static int
read_pubkey_keyid(PullFilter *pkt, uint8 *keyid_buf)
{
int res;
PGP_PubKey *pk = NULL;
res = _pgp_read_public_key(pkt, &pk);
if (res < 0)
goto err;
/* skip secret key part, if it exists */
res = pgp_skip_packet(pkt);
if (res < 0)
goto err;
/* is it encryption key */
switch (pk->algo)
{
case PGP_PUB_ELG_ENCRYPT:
case PGP_PUB_RSA_ENCRYPT:
case PGP_PUB_RSA_ENCRYPT_SIGN:
memcpy(keyid_buf, pk->key_id, 8);
res = 1;
break;
default:
res = 0;
}
err:
pgp_key_free(pk);
return res;
}
static int
internal_read_key(PullFilter *src, PGP_PubKey **pk_p,
const uint8 *psw, int psw_len, int pubtype)
{
PullFilter *pkt = NULL;
int res;
uint8 tag;
int len;
PGP_PubKey *enc_key = NULL;
PGP_PubKey *pk = NULL;
int got_main_key = 0;
/*
* Search for encryption key.
*
* Error out on anything fancy.
*/
while (1)
{
res = pgp_parse_pkt_hdr(src, &tag, &len, 0);
if (res <= 0)
break;
res = pgp_create_pkt_reader(&pkt, src, len, res, NULL);
if (res < 0)
break;
switch (tag)
{
case PGP_PKT_PUBLIC_KEY:
case PGP_PKT_SECRET_KEY:
if (got_main_key)
{
res = PXE_PGP_MULTIPLE_KEYS;
break;
}
got_main_key = 1;
res = pgp_skip_packet(pkt);
break;
case PGP_PKT_PUBLIC_SUBKEY:
if (pubtype != 0)
res = PXE_PGP_EXPECT_SECRET_KEY;
else
res = _pgp_read_public_key(pkt, &pk);
break;
case PGP_PKT_SECRET_SUBKEY:
if (pubtype != 1)
res = PXE_PGP_EXPECT_PUBLIC_KEY;
else
res = process_secret_key(pkt, &pk, psw, psw_len);
break;
case PGP_PKT_SIGNATURE:
case PGP_PKT_MARKER:
case PGP_PKT_TRUST:
case PGP_PKT_USER_ID:
case PGP_PKT_USER_ATTR:
case PGP_PKT_PRIV_61:
res = pgp_skip_packet(pkt);
break;
default:
px_debug("unknown/unexpected packet: %d", tag);
res = PXE_PGP_UNEXPECTED_PKT;
}
pullf_free(pkt);
pkt = NULL;
if (pk != NULL)
{
if (res >= 0 && pk->can_encrypt)
{
if (enc_key == NULL)
{
enc_key = pk;
pk = NULL;
}
else
res = PXE_PGP_MULTIPLE_SUBKEYS;
}
if (pk)
pgp_key_free(pk);
pk = NULL;
}
if (res < 0)
break;
}
if (pkt)
pullf_free(pkt);
if (res < 0)
{
if (enc_key)
pgp_key_free(enc_key);
return res;
}
if (!enc_key)
res = PXE_PGP_NO_USABLE_KEY;
else
*pk_p = enc_key;
return res;
}
static int
process_secret_key(PullFilter *pkt, PGP_PubKey **pk_p,
const uint8 *key, int key_len)
{
int res;
int hide_type;
int cipher_algo;
int bs;
uint8 iv[512];
PullFilter *pf_decrypt = NULL,
*pf_key;
PGP_CFB *cfb = NULL;
PGP_S2K s2k;
PGP_PubKey *pk;
/* first read public key part */
res = _pgp_read_public_key(pkt, &pk);
if (res < 0)
return res;
/*
* is secret key encrypted?
*/
GETBYTE(pkt, hide_type);
if (hide_type == HIDE_SHA1 || hide_type == HIDE_CKSUM)
{
if (key == NULL)
return PXE_PGP_NEED_SECRET_PSW;
GETBYTE(pkt, cipher_algo);
res = pgp_s2k_read(pkt, &s2k);
if (res < 0)
return res;
res = pgp_s2k_process(&s2k, cipher_algo, key, key_len);
if (res < 0)
return res;
bs = pgp_get_cipher_block_size(cipher_algo);
if (bs == 0)
{
px_debug("unknown cipher algo=%d", cipher_algo);
return PXE_PGP_UNSUPPORTED_CIPHER;
}
res = pullf_read_fixed(pkt, bs, iv);
if (res < 0)
return res;
/*
* create decrypt filter
*/
res = pgp_cfb_create(&cfb, cipher_algo, s2k.key, s2k.key_len, 0, iv);
if (res < 0)
return res;
res = pullf_create(&pf_decrypt, &pgp_decrypt_filter, cfb, pkt);
if (res < 0)
return res;
pf_key = pf_decrypt;
}
else if (hide_type == HIDE_CLEAR)
{
pf_key = pkt;
}
else
{
px_debug("unknown hide type");
return PXE_PGP_KEYPKT_CORRUPT;
}
/* read secret key */
switch (pk->algo)
{
case PGP_PUB_RSA_SIGN:
case PGP_PUB_RSA_ENCRYPT:
case PGP_PUB_RSA_ENCRYPT_SIGN:
res = pgp_mpi_read(pkt, &pk->sec.rsa.d);
if (res < 0)
break;
res = pgp_mpi_read(pkt, &pk->sec.rsa.p);
if (res < 0)
break;
res = pgp_mpi_read(pkt, &pk->sec.rsa.q);
if (res < 0)
break;
res = pgp_mpi_read(pkt, &pk->sec.rsa.u);
if (res < 0)
break;
break;
case PGP_PUB_ELG_ENCRYPT:
res = pgp_mpi_read(pf_key, &pk->sec.elg.x);
break;
case PGP_PUB_DSA_SIGN:
res = pgp_mpi_read(pf_key, &pk->sec.dsa.x);
break;
default:
px_debug("unknown public algo: %d", pk->algo);
res = PXE_PGP_KEYPKT_CORRUPT;
}
/* read checksum / sha1 */
if (res >= 0)
{
if (hide_type == HIDE_SHA1)
res = check_key_sha1(pf_key, pk);
else
res = check_key_cksum(pf_key, pk);
}
if (res >= 0)
res = pgp_expect_packet_end(pf_key);
if (pf_decrypt)
pullf_free(pf_decrypt);
if (cfb)
pgp_cfb_free(cfb);
if (res < 0)
pgp_key_free(pk);
else
*pk_p = pk;
return res;
}
