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Diffstat (limited to 'src/pk/ecc/ecc_export.c')
| -rw-r--r-- | src/pk/ecc/ecc_export.c | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/src/pk/ecc/ecc_export.c b/src/pk/ecc/ecc_export.c new file mode 100644 index 0000000..1919849 --- /dev/null +++ b/src/pk/ecc/ecc_export.c @@ -0,0 +1,82 @@ +/* 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, tomstdenis@gmail.com, 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_export.c + ECC Crypto, Tom St Denis +*/ + +#ifdef MECC + +/** + Export an ECC key as a binary packet + @param out [out] Destination for the key + @param outlen [in/out] Max size and resulting size of the exported key + @param type The type of key you want to export (PK_PRIVATE or PK_PUBLIC) + @param key The key to export + @return CRYPT_OK if successful +*/ +int ecc_export(unsigned char *out, unsigned long *outlen, int type, ecc_key *key) +{ + int err; + unsigned char flags[1]; + unsigned long key_size; + + LTC_ARGCHK(out != NULL); + LTC_ARGCHK(outlen != NULL); + LTC_ARGCHK(key != NULL); + + /* type valid? */ + if (key->type != PK_PRIVATE && type == PK_PRIVATE) { + return CRYPT_PK_TYPE_MISMATCH; + } + + if (ltc_ecc_is_valid_idx(key->idx) == 0) { + return CRYPT_INVALID_ARG; + } + + /* we store the NIST byte size */ + key_size = key->dp->size; + + if (type == PK_PRIVATE) { + flags[0] = 1; + err = der_encode_sequence_multi(out, outlen, + LTC_ASN1_BIT_STRING, 1UL, flags, + LTC_ASN1_SHORT_INTEGER, 1UL, &key_size, + LTC_ASN1_INTEGER, 1UL, key->pubkey.x, + LTC_ASN1_INTEGER, 1UL, key->pubkey.y, + LTC_ASN1_INTEGER, 1UL, key->k, + LTC_ASN1_EOL, 0UL, NULL); + } else { + flags[0] = 0; + err = der_encode_sequence_multi(out, outlen, + LTC_ASN1_BIT_STRING, 1UL, flags, + LTC_ASN1_SHORT_INTEGER, 1UL, &key_size, + LTC_ASN1_INTEGER, 1UL, key->pubkey.x, + LTC_ASN1_INTEGER, 1UL, key->pubkey.y, + LTC_ASN1_EOL, 0UL, NULL); + } + + return err; +} + +#endif +/* $Source: /cvs/libtom/libtomcrypt/src/pk/ecc/ecc_export.c,v $ */ +/* $Revision: 1.4 $ */ +/* $Date: 2006/11/21 00:10:18 $ */ + |