diff options
Diffstat (limited to 'tools/largeblob.c')
| -rw-r--r-- | tools/largeblob.c | 594 |
1 files changed, 594 insertions, 0 deletions
diff --git a/tools/largeblob.c b/tools/largeblob.c new file mode 100644 index 0000000..00cf79e --- /dev/null +++ b/tools/largeblob.c @@ -0,0 +1,594 @@ +/* + * Copyright (c) 2020 Yubico AB. All rights reserved. + * Use of this source code is governed by a BSD-style + * license that can be found in the LICENSE file. + * SPDX-License-Identifier: BSD-2-Clause + */ + +#include <sys/types.h> +#include <sys/stat.h> + +#include <fido.h> +#include <fido/credman.h> + +#include <cbor.h> +#include <fcntl.h> +#include <limits.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#ifdef HAVE_UNISTD_H +#include <unistd.h> +#endif +#include <zlib.h> + +#include "../openbsd-compat/openbsd-compat.h" +#include "extern.h" + +struct rkmap { + fido_credman_rp_t *rp; /* known rps */ + fido_credman_rk_t **rk; /* rk per rp */ +}; + +static void +free_rkmap(struct rkmap *map) +{ + if (map->rp != NULL) { + for (size_t i = 0; i < fido_credman_rp_count(map->rp); i++) + fido_credman_rk_free(&map->rk[i]); + fido_credman_rp_free(&map->rp); + } + free(map->rk); +} + +static int +map_known_rps(fido_dev_t *dev, const char *path, struct rkmap *map) +{ + const char *rp_id; + char *pin = NULL; + size_t n; + int r, ok = -1; + + if ((map->rp = fido_credman_rp_new()) == NULL) { + warnx("%s: fido_credman_rp_new", __func__); + goto out; + } + if ((pin = get_pin(path)) == NULL) + goto out; + if ((r = fido_credman_get_dev_rp(dev, map->rp, pin)) != FIDO_OK) { + warnx("fido_credman_get_dev_rp: %s", fido_strerr(r)); + goto out; + } + if ((n = fido_credman_rp_count(map->rp)) > UINT8_MAX) { + warnx("%s: fido_credman_rp_count > UINT8_MAX", __func__); + goto out; + } + if ((map->rk = calloc(n, sizeof(*map->rk))) == NULL) { + warnx("%s: calloc", __func__); + goto out; + } + for (size_t i = 0; i < n; i++) { + if ((rp_id = fido_credman_rp_id(map->rp, i)) == NULL) { + warnx("%s: fido_credman_rp_id %zu", __func__, i); + goto out; + } + if ((map->rk[i] = fido_credman_rk_new()) == NULL) { + warnx("%s: fido_credman_rk_new", __func__); + goto out; + } + if ((r = fido_credman_get_dev_rk(dev, rp_id, map->rk[i], + pin)) != FIDO_OK) { + warnx("%s: fido_credman_get_dev_rk %s: %s", __func__, + rp_id, fido_strerr(r)); + goto out; + } + } + + ok = 0; +out: + freezero(pin, PINBUF_LEN); + + return ok; +} + +static int +lookup_key(const char *path, fido_dev_t *dev, const char *rp_id, + const struct blob *cred_id, char **pin, struct blob *key) +{ + fido_credman_rk_t *rk = NULL; + const fido_cred_t *cred = NULL; + size_t i, n; + int r, ok = -1; + + if ((rk = fido_credman_rk_new()) == NULL) { + warnx("%s: fido_credman_rk_new", __func__); + goto out; + } + if ((r = fido_credman_get_dev_rk(dev, rp_id, rk, *pin)) != FIDO_OK && + *pin == NULL && should_retry_with_pin(dev, r)) { + if ((*pin = get_pin(path)) == NULL) + goto out; + r = fido_credman_get_dev_rk(dev, rp_id, rk, *pin); + } + if (r != FIDO_OK) { + warnx("%s: fido_credman_get_dev_rk: %s", __func__, + fido_strerr(r)); + goto out; + } + if ((n = fido_credman_rk_count(rk)) == 0) { + warnx("%s: rp id not found", __func__); + goto out; + } + if (n == 1 && cred_id->len == 0) { + /* use the credential we found */ + cred = fido_credman_rk(rk, 0); + } else { + if (cred_id->len == 0) { + warnx("%s: multiple credentials found", __func__); + goto out; + } + for (i = 0; i < n; i++) { + const fido_cred_t *x = fido_credman_rk(rk, i); + if (fido_cred_id_len(x) <= cred_id->len && + !memcmp(fido_cred_id_ptr(x), cred_id->ptr, + fido_cred_id_len(x))) { + cred = x; + break; + } + } + } + if (cred == NULL) { + warnx("%s: credential not found", __func__); + goto out; + } + if (fido_cred_largeblob_key_ptr(cred) == NULL) { + warnx("%s: no associated blob key", __func__); + goto out; + } + key->len = fido_cred_largeblob_key_len(cred); + if ((key->ptr = malloc(key->len)) == NULL) { + warnx("%s: malloc", __func__); + goto out; + } + memcpy(key->ptr, fido_cred_largeblob_key_ptr(cred), key->len); + + ok = 0; +out: + fido_credman_rk_free(&rk); + + return ok; +} + +static int +load_key(const char *keyf, const char *cred_id64, const char *rp_id, + const char *path, fido_dev_t *dev, char **pin, struct blob *key) +{ + struct blob cred_id; + FILE *fp; + int r; + + memset(&cred_id, 0, sizeof(cred_id)); + + if (keyf != NULL) { + if (rp_id != NULL || cred_id64 != NULL) + usage(); + fp = open_read(keyf); + if ((r = base64_read(fp, key)) < 0) + warnx("%s: base64_read %s", __func__, keyf); + fclose(fp); + return r; + } + if (rp_id == NULL) + usage(); + if (cred_id64 != NULL && base64_decode(cred_id64, (void *)&cred_id.ptr, + &cred_id.len) < 0) { + warnx("%s: base64_decode %s", __func__, cred_id64); + return -1; + } + r = lookup_key(path, dev, rp_id, &cred_id, pin, key); + free(cred_id.ptr); + + return r; +} + +int +blob_set(const char *path, const char *keyf, const char *rp_id, + const char *cred_id64, const char *blobf) +{ + fido_dev_t *dev; + struct blob key, blob; + char *pin = NULL; + int r, ok = 1; + + dev = open_dev(path); + memset(&key, 0, sizeof(key)); + memset(&blob, 0, sizeof(blob)); + + if (read_file(blobf, &blob.ptr, &blob.len) < 0 || + load_key(keyf, cred_id64, rp_id, path, dev, &pin, &key) < 0) + goto out; + if ((r = fido_dev_largeblob_set(dev, key.ptr, key.len, blob.ptr, + blob.len, pin)) != FIDO_OK && should_retry_with_pin(dev, r)) { + if ((pin = get_pin(path)) == NULL) + goto out; + r = fido_dev_largeblob_set(dev, key.ptr, key.len, blob.ptr, + blob.len, pin); + } + if (r != FIDO_OK) { + warnx("fido_dev_largeblob_set: %s", fido_strerr(r)); + goto out; + } + + ok = 0; /* success */ +out: + freezero(key.ptr, key.len); + freezero(blob.ptr, blob.len); + freezero(pin, PINBUF_LEN); + + fido_dev_close(dev); + fido_dev_free(&dev); + + exit(ok); +} + +int +blob_get(const char *path, const char *keyf, const char *rp_id, + const char *cred_id64, const char *blobf) +{ + fido_dev_t *dev; + struct blob key, blob; + char *pin = NULL; + int r, ok = 1; + + dev = open_dev(path); + memset(&key, 0, sizeof(key)); + memset(&blob, 0, sizeof(blob)); + + if (load_key(keyf, cred_id64, rp_id, path, dev, &pin, &key) < 0) + goto out; + if ((r = fido_dev_largeblob_get(dev, key.ptr, key.len, &blob.ptr, + &blob.len)) != FIDO_OK) { + warnx("fido_dev_largeblob_get: %s", fido_strerr(r)); + goto out; + } + if (write_file(blobf, blob.ptr, blob.len) < 0) + goto out; + + ok = 0; /* success */ +out: + freezero(key.ptr, key.len); + freezero(blob.ptr, blob.len); + freezero(pin, PINBUF_LEN); + + fido_dev_close(dev); + fido_dev_free(&dev); + + exit(ok); +} + +int +blob_delete(const char *path, const char *keyf, const char *rp_id, + const char *cred_id64) +{ + fido_dev_t *dev; + struct blob key; + char *pin = NULL; + int r, ok = 1; + + dev = open_dev(path); + memset(&key, 0, sizeof(key)); + + if (load_key(keyf, cred_id64, rp_id, path, dev, &pin, &key) < 0) + goto out; + if ((r = fido_dev_largeblob_remove(dev, key.ptr, key.len, + pin)) != FIDO_OK && should_retry_with_pin(dev, r)) { + if ((pin = get_pin(path)) == NULL) + goto out; + r = fido_dev_largeblob_remove(dev, key.ptr, key.len, pin); + } + if (r != FIDO_OK) { + warnx("fido_dev_largeblob_remove: %s", fido_strerr(r)); + goto out; + } + + ok = 0; /* success */ +out: + freezero(key.ptr, key.len); + freezero(pin, PINBUF_LEN); + + fido_dev_close(dev); + fido_dev_free(&dev); + + exit(ok); +} + +static int +decompress(const struct blob *plaintext, uint64_t origsiz) +{ + struct blob inflated; + u_long ilen, plen; + int ok = -1; + + memset(&inflated, 0, sizeof(inflated)); + + if (plaintext->len > ULONG_MAX) + return -1; + if (origsiz > ULONG_MAX || origsiz > SIZE_MAX) + return -1; + plen = (u_long)plaintext->len; + ilen = (u_long)origsiz; + inflated.len = (size_t)origsiz; + if ((inflated.ptr = calloc(1, inflated.len)) == NULL) + return -1; + if (uncompress(inflated.ptr, &ilen, plaintext->ptr, plen) != Z_OK || + ilen > SIZE_MAX || (size_t)ilen != (size_t)origsiz) + goto out; + + ok = 0; /* success */ +out: + freezero(inflated.ptr, inflated.len); + + return ok; +} + +static int +decode(const struct blob *ciphertext, const struct blob *nonce, + uint64_t origsiz, const fido_cred_t *cred) +{ + uint8_t aad[4 + sizeof(uint64_t)]; + EVP_CIPHER_CTX *ctx = NULL; + const EVP_CIPHER *cipher; + struct blob plaintext; + uint64_t tmp; + int ok = -1; + + memset(&plaintext, 0, sizeof(plaintext)); + + if (nonce->len != 12) + return -1; + if (cred == NULL || + fido_cred_largeblob_key_ptr(cred) == NULL || + fido_cred_largeblob_key_len(cred) != 32) + return -1; + if (ciphertext->len > UINT_MAX || + ciphertext->len > SIZE_MAX - 16 || + ciphertext->len < 16) + return -1; + plaintext.len = ciphertext->len - 16; + if ((plaintext.ptr = calloc(1, plaintext.len)) == NULL) + return -1; + if ((ctx = EVP_CIPHER_CTX_new()) == NULL || + (cipher = EVP_aes_256_gcm()) == NULL || + EVP_CipherInit(ctx, cipher, fido_cred_largeblob_key_ptr(cred), + nonce->ptr, 0) == 0) + goto out; + if (EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_GCM_SET_TAG, 16, + ciphertext->ptr + ciphertext->len - 16) == 0) + goto out; + aad[0] = 0x62; /* b */ + aad[1] = 0x6c; /* l */ + aad[2] = 0x6f; /* o */ + aad[3] = 0x62; /* b */ + tmp = htole64(origsiz); + memcpy(&aad[4], &tmp, sizeof(uint64_t)); + if (EVP_Cipher(ctx, NULL, aad, (u_int)sizeof(aad)) < 0 || + EVP_Cipher(ctx, plaintext.ptr, ciphertext->ptr, + (u_int)plaintext.len) < 0 || + EVP_Cipher(ctx, NULL, NULL, 0) < 0) + goto out; + if (decompress(&plaintext, origsiz) < 0) + goto out; + + ok = 0; +out: + freezero(plaintext.ptr, plaintext.len); + + if (ctx != NULL) + EVP_CIPHER_CTX_free(ctx); + + return ok; +} + +static const fido_cred_t * +try_rp(const fido_credman_rk_t *rk, const struct blob *ciphertext, + const struct blob *nonce, uint64_t origsiz) +{ + const fido_cred_t *cred; + + for (size_t i = 0; i < fido_credman_rk_count(rk); i++) + if ((cred = fido_credman_rk(rk, i)) != NULL && + decode(ciphertext, nonce, origsiz, cred) == 0) + return cred; + + return NULL; +} + +static int +decode_cbor_blob(struct blob *out, const cbor_item_t *item) +{ + if (out->ptr != NULL || + cbor_isa_bytestring(item) == false || + cbor_bytestring_is_definite(item) == false) + return -1; + out->len = cbor_bytestring_length(item); + if ((out->ptr = malloc(out->len)) == NULL) + return -1; + memcpy(out->ptr, cbor_bytestring_handle(item), out->len); + + return 0; +} + +static int +decode_blob_entry(const cbor_item_t *item, struct blob *ciphertext, + struct blob *nonce, uint64_t *origsiz) +{ + struct cbor_pair *v; + + if (item == NULL) + return -1; + if (cbor_isa_map(item) == false || + cbor_map_is_definite(item) == false || + (v = cbor_map_handle(item)) == NULL) + return -1; + if (cbor_map_size(item) > UINT8_MAX) + return -1; + + for (size_t i = 0; i < cbor_map_size(item); i++) { + if (cbor_isa_uint(v[i].key) == false || + cbor_int_get_width(v[i].key) != CBOR_INT_8) + continue; /* ignore */ + switch (cbor_get_uint8(v[i].key)) { + case 1: /* ciphertext */ + if (decode_cbor_blob(ciphertext, v[i].value) < 0) + return -1; + break; + case 2: /* nonce */ + if (decode_cbor_blob(nonce, v[i].value) < 0) + return -1; + break; + case 3: /* origSize */ + if (*origsiz != 0 || + cbor_isa_uint(v[i].value) == false || + (*origsiz = cbor_get_int(v[i].value)) > SIZE_MAX) + return -1; + } + } + if (ciphertext->ptr == NULL || nonce->ptr == NULL || *origsiz == 0) + return -1; + + return 0; +} + +static void +print_blob_entry(size_t idx, const cbor_item_t *item, const struct rkmap *map) +{ + struct blob ciphertext, nonce; + const fido_cred_t *cred = NULL; + const char *rp_id = NULL; + char *cred_id = NULL; + uint64_t origsiz = 0; + + memset(&ciphertext, 0, sizeof(ciphertext)); + memset(&nonce, 0, sizeof(nonce)); + + if (decode_blob_entry(item, &ciphertext, &nonce, &origsiz) < 0) { + printf("%02zu: <skipped: bad cbor>\n", idx); + goto out; + } + for (size_t i = 0; i < fido_credman_rp_count(map->rp); i++) { + if ((cred = try_rp(map->rk[i], &ciphertext, &nonce, + origsiz)) != NULL) { + rp_id = fido_credman_rp_id(map->rp, i); + break; + } + } + if (cred == NULL) { + if ((cred_id = strdup("<unknown>")) == NULL) { + printf("%02zu: <skipped: strdup failed>\n", idx); + goto out; + } + } else { + if (base64_encode(fido_cred_id_ptr(cred), + fido_cred_id_len(cred), &cred_id) < 0) { + printf("%02zu: <skipped: base64_encode failed>\n", idx); + goto out; + } + } + if (rp_id == NULL) + rp_id = "<unknown>"; + + printf("%02zu: %4zu %4zu %s %s\n", idx, ciphertext.len, + (size_t)origsiz, cred_id, rp_id); +out: + free(ciphertext.ptr); + free(nonce.ptr); + free(cred_id); +} + +static cbor_item_t * +get_cbor_array(fido_dev_t *dev) +{ + struct cbor_load_result cbor_result; + cbor_item_t *item = NULL; + u_char *cbor_ptr = NULL; + size_t cbor_len; + int r, ok = -1; + + if ((r = fido_dev_largeblob_get_array(dev, &cbor_ptr, + &cbor_len)) != FIDO_OK) { + warnx("%s: fido_dev_largeblob_get_array: %s", __func__, + fido_strerr(r)); + goto out; + } + if ((item = cbor_load(cbor_ptr, cbor_len, &cbor_result)) == NULL) { + warnx("%s: cbor_load", __func__); + goto out; + } + if (cbor_result.read != cbor_len) { + warnx("%s: cbor_result.read (%zu) != cbor_len (%zu)", __func__, + cbor_result.read, cbor_len); + /* continue */ + } + if (cbor_isa_array(item) == false || + cbor_array_is_definite(item) == false) { + warnx("%s: cbor type", __func__); + goto out; + } + if (cbor_array_size(item) > UINT8_MAX) { + warnx("%s: cbor_array_size > UINT8_MAX", __func__); + goto out; + } + if (cbor_array_size(item) == 0) { + ok = 0; /* nothing to do */ + goto out; + } + + printf("total map size: %zu byte%s\n", cbor_len, plural(cbor_len)); + + ok = 0; +out: + if (ok < 0 && item != NULL) { + cbor_decref(&item); + item = NULL; + } + free(cbor_ptr); + + return item; +} + +int +blob_list(const char *path) +{ + struct rkmap map; + fido_dev_t *dev = NULL; + cbor_item_t *item = NULL, **v; + int ok = 1; + + memset(&map, 0, sizeof(map)); + dev = open_dev(path); + if (map_known_rps(dev, path, &map) < 0 || + (item = get_cbor_array(dev)) == NULL) + goto out; + if (cbor_array_size(item) == 0) { + ok = 0; /* nothing to do */ + goto out; + } + if ((v = cbor_array_handle(item)) == NULL) { + warnx("%s: cbor_array_handle", __func__); + goto out; + } + for (size_t i = 0; i < cbor_array_size(item); i++) + print_blob_entry(i, v[i], &map); + + ok = 0; /* success */ +out: + free_rkmap(&map); + + if (item != NULL) + cbor_decref(&item); + + fido_dev_close(dev); + fido_dev_free(&dev); + + exit(ok); +} |