diff libtomcrypt/src/pk/ecc/ecc_ansi_x963_import.c @ 382:0cbe8f6dbf9e

propagate from branch 'au.asn.ucc.matt.ltc.dropbear' (head 2af22fb4e878750b88f80f90d439b316d229796f) to branch 'au.asn.ucc.matt.dropbear' (head 02c413252c90e9de8e03d91e9939dde3029f5c0a)
author Matt Johnston <matt@ucc.asn.au>
date Thu, 11 Jan 2007 02:41:05 +0000
parents
children f849a5ca2efc
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libtomcrypt/src/pk/ecc/ecc_ansi_x963_import.c	Thu Jan 11 02:41:05 2007 +0000
@@ -0,0 +1,104 @@
+/* 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.
+ *
+ * Tom St Denis, [email protected], http://libtomcrypt.com
+ */
+
+/* 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_ansi_x963_import.c
+  ECC Crypto, Tom St Denis
+*/  
+
+#ifdef MECC
+
+/** Import an ANSI X9.63 format public key 
+  @param in      The input data to read
+  @param inlen   The length of the input data
+  @param key     [out] destination to store imported key \
+*/
+int ecc_ansi_x963_import(const unsigned char *in, unsigned long inlen, ecc_key *key)
+{
+   return ecc_ansi_x963_import_ex(in, inlen, key, NULL);
+}
+
+int ecc_ansi_x963_import_ex(const unsigned char *in, unsigned long inlen, ecc_key *key, ltc_ecc_set_type *dp)
+{
+   int x, err;
+ 
+   LTC_ARGCHK(in  != NULL);
+   LTC_ARGCHK(key != NULL);
+   
+   /* must be odd */
+   if ((inlen & 1) == 0) {
+      return CRYPT_INVALID_ARG;
+   }
+
+   /* init key */
+   if (mp_init_multi(&key->pubkey.x, &key->pubkey.y, &key->pubkey.z, &key->k, NULL) != CRYPT_OK) {
+      return CRYPT_MEM;
+   }
+
+   /* check for 4, 6 or 7 */
+   if (in[0] != 4 && in[0] != 6 && in[0] != 7) {
+      err = CRYPT_INVALID_PACKET;
+      goto error;
+   }
+
+   /* read data */
+   if ((err = mp_read_unsigned_bin(key->pubkey.x, (unsigned char *)in+1, (inlen-1)>>1)) != CRYPT_OK) {
+      goto error;
+   }
+
+   if ((err = mp_read_unsigned_bin(key->pubkey.y, (unsigned char *)in+1+((inlen-1)>>1), (inlen-1)>>1)) != CRYPT_OK) {
+      goto error;
+   }
+   if ((err = mp_set(key->pubkey.z, 1)) != CRYPT_OK) { goto error; }
+
+   if (dp == NULL) {
+     /* determine the idx */
+      for (x = 0; ltc_ecc_sets[x].size != 0; x++) {
+         if ((unsigned)ltc_ecc_sets[x].size >= ((inlen-1)>>1)) {
+            break;
+         }
+      }
+      if (ltc_ecc_sets[x].size == 0) {
+         err = CRYPT_INVALID_PACKET;
+         goto error;
+      }
+      /* set the idx */
+      key->idx  = x;
+      key->dp = &ltc_ecc_sets[x];
+   } else {
+      if (((inlen-1)>>1) != (unsigned long) dp->size) {
+         err = CRYPT_INVALID_PACKET;
+         goto error;
+      }
+      key->idx = -1;
+      key->dp  = dp;
+   }
+   key->type = PK_PUBLIC;
+
+   /* we're done */
+   return CRYPT_OK;
+error:
+   mp_clear_multi(key->pubkey.x, key->pubkey.y, key->pubkey.z, key->k, NULL);
+   return err;
+}
+
+#endif
+
+/* $Source: /cvs/libtom/libtomcrypt/src/pk/ecc/ecc_ansi_x963_import.c,v $ */
+/* $Revision: 1.9 $ */
+/* $Date: 2006/12/04 22:17:46 $ */