/*
This file is part of GNUnet.
- (C) 2001, 2002, 2003, 2004, 2005, 2006, 2009, 2012 Christian Grothoff (and other contributing authors)
+ (C) 2012, 2013 Christian Grothoff (and other contributing authors)
GNUnet is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published
#define EXTRA_CHECKS ALLOW_EXTRA_CHECKS
-#define CURVE "NIST P-521"
+#define CURVE "NIST P-256"
#define LOG(kind,...) GNUNET_log_from (kind, "util", __VA_ARGS__)
return GNUNET_SYSERR;
if (GNUNET_OK != GNUNET_STRINGS_string_to_data (enc, enclen,
- (unsigned char*) pub,
- sizeof (struct GNUNET_CRYPTO_EccPublicKeyBinaryEncoded)))
+ pub,
+ sizeof (struct GNUNET_CRYPTO_EccPublicKeyBinaryEncoded)))
return GNUNET_SYSERR;
if ( (ntohs (pub->size) != sizeof (struct GNUNET_CRYPTO_EccPublicKeyBinaryEncoded)) ||
(ntohs (pub->len) > GNUNET_CRYPTO_ECC_SIGNATURE_DATA_ENCODING_LENGTH) )
LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_sexp_build", rc); /* erroff gives more info */
return NULL;
}
- // FIXME: is this key expected to pass pk_testkey?
-#if 0
-#if EXTRA_CHECKS
+#if EXTRA_CHECKS
if (0 != (rc = gcry_pk_testkey (result)))
{
LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_pk_testkey", rc);
gcry_sexp_release (result);
return NULL;
}
-#endif
#endif
return result;
}
}
-/**
- * Try to read the private key from the given file.
- *
- * @param filename file to read the key from
- * @return NULL on error
- */
-static struct GNUNET_CRYPTO_EccPrivateKey *
-try_read_key (const char *filename)
-{
- struct GNUNET_CRYPTO_EccPrivateKey *ret;
- struct GNUNET_DISK_FileHandle *fd;
- OFF_T fs;
-
- if (GNUNET_YES != GNUNET_DISK_file_test (filename))
- return NULL;
-
- /* key file exists already, read it! */
- if (NULL == (fd = GNUNET_DISK_file_open (filename, GNUNET_DISK_OPEN_READ,
- GNUNET_DISK_PERM_NONE)))
- {
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_ERROR, "open", filename);
- return NULL;
- }
- if (GNUNET_OK != (GNUNET_DISK_file_handle_size (fd, &fs)))
- {
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_ERROR, "stat", filename);
- (void) GNUNET_DISK_file_close (fd);
- return NULL;
- }
- if (0 == fs)
- {
- GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fd));
- return NULL;
- }
- if (fs > UINT16_MAX)
- {
- LOG (GNUNET_ERROR_TYPE_ERROR,
- _("File `%s' does not contain a valid private key (too long, %llu bytes). Deleting it.\n"),
- filename,
- (unsigned long long) fs);
- GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fd));
- if (0 != UNLINK (filename))
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "unlink", filename);
- return NULL;
- }
- {
- char enc[fs];
-
- GNUNET_break (fs == GNUNET_DISK_file_read (fd, enc, fs));
- if (NULL == (ret = GNUNET_CRYPTO_ecc_decode_key ((char *) enc, fs, GNUNET_YES)))
- {
- LOG (GNUNET_ERROR_TYPE_ERROR,
- _("File `%s' does not contain a valid private key (failed decode, %llu bytes). Deleting it.\n"),
- filename,
- (unsigned long long) fs);
- GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fd));
- if (0 != UNLINK (filename))
- LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "unlink", filename);
- return NULL;
- }
- }
- GNUNET_break (GNUNET_OK == GNUNET_DISK_file_close (fd));
- return ret;
-}
-
-
/**
* 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.).
/**
- * Handle to cancel private key generation and state for the
- * key generation operation.
