2 This file is part of GNUnet.
3 (C) 2001, 2002, 2003, 2004, 2005, 2006, 2009 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 2, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
22 * @file util/crypto_rsa.c
23 * @brief public key cryptography (RSA) with libgcrypt
24 * @author Christian Grothoff
28 #include "gnunet_common.h"
29 #include "gnunet_util_lib.h"
31 #define LOG(kind,...) GNUNET_log_from (kind, "util", __VA_ARGS__)
33 #define LOG_STRERROR(kind,syscall) GNUNET_log_from_strerror (kind, "util", syscall)
35 #define LOG_STRERROR_FILE(kind,syscall,filename) GNUNET_log_from_strerror_file (kind, "util", syscall, filename)
37 #define HOSTKEY_LEN 2048
39 #define EXTRA_CHECKS ALLOW_EXTRA_CHECKS
43 * The private information of an RSA key pair.
44 * NOTE: this must match the definition in crypto_ksk.c and gnunet-rsa.c!
46 struct GNUNET_CRYPTO_RsaPrivateKey
49 * Libgcrypt S-expression for the ECC key.
55 * Log an error message at log-level 'level' that indicates
56 * a failure of the command 'cmd' with the message given
57 * by gcry_strerror(rc).
59 #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);
62 * If target != size, move target bytes to the
63 * end of the size-sized buffer and zero out the
64 * first target-size bytes.
66 * @param buf original buffer
67 * @param size number of bytes in the buffer
68 * @param target target size of the buffer
71 adjust (unsigned char *buf, size_t size, size_t target)
75 memmove (&buf[target - size], buf, size);
76 memset (buf, 0, target - size);
82 * Free memory occupied by RSA private key.
84 * @param key pointer to the memory to free
87 GNUNET_CRYPTO_rsa_key_free (struct GNUNET_CRYPTO_RsaPrivateKey *key)
89 gcry_sexp_release (key->sexp);
95 * Extract values from an S-expression.
97 * @param array where to store the result(s)
98 * @param sexp S-expression to parse
99 * @param topname top-level name in the S-expression that is of interest
100 * @param elems names of the elements to extract
101 * @return 0 on success
104 key_from_sexp (gcry_mpi_t * array, gcry_sexp_t sexp, const char *topname,
113 if (! (list = gcry_sexp_find_token (sexp, topname, 0)))
115 l2 = gcry_sexp_cadr (list);
116 gcry_sexp_release (list);
121 for (s = elems; *s; s++, idx++)
123 if (! (l2 = gcry_sexp_find_token (list, s, 1)))
125 for (i = 0; i < idx; i++)
127 gcry_free (array[i]);
130 gcry_sexp_release (list);
131 return 3; /* required parameter not found */
133 array[idx] = gcry_sexp_nth_mpi (l2, 1, GCRYMPI_FMT_USG);
134 gcry_sexp_release (l2);
137 for (i = 0; i < idx; i++)
139 gcry_free (array[i]);
142 gcry_sexp_release (list);
143 return 4; /* required parameter is invalid */
146 gcry_sexp_release (list);
152 * Extract the public key of the host.
154 * @param priv the private key
155 * @param pub where to write the public key
158 GNUNET_CRYPTO_rsa_key_get_public (const struct GNUNET_CRYPTO_RsaPrivateKey
160 struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded
167 rc = key_from_sexp (skey, priv->sexp, "public-key", "ne");
169 rc = key_from_sexp (skey, priv->sexp, "private-key", "ne");
171 rc = key_from_sexp (skey, priv->sexp, "rsa", "ne");
172 GNUNET_assert (0 == rc);
174 htons (sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded) -
175 sizeof (pub->padding));
176 pub->sizen = htons (GNUNET_CRYPTO_RSA_DATA_ENCODING_LENGTH);
178 size = GNUNET_CRYPTO_RSA_DATA_ENCODING_LENGTH;
180 gcry_mpi_print (GCRYMPI_FMT_USG, &pub->key[0], size, &size,
182 adjust (&pub->key[0], size, GNUNET_CRYPTO_RSA_DATA_ENCODING_LENGTH);
183 size = GNUNET_CRYPTO_RSA_KEY_LENGTH - GNUNET_CRYPTO_RSA_DATA_ENCODING_LENGTH;
185 gcry_mpi_print (GCRYMPI_FMT_USG,
187 [GNUNET_CRYPTO_RSA_DATA_ENCODING_LENGTH], size,
189 adjust (&pub->key[GNUNET_CRYPTO_RSA_DATA_ENCODING_LENGTH], size,
190 GNUNET_CRYPTO_RSA_KEY_LENGTH -
191 GNUNET_CRYPTO_RSA_DATA_ENCODING_LENGTH);
192 gcry_mpi_release (skey[0]);
193 gcry_mpi_release (skey[1]);
198 * Convert a public key to a string.
