{
gcry_sexp_t result;
gcry_mpi_t d;
- size_t erroff;
int rc;
mpi_scan (&d,
priv->d,
sizeof (priv->d));
- rc = gcry_sexp_build (&result, &erroff,
+ rc = gcry_sexp_build (&result, NULL,
"(private-key(ecdsa(curve \"" CURVE "\")(d %m)))",
d);
gcry_mpi_release (d);
if (0 != rc)
{
- LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_sexp_build", rc); /* erroff gives more info */
+ LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_sexp_build", rc);
GNUNET_assert (0);
}
#if EXTRA_CHECKS
{
gcry_mpi_t q_x;
gcry_mpi_t q_y;
-
+
q_x = gcry_mpi_new (256);
q_y = gcry_mpi_new (256);
if (gcry_mpi_ec_get_affine (q_x, q_y, q, ctx))
LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "get_affine failed", 0);
return;
}
+
mpi_print (pub->q_x, sizeof (pub->q_x), q_x);
mpi_print (pub->q_y, sizeof (pub->q_y), q_y);
gcry_mpi_release (q_x);
gcry_sexp_t sexp;
gcry_ctx_t ctx;
gcry_mpi_point_t q;
- int rc;
sexp = decode_private_key (priv);
GNUNET_assert (NULL != sexp);
- if (0 != (rc = gcry_mpi_ec_new (&ctx, sexp, NULL)))
- {
- LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_ec_new", rc); /* erroff gives more info */
- return;
- }
+ GNUNET_assert (0 == gcry_mpi_ec_new (&ctx, sexp, NULL));
gcry_sexp_release (sexp);
q = gcry_mpi_ec_get_point ("q", ctx, 0);
point_to_public_key (q, ctx, pub);
gcry_mpi_t q_y;
gcry_mpi_point_t q;
gcry_ctx_t ctx;
- int rc;
mpi_scan (&q_x, pub->q_x, sizeof (pub->q_x));
mpi_scan (&q_y, pub->q_y, sizeof (pub->q_y));
gcry_mpi_release (q_x);
gcry_mpi_release (q_y);
- /* create basic ECC context */
- if (0 != (rc = gcry_mpi_ec_new (&ctx, NULL, CURVE)))
- {
- LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_ec_new", rc); /* erroff gives more info */
- gcry_mpi_point_release (q);
- return NULL;
- }
/* initialize 'ctx' with 'q' */
+ GNUNET_assert (0 == gcry_mpi_ec_new (&ctx, NULL, CURVE));
gcry_mpi_ec_set_point ("q", q, ctx);
gcry_mpi_point_release (q);
/* convert 'ctx' to 'sexp' */
- if (0 != (rc = gcry_pubkey_get_sexp (&pub_sexp, GCRY_PK_GET_PUBKEY, ctx)))
- {
- LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_sexp_from_context", rc);
- gcry_ctx_release (ctx);
- return NULL;
- }
+ GNUNET_assert (0 == gcry_pubkey_get_sexp (&pub_sexp, GCRY_PK_GET_PUBKEY, ctx));
gcry_ctx_release (ctx);
return pub_sexp;
}
return NULL;
}
gcry_sexp_release (priv_sexp);
- priv = GNUNET_malloc (sizeof (struct GNUNET_CRYPTO_EccPrivateKey));
+ priv = GNUNET_new (struct GNUNET_CRYPTO_EccPrivateKey);
mpi_print (priv->d, sizeof (priv->d), d);
gcry_mpi_release (d);
return priv;
}
+/**
+ * Get the shared private key we use for anonymous users.
+ *
+ * @return "anonymous" private key
+ */
+const struct GNUNET_CRYPTO_EccPrivateKey *
+GNUNET_CRYPTO_ecc_key_get_anonymous ()
+{
+ /**
+ * 'anonymous' pseudonym (global static, d=1, public key = G
+ * (generator).
+ */
+ static struct GNUNET_CRYPTO_EccPrivateKey anonymous;
+ static int once;
+
+ if (once)
+ return &anonymous;
+ mpi_print (anonymous.d,
+ sizeof (anonymous.d),
+ GCRYMPI_CONST_ONE);
+ once = 1;
+ return &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.).
