/*
This file is part of GNUnet.
- Copyright (C) 2012, 2013, 2015 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
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.
*/
/**
*/
#include "platform.h"
#include <gcrypt.h>
-#include "gnunet_util_lib.h"
+#include "gnunet_crypto_lib.h"
+#include "gnunet_strings_lib.h"
#define EXTRA_CHECKS 0
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);
/* 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);
{
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),
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
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 */
projects / oweals / gnunet.git / blobdiff