X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=src%2Futil%2Fcrypto_ecc.c;h=4bba395b32b8fc77a7d5425078ba7bf12ad20b3f;hb=225ea594e86e56160b0f89b5cace24291cc6184b;hp=2de97cb8c6195a1c081a40c19c120c52054dc61b;hpb=ba430ff1fbce68a8940e448f0e0fe7266fa638b5;p=oweals%2Fgnunet.git diff --git a/src/util/crypto_ecc.c b/src/util/crypto_ecc.c index 2de97cb8c..4bba395b3 100644 --- a/src/util/crypto_ecc.c +++ b/src/util/crypto_ecc.c @@ -1,6 +1,6 @@ /* This file is part of GNUnet. - (C) 2012, 2013 Christian Grothoff (and other contributing authors) + 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 General Public License as published @@ -14,8 +14,8 @@ You should have received a copy of the GNU General Public License along with GNUnet; see the file COPYING. If not, write to the - Free Software Foundation, Inc., 59 Temple Place - Suite 330, - Boston, MA 02111-1307, USA. + Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, + Boston, MA 02110-1301, USA. */ /** @@ -25,7 +25,8 @@ */ #include "platform.h" #include -#include "gnunet_util_lib.h" +#include "gnunet_crypto_lib.h" +#include "gnunet_strings_lib.h" #define EXTRA_CHECKS 0 @@ -61,7 +62,9 @@ * @return 0 on success */ static int -key_from_sexp (gcry_mpi_t * array, gcry_sexp_t sexp, const char *topname, +key_from_sexp (gcry_mpi_t * array, + gcry_sexp_t sexp, + const char *topname, const char *elems) { gcry_sexp_t list; @@ -127,7 +130,7 @@ decode_private_ecdsa_key (const struct GNUNET_CRYPTO_EcdsaPrivateKey *priv) rc = gcry_sexp_build (&result, NULL, "(private-key(ecc(curve \"" CURVE "\")" "(d %b)))", - (int)sizeof (priv->d), priv->d); + (int) sizeof (priv->d), priv->d); if (0 != rc) { LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_sexp_build", rc); @@ -229,7 +232,7 @@ GNUNET_CRYPTO_ecdsa_key_get_public (const struct GNUNET_CRYPTO_EcdsaPrivateKey * GNUNET_assert (0 == gcry_mpi_ec_new (&ctx, sexp, NULL)); gcry_sexp_release (sexp); q = gcry_mpi_ec_get_mpi ("q@eddsa", ctx, 0); - GNUNET_assert (q); + GNUNET_assert (NULL != q); GNUNET_CRYPTO_mpi_print_unsigned (pub->q_y, sizeof (pub->q_y), q); gcry_mpi_release (q); gcry_ctx_release (ctx); @@ -408,6 +411,35 @@ GNUNET_CRYPTO_eddsa_public_key_from_string (const char *enc, } +/** + * Convert a string representing a private key to a private key. + * + * @param enc encoded public key + * @param enclen number of bytes in @a enc (without 0-terminator) + * @param priv where to store the private key + * @return #GNUNET_OK on success + */ +int +GNUNET_CRYPTO_eddsa_private_key_from_string (const char *enc, + size_t enclen, + struct GNUNET_CRYPTO_EddsaPrivateKey *pub) +{ + size_t keylen = (sizeof (struct GNUNET_CRYPTO_EddsaPrivateKey)) * 8; + + if (keylen % 5 > 0) + keylen += 5 - keylen % 5; + keylen /= 5; + if (enclen != keylen) + return GNUNET_SYSERR; + + if (GNUNET_OK != GNUNET_STRINGS_string_to_data (enc, enclen, + pub, + sizeof (struct GNUNET_CRYPTO_EddsaPrivateKey))) + return GNUNET_SYSERR; + return GNUNET_OK; +} + + /** * @ingroup crypto * Clear memory that was used to store a private key. @@ -461,9 +493,14 @@ GNUNET_CRYPTO_ecdhe_key_create () gcry_mpi_t d; int rc; + /* NOTE: For libgcrypt >= 1.7, we do not need the 'eddsa' flag here, + but should also be