200 * @param pub key to convert
201 * @return string representing 'pub'
204 GNUNET_CRYPTO_rsa_public_key_to_string (const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *pub)
207 size_t keylen = (sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded)) * 8;
211 keylen += 5 - keylen % 5;
213 pubkeybuf = GNUNET_malloc (keylen + 1);
214 end = GNUNET_STRINGS_data_to_string ((unsigned char *) pub,
215 sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
220 GNUNET_free (pubkeybuf);
229 * Convert a string representing a public key to a public key.
231 * @param enc encoded public key
232 * @param enclen number of bytes in enc (without 0-terminator)
233 * @param pub where to store the public key
234 * @return GNUNET_OK on success
237 GNUNET_CRYPTO_rsa_public_key_from_string (const char *enc,
239 struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *pub)
241 size_t keylen = (sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded)) * 8;
244 keylen += 5 - keylen % 5;
246 if (enclen != keylen)
247 return GNUNET_SYSERR;
249 if (GNUNET_OK != GNUNET_STRINGS_string_to_data (enc, enclen,
250 (unsigned char*) pub,
251 sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded)))
252 return GNUNET_SYSERR;
253 if ( (ntohs (pub->len) != sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded)) ||
254 (ntohs (pub->padding) != 0) ||
255 (ntohs (pub->sizen) != GNUNET_CRYPTO_RSA_DATA_ENCODING_LENGTH) )
256 return GNUNET_SYSERR;
262 * Convert the given public key from the network format to the
263 * S-expression that can be used by libgcrypt.
265 * @param publicKey public key to decode
266 * @return NULL on error
269 decode_public_key (const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded *publicKey)
278 if ((ntohs (publicKey->sizen) != GNUNET_CRYPTO_RSA_DATA_ENCODING_LENGTH) ||
279 (ntohs (publicKey->len) !=
280 sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded) -
281 sizeof (publicKey->padding)))
286 size = GNUNET_CRYPTO_RSA_DATA_ENCODING_LENGTH;
287 if (0 != (rc = gcry_mpi_scan (&n, GCRYMPI_FMT_USG, &publicKey->key[0], size, &size)))
289 LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc);
292 size = GNUNET_CRYPTO_RSA_KEY_LENGTH - GNUNET_CRYPTO_RSA_DATA_ENCODING_LENGTH;
293 if (0 != (rc = gcry_mpi_scan (&e, GCRYMPI_FMT_USG,
294 &publicKey->key[GNUNET_CRYPTO_RSA_DATA_ENCODING_LENGTH],
297 LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc);
298 gcry_mpi_release (n);
301 rc = gcry_sexp_build (&result, &erroff, "(public-key(rsa(n %m)(e %m)))", n,
303 gcry_mpi_release (n);
304 gcry_mpi_release (e);
307 LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_sexp_build", rc); /* erroff gives more info */
315 * Encode the private key in a format suitable for
316 * storing it into a file.
318 * @return encoding of the private key.
319 * The first 4 bytes give the size of the array, as usual.
321 struct GNUNET_CRYPTO_RsaPrivateKeyBinaryEncoded *
322 GNUNET_CRYPTO_rsa_encode_key (const struct GNUNET_CRYPTO_RsaPrivateKey *hostkey)
324 struct GNUNET_CRYPTO_RsaPrivateKeyBinaryEncoded *retval;
333 if (gcry_pk_testkey (hostkey->sexp))
340 memset (pkv, 0, sizeof (gcry_mpi_t) * 6);
341 rc = key_from_sexp (pkv, hostkey->sexp, "private-key", "nedpqu");
343 rc = key_from_sexp (pkv, hostkey->sexp, "rsa", "nedpqu");
345 rc = key_from_sexp (pkv, hostkey->sexp, "private-key", "nedpq");
347 rc = key_from_sexp (pkv, hostkey->sexp, "rsa", "nedpq");
349 rc = key_from_sexp (pkv, hostkey->sexp, "private-key", "ned");
351 rc = key_from_sexp (pkv, hostkey->sexp, "rsa", "ned");
352 GNUNET_assert (0 == rc);
353 size = sizeof (struct GNUNET_CRYPTO_RsaPrivateKeyBinaryEncoded);
354 for (i = 0; i < 6; i++)
359 gcry_mpi_aprint (GCRYMPI_FMT_USG,
360 (unsigned char **) &pbu[i], &sizes[i],
370 GNUNET_assert (size < 65536);
371 retval = GNUNET_malloc (size);
372 retval->len = htons (size);
374 retval->sizen = htons (sizes[0]);
375 memcpy (&((char *) (&retval[1]))[i], pbu[0], sizes[0]);
377 retval->sizee = htons (sizes[1]);
378 memcpy (&((char *) (&retval[1]))[i], pbu[1], sizes[1]);
380 retval->sized = htons (sizes[2]);
381 memcpy (&((char *) (&retval[1]))[i], pbu[2], sizes[2]);
384 retval->sizep = htons (sizes[4]);
385 memcpy (&((char *) (&retval[1]))[i], pbu[4], sizes[4]);
387 retval->sizeq = htons (sizes[3]);
388 memcpy (&((char *) (&retval[1]))[i], pbu[3], sizes[3]);
390 retval->sizedmp1 = htons (0);
391 retval->sizedmq1 = htons (0);
392 memcpy (&((char *) (&retval[1]))[i], pbu[5], sizes[5]);
393 for (i = 0; i < 6; i++)
396 gcry_mpi_release (pkv[i]);
405 * Decode the private key from the file-format back
406 * to the "normal", internal format.
