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- /*
- This file is part of GNUnet.
- Copyright (C) 2012, 2013, 2015 GNUnet e.V.
- GNUnet is free software: you can redistribute it and/or modify it
- under the terms of the GNU Affero General Public License as published
- by the Free Software Foundation, either version 3 of the License,
- or (at your option) any later version.
- GNUnet 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
- Affero General Public License for more details.
- You should have received a copy of the GNU Affero General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>.
- SPDX-License-Identifier: AGPL3.0-or-later
- */
- /**
- * @file util/crypto_ecc_setup.c
- * @brief helper function for easy EdDSA key setup
- * @author Christian Grothoff
- */
- #include "platform.h"
- #include <gcrypt.h>
- #include "gnunet_util_lib.h"
- #define LOG(kind, ...) GNUNET_log_from (kind, "util-crypto-ecc", __VA_ARGS__)
- #define LOG_STRERROR(kind, syscall) \
- GNUNET_log_from_strerror (kind, "util-crypto-ecc", syscall)
- #define LOG_STRERROR_FILE(kind, syscall, filename) \
- GNUNET_log_from_strerror_file (kind, "util-crypto-ecc", syscall, filename)
- /**
- * Log an error message at log-level 'level' that indicates
- * a failure of the command 'cmd' with the message given
- * by gcry_strerror(rc).
- */
- #define LOG_GCRY(level, cmd, rc) \
- do \
- { \
- LOG (level, \
- _ ("`%s' failed at %s:%d with error: %s\n"), \
- cmd, \
- __FILE__, \
- __LINE__, \
- gcry_strerror (rc)); \
- } while (0)
- /**
- * Wait for a short time (we're trying to lock a file or want
- * to give another process a shot at finishing a disk write, etc.).
- * Sleeps for 100ms (as that should be long enough for virtually all
- * modern systems to context switch and allow another process to do
- * some 'real' work).
- */
- static void
- short_wait ()
- {
- struct GNUNET_TIME_Relative timeout;
- timeout = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, 100);
- (void) GNUNET_NETWORK_socket_select (NULL, NULL, NULL, timeout);
- }
- /**
- * Create a new private key by reading it from a file. If the
- * files does not exist, create a new key and write it to the
- * file. Caller must free return value. Note that this function
- * can not guarantee that another process might not be trying
- * the same operation on the same file at the same time.
- * If the contents of the file
- * are invalid the old file is deleted and a fresh key is
- * created.
- *
- * @param filename name of file to use to store the key
- * @return new private key, NULL on error (for example,
- * permission denied)
- */
- struct GNUNET_CRYPTO_EddsaPrivateKey *
- GNUNET_CRYPTO_eddsa_key_create_from_file (const char *filename)
- {
- struct GNUNET_CRYPTO_EddsaPrivateKey *priv;
- struct GNUNET_DISK_FileHandle *fd;
- unsigned int cnt;
- int ec;
- uint64_t fs;
- ssize_t sret;
- if (GNUNET_SYSERR == GNUNET_DISK_directory_create_for_file (filename))
- return NULL;
- while (GNUNET_YES != GNUNET_DISK_file_test (filename))
- {
- fd =
- GNUNET_DISK_file_open (filename,
- GNUNET_DISK_OPEN_WRITE | GNUNET_DISK_OPEN_CREATE
- | GNUNET_DISK_OPEN_FAILIFEXISTS,
- GNUNET_DISK_PERM_USER_READ
- | GNUNET_DISK_PERM_USER_WRITE);
- if (NULL == fd)
- {
- if (EEXIST == errno)
- {
- if (GNUNET_YES != GNUNET_DISK_file_test (filename))
- {
- /* must exist but not be accessible, fail for good! */
- if (0 != access (filename, R_OK))
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_ERROR, "access", filename);
- else
- GNUNET_break (0); /* what is going on!? */
- return NULL;
- }
- continue;
- }
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_ERROR, "open", filename);
- return NULL;
- }
- cnt = 0;
- while (GNUNET_YES !=
- GNUNET_DISK_file_lock (fd,
