diff options
Diffstat (limited to 'libtomcrypt/src/pk/ecc/ecc_ansi_x963_import.c')
-rw-r--r-- | libtomcrypt/src/pk/ecc/ecc_ansi_x963_import.c | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/libtomcrypt/src/pk/ecc/ecc_ansi_x963_import.c b/libtomcrypt/src/pk/ecc/ecc_ansi_x963_import.c new file mode 100644 index 0000000..e92f5f4 --- /dev/null +++ b/libtomcrypt/src/pk/ecc/ecc_ansi_x963_import.c @@ -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, 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_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 = <c_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 $ */ |