408 * @param buf the buffer where the private key data is stored
409 * @param len the length of the data in 'buffer'
410 * @return NULL on error
412 struct GNUNET_CRYPTO_RsaPrivateKey *
413 GNUNET_CRYPTO_rsa_decode_key (const char *buf, uint16_t len)
415 struct GNUNET_CRYPTO_RsaPrivateKey *ret;
416 const struct GNUNET_CRYPTO_RsaPrivateKeyBinaryEncoded *encoding =
417 (const struct GNUNET_CRYPTO_RsaPrivateKeyBinaryEncoded *) buf;
431 enc_len = ntohs (encoding->len);
436 size = ntohs (encoding->sizen);
437 rc = gcry_mpi_scan (&n, GCRYMPI_FMT_USG,
438 &((const unsigned char *) (&encoding[1]))[pos], size,
440 pos += ntohs (encoding->sizen);
443 LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc);
446 size = ntohs (encoding->sizee);
447 rc = gcry_mpi_scan (&e, GCRYMPI_FMT_USG,
448 &((const unsigned char *) (&encoding[1]))[pos], size,
450 pos += ntohs (encoding->sizee);
453 LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc);
454 gcry_mpi_release (n);
457 size = ntohs (encoding->sized);
458 rc = gcry_mpi_scan (&d, GCRYMPI_FMT_USG,
459 &((const unsigned char *) (&encoding[1]))[pos], size,
461 pos += ntohs (encoding->sized);
464 LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc);
465 gcry_mpi_release (n);
466 gcry_mpi_release (e);
470 size = ntohs (encoding->sizep);
473 rc = gcry_mpi_scan (&q, GCRYMPI_FMT_USG,
474 &((const unsigned char *) (&encoding[1]))[pos], size,
476 pos += ntohs (encoding->sizep);
479 LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc);
480 gcry_mpi_release (n);
481 gcry_mpi_release (e);
482 gcry_mpi_release (d);
488 size = ntohs (encoding->sizeq);
491 rc = gcry_mpi_scan (&p, GCRYMPI_FMT_USG,
492 &((const unsigned char *) (&encoding[1]))[pos], size,
494 pos += ntohs (encoding->sizeq);
497 LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc);
498 gcry_mpi_release (n);
499 gcry_mpi_release (e);
500 gcry_mpi_release (d);
502 gcry_mpi_release (q);
508 pos += ntohs (encoding->sizedmp1);
509 pos += ntohs (encoding->sizedmq1);
511 ntohs (encoding->len) - sizeof (struct GNUNET_CRYPTO_RsaPrivateKeyBinaryEncoded) - pos;
514 rc = gcry_mpi_scan (&u, GCRYMPI_FMT_USG,
515 &((const unsigned char *) (&encoding[1]))[pos], size,
519 LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc);
520 gcry_mpi_release (n);
521 gcry_mpi_release (e);
522 gcry_mpi_release (d);
524 gcry_mpi_release (p);
526 gcry_mpi_release (q);
533 if ((NULL != p) && (NULL != q) && (NULL != u))
535 rc = gcry_sexp_build (&res, &erroff,
536 "(private-key(rsa(n %m)(e %m)(d %m)(p %m)(q %m)(u %m)))",
541 if ((NULL != p) && (NULL != q))
543 rc = gcry_sexp_build (&res, &erroff,
544 "(private-key(rsa(n %m)(e %m)(d %m)(p %m)(q %m)))",
549 rc = gcry_sexp_build (&res, &erroff,
550 "(private-key(rsa(n %m)(e %m)(d %m)))", n, e, d);
553 gcry_mpi_release (n);
554 gcry_mpi_release (e);
555 gcry_mpi_release (d);
557 gcry_mpi_release (p);
559 gcry_mpi_release (q);
561 gcry_mpi_release (u);
564 LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_sexp_build", rc);
566 if (0 != (rc = gcry_pk_testkey (res)))
568 LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_pk_testkey", rc);
572 ret = GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_RsaPrivateKey));
579 * Create a new private key. Caller must free return value.
