diff options
Diffstat (limited to '')
| -rw-r--r-- | src/libdnssec/keystore.h | 155 | ||||
| -rw-r--r-- | src/libdnssec/keystore/internal.h | 50 | ||||
| -rw-r--r-- | src/libdnssec/keystore/keystore.c | 186 | ||||
| -rw-r--r-- | src/libdnssec/keystore/pkcs11.c | 397 | ||||
| -rw-r--r-- | src/libdnssec/keystore/pkcs8.c | 497 |
5 files changed, 1285 insertions, 0 deletions
diff --git a/src/libdnssec/keystore.h b/src/libdnssec/keystore.h new file mode 100644 index 0000000..8697935 --- /dev/null +++ b/src/libdnssec/keystore.h @@ -0,0 +1,155 @@ +/* Copyright (C) 2022 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz> + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. + */ + +/*! + * \file + * + * \addtogroup keystore + * + * \brief Private key store access. + * + * The module provides abstraction for private key store. Basically, PKCS #8 + * and PKCS #11 interfaces are supported. + * + * PKCS #8 uses unencrypted PEM. + * + * PKCS #11 provides access Hardware Security Modules. + * + * @{ + */ + +#pragma once + +#include <libdnssec/binary.h> +#include <libdnssec/key.h> + +struct dnssec_keystore; + +/*! + * DNSSEC private keys store. + */ +typedef struct dnssec_keystore dnssec_keystore_t; + +/*! + * Create default PKCS #8 private key store context. + * + * The default store maintains the private keys in one directory on the file + * system. The private keys are stored in unencrypted PEM format, named + * key-id.pem. The configuration string is a path to the directory. + * + * \param[out] store Opened key store. + * + * \return Error code, DNSSEC_EOK if successful. + */ +int dnssec_keystore_init_pkcs8(dnssec_keystore_t **store); + +/*! + * Crate new PKCS #11 private key store context. + * + * \param[out] store Opened key store. + * + * \return Error code, DNSSEC_EOK if successful. + */ +int dnssec_keystore_init_pkcs11(dnssec_keystore_t **store); + +/*! + * Deinitialize private key store context. + * + * \param store Key store to be deinitialized. + */ +int dnssec_keystore_deinit(dnssec_keystore_t *store); + +/*! + * Initialize new private key store. + */ +int dnssec_keystore_init(dnssec_keystore_t *store, const char *config); + +/*! + * Open private key store. + */ +int dnssec_keystore_open(dnssec_keystore_t *store, const char *config); + +/*! + * Close private key store. + * + * \param store Key store to be closed. + * + * \return Error code, DNSSEC_EOK if successful. + */ +int dnssec_keystore_close(dnssec_keystore_t *store); + +/*! + * Generate a new key in the key store. + * + * \param[in] store Key store. + * \param[in] algorithm Algorithm. + * \param[in] bits Bit length of the key to be generated. + * \param[in] label Optional key label for PKCS #11. + * \param[out] id_ptr ID of the generated key. Must be freed by the caller. + * + * \return Error code, DNSSEC_EOK if successful. + */ +int dnssec_keystore_generate(dnssec_keystore_t *store, + dnssec_key_algorithm_t algorithm, + unsigned bits, const char *label, char **id_ptr); + +/*! + * Import an existing key into the key store. + * + * \param[in] store Key store. + * \param[in] pem Private key material in PEM format. + * \param[out] id_ptr ID of the imported key. Must be freed by the caller. + * + * \return Error code, DNSSEC_EOK if successful. + */ +int dnssec_keystore_import(dnssec_keystore_t *store, const dnssec_binary_t *pem, + char **id_ptr); + +/*! + * Remove a private key from the key store. + * + * \param store Key store. + * \param id ID of the private key to be deleted. + * + * \return Error code, DNSSEC_EOK if