- */
-struct GNUNET_CRYPTO_EccKeyGenerationContext
-{
-
- /**
- * Continuation to call upon completion.
- */
- GNUNET_CRYPTO_EccKeyCallback cont;
-
- /**
- * Closure for 'cont'.
- */
- void *cont_cls;
-
- /**
- * Name of the file.
- */
- char *filename;
-
- /**
- * Handle to the helper process which does the key generation.
- */
- struct GNUNET_OS_Process *gnunet_ecc;
-
- /**
- * Handle to 'stdout' of gnunet-ecc. We 'read' on stdout to detect
- * process termination (instead of messing with SIGCHLD).
- */
- struct GNUNET_DISK_PipeHandle *gnunet_ecc_out;
-
- /**
- * Location where we store the private key if it already existed.
- * (if this is used, 'filename', 'gnunet_ecc' and 'gnunet_ecc_out' will
- * not be used).
- */
- struct GNUNET_CRYPTO_EccPrivateKey *pk;
-
- /**
- * Task reading from 'gnunet_ecc_out' to wait for process termination.
- */
- GNUNET_SCHEDULER_TaskIdentifier read_task;
-
-};
-
-
-/**
- * Abort ECC key generation.
+ * Create a new private key by reading our peer's key from
+ * the file specified in the configuration.
*
- * @param gc key generation context to abort
- */
-void
-GNUNET_CRYPTO_ecc_key_create_stop (struct GNUNET_CRYPTO_EccKeyGenerationContext *gc)
-{
- if (GNUNET_SCHEDULER_NO_TASK != gc->read_task)
- {
- GNUNET_SCHEDULER_cancel (gc->read_task);
- gc->read_task = GNUNET_SCHEDULER_NO_TASK;
- }
- if (NULL != gc->gnunet_ecc)
- {
- (void) GNUNET_OS_process_kill (gc->gnunet_ecc, SIGKILL);
- GNUNET_break (GNUNET_OK ==
- GNUNET_OS_process_wait (gc->gnunet_ecc));
- GNUNET_OS_process_destroy (gc->gnunet_ecc);
- GNUNET_DISK_pipe_close (gc->gnunet_ecc_out);
- }
-
- if (NULL != gc->filename)
- {
- if (0 != UNLINK (gc->filename))
- GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING, "unlink", gc->filename);
- GNUNET_free (gc->filename);
- }
- if (NULL != gc->pk)
- GNUNET_CRYPTO_ecc_key_free (gc->pk);
- GNUNET_free (gc);
-}
-
-
-/**
- * Task called upon shutdown or process termination of 'gnunet-ecc' during
- * ECC key generation. Check where we are and perform the appropriate
- * action.
- *
- * @param cls the 'struct GNUNET_CRYPTO_EccKeyGenerationContext'
- * @param tc scheduler context
- */
-static void
-check_key_generation_completion (void *cls,
- const struct GNUNET_SCHEDULER_TaskContext *tc)
-{
- struct GNUNET_CRYPTO_EccKeyGenerationContext *gc = cls;
- struct GNUNET_CRYPTO_EccPrivateKey *pk;
-
- gc->read_task = GNUNET_SCHEDULER_NO_TASK;
- if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
- {
- gc->cont (gc->cont_cls, NULL, _("interrupted by shutdown"));
- GNUNET_CRYPTO_ecc_key_create_stop (gc);
- return;
- }
- GNUNET_assert (GNUNET_OK ==
- GNUNET_OS_process_wait (gc->gnunet_ecc));
- GNUNET_OS_process_destroy (gc->gnunet_ecc);
- gc->gnunet_ecc = NULL;
- if (NULL == (pk = try_read_key (gc->filename)))
- {
- GNUNET_break (0);
- gc->cont (gc->cont_cls, NULL, _("gnunet-ecc failed"));
- GNUNET_CRYPTO_ecc_key_create_stop (gc);
- return;
- }
- gc->cont (gc->cont_cls, pk, NULL);
- GNUNET_DISK_pipe_close (gc->gnunet_ecc_out);
- GNUNET_free (gc->filename);
- GNUNET_free (gc);
-}
-
-
-/**
- * Return the private ECC key which already existed on disk
- * (asynchronously) to the caller.