581 * @return fresh private key
583 static struct GNUNET_CRYPTO_RsaPrivateKey *
586 struct GNUNET_CRYPTO_RsaPrivateKey *ret;
588 gcry_sexp_t s_keyparam;
591 gcry_sexp_build (&s_keyparam, NULL,
592 "(genkey(rsa(nbits %d)(rsa-use-e 3:257)))",
594 GNUNET_assert (0 == gcry_pk_genkey (&s_key, s_keyparam));
595 gcry_sexp_release (s_keyparam);
597 GNUNET_assert (0 == gcry_pk_testkey (s_key));
599 ret = GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_RsaPrivateKey));
606 * Try to read the private key from the given file.
608 * @param filename file to read the key from
609 * @return NULL on error
611 static struct GNUNET_CRYPTO_RsaPrivateKey *
612 try_read_key (const char *filename)
614 struct GNUNET_CRYPTO_RsaPrivateKey *ret;
615 struct GNUNET_CRYPTO_RsaPrivateKeyBinaryEncoded *enc;
616 struct GNUNET_DISK_FileHandle *fd;
620 if (GNUNET_YES != GNUNET_DISK_file_test (filename))
623 /* hostkey file exists already, read it! */
624 if (NULL == (fd = GNUNET_DISK_file_open (filename, GNUNET_DISK_OPEN_READ,
625 GNUNET_DISK_PERM_NONE)))
627 LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_ERROR, "open", filename);
630 if (GNUNET_OK != (GNUNET_DISK_file_handle_size (fd, &fs)))
632 LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_ERROR, "stat", filename);
633 (void) GNUNET_DISK_file_close (fd);
638 GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fd));
643 LOG (GNUNET_ERROR_TYPE_ERROR,
644 _("File `%s' does not contain a valid private key (too long, %llu bytes). Renaming it.\n"),
646 (unsigned long long) fs);
647 GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fd));
648 GNUNET_DISK_file_backup (filename);
652 enc = GNUNET_malloc (fs);
653 GNUNET_break (fs == GNUNET_DISK_file_read (fd, enc, fs));
654 len = ntohs (enc->len);
657 (NULL == (ret = GNUNET_CRYPTO_rsa_decode_key ((char *) enc, len))))
659 LOG (GNUNET_ERROR_TYPE_ERROR,
660 _("File `%s' does not contain a valid private key (failed decode, %llu bytes). Deleting it.\n"),
662 (unsigned long long) fs);
663 GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fd));
664 GNUNET_DISK_file_backup (filename);
670 GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fd));
676 * Wait for a short time (we're trying to lock a file or want
677 * to give another process a shot at finishing a disk write, etc.).
678 * Sleeps for 100ms (as that should be long enough for virtually all
679 * modern systems to context switch and allow another process to do
685 struct GNUNET_TIME_Relative timeout;
687 timeout = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, 100);
688 (void) GNUNET_NETWORK_socket_select (NULL, NULL, NULL, timeout);
693 * Create a new private key by reading it from a file. If the
694 * files does not exist, create a new key and write it to the
695 * file. Caller must free return value. Note that this function
696 * can not guarantee that another process might not be trying
697 * the same operation on the same file at the same time.
698 * If the contents of the file
699 * are invalid the old file is deleted and a fresh key is
702 * @return new private key, NULL on error (for example,
705 struct GNUNET_CRYPTO_RsaPrivateKey *
706 GNUNET_CRYPTO_rsa_key_create_from_file (const char *filename)
708 struct GNUNET_CRYPTO_RsaPrivateKey *ret;
709 struct GNUNET_CRYPTO_RsaPrivateKeyBinaryEncoded *enc;
711 struct GNUNET_DISK_FileHandle *fd;
715 struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded pub;
716 struct GNUNET_PeerIdentity pid;
718 if (GNUNET_SYSERR == GNUNET_DISK_directory_create_for_file (filename))
720 while (GNUNET_YES != GNUNET_DISK_file_test (filename))
722 fd = GNUNET_DISK_file_open (filename,
723 GNUNET_DISK_OPEN_WRITE | GNUNET_DISK_OPEN_CREATE
724 | GNUNET_DISK_OPEN_FAILIFEXISTS,
725 GNUNET_DISK_PERM_USER_READ |
726 GNUNET_DISK_PERM_USER_WRITE);
731 if (GNUNET_YES != GNUNET_DISK_file_test (filename))
733 /* must exist but not be accessible, fail for good! */
734 if (0 != ACCESS (filename, R_OK))
735 LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_ERROR, "access", filename);