successful. + */ +int dnssec_keystore_remove(dnssec_keystore_t *store, const char *id); + +/*! + * Export private key from the key store into a DNSSEC key. + * + * The key algorithm has to be set before calling this function. + * + * \param store Private key store. + * \param id ID of the key. + * \param key DNSSEC key to be initialized. + * + * \return Error code, DNSSEC_EOK if successful. + */ +int dnssec_keystore_get_private(dnssec_keystore_t *store, const char *id, + dnssec_key_t *key); + +/*! + * Import a DNSSEC private key into key store. + * + * \param store Key store. + * \param key DNSSEC key with a private key. + * + * \return Error code, DNSSEC_EOK if successful. + */ +int dnssec_keystore_set_private(dnssec_keystore_t *store, dnssec_key_t *key); + +/*! @} */ diff --git a/src/libdnssec/keystore/internal.h b/src/libdnssec/keystore/internal.h new file mode 100644 index 0000000..5afa8ce --- /dev/null +++ b/src/libdnssec/keystore/internal.h @@ -0,0 +1,50 @@ +/* Copyright (C) 2022 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz> + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. + */ + +#pragma once + +#include <gnutls/gnutls.h> +#include <gnutls/abstract.h> + +#include "libdnssec/binary.h" +#include "libdnssec/key.h" +#include "libdnssec/keystore.h" + +typedef struct keystore_functions { + // construction of internal context + int (*ctx_new)(void **ctx_ptr); + void (*ctx_free)(void *ctx); + // keystore init/open/close + int (*init)(void *ctx, const char *config); + int (*open)(void *ctx, const char *config); + int (*close)(void *ctx); + // keystore access + int (*generate_key)(void *ctx, gnutls_pk_algorithm_t algorithm, + unsigned bits, const char *label, char **id_ptr); + int (*import_key)(void *ctx, const dnssec_binary_t *pem, char **id_ptr); + int (*remove_key)(void *ctx, const char *id); + // private key access + int (*get_private)(void *ctx, const char *id, gnutls_privkey_t *key_ptr); + int (*set_private)(void *ctx, gnutls_privkey_t key); +} keystore_functions_t; + +struct dnssec_keystore { + const keystore_functions_t *functions; + void *ctx; +}; + +int keystore_create(dnssec_keystore_t **store_ptr, + const keystore_functions_t *functions); diff --git a/src/libdnssec/keystore/keystore.c b/src/libdnssec/keystore/keystore.c new file mode 100644 index 0000000..f88dd14 --- /dev/null +++ b/src/libdnssec/keystore/keystore.c @@ -0,0 +1,186 @@ +/* Copyright (C) 2022 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz> + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. + */ + +#include <assert.h> +#include <stdlib.h> + +#include "libdnssec/error.h" +#include "libdnssec/key.h" +#include "libdnssec/key/algorithm.h" +#include "libdnssec/key/dnskey.h" +#include "libdnssec/key/internal.h" +#include "libdnssec/key/privkey.h" +#include "libdnssec/keyid.h" +#include "libdnssec/keystore.h" +#include "libdnssec/keystore/internal.h" +#include "libdnssec/shared/shared.h" + +/* -- internal API --------------------------------------------------------- */ + +int keystore_create(dnssec_keystore_t **store_ptr, + const keystore_functions_t *functions) +{ + assert(store_ptr); + assert(functions); + + dnssec_keystore_t *store = calloc(1, sizeof(*store)); + if (!store) { + return DNSSEC_ENOMEM; + } + + store->functions = functions; + + int result = functions->ctx_new(&store->ctx); + if (result != DNSSEC_EOK) { + free(store); + return DNSSEC_ENOMEM; + } + + *store_ptr = store; + return DNSSEC_EOK; +} + +/* -- public API ----------------------------------------------------------- */ + +_public_ +int dnssec_keystore_deinit(dnssec_keystore_t *store) +{ + if (!store) { + return DNSSEC_EINVAL; + } + + dnssec_keystore_close(store); + store->functions->ctx_free(store->ctx); + + free(store); + + return DNSSEC_EOK; +} + +_public_ +int dnssec_keystore_init(dnssec_keystore_t *store, const char *config) +{ + if (!store) { + return DNSSEC_EINVAL; + } + + return store->functions->init(store->ctx, config); +} + +_public_ +int dnssec_keystore_open(dnssec_keystore_t *store, const char *config) +{ + if (!store) { + return DNSSEC_EINVAL; + } + + return store->functions->open(store->ctx, config); +} + +_public_ +int dnssec_keystore_close(dnssec_keystore_t *store) +{ + if (!store) { + return DNSSEC_EINVAL; + } + + return store->functions->close(store->ctx); +} + +_public_ +int dnssec_keystore_generate(dnssec_keystore_t *store, + dnssec_key_algorithm_t _algorithm, + unsigned bits, const char *label, char **id_ptr) +{ + if (!store || !_algorithm || !id_ptr) { + return DNSSEC_EINVAL; + } + + // prepare parameters + + gnutls_pk_algorithm_t algorithm = algorithm_to_gnutls(_algorithm); + if (algorithm == GNUTLS_PK_UNKNOWN) { + return DNSSEC_INVALID_KEY_ALGORITHM; + } + + if (!dnssec_algorithm_key_size_check(_algorithm, bits)) { + return DNSSEC_INVALID_KEY_SIZE; + } + + return store->functions->generate_key(store->ctx, algorithm, bits, label, id_ptr); +} + +_public_ +int dnssec_keystore_import(dnssec_keystore_t *store, const dnssec_binary_t *pem, + char **id_ptr) +{ + if (!store || !pem || !id_ptr) { + return DNSSEC_EINVAL; + } + + return store->functions->import_key(store->ctx, pem, id_ptr); +} + +_public_ +int dnssec_keystore_remove(dnssec_keystore_t *store, const char *id) +{ + if (!store || !id) { + return DNSSEC_EINVAL; + } + + return store->functions->remove_key(store->ctx, id); +} + +_public_ +int dnssec_keystore_get_private(dnssec_keystore_t *store, const char *id, + dnssec_key_t *key) +{ + if (!store || !id || dnssec_key_get_algorithm(key) == 0 || !key) { + return DNSSEC_EINVAL; + } + + if (key->private_key) { + return DNSSEC_KEY_ALREADY_PRESENT; + } + + gnutls_privkey_t privkey = NULL; + int r = store->functions->get_private(store->ctx, id, &privkey); + if (r != DNSSEC_EOK) { + return r; + } + + r = key_set_private_key(key, privkey); + if (r != DNSSEC_EOK) { + gnutls_privkey_deinit(privkey); + return r; + } + + return DNSSEC_EOK; +} + +_public_ +int dnssec_keystore_set_private(dnssec_keystore_t *store, dnssec_key_t *key) +{ + if (!store || !key) { + return DNSSEC_EINVAL; + } + + if (!key->private_key) { + return DNSSEC_NO_PRIVATE_KEY; + } + + return store->functions->set_private(store->ctx, key->private_key); +} diff --git a/src/libdnssec/keystore/pkcs11.c b/src/libdnssec/keystore/pkcs11.c new file mode 100644 index 0000000..2b8b6d5 --- /dev/null +++ b/src/libdnssec/keystore/pkcs11.c @@ -0,0 +1,397 @@ +/* Copyright (C) 2022 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz> + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. + */ + +#include <gnutls/gnutls.h> +#include <pthread.h> + +#include "contrib/string.h" +#include "libdnssec/error.h" +#include "libdnssec/keyid.h" +#include "libdnssec/shared/keyid_gnutls.h" +#include "libdnssec/keystore.h" +#include "libdnssec/keystore/internal.h" +#include "libdnssec/p11/p11.h" +#include "libdnssec/pem.h" +#include "libdnssec/shared/shared.h" + +#ifdef ENABLE_PKCS11 + +struct pkcs11_ctx { + char *url; +}; + +typedef struct pkcs11_ctx pkcs11_ctx_t; + +/*! + * Flags used when generating/import key into the token. + */ +static const