- *
- * @param cls the 'struct GNUNET_CRYPTO_EccKeyGenerationContext'
- * @param tc scheduler context (unused)
- */
-static void
-async_return_key (void *cls,
- const struct GNUNET_SCHEDULER_TaskContext *tc)
-{
- struct GNUNET_CRYPTO_EccKeyGenerationContext *gc = cls;
-
- gc->cont (gc->cont_cls,
- gc->pk,
- NULL);
- GNUNET_free (gc);
-}
-
-
-/**
- * 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. 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 for storage
- * @param cont function to call when done (or on errors)
- * @param cont_cls closure for 'cont'
- * @return handle to abort operation, NULL on fatal errors (cont will not be called if NULL is returned)
+ * @return new private key, NULL on error (for example,
+ * permission denied)
*/
-struct GNUNET_CRYPTO_EccKeyGenerationContext *
-GNUNET_CRYPTO_ecc_key_create_start (const char *filename,
- GNUNET_CRYPTO_EccKeyCallback cont,
- void *cont_cls)
+struct GNUNET_CRYPTO_EccPrivateKey *
+GNUNET_CRYPTO_ecc_key_create_from_configuration (const struct GNUNET_CONFIGURATION_Handle *cfg)
{
- struct GNUNET_CRYPTO_EccKeyGenerationContext *gc;
struct GNUNET_CRYPTO_EccPrivateKey *pk;
+ char *fn;
- if (NULL != (pk = try_read_key (filename)))
- {
- /* quick happy ending: key already exists! */
- gc = GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_EccKeyGenerationContext));
- gc->pk = pk;
- gc->cont = cont;
- gc->cont_cls = cont_cls;
- gc->read_task = GNUNET_SCHEDULER_add_now (&async_return_key,
- gc);
- return gc;
- }
- gc = GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_EccKeyGenerationContext));
- gc->filename = GNUNET_strdup (filename);
- gc->cont = cont;
- gc->cont_cls = cont_cls;
- gc->gnunet_ecc_out = GNUNET_DISK_pipe (GNUNET_NO,
- GNUNET_NO,
- GNUNET_NO,
- GNUNET_YES);
- if (NULL == gc->gnunet_ecc_out)
- {
- GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "pipe");
- GNUNET_free (gc->filename);
- GNUNET_free (gc);
- return NULL;
- }
- gc->gnunet_ecc = GNUNET_OS_start_process (GNUNET_NO,
- GNUNET_OS_INHERIT_STD_ERR,
- NULL,
- gc->gnunet_ecc_out,
- "gnunet-ecc",
- "gnunet-ecc",
- gc->filename,
- NULL);
- if (NULL == gc->gnunet_ecc)
- {
- GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "fork");
- GNUNET_DISK_pipe_close (gc->gnunet_ecc_out);
- GNUNET_free (gc->filename);
- GNUNET_free (gc);
+ if (GNUNET_OK !=
+ GNUNET_CONFIGURATION_get_value_filename (cfg, "PEER", "PRIVATE_KEY", &fn))
return NULL;
- }
- GNUNET_assert (GNUNET_OK ==
- GNUNET_DISK_pipe_close_end (gc->gnunet_ecc_out,
- GNUNET_DISK_PIPE_END_WRITE));
- gc->read_task = GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
- GNUNET_DISK_pipe_handle (gc->gnunet_ecc_out,
- GNUNET_DISK_PIPE_END_READ),
- &check_key_generation_completion,
- gc);
- return gc;
+ pk = GNUNET_CRYPTO_ecc_key_create_from_file (fn);
+ GNUNET_free (fn);
+ return pk;
}
{
struct GNUNET_CONFIGURATION_Handle *cfg;
struct GNUNET_CRYPTO_EccPrivateKey *pk;
- char *fn;
