| // SPDX-License-Identifier: BSD-2-Clause |
| /* 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. |
| */ |
| |
| #include "tomcrypt_private.h" |
| |
| #ifdef LTC_MDH |
| |
| /** |
| Export a DH key to a binary packet |
| @param out [out] The destination for the key |
| @param outlen [in/out] The max size and resulting size of the DH key |
| @param type Which type of key (PK_PRIVATE or PK_PUBLIC) |
| @param key The key you wish to export |
| @return CRYPT_OK if successful |
| */ |
| int dh_export(unsigned char *out, unsigned long *outlen, int type, const dh_key *key) |
| { |
| unsigned char flags[1]; |
| int err; |
| unsigned long version = 0; |
| |
| LTC_ARGCHK(out != NULL); |
| LTC_ARGCHK(outlen != NULL); |
| LTC_ARGCHK(key != NULL); |
| |
| if (type == PK_PRIVATE) { |
| /* export x - private key */ |
| flags[0] = 1; |
| err = der_encode_sequence_multi(out, outlen, |
| LTC_ASN1_SHORT_INTEGER, 1UL, &version, |
| LTC_ASN1_BIT_STRING, 1UL, flags, |
| LTC_ASN1_INTEGER, 1UL, key->prime, |
| LTC_ASN1_INTEGER, 1UL, key->base, |
| LTC_ASN1_INTEGER, 1UL, key->x, |
| LTC_ASN1_EOL, 0UL, NULL); |
| } |
| else { |
| /* export y - public key */ |
| flags[0] = 0; |
| err = der_encode_sequence_multi(out, outlen, |
| LTC_ASN1_SHORT_INTEGER, 1UL, &version, |
| LTC_ASN1_BIT_STRING, 1UL, flags, |
| LTC_ASN1_INTEGER, 1UL, key->prime, |
| LTC_ASN1_INTEGER, 1UL, key->base, |
| LTC_ASN1_INTEGER, 1UL, key->y, |
| LTC_ASN1_EOL, 0UL, NULL); |
| } |
| |
| return err; |
| } |
| |
| #endif /* LTC_MDH */ |
| |
| /* ref: $Format:%D$ */ |
| /* git commit: $Format:%H$ */ |
| /* commit time: $Format:%ai$ */ |