int TOKEN_ADD_FLAGS = GNUTLS_PKCS11_OBJ_FLAG_MARK_SENSITIVE + | GNUTLS_PKCS11_OBJ_FLAG_MARK_PRIVATE; + +static int key_url(const char *token_uri, const char *key_id, char **url_ptr) +{ + assert(token_uri); + assert(key_id); + assert(url_ptr); + + if (!dnssec_keyid_is_valid(key_id)) { + return DNSSEC_INVALID_KEY_ID; + } + + size_t token_len = strlen(token_uri); + size_t id_len = strlen(key_id); + + // url: <token-url>;id=%aa%bb%cc.. + + size_t len = token_len + 4 + (id_len / 2 * 3); + char *url = malloc(len + 1); + if (!url) { + return DNSSEC_ENOMEM; + } + + size_t prefix = snprintf(url, len, "%s;id=", token_uri); + if (prefix != token_len + 4) { + free(url); + return DNSSEC_ENOMEM; + } + + assert(id_len % 2 == 0); + char *pos = url + prefix; + for (int i = 0; i < id_len; i += 2, pos += 3) { + pos[0] = '%'; + pos[1] = key_id[i]; + pos[2] = key_id[i+1]; + } + assert(url + len == pos); + url[len] = '\0'; + + *url_ptr = url; + return DNSSEC_EOK; +} + +/*! + * Parse configuration string. Accepted format: "<pkcs11-url> <module-path>" + */ +static int parse_config(const char *config, char **uri_ptr, char **module_ptr) +{ + const char *space = strchr(config, ' '); + if (!space) { + return DNSSEC_KEYSTORE_INVALID_CONFIG; + } + + char *url = strndup(config, space - config); + char *module = strdup(space + 1); + + if (!url || !module) { + free(url); + free(module); + return DNSSEC_ENOMEM; + } + + *uri_ptr = url; + *module_ptr = module; + + return DNSSEC_EOK; +} + +/*! + * Load PKCS #11 module and check if the token is available. + */ +static int safe_open(const char *config, char **url_ptr) +{ + char *url = NULL; + char *module = NULL; + + int r = parse_config(config, &url, &module); + if (r != DNSSEC_EOK) { + return r; + } + + r = p11_load_module(module); + free(module); + if (r != GNUTLS_E_SUCCESS) { + free(url); + return DNSSEC_P11_FAILED_TO_LOAD_MODULE; + } + + unsigned int flags = 0; + r = gnutls_pkcs11_token_get_flags(url, &flags); + if (r != GNUTLS_E_SUCCESS) { + free(url); + return DNSSEC_P11_TOKEN_NOT_AVAILABLE; + } + + *url_ptr = url; + + return DNSSEC_EOK; +} + +/* -- internal API --------------------------------------------------------- */ + +static void disable_pkcs11_callbacks(void) +{ + gnutls_pkcs11_set_pin_function(NULL, NULL); + gnutls_pkcs11_set_token_function(NULL, NULL); +} + +static int pkcs11_ctx_new(void **ctx_ptr) +{ + static pthread_once_t once = PTHREAD_ONCE_INIT; + pthread_once(&once, disable_pkcs11_callbacks); + + pkcs11_ctx_t *ctx = calloc(1, sizeof(*ctx)); + if (!ctx) { + return DNSSEC_ENOMEM; + } + + *ctx_ptr = ctx; + + return DNSSEC_EOK; +} + +static void pkcs11_ctx_free(void *ctx) +{ + free(ctx); +} + +static int pkcs11_init(void *ctx, const char *config) +{ + /* + * Current keystore initialization is idempotent. We don't really + * initialize the token because don't want to wipe the data. We just + * check that the token is available the same way pkcs11_open() does. + */ + + _cleanup_free_ char *url = NULL; + + return safe_open(config, &url); +} + +static int pkcs11_open(void *_ctx, const char *config) +{ + pkcs11_ctx_t *ctx = _ctx; + + return safe_open(config, &ctx->url); +} + +static int pkcs11_close(void *_ctx) +{ + pkcs11_ctx_t *ctx = _ctx; + + free(ctx->url); + clear_struct(ctx); + + return DNSSEC_EOK; +} + +static int pkcs11_generate_key(void *_ctx, gnutls_pk_algorithm_t algorithm, + unsigned bits, const char *label, char **id_ptr) +{ + pkcs11_ctx_t *ctx = _ctx; + + uint8_t buf[20] = { 0 }; + gnutls_rnd(GNUTLS_RND_RANDOM, buf, sizeof(buf)); + dnssec_binary_t