737 GNUNET_break (0); /* what is going on!? */
742 LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_ERROR, "open", filename);
748 GNUNET_DISK_file_lock (fd, 0,
749 sizeof (struct GNUNET_CRYPTO_RsaPrivateKeyBinaryEncoded),
756 LOG (GNUNET_ERROR_TYPE_ERROR,
757 _("Could not acquire lock on file `%s': %s...\n"), filename,
761 LOG (GNUNET_ERROR_TYPE_INFO,
762 _("Creating a new private key. This may take a while.\n"));
763 ret = rsa_key_create ();
764 GNUNET_assert (ret != NULL);
765 enc = GNUNET_CRYPTO_rsa_encode_key (ret);
766 GNUNET_assert (enc != NULL);
767 GNUNET_assert (ntohs (enc->len) ==
768 GNUNET_DISK_file_write (fd, enc, ntohs (enc->len)));
771 GNUNET_DISK_file_sync (fd);
773 GNUNET_DISK_file_unlock (fd, 0,
774 sizeof (struct GNUNET_CRYPTO_RsaPrivateKeyBinaryEncoded)))
775 LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "fcntl", filename);
776 GNUNET_assert (GNUNET_YES == GNUNET_DISK_file_close (fd));
777 GNUNET_CRYPTO_rsa_key_get_public (ret, &pub);
778 GNUNET_CRYPTO_hash (&pub, sizeof (pub), &pid.hashPubKey);
781 /* hostkey file exists already, read it! */
782 fd = GNUNET_DISK_file_open (filename, GNUNET_DISK_OPEN_READ,
783 GNUNET_DISK_PERM_NONE);
786 LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_ERROR, "open", filename);
793 GNUNET_DISK_file_lock (fd, 0,
794 sizeof (struct GNUNET_CRYPTO_RsaPrivateKeyBinaryEncoded),
800 LOG (GNUNET_ERROR_TYPE_ERROR,
801 _("Could not acquire lock on file `%s': %s...\n"), filename,
803 LOG (GNUNET_ERROR_TYPE_ERROR,
805 ("This may be ok if someone is currently generating a private key.\n"));
810 if (GNUNET_YES != GNUNET_DISK_file_test (filename))
812 /* eh, what!? File we opened is now gone!? */
813 LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "stat", filename);
815 GNUNET_DISK_file_unlock (fd, 0,
816 sizeof (struct GNUNET_CRYPTO_RsaPrivateKeyBinaryEncoded)))
817 LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "fcntl", filename);
818 GNUNET_assert (GNUNET_OK == GNUNET_DISK_file_close (fd));
822 if (GNUNET_OK != GNUNET_DISK_file_size (filename, &fs, GNUNET_YES, GNUNET_YES))
824 if (fs < sizeof (struct GNUNET_CRYPTO_RsaPrivateKeyBinaryEncoded))
826 /* maybe we got the read lock before the key generating
827 * process had a chance to get the write lock; give it up! */
829 GNUNET_DISK_file_unlock (fd, 0,
830 sizeof (struct GNUNET_CRYPTO_RsaPrivateKeyBinaryEncoded)))
831 LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "fcntl", filename);
834 LOG (GNUNET_ERROR_TYPE_ERROR,
836 ("When trying to read key file `%s' I found %u bytes but I need at least %u.\n"),
837 filename, (unsigned int) fs,
838 (unsigned int) sizeof (struct GNUNET_CRYPTO_RsaPrivateKeyBinaryEncoded));
839 LOG (GNUNET_ERROR_TYPE_ERROR,
841 ("This may be ok if someone is currently generating a private key.\n"));
843 short_wait (); /* wait a bit longer! */
848 enc = GNUNET_malloc (fs);
849 GNUNET_assert (fs == GNUNET_DISK_file_read (fd, enc, fs));
850 len = ntohs (enc->len);
853 (NULL == (ret = GNUNET_CRYPTO_rsa_decode_key ((char *) enc, len))))
855 LOG (GNUNET_ERROR_TYPE_ERROR,
856 _("File `%s' does not contain a valid private key. Deleting it.\n"),
858 GNUNET_DISK_file_backup (filename);
862 GNUNET_DISK_file_unlock (fd, 0,
863 sizeof (struct GNUNET_CRYPTO_RsaPrivateKeyBinaryEncoded)))
864 LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "fcntl", filename);
865 GNUNET_assert (GNUNET_YES == GNUNET_DISK_file_close (fd));
868 GNUNET_CRYPTO_rsa_key_get_public (ret, &pub);
869 GNUNET_CRYPTO_hash (&pub, sizeof (pub), &pid.hashPubKey);
876 * Handle to cancel private key generation and state for the
877 * key generation operation.
879 struct GNUNET_CRYPTO_RsaKeyGenerationContext
883 * Continuation to call upon completion.
885 GNUNET_CRYPTO_RsaKeyCallback cont;
888 * Closure for 'cont'.
898 * Handle to the helper process which does the key generation.
900 struct GNUNET_OS_Process *gnunet_rsa;
903 * Handle to 'stdout' of gnunet-rsa. We 'read' on stdout to detect
904 * process termination (instead of messing with SIGCHLD).