- 0,
- sizeof(struct GNUNET_CRYPTO_EddsaPrivateKey),
- GNUNET_YES))
- {
- short_wait ();
- if (0 == ++cnt % 10)
- {
- ec = errno;
- LOG (GNUNET_ERROR_TYPE_ERROR,
- _ ("Could not acquire lock on file `%s': %s...\n"),
- filename,
- strerror (ec));
- }
- }
- LOG (GNUNET_ERROR_TYPE_INFO,
- _ ("Creating a new private key. This may take a while.\n"));
- priv = GNUNET_CRYPTO_eddsa_key_create ();
- GNUNET_assert (NULL != priv);
- GNUNET_assert (sizeof(*priv) ==
- GNUNET_DISK_file_write (fd, priv, sizeof(*priv)));
- GNUNET_DISK_file_sync (fd);
- if (GNUNET_YES !=
- GNUNET_DISK_file_unlock (fd,
- 0,
- sizeof(struct GNUNET_CRYPTO_EddsaPrivateKey)))
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "fcntl", filename);
- GNUNET_assert (GNUNET_YES == GNUNET_DISK_file_close (fd));
- return priv;
- }
- /* key file exists already, read it! */
- fd = GNUNET_DISK_file_open (filename,
- GNUNET_DISK_OPEN_READ,
- GNUNET_DISK_PERM_NONE);
- if (NULL == fd)
- {
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_ERROR, "open", filename);
- return NULL;
- }
- cnt = 0;
- while (1)
- {
- if (GNUNET_YES !=
- GNUNET_DISK_file_lock (fd,
- 0,
- sizeof(struct GNUNET_CRYPTO_EddsaPrivateKey),
- GNUNET_NO))
- {
- if (0 == ++cnt % 60)
- {
- ec = errno;
- LOG (GNUNET_ERROR_TYPE_ERROR,
- _ ("Could not acquire lock on file `%s': %s...\n"),
- filename,
- strerror (ec));
- LOG (
- GNUNET_ERROR_TYPE_ERROR,
- _ (
- "This may be ok if someone is currently generating a private key.\n"));
- }
- short_wait ();
- continue;
- }
- if (GNUNET_YES != GNUNET_DISK_file_test (filename))
- {
- /* eh, what!? File we opened is now gone!? */
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "stat", filename);
- if (GNUNET_YES !=
- GNUNET_DISK_file_unlock (fd,
- 0,
- sizeof(
- struct GNUNET_CRYPTO_EddsaPrivateKey)))
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "fcntl", filename);
- GNUNET_assert (GNUNET_OK == GNUNET_DISK_file_close (fd));
- return NULL;
- }
- if (GNUNET_OK !=
- GNUNET_DISK_file_size (filename, &fs, GNUNET_YES, GNUNET_YES))
- fs = 0;
- if (fs < sizeof(struct GNUNET_CRYPTO_EddsaPrivateKey))
- {
- /* maybe we got the read lock before the key generating
- * process had a chance to get the write lock; give it up! */
- if (GNUNET_YES !=
- GNUNET_DISK_file_unlock (fd,
- 0,
- sizeof(
- struct GNUNET_CRYPTO_EddsaPrivateKey)))
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "fcntl", filename);
- if (0 == ++cnt % 10)
- {
- LOG (GNUNET_ERROR_TYPE_ERROR,
- _ (
- "When trying to read key file `%s' I found %u bytes but I need at least %u.\n"),
- filename,
- (unsigned int) fs,
- (unsigned int) sizeof(struct GNUNET_CRYPTO_EddsaPrivateKey));
- LOG (GNUNET_ERROR_TYPE_ERROR,
- _ ("This may be ok if someone is currently generating a key.\n"));
- }
- short_wait (); /* wait a bit longer! */
- continue;
- }
- break;
- }
- fs = sizeof(struct GNUNET_CRYPTO_EddsaPrivateKey);
- priv = GNUNET_malloc (fs);
- sret = GNUNET_DISK_file_read (fd, priv, fs);
- GNUNET_assert ((sret >= 0) && (fs == (size_t) sret));
- if (GNUNET_YES !=
- GNUNET_DISK_file_unlock (fd,
- 0,
- sizeof(struct GNUNET_CRYPTO_EddsaPrivateKey)))
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "fcntl", filename);
- GNUNET_assert (GNUNET_YES == GNUNET_DISK_file_close (fd));
- #if CRYPTO_BUG
- if (GNUNET_OK != check_eddsa_key (priv))
- {
- GNUNET_break (0);
- GNUNET_free (priv);
- return NULL;
- }
- #endif
- return priv;
- }
- /**
- * Create a new private key by reading it from a file. If the
- * files does not exist, create a new key and write it to the
- * file. Caller must free return value. Note that this function
- * can not guarantee that another process might not be trying
- * the same operation on the same file at the same time.