cka_id = { .data = buf, .size = sizeof(buf) }; + + int flags = TOKEN_ADD_FLAGS | GNUTLS_PKCS11_OBJ_FLAG_LOGIN; + gnutls_datum_t gt_cka_id = binary_to_datum(&cka_id); + int r = gnutls_pkcs11_privkey_generate3(ctx->url, algorithm, bits, label, + >_cka_id, 0, NULL, 0, flags); + if (r != GNUTLS_E_SUCCESS) { + return DNSSEC_KEY_GENERATE_ERROR; + } + + char *id = bin_to_hex(cka_id.data, cka_id.size, false); + if (id == NULL) { + return DNSSEC_ENOMEM; + } + + *id_ptr = id; + + return DNSSEC_EOK; +} + +static int import_pem(const dnssec_binary_t *pem, + gnutls_x509_privkey_t *key_ptr, + gnutls_pubkey_t *pubkey_ptr) +{ + gnutls_x509_privkey_t x509_key = NULL; + gnutls_privkey_t key = NULL; + gnutls_pubkey_t pubkey = NULL; + + int r = dnssec_pem_to_x509(pem, &x509_key); + if (r != DNSSEC_EOK) { + goto fail; + } + + if (gnutls_privkey_init(&key) != GNUTLS_E_SUCCESS || + gnutls_pubkey_init(&pubkey) != GNUTLS_E_SUCCESS + ) { + r = DNSSEC_ENOMEM; + goto fail; + } + + if (gnutls_privkey_import_x509(key, x509_key, 0) != GNUTLS_E_SUCCESS || + gnutls_pubkey_import_privkey(pubkey, key, 0, 0) != GNUTLS_E_SUCCESS + ) { + r = DNSSEC_KEY_IMPORT_ERROR; + goto fail; + } + +fail: + gnutls_privkey_deinit(key); + + if (r == DNSSEC_EOK) { + *key_ptr = x509_key; + *pubkey_ptr = pubkey; + } else { + gnutls_x509_privkey_deinit(x509_key); + gnutls_pubkey_deinit(pubkey); + } + + return r; +} + +static int pkcs11_import_key(void *_ctx, const dnssec_binary_t *pem, char **id_ptr) +{ + pkcs11_ctx_t *ctx = _ctx; + + _cleanup_x509_privkey_ gnutls_x509_privkey_t key = NULL; + _cleanup_pubkey_ gnutls_pubkey_t pubkey = NULL; + + int r = import_pem(pem, &key, &pubkey); + if (r != DNSSEC_EOK) { + return r; + } + + _cleanup_binary_ dnssec_binary_t id = { 0 }; + r = keyid_x509(key, &id); + if (r != DNSSEC_EOK) { + return r; + } + + int flags = TOKEN_ADD_FLAGS | GNUTLS_PKCS11_OBJ_FLAG_LOGIN; + gnutls_datum_t gid = binary_to_datum(&id); + + r = gnutls_pkcs11_copy_x509_privkey2(ctx->url, key, NULL, &gid, 0, flags); + if (r != GNUTLS_E_SUCCESS) { + return DNSSEC_KEY_IMPORT_ERROR; + } + + r = gnutls_pkcs11_copy_pubkey(ctx->url, pubkey, NULL, &gid, 0, flags); + if (r != GNUTLS_E_SUCCESS) { + // note, we result with dangling private key in the token + return DNSSEC_KEY_IMPORT_ERROR; + } + + *id_ptr = bin_to_hex(id.data, id.size, false); + if (*id_ptr == NULL) { + return DNSSEC_ENOMEM; + } + + return DNSSEC_EOK; +} + +static int pkcs11_remove_key(void *_ctx, const char *id) +{ + pkcs11_ctx_t *ctx = _ctx; + + _cleanup_free_ char *url = NULL; + int r = key_url(ctx->url, id, &url); + if (r != DNSSEC_EOK) { + return r; + } + + r = gnutls_pkcs11_delete_url(url, GNUTLS_PKCS11_OBJ_FLAG_LOGIN); + if (r < 0) { + return DNSSEC_ERROR; + } else if (r == 0) { + return DNSSEC_ENOENT; + } + + return DNSSEC_EOK; +} + +static int pkcs11_get_private(void *_ctx, const char *id, gnutls_privkey_t *key_ptr) +{ + pkcs11_ctx_t *ctx = _ctx; + + _cleanup_free_ char *url = NULL; + int r = key_url(ctx->url, id, &url); + if (r != DNSSEC_EOK) { + return r; + } + + gnutls_privkey_t key = NULL; + r = gnutls_privkey_init(&key); + if (r != GNUTLS_E_SUCCESS) { + return DNSSEC_ENOMEM; + } + + r = gnutls_privkey_import_pkcs11_url(key, url); + if (r != GNUTLS_E_SUCCESS) { + gnutls_privkey_deinit(key); + return DNSSEC_NOT_FOUND; + } + + *key_ptr = key; + + return DNSSEC_EOK; +} + +static int pkcs11_set_private(void *ctx, gnutls_privkey_t key) +{ + _cleanup_binary_ dnssec_binary_t pem = { 0 }; + int r = dnssec_pem_from_privkey(key, &pem); + if (r != DNSSEC_EOK) { + return