X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=libtomcrypt%2Fsrc%2Fpk%2Fecc%2Fecc_make_key.c;fp=libtomcrypt%2Fsrc%2Fpk%2Fecc%2Fecc_make_key.c;h=113a9944298b305f48bc4ee1849bb03024d88410;hb=66bc25938679f1d6a1d1200f329093d82a5e99b4;hp=0000000000000000000000000000000000000000;hpb=a52ee0733f420ca20224049260d6fc5cf7d8f621;p=zpackage

diff --git a/libtomcrypt/src/pk/ecc/ecc_make_key.c b/libtomcrypt/src/pk/ecc/ecc_make_key.c
new file mode 100644
index 0000000..113a994
--- /dev/null
+++ b/libtomcrypt/src/pk/ecc/ecc_make_key.c
@@ -0,0 +1,128 @@
+/* LibTomCrypt, modular cryptographic library -- Tom St Denis
+ *
+ * LibTomCrypt is a library that provides various cryptographic
+ * algorithms in a highly modular and flexible manner.
+ *
+ * The library is free for all purposes without any express
+ * guarantee it works.
+ */
+
+/* Implements ECC over Z/pZ for curve y^2 = x^3 - 3x + b
+ *
+ * All curves taken from NIST recommendation paper of July 1999
+ * Available at http://csrc.nist.gov/cryptval/dss.htm
+ */
+#include "tomcrypt.h"
+
+/**
+  @file ecc_make_key.c
+  ECC Crypto, Tom St Denis
+*/
+
+#ifdef LTC_MECC
+
+/**
+  Make a new ECC key
+  @param prng         An active PRNG state
+  @param wprng        The index of the PRNG you wish to use
+  @param keysize      The keysize for the new key (in octets from 20 to 65 bytes)
+  @param key          [out] Destination of the newly created key
+  @return CRYPT_OK if successful, upon error all allocated memory will be freed
+*/
+int ecc_make_key(prng_state *prng, int wprng, int keysize, ecc_key *key)
+{
+   int x, err;
+
+   /* find key size */
+   for (x = 0; (keysize > ltc_ecc_sets[x].size) && (ltc_ecc_sets[x].size != 0); x++);
+   keysize = ltc_ecc_sets[x].size;
+
+   if (keysize > ECC_MAXSIZE || ltc_ecc_sets[x].size == 0) {
+      return CRYPT_INVALID_KEYSIZE;
+   }
+   err = ecc_make_key_ex(prng, wprng, key, &ltc_ecc_sets[x]);
+   key->idx = x;
+   return err;
+}
+
+int ecc_make_key_ex(prng_state *prng, int wprng, ecc_key *key, const ltc_ecc_set_type *dp)
+{
+   int            err;
+   ecc_point     *base;
+   void          *prime, *order;
+   unsigned char *buf;
+   int            keysize;
+
+   LTC_ARGCHK(key         != NULL);
+   LTC_ARGCHK(ltc_mp.name != NULL);
+   LTC_ARGCHK(dp          != NULL);
+
+   /* good prng? */
+   if ((err = prng_is_valid(wprng)) != CRYPT_OK) {
+      return err;
+   }
+
+   key->idx = -1;
+   key->dp  = dp;
+   keysize  = dp->size;
+
+   /* allocate ram */
+   base = NULL;
+   buf  = XMALLOC(ECC_MAXSIZE);
+   if (buf == NULL) {
+      return CRYPT_MEM;
+   }
+
+   /* make up random string */
+   if (prng_descriptor[wprng].read(buf, (unsigned long)keysize, prng) != (unsigned long)keysize) {
+      err = CRYPT_ERROR_READPRNG;
+      goto ERR_BUF;
+   }
+
+   /* setup the key variables */
+   if ((err = mp_init_multi(&key->pubkey.x, &key->pubkey.y, &key->pubkey.z, &key->k, &prime, &order, NULL)) != CRYPT_OK) {
+      goto ERR_BUF;
+   }
+   base = ltc_ecc_new_point();
+   if (base == NULL) {
+      err = CRYPT_MEM;
+      goto errkey;
+   }
+
+   /* read in the specs for this key */
+   if ((err = mp_read_radix(prime,   (char *)key->dp->prime, 16)) != CRYPT_OK)                  { goto errkey; }
+   if ((err = mp_read_radix(order,   (char *)key->dp->order, 16)) != CRYPT_OK)                  { goto errkey; }
+   if ((err = mp_read_radix(base->x, (char *)key->dp->Gx, 16)) != CRYPT_OK)                     { goto errkey; }
+   if ((err = mp_read_radix(base->y, (char *)key->dp->Gy, 16)) != CRYPT_OK)                     { goto errkey; }
+   if ((err = mp_set(base->z, 1)) != CRYPT_OK)                                                  { goto errkey; }
+   if ((err = mp_read_unsigned_bin(key->k, (unsigned char *)buf, keysize)) != CRYPT_OK)         { goto errkey; }
+
+   /* the key should be smaller than the order of base point */
+   if (mp_cmp(key->k, order) != LTC_MP_LT) {
+       if((err = mp_mod(key->k, order, key->k)) != CRYPT_OK)                                    { goto errkey; }
+   }
+   /* make the public key */
+   if ((err = ltc_mp.ecc_ptmul(key->k, base, &key->pubkey, prime, 1)) != CRYPT_OK)              { goto errkey; }
+   key->type = PK_PRIVATE;
+
+   /* free up ram */
+   err = CRYPT_OK;
+   goto cleanup;
+errkey:
+   mp_clear_multi(key->pubkey.x, key->pubkey.y, key->pubkey.z, key->k, NULL);
+cleanup:
+   ltc_ecc_del_point(base);
+   mp_clear_multi(prime, order, NULL);
+ERR_BUF:
+#ifdef LTC_CLEAN_STACK
+   zeromem(buf, ECC_MAXSIZE);
+#endif
+   XFREE(buf);
+   return err;
+}
+
+#endif
+/* ref:         $Format:%D$ */
+/* git commit:  $Format:%H$ */
+/* commit time: $Format:%ai$ */
+