GNUNET_DISK_PERM_USER_WRITE);
if (NULL == fd)
{
- if (errno == EEXIST)
+ if (EEXIST == errno)
{
if (GNUNET_YES != GNUNET_DISK_file_test (filename))
{
return NULL;
}
cnt = 0;
-
while (GNUNET_YES !=
GNUNET_DISK_file_lock (fd, 0,
sizeof (struct GNUNET_CRYPTO_EccPrivateKey),
gcry_sexp_t data;
gcry_sexp_t sig_sexpr;
gcry_sexp_t pub_sexpr;
- size_t erroff;
int rc;
gcry_mpi_t r;
gcry_mpi_t s;
/* build s-expression for signature */
mpi_scan (&r, sig->r, sizeof (sig->r));
mpi_scan (&s, sig->s, sizeof (sig->s));
- if (0 != (rc = gcry_sexp_build (&sig_sexpr, &erroff, "(sig-val(ecdsa(r %m)(s %m)))",
+ if (0 != (rc = gcry_sexp_build (&sig_sexpr, NULL,
+ "(sig-val(ecdsa(r %m)(s %m)))",
r, s)))
{
LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_sexp_build", rc);
gcry_sexp_release (sig_sexpr);
if (0 != rc)
{
- LOG (GNUNET_ERROR_TYPE_WARNING,
+ LOG (GNUNET_ERROR_TYPE_INFO,
_("ECC signature verification failed at %s:%d: %s\n"), __FILE__,
__LINE__, gcry_strerror (rc));
return GNUNET_SYSERR;
struct GNUNET_HashCode *key_material)
{
size_t slen;
- size_t erroff;
- int rc;
- unsigned char sdata_buf[2048]; /* big enough to print dh-shared-secret as S-expression */
+ 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_sexp_t ecdh_sexp;
gcry_mpi_t result_x;
gcry_mpi_t result_y;
+ int rc;
/* first, extract the q = dP value from the public key */
if (! (pub_sexpr = decode_public_key (pub)))
return GNUNET_SYSERR;
- if (0 != (rc = gcry_mpi_ec_new (&ctx, pub_sexpr, NULL)))
- {
- LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_ec_new", rc); /* erroff gives more info */
- 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);
- gcry_ctx_release (ctx);
/* second, extract the d value from our private key */
mpi_scan (&d, priv->d, sizeof (priv->d));
- /* 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, CURVE)))
- {
- 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;
- }
-
/* 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_point_release (result);
gcry_ctx_release (ctx);
- if (0 != (rc = gcry_sexp_build (&ecdh_sexp, &erroff,
+ if (0 != (rc = gcry_sexp_build (&ecdh_sexp, NULL,
"(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 */
+ LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_sexp_build", rc);
gcry_mpi_release (result_x);
gcry_mpi_release (result_y);
return GNUNET_SYSERR;
*
* @param pub public key for deriviation
* @param label label for deriviation
+ * @param context additional context to use for HKDF of 'h';
+ * typically the name of the subsystem/application
* @return h value
*/
static gcry_mpi_t
derive_h (const struct GNUNET_CRYPTO_EccPublicKey *pub,
- const char *label)
+ const char *label,
+ const char *context)
{
gcry_mpi_t h;
struct GNUNET_HashCode hc;
GNUNET_CRYPTO_kdf (&hc, sizeof (hc),
"key-derivation", strlen ("key-derivation"),
pub, sizeof (*pub),
- label, sizeof (label),
+ label, strlen (label),
+ context, strlen (context),
NULL, 0);
mpi_scan (&h, (unsigned char *) &hc, sizeof (hc));
return h;
*
* @param priv original private key
* @param label label to use for key deriviation
+ * @param context additional context to use for HKDF of 'h';
+ * typically the name of the subsystem/application