harmless. For libgcrypt < 1.7, using 'eddsa' + disables an expensive key testing routine. We do not want to run + the expensive check for ECDHE, as we generate TONS of keys to + use for a very short time. */ if (0 != (rc = gcry_sexp_build (&s_keyparam, NULL, "(genkey(ecc(curve \"" CURVE "\")" - "(flags)))"))) + "(flags eddsa no-keytest)))"))) { LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_sexp_build", rc); return NULL; @@ -621,407 +658,6 @@ GNUNET_CRYPTO_ecdsa_key_get_anonymous () } -/** - * 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; - - 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); - GNUNET_assert (fs == GNUNET_DISK_file_read (fd, priv, fs)); - 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; -} - - -/** - * 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; - - 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); - GNUNET_assert (fs == GNUNET_DISK_file_read (fd, priv, fs)); - 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; -} - - -/** - * 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); -} - - -/** - * 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; -} - - /** * Compare two Peer Identities. * @@ -1219,16 +855,16 @@ GNUNET_CRYPTO_ecdsa_verify (uint32_t purpose, /* build s-expression for signature */ if (0 != (rc = gcry_sexp_build (&sig_sexpr, NULL, "(sig-val(ecdsa(r %b)(s %b)))", - (int)sizeof (sig->r), sig->r, - (int)sizeof (sig->s), sig->s))) + (int) sizeof (sig->r), sig->r, + (int) sizeof (sig->s), sig->s))) { LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_sexp_build", rc); return GNUNET_SYSERR; } data = data_to_ecdsa_value (validate); if (0 != (rc = gcry_sexp_build (&pub_sexpr, NULL, - "(public-key(ecc(curve " CURVE ")(q %b)))", - (int)sizeof (pub->q_y), pub->q_y))) + "(public-key(ecc(curve " CURVE ")(q %b)))", + (int) sizeof (pub->q_y), pub->q_y))) { gcry_sexp_release (data); gcry_sexp_release (sig_sexpr); @@ -1284,7 +920,7 @@ GNUNET_CRYPTO_eddsa_verify (uint32_t purpose, } data = data_to_eddsa_value (validate); if (0 != (rc = gcry_sexp_build (&pub_sexpr, NULL, - "(public-key(ecc(curve " CURVE ")(q %b)))", + "(public-key(ecc(curve " CURVE ")(flags eddsa)(q %b)))", (int)sizeof (pub->q_y), pub->q_y))) { gcry_sexp_release (data); @@ -1367,7 +1003,9 @@ GNUNET_CRYPTO_ecc_ecdh (const struct GNUNET_CRYPTO_EcdhePrivateKey *priv, GNUNET_assert (0 == gcry_mpi_print (GCRYMPI_FMT_STD, xbuf, rsize, &rsize, result_x)); - GNUNET_CRYPTO_hash (xbuf, rsize, key_material); + GNUNET_CRYPTO_hash (xbuf, + rsize, + key_material); gcry_mpi_release (result_x); return GNUNET_OK; } @@ -1390,14 +1028,17 @@ derive_h (const struct GNUNET_CRYPTO_EcdsaPublicKey *pub, { gcry_mpi_t h; struct GNUNET_HashCode hc; + static const char *const salt = "key-derivation"; GNUNET_CRYPTO_kdf (&hc, sizeof (hc), - "key-derivation", strlen ("key-derivation"), + salt, strlen (salt), pub, sizeof (*pub), label, strlen (label), context, strlen (context), NULL, 0); - GNUNET_CRYPTO_mpi_scan_unsigned (&h, (unsigned char *) &hc, sizeof (hc)); + GNUNET_CRYPTO_mpi_scan_unsigned (&h, + (unsigned char *) &hc, + sizeof (hc)); return h; } @@ -1433,7 +1074,9 @@ GNUNET_CRYPTO_ecdsa_private_key_derive (const struct GNUNET_CRYPTO_EcdsaPrivateK