return dlopen_many_sym_or_warn( |
| &libfido2_dl, "libfido2.so.1", LOG_DEBUG, |
| DLSYM_ARG(fido_assert_allow_cred), |
| DLSYM_ARG(fido_assert_free), |
| DLSYM_ARG(fido_assert_hmac_secret_len), |
| DLSYM_ARG(fido_assert_hmac_secret_ptr), |
| DLSYM_ARG(fido_assert_new), |
| DLSYM_ARG(fido_assert_set_clientdata_hash), |
| DLSYM_ARG(fido_assert_set_extensions), |
| DLSYM_ARG(fido_assert_set_hmac_salt), |
| DLSYM_ARG(fido_assert_set_rp), |
| DLSYM_ARG(fido_assert_set_up), |
| DLSYM_ARG(fido_assert_set_uv), |
| DLSYM_ARG(fido_cbor_info_extensions_len), |
| DLSYM_ARG(fido_cbor_info_extensions_ptr), |
| DLSYM_ARG(fido_cbor_info_free), |
| DLSYM_ARG(fido_cbor_info_new), |
| DLSYM_ARG(fido_cbor_info_options_len), |
| DLSYM_ARG(fido_cbor_info_options_name_ptr), |
| DLSYM_ARG(fido_cbor_info_options_value_ptr), |
| DLSYM_ARG(fido_cred_free), |
| DLSYM_ARG(fido_cred_id_len), |
| DLSYM_ARG(fido_cred_id_ptr), |
| DLSYM_ARG(fido_cred_new), |
| DLSYM_ARG(fido_cred_set_clientdata_hash), |
| DLSYM_ARG(fido_cred_set_extensions), |
| DLSYM_ARG(fido_cred_set_rk), |
| DLSYM_ARG(fido_cred_set_rp), |
| DLSYM_ARG(fido_cred_set_type), |
| DLSYM_ARG(fido_cred_set_user), |
| DLSYM_ARG(fido_cred_set_uv), |
| DLSYM_ARG(fido_dev_free), |
| DLSYM_ARG(fido_dev_get_assert), |
| DLSYM_ARG(fido_dev_get_cbor_info), |
| DLSYM_ARG(fido_dev_info_free), |
| DLSYM_ARG(fido_dev_info_manifest), |
| DLSYM_ARG(fido_dev_info_manufacturer_string), |
| DLSYM_ARG(fido_dev_info_new), |
| DLSYM_ARG(fido_dev_info_path), |
| DLSYM_ARG(fido_dev_info_product_string), |
| DLSYM_ARG(fido_dev_info_ptr), |
| DLSYM_ARG(fido_dev_is_fido2), |
| DLSYM_ARG(fido_dev_make_cred), |
| DLSYM_ARG(fido_dev_new), |
| DLSYM_ARG(fido_dev_open), |
| DLSYM_ARG(fido_dev_close), |
| DLSYM_ARG(fido_strerr)); |
| } |
| |
| static int verify_features( |
| fido_dev_t *d, |
| const char *path, |
| int log_level, /* the log level to use when device is not FIDO2 with hmac-secret */ |
| bool *ret_has_rk, |
| bool *ret_has_client_pin, |
| bool *ret_has_up, |
| bool *ret_has_uv) { |
| |
| _cleanup_(fido_cbor_info_free_wrapper) fido_cbor_info_t *di = NULL; |
| bool found_extension = false; |
| char **e, **o; |
| const bool *b; |
| bool has_rk = false, has_client_pin = false, has_up = true, has_uv = false; /* Defaults are per table in 5.4 in FIDO2 spec */ |
| size_t n; |
| int r; |
| |
| assert(d); |
| assert(path); |
| |
| if (!sym_fido_dev_is_fido2(d)) |
| return log_full_errno(log_level, |
| SYNTHETIC_ERRNO(ENODEV), |
| "Specified device %s is not a FIDO2 device.", path); |
| |
| di = sym_fido_cbor_info_new(); |
| if (!di) |
| return log_oom(); |
| |
| r = sym_fido_dev_get_cbor_info(d, di); |
| if (r != FIDO_OK) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to get CBOR device info for %s: %s", path, sym_fido_strerr(r)); |
| |
| e = sym_fido_cbor_info_extensions_ptr(di); |
| n = sym_fido_cbor_info_extensions_len(di); |
| for (size_t i = 0; i < n; i++) { |
| log_debug("FIDO2 device implements extension: %s", e[i]); |
| if (streq(e[i], "hmac-secret")) |
| found_extension = true; |
| } |
| |
| o = sym_fido_cbor_info_options_name_ptr(di); |
| b = sym_fido_cbor_info_options_value_ptr(di); |
| n = sym_fido_cbor_info_options_len(di); |
| for (size_t i = 0; i < n; i++) { |
| log_debug("FIDO2 device implements option %s: %s", o[i], yes_no(b[i])); |
| if (streq(o[i], "rk")) |
| has_rk = b[i]; |
| if (streq(o[i], "clientPin")) |
| has_client_pin = b[i]; |
| if (streq(o[i], "up")) |
| has_up = b[i]; |
| if (streq(o[i], "uv")) |
| has_uv = b[i]; |
| } |
| |
| if (!found_extension) |
| return log_full_errno(log_level, |
| SYNTHETIC_ERRNO(ENODEV), |
| "Specified device %s is a FIDO2 device, but does not support the required HMAC-SECRET extension.", path); |
| |
| log_debug("Has rk ('Resident Key') support: %s\n" |
| "Has clientPin support: %s\n" |
| "Has up ('User Presence') support: %s\n" |
| "Has uv ('User Verification') support: %s\n", |
| yes_no(has_rk), |
| yes_no(has_client_pin), |
| yes_no(has_up), |
| yes_no(has_uv)); |
| |
| if (ret_has_rk) |
| *ret_has_rk = has_rk; |
| if (ret_has_client_pin) |
| *ret_has_client_pin = has_client_pin; |
| if (ret_has_up) |