cfg = GNUNET_CONFIGURATION_create ();
(void) GNUNET_CONFIGURATION_load (cfg, cfg_name);
- if (GNUNET_OK ==
- GNUNET_CONFIGURATION_get_value_filename (cfg, "PEER", "PRIVATE_KEY", &fn))
+ pk = GNUNET_CRYPTO_ecc_key_create_from_configuration (cfg);
+ if (NULL != pk)
+ GNUNET_CRYPTO_ecc_key_free (pk);
+ 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_host_identity (const struct GNUNET_CONFIGURATION_Handle *cfg,
+ struct GNUNET_PeerIdentity *dst)
+{
+ struct GNUNET_CRYPTO_EccPrivateKey *my_private_key;
+ struct GNUNET_CRYPTO_EccPublicKeyBinaryEncoded my_public_key;
+
+ if (NULL == (my_private_key = GNUNET_CRYPTO_ecc_key_create_from_configuration (cfg)))
{
- pk = GNUNET_CRYPTO_ecc_key_create_from_file (fn);
- if (NULL != pk)
- GNUNET_CRYPTO_ecc_key_free (pk);
- GNUNET_free (fn);
+ GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+ _("Could not load peer's private key\n"));
+ return GNUNET_SYSERR;
}
- GNUNET_CONFIGURATION_destroy (cfg);
+ GNUNET_CRYPTO_ecc_key_get_public (my_private_key, &my_public_key);
+ GNUNET_CRYPTO_ecc_key_free (my_private_key);
+ GNUNET_CRYPTO_hash (&my_public_key, sizeof (my_public_key), &dst->hashPubKey);
+ return GNUNET_OK;
}
LOG (GNUNET_ERROR_TYPE_WARNING,
_("ECC signing failed at %s:%d: %s\n"), __FILE__,
__LINE__, gcry_strerror (rc));
+ gcry_sexp_release (data);
+ return GNUNET_SYSERR;
}
gcry_sexp_release (data);
ssize = gcry_sexp_sprint (result,
const struct GNUNET_CRYPTO_EccPublicKeyBinaryEncoded *pub,
struct GNUNET_HashCode *key_material)
{
- size_t size;
size_t slen;
+ size_t erroff;
int rc;
- gcry_sexp_t data;
- unsigned char sdata_buf[2048]; /* big enough to print 'sdata' and 'r_sig' */
+ unsigned char sdata_buf[2048]; /* big enough to print dh-shared-secret as S-expression */
+ gcry_mpi_point_t result;
+ gcry_mpi_point_t q;
+ gcry_mpi_t d;
+ gcry_ctx_t ctx;
+ gcry_sexp_t psexp;
+ gcry_mpi_t result_x;
+ gcry_mpi_t result_y;
- /* first, extract the q value from the public key */
+ /* first, extract the q = dP value from the public key */
+ if (! (psexp = decode_public_key (pub)))
+ return GNUNET_SYSERR;
+ if (0 != (rc = gcry_mpi_ec_new (&ctx, psexp, NULL)))
{
- gcry_sexp_t psexp;
- gcry_mpi_t sdata;
-
- if (! (psexp = decode_public_key (pub)))
- return GNUNET_SYSERR;
- rc = key_from_sexp (&sdata, psexp, "public-key", "q");
- if (rc)
- rc = key_from_sexp (&sdata, psexp, "ecc", "q");
- GNUNET_assert (0 == rc);
- gcry_sexp_release (psexp);
- size = sizeof (sdata_buf);
- GNUNET_assert (0 ==
- gcry_mpi_print (GCRYMPI_FMT_USG, sdata_buf, size, &size,
- sdata));
- gcry_mpi_release (sdata);
+ LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_ec_new", rc); /* erroff gives more info */
+ return GNUNET_SYSERR;
}
- /* convert q value into an S-expression -- whatever format libgcrypt wants,
- re-using format from sign operation for now... */
+ gcry_sexp_release (psexp);
+ q = gcry_mpi_ec_get_point ("q", ctx, 0);
+ gcry_ctx_release (ctx);