GNUNET_CRYPTO_ecdsa_key_get_public (priv, &pub); h = derive_h (&pub, label, context); - GNUNET_CRYPTO_mpi_scan_unsigned (&x, priv->d, sizeof (priv->d)); + GNUNET_CRYPTO_mpi_scan_unsigned (&x, + priv->d, + sizeof (priv->d)); d = gcry_mpi_new (256); gcry_mpi_mulm (d, h, x, n); gcry_mpi_release (h); @@ -1447,73 +1090,6 @@ GNUNET_CRYPTO_ecdsa_private_key_derive (const struct GNUNET_CRYPTO_EcdsaPrivateK } -/** - * Computes a new PeerIdentity using the Chord formula. - * new_peer_identity = ((my_identity + pow(2,i)) mod (pow(2,m) - * where m, size of struct GNUNET_PeerIdentity in bits. - * i, 0 <= i <= m - * @param my_identity original PeerIdentity - * @param value of i. - * @return finger_identity - */ -struct GNUNET_PeerIdentity * -GNUNET_CRYPTO_compute_finger(struct GNUNET_PeerIdentity *my_identity, unsigned int index) -{ - gcry_mpi_t my_identity_mpi; - gcry_mpi_t finger_identity_mpi; - gcry_mpi_t add; - gcry_mpi_t mod; - gcry_error_t rc; - struct GNUNET_PeerIdentity *finger_identity; - size_t read = 0; - size_t write = 0; - - finger_identity = GNUNET_malloc(sizeof(struct GNUNET_PeerIdentity)); - - /* Initialize my_identity_mpi. */ - my_identity_mpi = gcry_mpi_new(8*sizeof(struct GNUNET_PeerIdentity)); - - /* Copy my_identity into my_id */ - if(0 != (rc = gcry_mpi_scan(&my_identity_mpi, GCRYMPI_FMT_USG, my_identity->public_key.q_y, - sizeof(struct GNUNET_PeerIdentity), &read))) - { - LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_scan", rc); - GNUNET_free(finger_identity); - return NULL; - } - - /* Initialize finger_identity_mpi */ - finger_identity_mpi = gcry_mpi_new(8*sizeof(struct GNUNET_PeerIdentity)); - - /* Initialize add */ - add = gcry_mpi_new(8*sizeof(struct GNUNET_PeerIdentity)); - - /* Set the index bit in add.*/ - gcry_mpi_set_bit(add,index); - - /* Initialize mod */ - mod = gcry_mpi_new(8*sizeof(struct GNUNET_PeerIdentity) + 1); - gcry_mpi_set_bit(mod,257); - gcry_mpi_sub_ui(mod,mod,(unsigned long)1); - - - /* finger_identity_mpi = (my_identity_mpi + add) % mod */ - gcry_mpi_addm(finger_identity_mpi,my_identity_mpi,add,mod); - - - /* Copy finger_identity_mpi to finger_identity */ - if(0 != (rc = gcry_mpi_print(GCRYMPI_FMT_USG,finger_identity->public_key.q_y, - 32,&write,finger_identity_mpi))) - { - LOG_GCRY (GNUNET_ERROR_TYPE_DEBUG, "gcry_mpi_print", rc); - GNUNET_free(finger_identity); - return NULL; - } - - return finger_identity; -} - - /** * Derive a public key from a given public key and a label. * Essentially calculates a public key 'V = H(l,P) * P'. @@ -1544,7 +1120,7 @@ GNUNET_CRYPTO_ecdsa_public_key_derive (const struct GNUNET_CRYPTO_EcdsaPublicKey compressed thus we first store it in the context and then get it back as a (decompresssed) point. */ q_y = gcry_mpi_set_opaque_copy (NULL, pub->q_y, 8*sizeof (pub->q_y)); - GNUNET_assert (q_y); + GNUNET_assert (NULL != q_y); GNUNET_assert (0 == gcry_mpi_ec_set_mpi ("q", q_y, ctx)); gcry_mpi_release (q_y); q = gcry_mpi_ec_get_point ("q", ctx, 0); @@ -1568,10 +1144,321 @@ GNUNET_CRYPTO_ecdsa_public_key_derive (const struct GNUNET_CRYPTO_EcdsaPublicKey gcry_mpi_point_release (v); q_y = gcry_mpi_ec_get_mpi ("q@eddsa", ctx, 0); GNUNET_assert (q_y); - GNUNET_CRYPTO_mpi_print_unsigned (result->q_y, sizeof result->q_y, q_y); + GNUNET_CRYPTO_mpi_print_unsigned (result->q_y, + sizeof (result->q_y), + q_y); gcry_mpi_release (q_y); gcry_ctx_release (ctx); } +/** + * Reverse the sequence of the bytes in @a buffer + * + * @param[in|out] buffer buffer to invert + * @param length number of bytes in @a buffer + */ +static void +reverse_buffer (unsigned char *buffer, + size_t length) +{ + unsigned char tmp; + size_t i; + + for (i=0; i < length/2; i++) + { + tmp = buffer[i]; + buffer[i] = buffer[length-1-i]; + buffer[length-1-i] = tmp; + } +} + + +/** + * Convert the secret @a d of an EdDSA key to the + * value that is actually used in the EdDSA computation. + * + * @param d secret input + * @return value used for the calculation in EdDSA + */ +static gcry_mpi_t +eddsa_d_to_a (gcry_mpi_t d) +{ + unsigned char rawmpi[32]; /* 256-bit value */ + size_t rawmpilen; + unsigned char digest[64]; /* 512-bit hash value */ + gcry_buffer_t hvec[2]; + int b; + gcry_mpi_t a; + + b = 256 / 8; /* number of bytes in `d` */ + + /* Note that we clear DIGEST so we can use it as input to left pad + the key with zeroes for hashing. */ + memset (hvec, 0, sizeof hvec); + rawmpilen = sizeof (rawmpi); + GNUNET_assert (0 == + gcry_mpi_print (GCRYMPI_FMT_USG, + rawmpi, rawmpilen, &rawmpilen, + d)); + hvec[0].data = digest; + hvec[0].off = 0; + hvec[0].len = b > rawmpilen? b - rawmpilen : 0; + hvec[1].data = rawmpi; + hvec[1].off = 0; + hvec[1].len = rawmpilen; + GNUNET_assert (0 == + gcry_md_hash_buffers (GCRY_MD_SHA512, + 0 /* flags */, + digest, + hvec, 2)); + /* Compute the A value. */ + reverse_buffer (digest, 32); /* Only the first half of the hash. */ + digest[0] = (digest[0] & 0x7f) | 0x40; + digest[31] &= 0xf8; + + GNUNET_CRYPTO_mpi_scan_unsigned (&a, + digest, + 32); + return a; +} + + +/** + * @ingroup crypto + * Derive key material from a ECDH public key and a private EdDSA key. + * Dual to #GNUNET_CRRYPTO_ecdh_eddsa. + * + * @param priv private key from EdDSA to use for the ECDH (x) + * @param pub public key to use for the ECDH (yG) + * @param key_material where to write the key material H(h(x)yG) + * @return #GNUNET_SYSERR on error, #GNUNET_OK on success + */ +int +GNUNET_CRYPTO_eddsa_ecdh (const struct GNUNET_CRYPTO_EddsaPrivateKey *priv, + const struct GNUNET_CRYPTO_EcdhePublicKey *pub, + struct GNUNET_HashCode *key_material) +{ + gcry_mpi_point_t result; + gcry_mpi_point_t q; + gcry_mpi_t d; + gcry_mpi_t a; + gcry_ctx_t ctx; + gcry_sexp_t pub_sexpr; + gcry_mpi_t result_x; + unsigned char xbuf[256 / 8]; + size_t rsize; + + /* first, extract the q = dP value from the public key */ + if (0 != gcry_sexp_build (&pub_sexpr, NULL, + "(public-key(ecc(curve " CURVE ")(q %b)))", + (int)sizeof (pub->q_y), pub->q_y)) + return GNUNET_SYSERR; + GNUNET_assert (0 == gcry_mpi_ec_new (&ctx, pub_sexpr, NULL)); + gcry_sexp_release (pub_sexpr); + q = gcry_mpi_ec_get_point ("q", ctx, 0); + + /* second, extract the d value from our private key */ + GNUNET_CRYPTO_mpi_scan_unsigned (&d, priv->d, sizeof (priv->d)); + + /* NOW, because this is EdDSA, HASH 'd' first! */ + a = eddsa_d_to_a (d); + gcry_mpi_release (d); + + /* then call the 'multiply' function, to compute the