| *ret_has_up = has_up; |
| if (ret_has_uv) |
| *ret_has_uv = has_uv; |
| |
| return 0; |
| } |
| |
| static int fido2_use_hmac_hash_specific_token( |
| const char *path, |
| const char *rp_id, |
| const void *salt, |
| size_t salt_size, |
| const void *cid, |
| size_t cid_size, |
| char **pins, |
| Fido2EnrollFlags required, /* client pin/user presence required */ |
| void **ret_hmac, |
| size_t *ret_hmac_size) { |
| |
| _cleanup_(fido_assert_free_wrapper) fido_assert_t *a = NULL; |
| _cleanup_(fido_dev_free_wrapper) fido_dev_t *d = NULL; |
| _cleanup_(erase_and_freep) void *hmac_copy = NULL; |
| bool has_up, has_client_pin, has_uv; |
| size_t hmac_size; |
| const void *hmac; |
| int r; |
| |
| assert(path); |
| assert(rp_id); |
| assert(salt); |
| assert(cid); |
| assert(ret_hmac); |
| assert(ret_hmac_size); |
| |
| d = sym_fido_dev_new(); |
| if (!d) |
| return log_oom(); |
| |
| r = sym_fido_dev_open(d, path); |
| if (r != FIDO_OK) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to open FIDO2 device %s: %s", path, sym_fido_strerr(r)); |
| |
| r = verify_features(d, path, LOG_ERR, NULL, &has_client_pin, &has_up, &has_uv); |
| if (r < 0) |
| return r; |
| |
| if (!has_client_pin && FLAGS_SET(required, FIDO2ENROLL_PIN)) |
| return log_error_errno(SYNTHETIC_ERRNO(EHWPOISON), |
| "PIN required to unlock, but FIDO2 device %s does not support it.", |
| path); |
| |
| if (!has_up && FLAGS_SET(required, FIDO2ENROLL_UP)) |
| return log_error_errno(SYNTHETIC_ERRNO(EHWPOISON), |
| "User presence test required to unlock, but FIDO2 device %s does not support it.", |
| path); |
| |
| if (!has_uv && FLAGS_SET(required, FIDO2ENROLL_UV)) |
| return log_error_errno(SYNTHETIC_ERRNO(EHWPOISON), |
| "User verification required to unlock, but FIDO2 device %s does not support it.", |
| path); |
| |
| a = sym_fido_assert_new(); |
| if (!a) |
| return log_oom(); |
| |
| r = sym_fido_assert_set_extensions(a, FIDO_EXT_HMAC_SECRET); |
| if (r != FIDO_OK) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to enable HMAC-SECRET extension on FIDO2 assertion: %s", sym_fido_strerr(r)); |
| |
| r = sym_fido_assert_set_hmac_salt(a, salt, salt_size); |
| if (r != FIDO_OK) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to set salt on FIDO2 assertion: %s", sym_fido_strerr(r)); |
| |
| r = sym_fido_assert_set_rp(a, rp_id); |
| if (r != FIDO_OK) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to set FIDO2 assertion ID: %s", sym_fido_strerr(r)); |
| |
| r = sym_fido_assert_set_clientdata_hash(a, (const unsigned char[32]) {}, 32); |
| if (r != FIDO_OK) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to set FIDO2 assertion client data hash: %s", sym_fido_strerr(r)); |
| |
| r = sym_fido_assert_allow_cred(a, cid, cid_size); |
| if (r != FIDO_OK) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to add FIDO2 assertion credential ID: %s", sym_fido_strerr(r)); |
| |
| log_info("Asking FIDO2 token for authentication."); |
| |
| if (has_up) { |
| r = sym_fido_assert_set_up(a, FLAGS_SET(required, FIDO2ENROLL_UP) ? FIDO_OPT_TRUE : FIDO_OPT_FALSE); |
| if (r != FIDO_OK) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to %s FIDO2 user presence test: %s", |
| enable_disable(FLAGS_SET(required, FIDO2ENROLL_UP)), |
| sym_fido_strerr(r)); |
| |
| if (FLAGS_SET(required, FIDO2ENROLL_UP)) |
| log_notice("%s%sPlease confirm presence on security token to unlock.", |
| emoji_enabled() ? special_glyph(SPECIAL_GLYPH_TOUCH) : "", |
| emoji_enabled() ? " " : ""); |
| } |
| |
| if (has_uv && !FLAGS_SET(required, FIDO2ENROLL_UV_OMIT)) { |
| r = sym_fido_assert_set_uv(a, FLAGS_SET(required, FIDO2ENROLL_UV) ? FIDO_OPT_TRUE : FIDO_OPT_FALSE); |
| if (r != FIDO_OK) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to %s FIDO2 user verification: %s", |
| enable_disable(FLAGS_SET(required, FIDO2ENROLL_UV)), |
| sym_fido_strerr(r)); |
| |
| if (FLAGS_SET(required, FIDO2ENROLL_UV)) |
| log_notice("%s%sPlease verify user on security token to unlock.", |
| emoji_enabled() ? special_glyph(SPECIAL_GLYPH_TOUCH) : "", |
| emoji_enabled() ? " " : ""); |
| } |
| |
| for (;;) { |
| bool retry_with_up = false, retry_with_pin = false; |