- * If the contents of the file
- * are invalid the old file is deleted and a fresh key is
- * created.
- *
- * @param filename name of file to use to store the key
- * @return new private key, NULL on error (for example,
- * permission denied)
- */
- struct GNUNET_CRYPTO_EcdsaPrivateKey *
- GNUNET_CRYPTO_ecdsa_key_create_from_file (const char *filename)
- {
- struct GNUNET_CRYPTO_EcdsaPrivateKey *priv;
- struct GNUNET_DISK_FileHandle *fd;
- unsigned int cnt;
- int ec;
- uint64_t fs;
- ssize_t sret;
- if (GNUNET_SYSERR == GNUNET_DISK_directory_create_for_file (filename))
- return NULL;
- while (GNUNET_YES != GNUNET_DISK_file_test (filename))
- {
- fd =
- GNUNET_DISK_file_open (filename,
- GNUNET_DISK_OPEN_WRITE | GNUNET_DISK_OPEN_CREATE
- | GNUNET_DISK_OPEN_FAILIFEXISTS,
- GNUNET_DISK_PERM_USER_READ
- | GNUNET_DISK_PERM_USER_WRITE);
- if (NULL == fd)
- {
- if (EEXIST == errno)
- {
- if (GNUNET_YES != GNUNET_DISK_file_test (filename))
- {
- /* must exist but not be accessible, fail for good! */
- if (0 != access (filename, R_OK))
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_ERROR, "access", filename);
- else
- GNUNET_break (0); /* what is going on!? */
- return NULL;
- }
- continue;
- }
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_ERROR, "open", filename);
- return NULL;
- }
- cnt = 0;
- while (GNUNET_YES !=
- GNUNET_DISK_file_lock (fd,
- 0,
- sizeof(struct GNUNET_CRYPTO_EcdsaPrivateKey),
- GNUNET_YES))
- {
- short_wait ();
- if (0 == ++cnt % 10)
- {
- ec = errno;
- LOG (GNUNET_ERROR_TYPE_ERROR,
- _ ("Could not acquire lock on file `%s': %s...\n"),
- filename,
- strerror (ec));
- }
- }
- LOG (GNUNET_ERROR_TYPE_INFO,
- _ ("Creating a new private key. This may take a while.\n"));
- priv = GNUNET_CRYPTO_ecdsa_key_create ();
- GNUNET_assert (NULL != priv);
- GNUNET_assert (sizeof(*priv) ==
- GNUNET_DISK_file_write (fd, priv, sizeof(*priv)));
- GNUNET_DISK_file_sync (fd);
- if (GNUNET_YES !=
- GNUNET_DISK_file_unlock (fd,
- 0,
- sizeof(struct GNUNET_CRYPTO_EcdsaPrivateKey)))
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "fcntl", filename);
- GNUNET_assert (GNUNET_YES == GNUNET_DISK_file_close (fd));
- return priv;
- }
- /* key file exists already, read it! */
- fd = GNUNET_DISK_file_open (filename,
- GNUNET_DISK_OPEN_READ,
- GNUNET_DISK_PERM_NONE);
- if (NULL == fd)
- {
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_ERROR, "open", filename);
- return NULL;
- }
- cnt = 0;
- while (1)
- {
- if (GNUNET_YES !=
- GNUNET_DISK_file_lock (fd,
- 0,
- sizeof(struct GNUNET_CRYPTO_EcdsaPrivateKey),
- GNUNET_NO))
- {
- if (0 == ++cnt % 60)
- {
- ec = errno;
- LOG (GNUNET_ERROR_TYPE_ERROR,
- _ ("Could not acquire lock on file `%s': %s...\n"),
- filename,
- strerror (ec));
- LOG (
- GNUNET_ERROR_TYPE_ERROR,
- _ (
- "This may be ok if someone is currently generating a private key.\n"));
- }
- short_wait ();
- continue;
- }
- if (GNUNET_YES != GNUNET_DISK_file_test (filename))
- {
- /* eh, what!? File we opened is now gone!? */
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "stat", filename);
- if (GNUNET_YES !=
- GNUNET_DISK_file_unlock (fd,
- 0,
- sizeof(
- struct GNUNET_CRYPTO_EcdsaPrivateKey)))
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "fcntl", filename);
- GNUNET_assert (GNUNET_OK == GNUNET_DISK_file_close (fd));
- return NULL;
- }
- if (GNUNET_OK !=
- GNUNET_DISK_file_size (filename, &fs, GNUNET_YES, GNUNET_YES))
- fs = 0;
