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/* 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.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, 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: $Format:%ai$ */
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