| |
| if (FLAGS_SET(required, FIDO2ENROLL_PIN)) { |
| char **i; |
| |
| /* OK, we need a pin, try with all pins in turn */ |
| if (strv_isempty(pins)) |
| r = FIDO_ERR_PIN_REQUIRED; |
| else |
| STRV_FOREACH(i, pins) { |
| r = sym_fido_dev_get_assert(d, a, *i); |
| if (r != FIDO_ERR_PIN_INVALID) |
| break; |
| } |
| |
| } else |
| r = sym_fido_dev_get_assert(d, a, NULL); |
| |
| /* In some conditions, where a PIN or UP is required we might accept that. Let's check the |
| * conditions and if so try immediately again. */ |
| |
| switch (r) { |
| |
| case FIDO_ERR_UP_REQUIRED: |
| /* So the token asked for "up". Try to turn it on, for compat with systemd 248 and try again. */ |
| |
| if (!has_up) |
| return log_error_errno(SYNTHETIC_ERRNO(EINVAL), |
| "Token asks for user presence test but doesn't advertise 'up' feature."); |
| |
| if (FLAGS_SET(required, FIDO2ENROLL_UP)) |
| return log_error_errno(SYNTHETIC_ERRNO(EINVAL), |
| "Token asks for user presence test but was already enabled."); |
| |
| if (FLAGS_SET(required, FIDO2ENROLL_UP_IF_NEEDED)) { |
| log_notice("%s%sPlease confirm presence on security to unlock.", |
| emoji_enabled() ? special_glyph(SPECIAL_GLYPH_TOUCH) : "", |
| emoji_enabled() ? " " : ""); |
| retry_with_up = true; |
| } |
| |
| break; |
| |
| case FIDO_ERR_UNSUPPORTED_OPTION: |
| /* AuthenTrend ATKey.Pro returns this instead of FIDO_ERR_UP_REQUIRED, let's handle |
| * it gracefully (also see below.) */ |
| |
| if (has_up && (required & (FIDO2ENROLL_UP|FIDO2ENROLL_UP_IF_NEEDED)) == FIDO2ENROLL_UP_IF_NEEDED) { |
| log_notice("%s%sGot unsupported option error when when user presence test is turned off. Trying with user presence test turned on.", |
| emoji_enabled() ? special_glyph(SPECIAL_GLYPH_TOUCH) : "", |
| emoji_enabled() ? " " : ""); |
| retry_with_up = true; |
| } |
| |
| break; |
| |
| case FIDO_ERR_PIN_REQUIRED: |
| /* A pin was requested. Maybe supply one, if we are configured to do so on request */ |
| |
| if (!has_client_pin) |
| return log_error_errno(SYNTHETIC_ERRNO(EINVAL), |
| "Token asks for PIN but doesn't advertise 'clientPin' feature."); |
| |
| if (FLAGS_SET(required, FIDO2ENROLL_PIN) && !strv_isempty(pins)) |
| return log_error_errno(SYNTHETIC_ERRNO(EINVAL), |
| "Token asks for PIN but one was already supplied."); |
| |
| if ((required & (FIDO2ENROLL_PIN|FIDO2ENROLL_PIN_IF_NEEDED)) == FIDO2ENROLL_PIN_IF_NEEDED) { |
| /* If a PIN so far wasn't specified but is requested by the device, and |
| * FIDO2ENROLL_PIN_IF_NEEDED is set, then provide it */ |
| log_debug("Retrying to create credential with PIN."); |
| retry_with_pin = true; |
| } |
| |
| break; |
| |
| default: |
| break; |
| } |
| |
| if (!retry_with_up && !retry_with_pin) |
| break; |
| |
| if (retry_with_up) { |
| r = sym_fido_assert_set_up(a, FIDO_OPT_TRUE); |
| if (r != FIDO_OK) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to enable FIDO2 user presence test: %s", sym_fido_strerr(r)); |
| |
| required |= FIDO2ENROLL_UP; |
| } |
| |
| if (retry_with_pin) |
| required |= FIDO2ENROLL_PIN; |
| } |
| |
| switch (r) { |
| case FIDO_OK: |
| break; |
| case FIDO_ERR_NO_CREDENTIALS: |
| return log_error_errno(SYNTHETIC_ERRNO(EBADSLT), |
| "Wrong security token; needed credentials not present on token."); |
| case FIDO_ERR_PIN_REQUIRED: |
| return log_error_errno(SYNTHETIC_ERRNO(ENOANO), |
| "Security token requires PIN."); |
| case FIDO_ERR_PIN_AUTH_BLOCKED: |
| return log_error_errno(SYNTHETIC_ERRNO(EOWNERDEAD), |
| "PIN of security token is blocked, please remove/reinsert token."); |
| #ifdef FIDO_ERR_UV_BLOCKED |
| case FIDO_ERR_UV_BLOCKED: |
| return log_error_errno(SYNTHETIC_ERRNO(EOWNERDEAD), |
| "Verification of security token is blocked, please remove/reinsert token."); |
| #endif |
| case FIDO_ERR_PIN_INVALID: |
| return log_error_errno(SYNTHETIC_ERRNO(ENOLCK), |
| "PIN of security token incorrect."); |
| case FIDO_ERR_UP_REQUIRED: |
| return log_error_errno(SYNTHETIC_ERRNO(EMEDIUMTYPE), |
| "User presence required."); |
| case FIDO_ERR_ACTION_TIMEOUT: |
| return log_error_errno(SYNTHETIC_ERRNO(ENOSTR), |
| "Token action timeout. (User didn't interact with token quickly enough.)"); |