- if (fs < sizeof(struct GNUNET_CRYPTO_EcdsaPrivateKey))
- {
- /* maybe we got the read lock before the key generating
- * process had a chance to get the write lock; give it up! */
- if (GNUNET_YES !=
- GNUNET_DISK_file_unlock (fd,
- 0,
- sizeof(
- struct GNUNET_CRYPTO_EcdsaPrivateKey)))
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "fcntl", filename);
- if (0 == ++cnt % 10)
- {
- LOG (GNUNET_ERROR_TYPE_ERROR,
- _ (
- "When trying to read key file `%s' I found %u bytes but I need at least %u.\n"),
- filename,
- (unsigned int) fs,
- (unsigned int) sizeof(struct GNUNET_CRYPTO_EcdsaPrivateKey));
- LOG (GNUNET_ERROR_TYPE_ERROR,
- _ ("This may be ok if someone is currently generating a key.\n"));
- }
- short_wait (); /* wait a bit longer! */
- continue;
- }
- break;
- }
- fs = sizeof(struct GNUNET_CRYPTO_EcdsaPrivateKey);
- priv = GNUNET_malloc (fs);
- sret = GNUNET_DISK_file_read (fd, priv, fs);
- GNUNET_assert ((sret >= 0) && (fs == (size_t) sret));
- if (GNUNET_YES !=
- GNUNET_DISK_file_unlock (fd,
- 0,
- sizeof(struct GNUNET_CRYPTO_EcdsaPrivateKey)))
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "fcntl", filename);
- GNUNET_assert (GNUNET_YES == GNUNET_DISK_file_close (fd));
- return priv;
- }
- /**
- * Create a new private key by reading our peer's key from
- * the file specified in the configuration.
- *
- * @param cfg the configuration to use
- * @return new private key, NULL on error (for example,
- * permission denied)
- */
- struct GNUNET_CRYPTO_EddsaPrivateKey *
- GNUNET_CRYPTO_eddsa_key_create_from_configuration (
- const struct GNUNET_CONFIGURATION_Handle *cfg)
- {
- struct GNUNET_CRYPTO_EddsaPrivateKey *priv;
- char *fn;
- if (GNUNET_OK !=
- GNUNET_CONFIGURATION_get_value_filename (cfg, "PEER", "PRIVATE_KEY", &fn))
- return NULL;
- priv = GNUNET_CRYPTO_eddsa_key_create_from_file (fn);
- GNUNET_free (fn);
- return priv;
- }
- /**
- * Retrieve the identity of the host's peer.
- *
- * @param cfg configuration to use
- * @param dst pointer to where to write the peer identity
- * @return #GNUNET_OK on success, #GNUNET_SYSERR if the identity
- * could not be retrieved
- */
- int
- GNUNET_CRYPTO_get_peer_identity (const struct GNUNET_CONFIGURATION_Handle *cfg,
- struct GNUNET_PeerIdentity *dst)
- {
- struct GNUNET_CRYPTO_EddsaPrivateKey *priv;
- if (NULL == (priv = GNUNET_CRYPTO_eddsa_key_create_from_configuration (cfg)))
- {
- GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
- _ ("Could not load peer's private key\n"));
- return GNUNET_SYSERR;
- }
- GNUNET_CRYPTO_eddsa_key_get_public (priv, &dst->public_key);
- GNUNET_free (priv);
- return GNUNET_OK;
- }
- /**
- * Setup a key file for a peer given the name of the
- * configuration file (!). This function is used so that
- * at a later point code can be certain that reading a
- * key is fast (for example in time-dependent testcases).
- *
- * @param cfg_name name of the configuration file to use
- */
- void
- GNUNET_CRYPTO_eddsa_setup_key (const char *cfg_name)
- {
- struct GNUNET_CONFIGURATION_Handle *cfg;
- struct GNUNET_CRYPTO_EddsaPrivateKey *priv;
- cfg = GNUNET_CONFIGURATION_create ();
- (void) GNUNET_CONFIGURATION_load (cfg, cfg_name);
- priv = GNUNET_CRYPTO_eddsa_key_create_from_configuration (cfg);
- if (NULL != priv)
- GNUNET_free (priv);
- GNUNET_CONFIGURATION_destroy (cfg);
- }
- /* end of crypto_ecc_setup.c */
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