906 struct GNUNET_DISK_PipeHandle *gnunet_rsa_out;
909 * Location where we store the private key if it already existed.
910 * (if this is used, 'filename', 'gnunet_rsa' and 'gnunet_rsa_out' will
913 struct GNUNET_CRYPTO_RsaPrivateKey *pk;
916 * Task reading from 'gnunet_rsa_out' to wait for process termination.
918 GNUNET_SCHEDULER_TaskIdentifier read_task;
924 * Task called upon shutdown or process termination of 'gnunet-rsa' during
925 * RSA key generation. Check where we are and perform the appropriate
928 * @param cls the 'struct GNUNET_CRYPTO_RsaKeyGenerationContext'
929 * @param tc scheduler context
932 check_key_generation_completion (void *cls,
933 const struct GNUNET_SCHEDULER_TaskContext *tc)
935 struct GNUNET_CRYPTO_RsaKeyGenerationContext *gc = cls;
936 struct GNUNET_CRYPTO_RsaPrivateKey *pk;
938 gc->read_task = GNUNET_SCHEDULER_NO_TASK;
939 if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
941 gc->cont (gc->cont_cls, NULL, _("interrupted by shutdown"));
942 GNUNET_CRYPTO_rsa_key_create_stop (gc);
945 GNUNET_assert (GNUNET_OK ==
946 GNUNET_OS_process_wait (gc->gnunet_rsa));
947 GNUNET_OS_process_destroy (gc->gnunet_rsa);
948 gc->gnunet_rsa = NULL;
949 if (NULL == (pk = try_read_key (gc->filename)))
952 gc->cont (gc->cont_cls, NULL, _("gnunet-rsa failed"));
953 GNUNET_CRYPTO_rsa_key_create_stop (gc);
956 gc->cont (gc->cont_cls, pk, NULL);
957 GNUNET_DISK_pipe_close (gc->gnunet_rsa_out);
958 GNUNET_free (gc->filename);
964 * Return the private RSA key which already existed on disk
965 * (asynchronously) to the caller.
967 * @param cls the 'struct GNUNET_CRYPTO_RsaKeyGenerationContext'
968 * @param tc scheduler context (unused)
971 async_return_key (void *cls,
972 const struct GNUNET_SCHEDULER_TaskContext *tc)
974 struct GNUNET_CRYPTO_RsaKeyGenerationContext *gc = cls;
976 gc->cont (gc->cont_cls,
984 * Create a new private key by reading it from a file. If the files
985 * does not exist, create a new key and write it to the file. If the
986 * contents of the file are invalid the old file is deleted and a
987 * fresh key is created.
989 * @param filename name of file to use for storage
990 * @param cont function to call when done (or on errors)
991 * @param cont_cls closure for 'cont'
992 * @return handle to abort operation, NULL on fatal errors (cont will not be called if NULL is returned)
994 struct GNUNET_CRYPTO_RsaKeyGenerationContext *
995 GNUNET_CRYPTO_rsa_key_create_start (const char *filename,
996 GNUNET_CRYPTO_RsaKeyCallback cont,
999 struct GNUNET_CRYPTO_RsaKeyGenerationContext *gc;
1000 struct GNUNET_CRYPTO_RsaPrivateKey *pk;
1002 if (NULL != (pk = try_read_key (filename)))
1004 /* quick happy ending: key already exists! */
1005 gc = GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_RsaKeyGenerationContext));
1008 gc->cont_cls = cont_cls;
1009 gc->read_task = GNUNET_SCHEDULER_add_now (&async_return_key,
1013 gc = GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_RsaKeyGenerationContext));
1014 gc->filename = GNUNET_strdup (filename);
1016 gc->cont_cls = cont_cls;
1017 gc->gnunet_rsa_out = GNUNET_DISK_pipe (GNUNET_NO,
1021 if (NULL == gc->gnunet_rsa_out)
1023 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "pipe");
1024 GNUNET_free (gc->filename);
1028 gc->gnunet_rsa = GNUNET_OS_start_process (GNUNET_NO,
1029 GNUNET_OS_INHERIT_STD_ERR,
1036 if (NULL == gc->gnunet_rsa)
1038 GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "fork");
1039 GNUNET_DISK_pipe_close (gc->gnunet_rsa_out);
1040 GNUNET_free (gc->filename);
1044 GNUNET_assert (GNUNET_OK ==
1045 GNUNET_DISK_pipe_close_end (gc->gnunet_rsa_out,
1046 GNUNET_DISK_PIPE_END_WRITE));
1047 gc->read_task = GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
1048 GNUNET_DISK_pipe_handle (gc->gnunet_rsa_out,
1049 GNUNET_DISK_PIPE_END_READ),
1050 &check_key_generation_completion,
1057 * Abort RSA key generation.