| default: |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to ask token for assertion: %s", sym_fido_strerr(r)); |
| } |
| |
| hmac = sym_fido_assert_hmac_secret_ptr(a, 0); |
| if (!hmac) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to retrieve HMAC secret."); |
| |
| hmac_size = sym_fido_assert_hmac_secret_len(a, 0); |
| |
| hmac_copy = memdup(hmac, hmac_size); |
| if (!hmac_copy) |
| return log_oom(); |
| |
| *ret_hmac = TAKE_PTR(hmac_copy); |
| *ret_hmac_size = hmac_size; |
| return 0; |
| } |
| |
| int fido2_use_hmac_hash( |
| const char *device, |
| const char *rp_id, |
| const void *salt, |
| size_t salt_size, |
| const void *cid, |
| size_t cid_size, |
| char **pins, |
| Fido2EnrollFlags required, /* client pin/user presence required */ |
| void **ret_hmac, |
| size_t *ret_hmac_size) { |
| |
| size_t allocated = 64, found = 0; |
| fido_dev_info_t *di = NULL; |
| int r; |
| |
| r = dlopen_libfido2(); |
| if (r < 0) |
| return log_error_errno(r, "FIDO2 support is not installed."); |
| |
| if (device) |
| return fido2_use_hmac_hash_specific_token(device, rp_id, salt, salt_size, cid, cid_size, pins, required, ret_hmac, ret_hmac_size); |
| |
| di = sym_fido_dev_info_new(allocated); |
| if (!di) |
| return log_oom(); |
| |
| r = sym_fido_dev_info_manifest(di, allocated, &found); |
| if (r == FIDO_ERR_INTERNAL) { |
| /* The library returns FIDO_ERR_INTERNAL when no devices are found. I wish it wouldn't. */ |
| r = log_debug_errno(SYNTHETIC_ERRNO(EAGAIN), "Got FIDO_ERR_INTERNAL, assuming no devices."); |
| goto finish; |
| } |
| if (r != FIDO_OK) { |
| r = log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to enumerate FIDO2 devices: %s", sym_fido_strerr(r)); |
| goto finish; |
| } |
| |
| for (size_t i = 0; i < found; i++) { |
| const fido_dev_info_t *entry; |
| const char *path; |
| |
| entry = sym_fido_dev_info_ptr(di, i); |
| if (!entry) { |
| r = log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to get device information for FIDO device %zu.", i); |
| goto finish; |
| } |
| |
| path = sym_fido_dev_info_path(entry); |
| if (!path) { |
| r = log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to query FIDO device path."); |
| goto finish; |
| } |
| |
| r = fido2_use_hmac_hash_specific_token(path, rp_id, salt, salt_size, cid, cid_size, pins, required, ret_hmac, ret_hmac_size); |
| if (!IN_SET(r, |
| -EBADSLT, /* device doesn't understand our credential hash */ |
| -ENODEV /* device is not a FIDO2 device with HMAC-SECRET */)) |
| goto finish; |
| } |
| |
| r = -EAGAIN; |
| |
| finish: |
| sym_fido_dev_info_free(&di, allocated); |
| return r; |
| } |
| |
| #define FIDO2_SALT_SIZE 32 |
| |
| int fido2_generate_hmac_hash( |
| const char *device, |
| const char *rp_id, |
| const char *rp_name, |
| const void *user_id, size_t user_id_len, |
| const char *user_name, |
| const char *user_display_name, |
| const char *user_icon, |
| const char *askpw_icon_name, |
| Fido2EnrollFlags lock_with, |
| void **ret_cid, size_t *ret_cid_size, |
| void **ret_salt, size_t *ret_salt_size, |
| void **ret_secret, size_t *ret_secret_size, |
| char **ret_usedpin, |
| Fido2EnrollFlags *ret_locked_with) { |
| |
| _cleanup_(erase_and_freep) void *salt = NULL, *secret_copy = NULL; |
| _cleanup_(fido_assert_free_wrapper) fido_assert_t *a = NULL; |
| _cleanup_(fido_cred_free_wrapper) fido_cred_t *c = NULL; |
| _cleanup_(fido_dev_free_wrapper) fido_dev_t *d = NULL; |
| _cleanup_(erase_and_freep) char *used_pin = NULL; |
| bool has_rk, has_client_pin, has_up, has_uv; |
| _cleanup_free_ char *cid_copy = NULL; |
| size_t cid_size, secret_size; |
| const void *cid, *secret; |
| int r; |
| |
| assert(device); |
| assert(ret_cid); |
| assert(ret_cid_size); |
| assert(ret_salt); |
| assert(ret_salt_size); |
| assert(ret_secret); |
| assert(ret_secret_size); |
| |
| /* Construction is like this: we generate a salt of 32 bytes. We then ask the FIDO2 device to |
| * HMAC-SHA256 it for us with its internal key. The result is the key used by LUKS and account |
| * authentication. LUKS and UNIX password auth all do their own salting before hashing, so that FIDO2 |