r; + } + + _cleanup_free_ char *keyid = NULL; + + return pkcs11_import_key(ctx, &pem, &keyid); +} + +/* -- public API ----------------------------------------------------------- */ + +_public_ +int dnssec_keystore_init_pkcs11(dnssec_keystore_t **store_ptr) +{ + static const keystore_functions_t IMPLEMENTATION = { + .ctx_new = pkcs11_ctx_new, + .ctx_free = pkcs11_ctx_free, + .init = pkcs11_init, + .open = pkcs11_open, + .close = pkcs11_close, + .generate_key = pkcs11_generate_key, + .import_key = pkcs11_import_key, + .remove_key = pkcs11_remove_key, + .get_private = pkcs11_get_private, + .set_private = pkcs11_set_private, + }; + + return keystore_create(store_ptr, &IMPLEMENTATION); +} + +#else // !ENABLE_PKCS11 + +_public_ +int dnssec_keystore_init_pkcs11(dnssec_keystore_t **store_ptr) +{ + return DNSSEC_NOT_IMPLEMENTED_ERROR; +} + +#endif diff --git a/src/libdnssec/keystore/pkcs8.c b/src/libdnssec/keystore/pkcs8.c new file mode 100644 index 0000000..047bde8 --- /dev/null +++ b/src/libdnssec/keystore/pkcs8.c @@ -0,0 +1,497 @@ +/* Copyright (C) 2022 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz> + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. + */ + +#include <assert.h> +#include <fcntl.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/stat.h> +#include <sys/types.h> + +#include "contrib/files.h" +#include "libdnssec/binary.h" +#include "libdnssec/error.h" +#include "libdnssec/keystore.h" +#include "libdnssec/keystore/internal.h" +#include "libdnssec/pem.h" +#include "libdnssec/shared/shared.h" +#include "libdnssec/shared/keyid_gnutls.h" + +#define DIR_INIT_MODE 0750 + +/*! + * Context for PKCS #8 key directory. + */ +typedef struct { + char *dir_name; +} pkcs8_dir_handle_t; + +/* -- internal functions --------------------------------------------------- */ + +/*! + * Get path to a private key in PKCS #8 PEM format. + */ +static char *key_path(const char *dir, const char *id) +{ + char *strp = NULL; + + int ret = asprintf(&strp, "%s/%s.pem", dir, id); + if (ret < 0) { + return NULL; + } + return strp; +} + +/*! + * Get size of the file and reset the position to the beginning of the file. + */ +static int file_size(int fd, size_t *size) +{ + off_t offset = lseek(fd, 0, SEEK_END); + if (offset == -1) { + return dnssec_errno_to_error(errno); + } + + if (lseek(fd, 0, SEEK_SET) == -1) { + return dnssec_errno_to_error(errno); + } + + assert(offset >= 0); + *size = offset; + + return DNSSEC_EOK; +} + +/*! + * Open a key file and get the descriptor. + */ +static int key_open(const char *dir_name, const char *id, int flags, + mode_t mode, int *fd_ptr) +{ + assert(dir_name); + assert(id); + assert(fd_ptr); + + _cleanup_free_ char *filename = key_path(dir_name, id); + if (!filename) { + return DNSSEC_ENOMEM; + } + + int fd = open(filename, flags, mode); + if (fd == -1) { + return dnssec_errno_to_error(errno); + } + + *fd_ptr = fd; + + return DNSSEC_EOK; +} + +static int key_open_read(const char *dir_name, const char *id, int *fd_ptr) +{ + return key_open(dir_name, id, O_RDONLY, 0, fd_ptr); +} + +static int key_open_write(const char *dir_name, const char *id, int *fd_ptr) +{ + return key_open(dir_name, id, O_WRONLY|O_CREAT|O_EXCL, + S_IRUSR|S_IWUSR|S_IRGRP, fd_ptr); +} + +static int pkcs8_dir_read(pkcs8_dir_handle_t *handle, const char *id, dnssec_binary_t *pem) +{ + if (!handle || !id || !pem) { + return DNSSEC_EINVAL; + } + + // open file and get it's size + + _cleanup_close_ int file = -1; + int result = key_open_read(handle->dir_name, id, &file); + if (result != DNSSEC_EOK) { + return result; + } + + size_t size = 0; + result = file_size(file, &size); + if (result != DNSSEC_EOK) { + return result; + } + + if (size == 0) { + return DNSSEC_MALFORMED_DATA; + } + + // read the stored data + + dnssec_binary_t read_pem = { 0 }; + result = dnssec_binary_alloc(&read_pem, size); + if (result != DNSSEC_EOK) { + return result; + } + + ssize_t read_count = read(file, read_pem.data, read_pem.size); + if (read_count == -1) { + dnssec_binary_free(&read_pem); + return dnssec_errno_to_error(errno); + } + + assert(read_count == read_pem.size); + *pem = read_pem; + + return DNSSEC_EOK; +} + +static bool key_is_duplicate(int open_error, pkcs8_dir_handle_t *handle, + const char *id, const dnssec_binary_t *pem) +{ + assert(handle); + assert(id); + assert(pem); + + if (open_error != dnssec_errno_to_error(EEXIST)) { + return false; + } + + _cleanup_binary_ dnssec_binary_t old = { 0 }; + int r = pkcs8_dir_read(handle, id, &old); + if (r != DNSSEC_EOK) { + return false; + } + + return dnssec_binary_cmp(&old, pem) == 0; +} + +static int pem_generate(gnutls_pk_algorithm_t algorithm, unsigned bits, + dnssec_binary_t *pem, char **id) +{ + assert(pem); + assert(id); + + // generate key + + _cleanup_x509_privkey_ gnutls_x509_privkey_t key = NULL; + int r = gnutls_x509_privkey_init(&key); + if (r != GNUTLS_E_SUCCESS) { + return DNSSEC_ENOMEM; + } + + r = gnutls_x509_privkey_generate(key, algorithm, bits, 0); + if (r != GNUTLS_E_SUCCESS) { + return DNSSEC_KEY_GENERATE_ERROR; + } + + // convert to PEM and export the ID + + dnssec_binary_t _pem = { 0 }; + r = dnssec_pem_from_x509(key, &_pem); + if (r != DNSSEC_EOK) { + return r; + } + + // export key ID + + char *_id = NULL; + r = keyid_x509_hex(key, &_id); + if (r != DNSSEC_EOK) { + dnssec_binary_free(&_pem); + return r; + } + + *id = _id; + *pem = _pem; + + return DNSSEC_EOK; +} + +/* -- internal API --------------------------------------------------------- */ + +static int pkcs8_ctx_new(void **ctx_ptr) +{ + if (!ctx_ptr) { + return DNSSEC_EINVAL; + } + + pkcs8_dir_handle_t *ctx = calloc(1, sizeof(*ctx)); + if (!ctx) { + return DNSSEC_ENOMEM; + } + + *ctx_ptr = ctx; + + return DNSSEC_EOK; +} + +static void pkcs8_ctx_free(void *ctx) +{ + free(ctx); +} + +static int pkcs8_init(void *ctx, const char *config) +{ + if (!ctx || !config) { + return DNSSEC_EINVAL; + } + + return make_dir(config, DIR_INIT_MODE, true); +} + +static int pkcs8_open(void *ctx, const char *config) +{ + if (!ctx || !config) { + return DNSSEC_EINVAL; + } + + pkcs8_dir_handle_t *handle = ctx; + + char *path = realpath(config, NULL); + if (!path) { + return DNSSEC_NOT_FOUND; + } + + handle->dir_name = path; + + return DNSSEC_EOK; +} + +static int pkcs8_close(void *ctx) +{ + if (!ctx) { + return DNSSEC_EINVAL; + } + + pkcs8_dir_handle_t *handle = ctx; + + free(handle->dir_name); + memset(handle, 0, sizeof(*handle)); + + return DNSSEC_EOK; +} + +static int pkcs8_generate_key(void *ctx, gnutls_pk_algorithm_t algorithm, + unsigned bits, const char *label, char **id_ptr) +{ + if (!ctx || !id_ptr) { + return DNSSEC_EINVAL; + } + + (void)label; + + pkcs8_dir_handle_t *handle = ctx; + + // generate key + + char *id = NULL; + _cleanup_binary_ dnssec_binary_t pem = { 0 }; + int r = pem_generate(algorithm, bits, &pem, &id); + if (r != DNSSEC_EOK) { + return r; + } + + // create the file + + _cleanup_close_ int file = -1; + r = key_open_write(handle->dir_name, id, &file); + if (r != DNSSEC_EOK) { + if (key_is_duplicate(r, handle, id, &pem)) { + return DNSSEC_EOK; + } + return