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/*
* keyid.c - Routines to calculate key IDs.
*
* Copyright 2002,2011 Jonathan McDowell <noodles@earth.li>
*
* This program is free software: you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 51
* Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include <string.h>
#include <sys/types.h>
#include <arpa/inet.h>
#include "config.h"
#include "keyid.h"
#include "keystructs.h"
#include "onak.h"
#include "parsekey.h"
#include "mem.h"
#include "merge.h"
#ifdef HAVE_NETTLE
#include <nettle/md5.h>
#include <nettle/ripemd160.h>
#include <nettle/sha.h>
#else
#include "md5.h"
#include "sha1.h"
#endif
uint64_t fingerprint2keyid(struct openpgp_fingerprint *fingerprint)
{
uint64_t keyid;
int i;
for (keyid = 0, i = 12; i < 20; i++) {
keyid <<= 8;
keyid += fingerprint->fp[i];
}
return keyid;
}
/**
* get_keyid - Given a public key returns the keyid.
* @publickey: The key to calculate the id for.
*/
onak_status_t get_keyid(struct openpgp_publickey *publickey, uint64_t *keyid)
{
return (get_packetid(publickey->publickey, keyid));
}
/**
* get_fingerprint - Given a public key returns the fingerprint.
* @publickey: The key to calculate the id for.
* @fingerprint: The fingerprint (must be at least 20 bytes of space).
* @len: The length of the returned fingerprint.
*
* This function returns the fingerprint for a given public key. As Type 3
* fingerprints are 16 bytes and Type 4 are 20 the len field indicates
* which we've returned.
*/
onak_status_t get_fingerprint(struct openpgp_packet *packet,
struct openpgp_fingerprint *fingerprint)
{
struct sha1_ctx sha_ctx;
struct md5_ctx md5_context;
unsigned char c;
size_t modlen, explen;
if (fingerprint == NULL)
return ONAK_E_INVALID_PARAM;
fingerprint->length = 0;
switch (packet->data[0]) {
case 2:
case 3:
md5_init(&md5_context);
/*
* MD5 the modulus and exponent.
*/
modlen = ((packet->data[8] << 8) +
packet->data[9] + 7) >> 3;
md5_update(&md5_context, modlen, &packet->data[10]);
explen = ((packet->data[10+modlen] << 8) +
packet->data[11+modlen] + 7) >> 3;
md5_update(&md5_context, explen, &packet->data[12 + modlen]);
fingerprint->length = 16;
md5_digest(&md5_context, fingerprint->length, fingerprint->fp);
break;
case 4:
sha1_init(&sha_ctx);
/*
* TODO: Can this be 0x99? Are all public key packets old
* format with 2 bytes of length data?
*/
c = 0x99;
sha1_update(&sha_ctx, sizeof(c), &c);
c = packet->length >> 8;
sha1_update(&sha_ctx, sizeof(c), &c);
c = packet->length & 0xFF;
sha1_update(&sha_ctx, sizeof(c), &c);
sha1_update(&sha_ctx, packet->length,
packet->data);
fingerprint->length = 20;
sha1_digest(&sha_ctx, fingerprint->length, fingerprint->fp);
break;
default:
return ONAK_E_UNKNOWN_VER;
}
return ONAK_E_OK;
}
/**
* get_packetid - Given a PGP packet returns the keyid.
* @packet: The packet to calculate the id for.
*/
onak_status_t get_packetid(struct openpgp_packet *packet, uint64_t *keyid)
{
int offset = 0;
int i = 0;
struct openpgp_fingerprint fingerprint;
#ifdef NETTLE_WITH_RIPEMD160
struct ripemd160_ctx ripemd160_context;
uint8_t data;
#endif
if (packet == NULL || packet->data == NULL)
return ONAK_E_INVALID_PARAM;
switch (packet->data[0]) {
case 2:
case 3:
/*
* Old versions of GnuPG would put Elgamal keys inside
* a V3 key structure, then generate the keyid using
* RIPED160.