product */ + result = gcry_mpi_point_new (0); + gcry_mpi_ec_mul (result, a, q, ctx); + gcry_mpi_point_release (q); + gcry_mpi_release (a); + + /* finally, convert point to string for hashing */ + result_x = gcry_mpi_new (256); + if (gcry_mpi_ec_get_affine (result_x, NULL, result, ctx)) + { + LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "get_affine failed", 0); + gcry_mpi_point_release (result); + gcry_ctx_release (ctx); + return GNUNET_SYSERR; + } + gcry_mpi_point_release (result); + gcry_ctx_release (ctx); + + rsize = sizeof (xbuf); + GNUNET_assert (! gcry_mpi_get_flag (result_x, GCRYMPI_FLAG_OPAQUE)); + /* result_x can be negative here, so we do not use 'GNUNET_CRYPTO_mpi_print_unsigned' + as that does not include the sign bit; x should be a 255-bit + value, so with the sign it should fit snugly into the 256-bit + xbuf */ + GNUNET_assert (0 == + gcry_mpi_print (GCRYMPI_FMT_STD, xbuf, rsize, &rsize, + result_x)); + GNUNET_CRYPTO_hash (xbuf, + rsize, + key_material); + gcry_mpi_release (result_x); + return GNUNET_OK; +} + +/** + * @ingroup crypto + * Derive key material from a ECDH public key and a private ECDSA key. + * Dual to #GNUNET_CRRYPTO_ecdh_eddsa. + * + * @param priv private key from ECDSA to use for the ECDH (x) + * @param pub public key to use for the ECDH (yG) + * @param key_material where to write the key material H(h(x)yG) + * @return #GNUNET_SYSERR on error, #GNUNET_OK on success + */ +int +GNUNET_CRYPTO_ecdsa_ecdh (const struct GNUNET_CRYPTO_EcdsaPrivateKey *priv, + const struct GNUNET_CRYPTO_EcdhePublicKey *pub, + struct GNUNET_HashCode *key_material) +{ + gcry_mpi_point_t result; + gcry_mpi_point_t q; + gcry_mpi_t d; + gcry_ctx_t ctx; + gcry_sexp_t pub_sexpr; + gcry_mpi_t result_x; + unsigned char xbuf[256 / 8]; + size_t rsize; + + /* first, extract the q = dP value from the public key */ + if (0 != gcry_sexp_build (&pub_sexpr, NULL, + "(public-key(ecc(curve " CURVE ")(q %b)))", + (int)sizeof (pub->q_y), pub->q_y)) + return GNUNET_SYSERR; + GNUNET_assert (0 == gcry_mpi_ec_new (&ctx, pub_sexpr, NULL)); + gcry_sexp_release (pub_sexpr); + q = gcry_mpi_ec_get_point ("q", ctx, 0); + + /* second, extract the d value from our private key */ + GNUNET_CRYPTO_mpi_scan_unsigned (&d, priv->d, sizeof (priv->d)); + + /* then call the 'multiply' function, to compute the product */ + result = gcry_mpi_point_new (0); + gcry_mpi_ec_mul (result, d, q, ctx); + gcry_mpi_point_release (q); + gcry_mpi_release (d); + + /* finally, convert point to string for hashing */ + result_x = gcry_mpi_new (256); + if (gcry_mpi_ec_get_affine (result_x, NULL, result, ctx)) + { + LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "get_affine failed", 0); + gcry_mpi_point_release (result); + gcry_ctx_release (ctx); + return GNUNET_SYSERR; + } + gcry_mpi_point_release (result); + gcry_ctx_release (ctx); + + rsize = sizeof (xbuf); + GNUNET_assert (! gcry_mpi_get_flag (result_x, GCRYMPI_FLAG_OPAQUE)); + /* result_x can be negative here, so we do not use 'GNUNET_CRYPTO_mpi_print_unsigned' + as that does not include the sign bit; x should be a 255-bit + value, so with the sign it should fit snugly into the 256-bit + xbuf */ + GNUNET_assert (0 == + gcry_mpi_print (GCRYMPI_FMT_STD, xbuf, rsize, &rsize, + result_x)); + GNUNET_CRYPTO_hash (xbuf, + rsize, + key_material); + gcry_mpi_release (result_x); + return GNUNET_OK; +} + + + +/** + * @ingroup crypto + * Derive key material from a EdDSA public key and a private ECDH key. + * Dual to #GNUNET_CRRYPTO_eddsa_ecdh. + * + * @param priv private key to use for the ECDH (y) + * @param pub public key from EdDSA to use for the ECDH (X=h(x)G) + * @param key_material where to write the key material H(yX)=H(h(x)yG) + * @return #GNUNET_SYSERR on error, #GNUNET_OK on success + */ +int +GNUNET_CRYPTO_ecdh_eddsa (const struct GNUNET_CRYPTO_EcdhePrivateKey *priv, + const struct GNUNET_CRYPTO_EddsaPublicKey *pub, + struct GNUNET_HashCode *key_material) +{ + gcry_mpi_point_t result; + gcry_mpi_point_t q; + gcry_mpi_t d; + gcry_ctx_t ctx; + gcry_sexp_t pub_sexpr; + gcry_mpi_t result_x; + unsigned char xbuf[256 / 8]; + size_t rsize; + + /* first, extract the q = dP value from the public key */ + if (0 != gcry_sexp_build (&pub_sexpr, NULL, + "(public-key(ecc(curve " CURVE ")(q %b)))", + (int)sizeof (pub->q_y), pub->q_y)) + return GNUNET_SYSERR; + GNUNET_assert (0 == gcry_mpi_ec_new (&ctx, pub_sexpr, NULL)); + gcry_sexp_release (pub_sexpr); + q = gcry_mpi_ec_get_point ("q", ctx, 0); + + /* second, extract the d value from our private key */ + GNUNET_CRYPTO_mpi_scan_unsigned (&d, priv->d, sizeof (priv->d)); + + /* then call the 'multiply' function, to compute the product */ + result = gcry_mpi_point_new (0); + gcry_mpi_ec_mul (result, d, q, ctx); + gcry_mpi_point_release (q); + gcry_mpi_release (d); + + /* finally, convert point to string for hashing */ + result_x = gcry_mpi_new (256); + if (gcry_mpi_ec_get_affine (result_x, NULL, result, ctx)) + { + LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "get_affine failed", 0); + gcry_mpi_point_release (result); + gcry_ctx_release (ctx); + return GNUNET_SYSERR; + } + gcry_mpi_point_release (result); + gcry_ctx_release (ctx); + + rsize = sizeof (xbuf); + GNUNET_assert (! gcry_mpi_get_flag (result_x, GCRYMPI_FLAG_OPAQUE)); + /* result_x can be negative here, so we do not use 'GNUNET_CRYPTO_mpi_print_unsigned' + as that does not include the sign bit; x should be a 255-bit + value, so with the sign it should fit snugly into the 256-bit + xbuf */ + GNUNET_assert (0 == + gcry_mpi_print (GCRYMPI_FMT_STD, xbuf, rsize, &rsize, + result_x)); + GNUNET_CRYPTO_hash (xbuf, + rsize, + key_material); + gcry_mpi_release (result_x); + return GNUNET_OK; +} + +/** + * @ingroup crypto + * Derive key material from a ECDSA public key and a private ECDH key. + * Dual to #GNUNET_CRRYPTO_eddsa_ecdh. + * + * @param priv private key to use for the ECDH (y) + * @param pub public key from ECDSA to use for the ECDH (X=h(x)G) + * @param key_material where to write the key material H(yX)=H(h(x)yG) + * @return #GNUNET_SYSERR on error, #GNUNET_OK on success + */ +int +GNUNET_CRYPTO_ecdh_ecdsa (const struct GNUNET_CRYPTO_EcdhePrivateKey *priv, + const struct GNUNET_CRYPTO_EcdsaPublicKey *pub, + struct GNUNET_HashCode *key_material) +{ + return GNUNET_CRYPTO_ecdh_eddsa (priv, + (const struct GNUNET_CRYPTO_EddsaPublicKey *)pub, + key_material); +} + /* end of crypto_ecc.c */