New file, implementing RSA ref signature and

verification functions.

Rev: src/nettle/rsa-compat.c:1.1

rsa-compat.c

+/* rsa-compat.c
+ *
+ * The RSA publickey algorithm, RSAREF compatible interface.
+ */
+
+/* nettle, low-level cryptographics library
+ *
+ * Copyright (C) 2001 Niels Mller
+ *  
+ * The nettle library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or (at your
+ * option) any later version.
+ * 
+ * The nettle library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
+ * License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with the nettle library; see the file COPYING.LIB.  If not, write to
+ * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+#include "rsa-compat.h"
+
+#include "md5.h"
+
+int
+R_SignInit(R_SIGNATURE_CTX *ctx,
+           int digestAlgorithm)
+{
+  if (digestAlgorithm != DA_MD5)
+    return RE_DIGEST_ALGORITHM;
+
+  md5_init(&ctx->hash);
+
+  return 0;
+}
+
+int
+R_SignUpdate(R_SIGNATURE_CTX *ctx,
+             const uint8_t *data,
+             /* Length is an unsigned char according to rsaref.txt,
+              * but that must be a typo. */
+             unsigned length)
+{
+  md5_update(&ctx->hash, length, data);
+
+  return RE_SUCCESS;
+}
+
+int
+R_SignFinal(R_SIGNATURE_CTX *ctx,
+            uint8_t *signature,
+            unsigned *length,
+            R_RSA_PRIVATE_KEY *key)
+{
+  struct rsa_private_key k;
+  int res;
+  
+  nettle_mpz_init_set_str_256(k.pub.n,
+                              MAX_RSA_MODULUS_LEN, key->modulus);
+  nettle_mpz_init_set_str_256(k.pub.e,
+                              MAX_RSA_MODULUS_LEN, key->publicExponent);
+  nettle_mpz_init_set_str_256(k.p,
+                              MAX_RSA_MODULUS_LEN, key->prime[0]);
+  nettle_mpz_init_set_str_256(k.q,
+                              MAX_RSA_MODULUS_LEN, key->prime[1]);
+  nettle_mpz_init_set_str_256(k.a,
+                              MAX_RSA_MODULUS_LEN, key->primeExponent[0]);
+  nettle_mpz_init_set_str_256(k.b,
+                              MAX_RSA_MODULUS_LEN, key->primeExponent[1]);
+  nettle_mpz_init_set_str_256(k.c,
+                              MAX_RSA_MODULUS_LEN, key->coefficient);
+
+  if (rsa_init_private_key(&k) && (k.size <= MAX_RSA_MODULUS_LEN))
+    {
+      *length = k->size;
+      rsa_md5_sign(&key, &ctx->hash, signature);
+      res = RE_SUCCESS;
+    }
+  else
+    res = RE_PRIVATE_KEY;
+  
+  mpz_clear(k.pub.n);
+  mpz_clear(k.pub.e);
+  mpz_clear(k.p);
+  mpz_clear(k.q);
+  mpz_clear(k.a);
+  mpz_clear(k.b);
+  mpz_clear(k.c);
+
+  return res;
+}
+
+int
+R_VerifyInit(R_SIGNATURE_CTX *ctx,
+             int digestAlgorithm)
+{
+  return R_SignInit(ctx, digestAlgorithm);
+}
+
+int
+R_VerifyUpdate(R_SIGNATURE_CTX *ctx,
+               const uint8_t *data,
+               /* Length is an unsigned char according to rsaref.txt,
+                * but that must be a typo. */
+               unsigned length)
+{
+  return R_SignUpdate(ctx, data, length);
+}
+
+int
+R_VerifyFinal(R_SIGNATURE_CTX *ctx,
+              uint8_t *signature,
+              unsigned length,
+              R_RSA_PUBLIC_KEY *key)
+{
+  struct rsa_public_key k;
+  int res;
+
+  nettle_mpz_init_set_str_256(k.n,
+                              MAX_RSA_MODULUS_LEN, key->modulus);
+  nettle_mpz_init_set_str_256(k.e,
+                              MAX_RSA_MODULUS_LEN, key->publicExponent);
+
+  if (rsa_init_private_key(&k) && (k.size == length))
+    res = rsa_md5_verify(&k, &ctx->hash, signature)
+      ? RE_SUCCESS : RE_SIGNATURE;
+  else
+    res = RE_PUBLIC_KEY;
+
+  mpz_clear(k.n);
+  mpz_clear(k.e);
+
+  return res;
+}
+