* @return derived private key
*/
struct GNUNET_CRYPTO_EccPrivateKey *
GNUNET_CRYPTO_ecc_key_derive (const struct GNUNET_CRYPTO_EccPrivateKey *priv,
- const char *label)
+ const char *label,
+ const char *context)
{
struct GNUNET_CRYPTO_EccPublicKey pub;
struct GNUNET_CRYPTO_EccPrivateKey *ret;
gcry_mpi_t x;
gcry_mpi_t d;
gcry_mpi_t n;
- int rc;
+ gcry_ctx_t ctx;
+ GNUNET_assert (0 == gcry_mpi_ec_new (&ctx, NULL, CURVE));
+ n = gcry_mpi_ec_get_mpi ("n", ctx, 1);
GNUNET_CRYPTO_ecc_key_get_public (priv, &pub);
- h = derive_h (&pub, label);
+ h = derive_h (&pub, label, context);
mpi_scan (&x, priv->d, sizeof (priv->d));
- /* initialize 'n' from P-256; hex copied from libgcrypt code */
- if (0 != (rc = gcry_mpi_scan (&n, GCRYMPI_FMT_HEX,
- "0xffffffff00000000ffffffffffffffffbce6faada7179e84f3b9cac2fc632551", 0, NULL)))
- {
- LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_scan", rc);
- gcry_mpi_release (h);
- return NULL;
- }
d = gcry_mpi_new (256);
gcry_mpi_mulm (d, h, x, n);
gcry_mpi_release (h);
gcry_mpi_release (x);
gcry_mpi_release (n);
+ gcry_ctx_release (ctx);
ret = GNUNET_new (struct GNUNET_CRYPTO_EccPrivateKey);
mpi_print (ret->d, sizeof (ret->d), d);
gcry_mpi_release (d);
*
* @param pub original public key
* @param label label to use for key deriviation
+ * @param context additional context to use for HKDF of 'h';
+ * typically the name of the subsystem/application
* @param result where to write the derived public key
*/
void
GNUNET_CRYPTO_ecc_public_key_derive (const struct GNUNET_CRYPTO_EccPublicKey *pub,
const char *label,
+ const char *context,
struct GNUNET_CRYPTO_EccPublicKey *result)
{
- gcry_mpi_t h;
gcry_ctx_t ctx;
+ gcry_mpi_t h;
+ gcry_mpi_t n;
+ gcry_mpi_t h_mod_n;
gcry_mpi_t q_x;
gcry_mpi_t q_y;
gcry_mpi_point_t q;
gcry_mpi_point_t v;
- int rc;
- h = derive_h (pub, label);
+ GNUNET_assert (0 == gcry_mpi_ec_new (&ctx, NULL, CURVE));
+
+ /* obtain point 'q' from original public key */
mpi_scan (&q_x, pub->q_x, sizeof (pub->q_x));
mpi_scan (&q_y, pub->q_y, sizeof (pub->q_y));
- q = gcry_mpi_point_new (256);
+
+ q = gcry_mpi_point_new (0);
gcry_mpi_point_set (q, q_x, q_y, GCRYMPI_CONST_ONE);
gcry_mpi_release (q_x);
gcry_mpi_release (q_y);
- /* create basic ECC context */
- if (0 != (rc = gcry_mpi_ec_new (&ctx, NULL, CURVE)))
- {
- LOG_GCRY (GNUNET_ERROR_TYPE_ERROR, "gcry_mpi_ec_new", rc);
- gcry_mpi_point_release (q);
- gcry_mpi_release (h);
- return;
- }
- v = gcry_mpi_point_new (256);
- /* we could calculate 'h mod n' here first, but hopefully
- libgcrypt is smart enough to do that for us... */
- gcry_mpi_ec_mul (v, h, q, ctx);
+ /* calulcate h_mod_n = h % n */
+ h = derive_h (pub, label, context);
+ n = gcry_mpi_ec_get_mpi ("n", ctx, 1);
+ h_mod_n = gcry_mpi_new (256);
+ gcry_mpi_mod (h_mod_n, h, n);
+ /* calculate v = h_mod_n * q */
+ v = gcry_mpi_point_new (0);
+ gcry_mpi_ec_mul (v, h_mod_n, q, ctx);
+ gcry_mpi_release (h_mod_n);
gcry_mpi_release (h);
+ gcry_mpi_release (n);
gcry_mpi_point_release (q);
+ /* convert point 'v' to public key that we return */
point_to_public_key (v, ctx, result);
gcry_mpi_point_release (v);
gcry_ctx_release (ctx);
projects / oweals / gnunet.git / blobdiff