1059 * @param gc key generation context to abort
1062 GNUNET_CRYPTO_rsa_key_create_stop (struct GNUNET_CRYPTO_RsaKeyGenerationContext *gc)
1064 if (GNUNET_SCHEDULER_NO_TASK != gc->read_task)
1066 GNUNET_SCHEDULER_cancel (gc->read_task);
1067 gc->read_task = GNUNET_SCHEDULER_NO_TASK;
1069 if (NULL != gc->gnunet_rsa)
1071 (void) GNUNET_OS_process_kill (gc->gnunet_rsa, SIGKILL);
1072 GNUNET_break (GNUNET_OK ==
1073 GNUNET_OS_process_wait (gc->gnunet_rsa));
1074 GNUNET_OS_process_destroy (gc->gnunet_rsa);
1075 GNUNET_DISK_pipe_close (gc->gnunet_rsa_out);
1078 if (NULL != gc->filename)
1080 if (0 != UNLINK (gc->filename))
1081 GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING, "unlink", gc->filename);
1082 GNUNET_free (gc->filename);
1085 GNUNET_CRYPTO_rsa_key_free (gc->pk);
1091 * Setup a key file for a peer given the name of the
1092 * configuration file (!). This function is used so that
1093 * at a later point code can be certain that reading a
1094 * key is fast (for example in time-dependent testcases).
1096 * @param cfg_name name of the configuration file to use
1099 GNUNET_CRYPTO_rsa_setup_hostkey (const char *cfg_name)
1101 struct GNUNET_CONFIGURATION_Handle *cfg;
1102 struct GNUNET_CRYPTO_RsaPrivateKey *pk;
1105 cfg = GNUNET_CONFIGURATION_create ();
1106 (void) GNUNET_CONFIGURATION_load (cfg, cfg_name);
1108 GNUNET_CONFIGURATION_get_value_filename (cfg, "GNUNETD", "HOSTKEY", &fn))
1110 pk = GNUNET_CRYPTO_rsa_key_create_from_file (fn);
1112 GNUNET_CRYPTO_rsa_key_free (pk);
1115 GNUNET_CONFIGURATION_destroy (cfg);
1120 * Encrypt a block with the public key of another host that uses the
1123 * @param block the block to encrypt
1124 * @param size the size of block
1125 * @param publicKey the encoded public key used to encrypt
1126 * @param target where to store the encrypted block
1127 * @returns GNUNET_SYSERR on error, GNUNET_OK if ok
1130 GNUNET_CRYPTO_rsa_encrypt (const void *block, size_t size,
1131 const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded
1133 struct GNUNET_CRYPTO_RsaEncryptedData *target)
1143 GNUNET_assert (size <= sizeof (struct GNUNET_HashCode));
1144 if (! (psexp = decode_public_key (publicKey)))
1145 return GNUNET_SYSERR;
1148 gcry_mpi_scan (&val, GCRYMPI_FMT_USG, block, isize, &isize));
1150 gcry_sexp_build (&data, &erroff,
1151 "(data (flags pkcs1)(value %m))", val));
1152 gcry_mpi_release (val);
1153 GNUNET_assert (0 == gcry_pk_encrypt (&result, data, psexp));
1154 gcry_sexp_release (data);
1155 gcry_sexp_release (psexp);
1156 GNUNET_assert (0 == key_from_sexp (&rval, result, "rsa", "a"));
1157 gcry_sexp_release (result);
1158 isize = sizeof (struct GNUNET_CRYPTO_RsaEncryptedData);
1160 gcry_mpi_print (GCRYMPI_FMT_USG, (unsigned char *) target,
1161 isize, &isize, rval));
1162 gcry_mpi_release (rval);
1163 adjust (&target->encoding[0], isize,
1164 sizeof (struct GNUNET_CRYPTO_RsaEncryptedData));
1170 * Decrypt a given block with the key.
1172 * @param key the key with which to decrypt this block
1173 * @param block the data to decrypt, encoded as returned by encrypt
1174 * @param result pointer to a location where the result can be stored
1175 * @param max the maximum number of bits to store for the result, if
1176 * the decrypted block is bigger, an error is returned
1177 * @return the size of the decrypted block, -1 on error
1180 GNUNET_CRYPTO_rsa_decrypt (const struct GNUNET_CRYPTO_RsaPrivateKey * key,
1181 const struct GNUNET_CRYPTO_RsaEncryptedData * block,
1182 void *result, size_t max)
1184 gcry_sexp_t resultsexp;
1189 unsigned char *endp;
1193 GNUNET_assert (0 == gcry_pk_testkey (key->sexp));
1195 size = sizeof (struct GNUNET_CRYPTO_RsaEncryptedData);
1197 gcry_mpi_scan (&val, GCRYMPI_FMT_USG, &block->encoding[0],
1200 gcry_sexp_build (&data, &erroff, "(enc-val(flags)(rsa(a %m)))",
1202 gcry_mpi_release (val);
1203 GNUNET_assert (0 == gcry_pk_decrypt (&resultsexp, data, key->sexp));
1204 gcry_sexp_release (data);
1205 /* resultsexp has format "(value %m)" */
1206 GNUNET_assert (NULL !=
1207 (val = gcry_sexp_nth_mpi (resultsexp, 1, GCRYMPI_FMT_USG)));
1208 gcry_sexp_release (resultsexp);
1209 tmp = GNUNET_malloc (max + HOSTKEY_LEN / 8);
1210 size = max + HOSTKEY_LEN / 8;
1211 GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_USG, tmp, size, &size, val));
1212 gcry_mpi_release (val);
1214 endp += (size - max);
1216 memcpy (result, endp, size);
1223 * Convert the data specified in the given purpose argument to an
1224 * S-expression suitable for signature operations.