| * device never sees the volume key. |
| * |
| * S = HMAC-SHA256(I, D) |
| * |
| * with: S → LUKS/account authentication key (never stored) |
| * I → internal key on FIDO2 device (stored in the FIDO2 device) |
| * D → salt we generate here (stored in the privileged part of the JSON record) |
| * |
| */ |
| |
| assert(device); |
| assert((lock_with & ~(FIDO2ENROLL_PIN|FIDO2ENROLL_UP|FIDO2ENROLL_UV)) == 0); |
| |
| r = dlopen_libfido2(); |
| if (r < 0) |
| return log_error_errno(r, "FIDO2 token support is not installed."); |
| |
| salt = malloc(FIDO2_SALT_SIZE); |
| if (!salt) |
| return log_oom(); |
| |
| r = genuine_random_bytes(salt, FIDO2_SALT_SIZE, RANDOM_BLOCK); |
| if (r < 0) |
| return log_error_errno(r, "Failed to generate salt: %m"); |
| |
| d = sym_fido_dev_new(); |
| if (!d) |
| return log_oom(); |
| |
| r = sym_fido_dev_open(d, device); |
| if (r != FIDO_OK) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to open FIDO2 device %s: %s", device, sym_fido_strerr(r)); |
| |
| r = verify_features(d, device, LOG_ERR, &has_rk, &has_client_pin, &has_up, &has_uv); |
| if (r < 0) |
| return r; |
| |
| /* While enrolling degrade gracefully if the requested feature set isn't available, but let the user know */ |
| if (!has_client_pin && FLAGS_SET(lock_with, FIDO2ENROLL_PIN)) { |
| log_notice("Requested to lock with PIN, but FIDO2 device %s does not support it, disabling.", device); |
| lock_with &= ~FIDO2ENROLL_PIN; |
| } |
| |
| if (!has_up && FLAGS_SET(lock_with, FIDO2ENROLL_UP)) { |
| log_notice("Locking with user presence test requested, but FIDO2 device %s does not support it, disabling.", device); |
| lock_with &= ~FIDO2ENROLL_UP; |
| } |
| |
| if (!has_uv && FLAGS_SET(lock_with, FIDO2ENROLL_UV)) { |
| log_notice("Locking with user verification test requested, but FIDO2 device %s does not support it, disabling.", device); |
| lock_with &= ~FIDO2ENROLL_UV; |
| } |
| |
| c = sym_fido_cred_new(); |
| if (!c) |
| return log_oom(); |
| |
| r = sym_fido_cred_set_extensions(c, FIDO_EXT_HMAC_SECRET); |
| if (r != FIDO_OK) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to enable HMAC-SECRET extension on FIDO2 credential: %s", sym_fido_strerr(r)); |
| |
| r = sym_fido_cred_set_rp(c, rp_id, rp_name); |
| if (r != FIDO_OK) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to set FIDO2 credential relying party ID/name: %s", sym_fido_strerr(r)); |
| |
| r = sym_fido_cred_set_type(c, COSE_ES256); |
| if (r != FIDO_OK) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to set FIDO2 credential type to ES256: %s", sym_fido_strerr(r)); |
| |
| r = sym_fido_cred_set_user( |
| c, |
| user_id, user_id_len, |
| user_name, |
| user_display_name, |
| user_icon); |
| if (r != FIDO_OK) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to set FIDO2 credential user data: %s", sym_fido_strerr(r)); |
| |
| r = sym_fido_cred_set_clientdata_hash(c, (const unsigned char[32]) {}, 32); |
| if (r != FIDO_OK) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to set FIDO2 client data hash: %s", sym_fido_strerr(r)); |
| |
| if (has_rk) { |
| r = sym_fido_cred_set_rk(c, FIDO_OPT_FALSE); |
| if (r != FIDO_OK) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to turn off FIDO2 resident key option of credential: %s", sym_fido_strerr(r)); |
| } |
| |
| if (has_uv) { |
| r = sym_fido_cred_set_uv(c, FIDO_OPT_FALSE); |
| if (r != FIDO_OK) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to turn off FIDO2 user verification option of credential: %s", sym_fido_strerr(r)); |
| } |
| |
| /* As per specification "up" is assumed to be implicit when making credentials, hence we don't |
| * explicitly enable/disable it here */ |
| |
| log_info("Initializing FIDO2 credential on security token."); |
| |
| if (has_uv || has_up) |
| log_notice("%s%s(Hint: This might require confirmation of user presence on security token.)", |
| emoji_enabled() ? special_glyph(SPECIAL_GLYPH_TOUCH) : "", |
| emoji_enabled() ? " " : ""); |
| |
| r = sym_fido_dev_make_cred(d, c, NULL); |
| if (r == FIDO_ERR_PIN_REQUIRED) { |
| |
| if (!has_client_pin) |
| return log_error_errno(SYNTHETIC_ERRNO(EINVAL), |