r; + } + + // write the data + + ssize_t wrote_count = write(file, pem.data, pem.size); + if (wrote_count == -1) { + return dnssec_errno_to_error(errno); + } + + assert(wrote_count == pem.size); + + // finish + + *id_ptr = id; + + return DNSSEC_EOK; +} + +static int pkcs8_import_key(void *ctx, const dnssec_binary_t *pem, char **id_ptr) +{ + if (!ctx || !pem || !id_ptr) { + return DNSSEC_EINVAL; + } + + pkcs8_dir_handle_t *handle = ctx; + + // retrieve key ID + + char *id = NULL; + _cleanup_x509_privkey_ gnutls_x509_privkey_t key = NULL; + int r = dnssec_pem_to_x509(pem, &key); + if (r != DNSSEC_EOK) { + return r; + } + + r = keyid_x509_hex(key, &id); + if (r != DNSSEC_EOK) { + return r; + } + + // create the file + + _cleanup_close_ int file = -1; + r = key_open_write(handle->dir_name, id, &file); + if (r != DNSSEC_EOK) { + if (key_is_duplicate(r, handle, id, pem)) { + *id_ptr = id; + return DNSSEC_EOK; + } + free(id); + return r; + } + + // write the data + + ssize_t wrote_count = write(file, pem->data, pem->size); + if (wrote_count == -1) { + free(id); + return dnssec_errno_to_error(errno); + } + + assert(wrote_count == pem->size); + + // finish + + *id_ptr = id; + + return DNSSEC_EOK; +} + +static int pkcs8_remove_key(void *ctx, const char *id) +{ + if (!ctx || !id) { + return DNSSEC_EINVAL; + } + + pkcs8_dir_handle_t *handle = ctx; + + _cleanup_free_ char *filename = key_path(handle->dir_name, id); + if (!filename) { + return DNSSEC_ENOMEM; + } + + if (unlink(filename) == -1) { + return dnssec_errno_to_error(errno); + } + + return DNSSEC_EOK; +} + +static int pkcs8_get_private(void *ctx, const char *id, gnutls_privkey_t *key_ptr) +{ + if (!ctx || !id || !key_ptr) { + return DNSSEC_EINVAL; + } + + pkcs8_dir_handle_t *handle = ctx; + + // load private key data + + _cleanup_close_ int file = -1; + int r = key_open_read(handle->dir_name, id, &file); + if (r != DNSSEC_EOK) { + return r; + } + + size_t size = 0; + r = file_size(file, &size); + if (r != DNSSEC_EOK) { + return r; + } + + if (size == 0) { + return DNSSEC_MALFORMED_DATA; + } + + // read the stored data + + _cleanup_binary_ dnssec_binary_t pem = { 0 }; + r = dnssec_binary_alloc(&pem, size); + if (r != DNSSEC_EOK) { + return r; + } + + ssize_t read_count = read(file, pem.data, pem.size); + if (read_count == -1) { + dnssec_binary_free(&pem); + return dnssec_errno_to_error(errno); + } + + assert(read_count == pem.size); + + // construct the key + + gnutls_privkey_t key = NULL; + r = dnssec_pem_to_privkey(&pem, &key); + if (r != DNSSEC_EOK) { + return r; + } + + // finish + + *key_ptr = key; + + return DNSSEC_EOK; +} + +static int pkcs8_set_private(void *ctx, gnutls_privkey_t key) +{ + if (!ctx) { + return DNSSEC_EINVAL; + } + + _cleanup_binary_ dnssec_binary_t pem = { 0 }; + int r = dnssec_pem_from_privkey(key, &pem); + if (r != DNSSEC_EOK) { + return r; + } + + _cleanup_free_ char *keyid = NULL; + + return pkcs8_import_key(ctx, &pem, &keyid); +} + +/* -- public API ----------------------------------------------------------- */ + +_public_ +int dnssec_keystore_init_pkcs8(dnssec_keystore_t **store_ptr) +{ + static const keystore_functions_t IMPLEMENTATION = { + .ctx_new = pkcs8_ctx_new, + .ctx_free = pkcs8_ctx_free, + .init = pkcs8_init, + .open = pkcs8_open, + .close = pkcs8_close, + .generate_key = pkcs8_generate_key, + .import_key = pkcs8_import_key, + .remove_key = pkcs8_remove_key, + .get_private = pkcs8_get_private, + .set_private = pkcs8_set_private, + }; + + return keystore_create(store_ptr, &IMPLEMENTATION); +} |