diff options
Diffstat (limited to 'libtomcrypt/src/pk/ecc/ecc_ansi_x963_export.c')
| -rw-r--r-- | libtomcrypt/src/pk/ecc/ecc_ansi_x963_export.c | 25 |
1 files changed, 15 insertions, 10 deletions
diff --git a/libtomcrypt/src/pk/ecc/ecc_ansi_x963_export.c b/libtomcrypt/src/pk/ecc/ecc_ansi_x963_export.c index 09dae07..773b683 100644 --- a/libtomcrypt/src/pk/ecc/ecc_ansi_x963_export.c +++ b/libtomcrypt/src/pk/ecc/ecc_ansi_x963_export.c @@ -5,8 +5,6 @@ * * The library is free for all purposes without any express * guarantee it works. - * - * Tom St Denis, tomstdenis@gmail.com, http://libtom.org */ /* Implements ECC over Z/pZ for curve y^2 = x^3 - 3x + b @@ -19,7 +17,7 @@ /** @file ecc_ansi_x963_export.c ECC Crypto, Tom St Denis -*/ +*/ #ifdef LTC_MECC @@ -32,33 +30,40 @@ int ecc_ansi_x963_export(ecc_key *key, unsigned char *out, unsigned long *outlen) { unsigned char buf[ECC_BUF_SIZE]; - unsigned long numlen; + unsigned long numlen, xlen, ylen; LTC_ARGCHK(key != NULL); - LTC_ARGCHK(out != NULL); LTC_ARGCHK(outlen != NULL); if (ltc_ecc_is_valid_idx(key->idx) == 0) { return CRYPT_INVALID_ARG; } numlen = key->dp->size; + xlen = mp_unsigned_bin_size(key->pubkey.x); + ylen = mp_unsigned_bin_size(key->pubkey.y); + + if (xlen > numlen || ylen > numlen || sizeof(buf) < numlen) { + return CRYPT_BUFFER_OVERFLOW; + } if (*outlen < (1 + 2*numlen)) { *outlen = 1 + 2*numlen; return CRYPT_BUFFER_OVERFLOW; } + LTC_ARGCHK(out != NULL); + /* store byte 0x04 */ out[0] = 0x04; /* pad and store x */ zeromem(buf, sizeof(buf)); - mp_to_unsigned_bin(key->pubkey.x, buf + (numlen - mp_unsigned_bin_size(key->pubkey.x))); + mp_to_unsigned_bin(key->pubkey.x, buf + (numlen - xlen)); XMEMCPY(out+1, buf, numlen); /* pad and store y */ zeromem(buf, sizeof(buf)); - mp_to_unsigned_bin(key->pubkey.y, buf + (numlen - mp_unsigned_bin_size(key->pubkey.y))); + mp_to_unsigned_bin(key->pubkey.y, buf + (numlen - ylen)); XMEMCPY(out+1+numlen, buf, numlen); *outlen = 1 + 2*numlen; @@ -67,6 +72,6 @@ int ecc_ansi_x963_export(ecc_key *key, unsigned char *out, unsigned long *outlen #endif -/* $Source$ */ -/* $Revision$ */ -/* $Date$ */ +/* ref: $Format:%D$ */ +/* git commit: $Format:%H$ */ +/* commit time: $Format:%ai$ */ |