*/
#ifdef NETTLE_WITH_RIPEMD160
if (packet->data[7] == 16) {
ripemd160_init(&ripemd160_context);
data = 0x99;
ripemd160_update(&ripemd160_context, 1, &data);
data = packet->length >> 8;
ripemd160_update(&ripemd160_context, 1, &data);
data = packet->length & 0xFF;
ripemd160_update(&ripemd160_context, 1, &data);
ripemd160_update(&ripemd160_context,
packet->length,
packet->data);
ripemd160_digest(&ripemd160_context,
RIPEMD160_DIGEST_SIZE,
fingerprint.fp);
fingerprint.length = RIPEMD160_DIGEST_SIZE;
*keyid = fingerprint2keyid(&fingerprint);
return ONAK_E_OK;
}
#endif
/*
* Check for an RSA key; if not return an error.
* 1 == RSA
* 2 == RSA Encrypt-Only
* 3 == RSA Sign-Only
*/
if (packet->data[7] < 1 || packet->data[7] > 3) {
return ONAK_E_INVALID_PKT;
}
/*
* For a type 2 or 3 key the keyid is the last 64 bits of the
* public modulus n, which is stored as an MPI from offset 8
* onwards.
*/
offset = (packet->data[8] << 8) +
packet->data[9];
offset = ((offset + 7) / 8) + 2;
for (*keyid = 0, i = 0; i < 8; i++) {
*keyid <<= 8;
*keyid += packet->data[offset++];
}
break;
case 4:
get_fingerprint(packet, &fingerprint);
*keyid = fingerprint2keyid(&fingerprint);
break;
default:
return ONAK_E_UNKNOWN_VER;
}
return ONAK_E_OK;
}
static struct openpgp_packet_list *sortpackets(struct openpgp_packet_list
*packets)
{
struct openpgp_packet_list *sorted, **cur, *next;
sorted = NULL;
while (packets != NULL) {
cur = &sorted;
while (*cur != NULL && compare_packets((*cur)->packet,
packets->packet) < 0) {
cur = &((*cur)->next);
}
next = *cur;
*cur = packets;
packets = packets->next;
(*cur)->next = next;
}
return sorted;
}
onak_status_t get_skshash(struct openpgp_publickey *key, struct skshash *hash)
{
struct openpgp_packet_list *packets = NULL, *list_end = NULL;
struct openpgp_packet_list *curpacket;
struct md5_ctx md5_context;
struct openpgp_publickey *next;
uint32_t tmp;
/*
* We only want a single key, so clear any link to the next
* one for the period during the flatten.
*/
next = key->next;
key->next = NULL;
flatten_publickey(key, &packets, &list_end);
key->next = next;
packets = sortpackets(packets);
md5_init(&md5_context);
for (curpacket = packets; curpacket != NULL;
curpacket = curpacket->next) {
tmp = htonl(curpacket->packet->tag);
md5_update(&md5_context, sizeof(tmp), (void *) &tmp);
tmp = htonl(curpacket->packet->length);
md5_update(&md5_context, sizeof(tmp), (void *) &tmp);
md5_update(&md5_context,
curpacket->packet->length,
curpacket->packet->data);
}
md5_digest(&md5_context, 16, (uint8_t *) &hash->hash);
free_packet_list(packets);
return ONAK_E_OK;
}
uint8_t hexdigit(char c)
{
if (c >= '0' && c <= '9')
return c - '0';
else if (c >= 'a' && c <= 'f')
return c - 'a' + 10;
else if (c >= 'A' && c <= 'F')
return c - 'A' + 10;
else
return 0;
}
int parse_skshash(char *search, struct skshash *hash)
{
int i, len;
len = strlen(search);
if (len > 32) {
return 0;
}
for (i = 0; i < len; i += 2) {
hash->hash[i >> 1] = (hexdigit(search[i]) << 4) +
hexdigit(search[i + 1]);
}
return 1;
}
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