| "Token asks for PIN but doesn't advertise 'clientPin' feature."); |
| |
| for (;;) { |
| _cleanup_(strv_free_erasep) char **pin = NULL; |
| char **i; |
| |
| r = ask_password_auto("Please enter security token PIN:", askpw_icon_name, NULL, "fido2-pin", "fido2-pin", USEC_INFINITY, 0, &pin); |
| if (r < 0) |
| return log_error_errno(r, "Failed to acquire user PIN: %m"); |
| |
| r = FIDO_ERR_PIN_INVALID; |
| STRV_FOREACH(i, pin) { |
| if (isempty(*i)) { |
| log_notice("PIN may not be empty."); |
| continue; |
| } |
| |
| r = sym_fido_dev_make_cred(d, c, *i); |
| if (r == FIDO_OK) { |
| used_pin = strdup(*i); |
| if (!used_pin) |
| return log_oom(); |
| break; |
| } |
| if (r != FIDO_ERR_PIN_INVALID) |
| break; |
| } |
| |
| if (r != FIDO_ERR_PIN_INVALID) |
| break; |
| |
| log_notice("PIN incorrect, please try again."); |
| } |
| } |
| if (r == FIDO_ERR_PIN_AUTH_BLOCKED) |
| return log_notice_errno(SYNTHETIC_ERRNO(EPERM), |
| "Token PIN is currently blocked, please remove and reinsert token."); |
| #ifdef FIDO_ERR_UV_BLOCKED |
| if (r == FIDO_ERR_UV_BLOCKED) |
| return log_notice_errno(SYNTHETIC_ERRNO(EPERM), |
| "Token verification is currently blocked, please remove and reinsert token."); |
| #endif |
| if (r == FIDO_ERR_ACTION_TIMEOUT) |
| return log_error_errno(SYNTHETIC_ERRNO(ENOSTR), |
| "Token action timeout. (User didn't interact with token quickly enough.)"); |
| if (r != FIDO_OK) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to generate FIDO2 credential: %s", sym_fido_strerr(r)); |
| |
| cid = sym_fido_cred_id_ptr(c); |
| if (!cid) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to get FIDO2 credential ID."); |
| |
| cid_size = sym_fido_cred_id_len(c); |
| |
| a = sym_fido_assert_new(); |
| if (!a) |
| return log_oom(); |
| |
| r = sym_fido_assert_set_extensions(a, FIDO_EXT_HMAC_SECRET); |
| if (r != FIDO_OK) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to enable HMAC-SECRET extension on FIDO2 assertion: %s", sym_fido_strerr(r)); |
| |
| r = sym_fido_assert_set_hmac_salt(a, salt, FIDO2_SALT_SIZE); |
| if (r != FIDO_OK) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to set salt on FIDO2 assertion: %s", sym_fido_strerr(r)); |
| |
| r = sym_fido_assert_set_rp(a, rp_id); |
| if (r != FIDO_OK) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to set FIDO2 assertion ID: %s", sym_fido_strerr(r)); |
| |
| r = sym_fido_assert_set_clientdata_hash(a, (const unsigned char[32]) {}, 32); |
| if (r != FIDO_OK) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to set FIDO2 assertion client data hash: %s", sym_fido_strerr(r)); |
| |
| r = sym_fido_assert_allow_cred(a, cid, cid_size); |
| if (r != FIDO_OK) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to add FIDO2 assertion credential ID: %s", sym_fido_strerr(r)); |
| |
| log_info("Generating secret key on FIDO2 security token."); |
| |
| if (has_up) { |
| r = sym_fido_assert_set_up(a, FLAGS_SET(lock_with, FIDO2ENROLL_UP) ? FIDO_OPT_TRUE : FIDO_OPT_FALSE); |
| if (r != FIDO_OK) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to %s FIDO2 user presence test: %s", |
| enable_disable(FLAGS_SET(lock_with, FIDO2ENROLL_UP)), |
| sym_fido_strerr(r)); |
| |
| if (FLAGS_SET(lock_with, FIDO2ENROLL_UP)) |
| log_notice("%s%sIn order to allow secret key generation, please confirm presence on security token.", |
| emoji_enabled() ? special_glyph(SPECIAL_GLYPH_TOUCH) : "", |
| emoji_enabled() ? " " : ""); |
| } |
| |
| if (has_uv) { |
| r = sym_fido_assert_set_uv(a, FLAGS_SET(lock_with, FIDO2ENROLL_UV) ? FIDO_OPT_TRUE : FIDO_OPT_FALSE); |
| if (r != FIDO_OK) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to %s FIDO user verification: %s", |
| enable_disable(FLAGS_SET(lock_with, FIDO2ENROLL_UV)), |
| sym_fido_strerr(r)); |
| |
| if (FLAGS_SET(lock_with, FIDO2ENROLL_UV)) |
| log_notice("%s%sIn order to allow secret key generation, please verify user on security token.", |
| emoji_enabled() ? special_glyph(SPECIAL_GLYPH_TOUCH) : "", |
| emoji_enabled() ? " " : ""); |
| } |
| |
| for (;;) { |
| bool retry_with_up = false, retry_with_pin = false; |
| |
| r = sym_fido_dev_get_assert(d, a, FLAGS_SET(lock_with, FIDO2ENROLL_PIN) ? used_pin : NULL); |