+
+ /* second, extract the d value from our private key */
+ rc = key_from_sexp (&d, key->sexp, "private-key", "d");
+ if (rc)
+ rc = key_from_sexp (&d, key->sexp, "ecc", "d");
+ if (0 != rc)
{
- char *sexp_string;
-
-#define FORMATPREFIX "(4:data(5:flags3:raw)(5:value%u:"
-#define FORMATPOSTFIX "))"
- sexp_string = GNUNET_malloc (strlen (FORMATPREFIX) + size + 12 +
- strlen (FORMATPOSTFIX) + 1);
- GNUNET_snprintf (sexp_string,
- strlen (FORMATPREFIX) + 12,
- FORMATPREFIX,
- size);
- slen = strlen (sexp_string);
- memcpy (&sexp_string[slen],
- sdata_buf,
- size);
- memcpy (&sexp_string[slen + size],
- FORMATPOSTFIX,
- strlen (FORMATPOSTFIX) + 1);
- GNUNET_assert (0 == gcry_sexp_new (&data,
- sexp_string,
- slen + size + strlen (FORMATPOSTFIX),
- 0));
- GNUNET_free (sexp_string);
+ GNUNET_break (0);
+ gcry_mpi_point_release (q);
+ return GNUNET_SYSERR;
}
- /* then call the 'multiply' function, hoping it simply multiplies the points;
- here we need essentially a WRAPPER around _gcry_mpi_ex_mul_point! - FIXME-WK!*/
-#if WK
+
+ /* create a new context for definitively the correct curve;
+ theoretically the 'public_key' might not use the right curve */
+ if (0 != (rc = gcry_mpi_ec_new (&ctx, NULL, "NIST P-256")))
{
- gcry_sexp_t result;
-
- rc = gcry_ecc_mul_point (&result, data /* scalar */, key->sexp /* point and ctx */);
- GNUNET_assert (0 == rc);
- slen = gcry_sexp_sprint (result, GCRYSEXP_FMT_DEFAULT, sdata_buf, sizeof (sdata_buf));
- GNUNET_assert (0 != slen);
+ LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_ec_new", rc); /* erroff gives more info */
+ gcry_mpi_release (d);
+ gcry_mpi_point_release (q);
+ return GNUNET_SYSERR;
}
-#else
- /* use broken version, insecure! */
- GNUNET_log (GNUNET_ERROR_TYPE_WARNING, _("To be implemented: not secure at the moment, please read README\n"));
- slen = sprintf ((char*) sdata_buf, "FIXME-this is not key material");
-#endif
- gcry_sexp_release (data);
+ /* then call the 'multiply' function, to compute the product */
+ GNUNET_assert (NULL != ctx);
+ 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);
+ result_y = gcry_mpi_new (256);
+ if (gcry_mpi_ec_get_affine (result_x, result_y, 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);
+ if (0 != (rc = gcry_sexp_build (&psexp, &erroff,
+ "(dh-shared-secret (x %m)(y %m))",
+ result_x,
+ result_y)))
+ {
+ LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_sexp_build", rc); /* erroff gives more info */
+ gcry_mpi_release (result_x);
+ gcry_mpi_release (result_y);
+ return GNUNET_SYSERR;
+ }
+ gcry_mpi_release (result_x);
+ gcry_mpi_release (result_y);
+ slen = gcry_sexp_sprint (psexp, GCRYSEXP_FMT_DEFAULT, sdata_buf, sizeof (sdata_buf));
+ GNUNET_assert (0 != slen);
+ gcry_sexp_release (psexp);
/* finally, get a string of the resulting S-expression and hash it to generate the key material */
GNUNET_CRYPTO_hash (sdata_buf, slen, key_material);
return GNUNET_OK;