1226 * @param purpose data to convert
1227 * @return converted s-expression
1230 data_to_pkcs1 (const struct GNUNET_CRYPTO_RsaSignaturePurpose *purpose)
1232 struct GNUNET_HashCode hc;
1236 GNUNET_CRYPTO_hash (purpose, ntohl (purpose->size), &hc);
1237 #define FORMATSTRING "(4:data(5:flags5:pkcs1)(4:hash6:sha51264:0123456789012345678901234567890123456789012345678901234567890123))"
1238 bufSize = strlen (FORMATSTRING) + 1;
1242 memcpy (buff, FORMATSTRING, bufSize);
1246 ("0123456789012345678901234567890123456789012345678901234567890123))")
1247 - 1], &hc, sizeof (struct GNUNET_HashCode));
1248 GNUNET_assert (0 == gcry_sexp_new (&data, buff, bufSize, 0));
1256 * Sign a given block.
1258 * @param key private key to use for the signing
1259 * @param purpose what to sign (size, purpose)
1260 * @param sig where to write the signature
1261 * @return GNUNET_SYSERR on error, GNUNET_OK on success
1264 GNUNET_CRYPTO_rsa_sign (const struct GNUNET_CRYPTO_RsaPrivateKey *key,
1265 const struct GNUNET_CRYPTO_RsaSignaturePurpose *purpose,
1266 struct GNUNET_CRYPTO_RsaSignature *sig)
1273 data = data_to_pkcs1 (purpose);
1274 GNUNET_assert (0 == gcry_pk_sign (&result, data, key->sexp));
1275 gcry_sexp_release (data);
1276 GNUNET_assert (0 == key_from_sexp (&rval, result, "rsa", "s"));
1277 gcry_sexp_release (result);
1278 ssize = sizeof (struct GNUNET_CRYPTO_RsaSignature);
1280 gcry_mpi_print (GCRYMPI_FMT_USG, (unsigned char *) sig, ssize,
1282 gcry_mpi_release (rval);
1283 adjust (sig->sig, ssize, sizeof (struct GNUNET_CRYPTO_RsaSignature));
1291 * @param purpose what is the purpose that the signature should have?
1292 * @param validate block to validate (size, purpose, data)
1293 * @param sig signature that is being validated
1294 * @param publicKey public key of the signer
1295 * @returns GNUNET_OK if ok, GNUNET_SYSERR if invalid
1298 GNUNET_CRYPTO_rsa_verify (uint32_t purpose,
1299 const struct GNUNET_CRYPTO_RsaSignaturePurpose
1301 const struct GNUNET_CRYPTO_RsaSignature *sig,
1302 const struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded
1306 gcry_sexp_t sigdata;
1313 if (purpose != ntohl (validate->purpose))
1314 return GNUNET_SYSERR; /* purpose mismatch */
1315 size = sizeof (struct GNUNET_CRYPTO_RsaSignature);
1317 gcry_mpi_scan (&val, GCRYMPI_FMT_USG,
1318 (const unsigned char *) sig, size, &size));
1320 gcry_sexp_build (&sigdata, &erroff, "(sig-val(rsa(s %m)))",
1322 gcry_mpi_release (val);
1323 data = data_to_pkcs1 (validate);
1324 if (! (psexp = decode_public_key (publicKey)))
1326 gcry_sexp_release (data);
1327 gcry_sexp_release (sigdata);
1328 return GNUNET_SYSERR;
1330 rc = gcry_pk_verify (sigdata, data, psexp);
1331 gcry_sexp_release (psexp);
1332 gcry_sexp_release (data);
1333 gcry_sexp_release (sigdata);
1336 LOG (GNUNET_ERROR_TYPE_WARNING,
1337 _("RSA signature verification failed at %s:%d: %s\n"), __FILE__,
1338 __LINE__, gcry_strerror (rc));
1339 return GNUNET_SYSERR;
1345 /* end of crypto_rsa.c */