| |
| switch (r) { |
| |
| case FIDO_ERR_UP_REQUIRED: |
| /* If the token asks for "up" when we turn off, then this might be a feature that |
| * isn't optional. Let's enable it */ |
| |
| if (!has_up) |
| return log_error_errno(SYNTHETIC_ERRNO(EINVAL), |
| "Token asks for user presence test but doesn't advertise 'up' feature."); |
| |
| if (FLAGS_SET(lock_with, FIDO2ENROLL_UP)) |
| return log_error_errno(SYNTHETIC_ERRNO(EINVAL), |
| "Token asks for user presence test but was already enabled."); |
| |
| log_notice("%s%sLocking without user presence test requested, but FIDO2 device %s requires it, enabling.", |
| emoji_enabled() ? special_glyph(SPECIAL_GLYPH_TOUCH) : "", |
| emoji_enabled() ? " " : "", |
| device); |
| |
| retry_with_up = true; |
| break; |
| |
| case FIDO_ERR_UNSUPPORTED_OPTION: |
| /* AuthenTrend ATKey.Pro says it supports "up", but if we disable it it will fail |
| * with FIDO_ERR_UNSUPPORTED_OPTION, probably because it isn't actually |
| * optional. Let's see if turning it on works. This is very similar to the |
| * FIDO_ERR_UP_REQUIRED case, but since the error is so vague we implement it |
| * slightly more defensively. */ |
| |
| if (has_up && !FLAGS_SET(lock_with, FIDO2ENROLL_UP)) { |
| log_notice("%s%sGot unsupported option error when when user presence test is turned off. Trying with user presence test turned on.", |
| emoji_enabled() ? special_glyph(SPECIAL_GLYPH_TOUCH) : "", |
| emoji_enabled() ? " " : ""); |
| retry_with_up = true; |
| } |
| |
| break; |
| |
| case FIDO_ERR_PIN_REQUIRED: |
| if (!has_client_pin) |
| return log_error_errno(SYNTHETIC_ERRNO(EINVAL), |
| "Token asks for client PIN check but doesn't advertise 'clientPin' feature."); |
| |
| if (FLAGS_SET(lock_with, FIDO2ENROLL_PIN)) |
| return log_error_errno(SYNTHETIC_ERRNO(EINVAL), |
| "Token asks for user client PIN check but was already enabled."); |
| |
| log_debug("Token requires PIN for assertion, enabling."); |
| retry_with_pin = true; |
| break; |
| |
| default: |
| break; |
| } |
| |
| if (!retry_with_up && !retry_with_pin) |
| break; |
| |
| if (retry_with_up) { |
| r = sym_fido_assert_set_up(a, FIDO_OPT_TRUE); |
| if (r != FIDO_OK) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to enable FIDO2 user presence test: %s", sym_fido_strerr(r)); |
| |
| lock_with |= FIDO2ENROLL_UP; |
| } |
| |
| if (retry_with_pin) |
| lock_with |= FIDO2ENROLL_PIN; |
| } |
| |
| if (r == FIDO_ERR_ACTION_TIMEOUT) |
| return log_error_errno(SYNTHETIC_ERRNO(ENOSTR), |
| "Token action timeout. (User didn't interact with token quickly enough.)"); |
| if (r != FIDO_OK) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to ask token for assertion: %s", sym_fido_strerr(r)); |
| |
| secret = sym_fido_assert_hmac_secret_ptr(a, 0); |
| if (!secret) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to retrieve HMAC secret."); |
| |
| secret_size = sym_fido_assert_hmac_secret_len(a, 0); |
| |
| secret_copy = memdup(secret, secret_size); |
| if (!secret_copy) |
| return log_oom(); |
| |
| cid_copy = memdup(cid, cid_size); |
| if (!cid_copy) |
| return log_oom(); |
| |
| *ret_cid = TAKE_PTR(cid_copy); |
| *ret_cid_size = cid_size; |
| *ret_salt = TAKE_PTR(salt); |
| *ret_salt_size = FIDO2_SALT_SIZE; |
| *ret_secret = TAKE_PTR(secret_copy); |
| *ret_secret_size = secret_size; |
| |
| if (ret_usedpin) |
| *ret_usedpin = TAKE_PTR(used_pin); |
| |
| if (ret_locked_with) |
| *ret_locked_with = lock_with; |
| |
| return 0; |
| } |
| #endif |
| |
| #if HAVE_LIBFIDO2 |
| static int check_device_is_fido2_with_hmac_secret(const char *path) { |
| _cleanup_(fido_dev_free_wrapper) fido_dev_t *d = NULL; |
| int r; |
| |
| d = sym_fido_dev_new(); |
| if (!d) |
| return log_oom(); |
| |
| r = sym_fido_dev_open(d, path); |
| if (r != FIDO_OK) |
| return log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to open FIDO2 device %s: %s", path, sym_fido_strerr(r)); |
| |
| r = verify_features(d, path, LOG_DEBUG, NULL, NULL, NULL, NULL); |
| if (r == -ENODEV) /* Not a FIDO2 device, or not implementing 'hmac-secret' */ |
| return false; |
| if (r < 0) |
| return r; |
| |
| return true; |
| } |
| #endif |
| |
| int fido2_list_devices(void) { |
| #if HAVE_LIBFIDO2 |
| _cleanup_(table_unrefp) Table *t = NULL; |
| size_t allocated = 64, found = 0; |
| fido_dev_info_t *di = NULL; |
| int r; |
| |
| r = dlopen_libfido2(); |
| if (r < 0) |
| return log_error_errno(r, "FIDO2 token support is not installed."); |
| |
| di = sym_fido_dev_info_new(allocated); |
| if (!di) |
| return log_oom(); |
| |
| r = sym_fido_dev_info_manifest(di, allocated, &found); |
| if (r == FIDO_ERR_INTERNAL || (r == FIDO_OK && found == 0)) { |
| /* The library returns FIDO_ERR_INTERNAL when no devices are found. I wish it wouldn't. */ |
| log_info("No FIDO2 devices found."); |
| r = 0; |
| goto finish; |
| } |
| if (r != FIDO_OK) { |
| r = log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to enumerate FIDO2 devices: %s", sym_fido_strerr(r)); |
| goto finish; |
| } |
| |
| t = table_new("path", "manufacturer", "product"); |
| if (!t) { |
| r = log_oom(); |
| goto finish; |
| } |
| |
| for (size_t i = 0; i < found; i++) { |
| const fido_dev_info_t *entry; |
| |
| entry = sym_fido_dev_info_ptr(di, i); |
| if (!entry) { |
| r = log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to get device information for FIDO device %zu.", i); |
| goto finish; |
| } |
| |
| r = check_device_is_fido2_with_hmac_secret(sym_fido_dev_info_path(entry)); |
| if (r < 0) |
| goto finish; |
| if (!r) |
| continue; |
| |
| r = table_add_many( |
| t, |
| TABLE_PATH, sym_fido_dev_info_path(entry), |
| TABLE_STRING, sym_fido_dev_info_manufacturer_string(entry), |
| TABLE_STRING, sym_fido_dev_info_product_string(entry)); |
| if (r < 0) { |
| table_log_add_error(r); |
| goto finish; |
| } |
| } |
| |
| r = table_print(t, stdout); |
| if (r < 0) { |
| log_error_errno(r, "Failed to show device table: %m"); |
| goto finish; |
| } |
| |
| r = 0; |
| |
| finish: |
| sym_fido_dev_info_free(&di, allocated); |
| return r; |
| #else |
| return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), |
| "FIDO2 tokens not supported on this build."); |
| #endif |
| } |
| |
| int fido2_find_device_auto(char **ret) { |
| #if HAVE_LIBFIDO2 |
| _cleanup_free_ char *copy = NULL; |
| size_t di_size = 64, found = 0; |
| const fido_dev_info_t *entry; |
| fido_dev_info_t *di = NULL; |
| const char *path; |
| int r; |
| |
| r = dlopen_libfido2(); |
| if (r < 0) |
| return log_error_errno(r, "FIDO2 token support is not installed."); |
| |
| di = sym_fido_dev_info_new(di_size); |
| if (!di) |
| return log_oom(); |
| |
| r = sym_fido_dev_info_manifest(di, di_size, &found); |
| if (r == FIDO_ERR_INTERNAL || (r == FIDO_OK && found == 0)) { |
| /* The library returns FIDO_ERR_INTERNAL when no devices are found. I wish it wouldn't. */ |
| r = log_error_errno(SYNTHETIC_ERRNO(ENODEV), "No FIDO devices found."); |
| goto finish; |
| } |
| if (r != FIDO_OK) { |
| r = log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to enumerate FIDO devices: %s", sym_fido_strerr(r)); |
| goto finish; |
| } |
| if (found > 1) { |
| r = log_error_errno(SYNTHETIC_ERRNO(ENOTUNIQ), "More than one FIDO device found."); |
| goto finish; |
| } |
| |
| entry = sym_fido_dev_info_ptr(di, 0); |
| if (!entry) { |
| r = log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to get device information for FIDO device 0."); |
| goto finish; |
| } |
| |
| r = check_device_is_fido2_with_hmac_secret(sym_fido_dev_info_path(entry)); |
| if (r < 0) |
| goto finish; |
| if (!r) { |
| r = log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "FIDO device discovered does not implement FIDO2 with 'hmac-secret' extension."); |
| goto finish; |
| } |
| |
| path = sym_fido_dev_info_path(entry); |
| if (!path) { |
| r = log_error_errno(SYNTHETIC_ERRNO(EIO), |
| "Failed to query FIDO device path."); |
| goto finish; |
| } |
| |
| copy = strdup(path); |
| if (!copy) { |
| r = log_oom(); |
| goto finish; |
| } |
| |
| *ret = TAKE_PTR(copy); |
| r = 0; |
| |
| finish: |
| sym_fido_dev_info_free(&di, di_size); |
| return r; |
| #else |
| return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), |
| "FIDO2 tokens not supported on this build."); |
| #endif |
| } |