X-Git-Url: https://git.sommitrealweird.co.uk/onak.git/blobdiff_plain/d5ee45b742e49fa30cc8d0a5a69ee47c8c5b1eb5..d38e1f468376f8b19b208f2da4d20cb2919875dd:/keyid.c diff --git a/keyid.c b/keyid.c index 6bb2e19..c75f0a1 100644 --- a/keyid.c +++ b/keyid.c @@ -1,17 +1,41 @@ /* * keyid.c - Routines to calculate key IDs. * - * Jonathan McDowell + * Copyright 2002,2011 Jonathan McDowell * - * Copyright 2002 Project Purple + * 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 #include +#include +#include "config.h" #include "keyid.h" #include "keystructs.h" +#include "log.h" +#include "parsekey.h" +#include "mem.h" +#include "merge.h" + +#ifdef HAVE_NETTLE +#include +#include +#else #include "md5.h" -#include "sha.h" +#include "sha1.h" +#endif /** @@ -24,67 +48,122 @@ uint64_t get_keyid(struct openpgp_publickey *publickey) } /** - * get_packetid - Given a PGP packet returns the keyid. - * @packet: The packet to calculate the id for. + * 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. */ -uint64_t get_packetid(struct openpgp_packet *packet) +unsigned char *get_fingerprint(struct openpgp_packet *packet, + unsigned char *fingerprint, + size_t *len) { - SHA1_CONTEXT sha_ctx; - uint64_t keyid = 0; - int offset = 0; - int i = 0; + struct sha1_ctx sha_ctx; + struct md5_ctx md5_context; unsigned char c; - unsigned char *buff = NULL; + size_t modlen, explen; - assert(packet != NULL); + log_assert(fingerprint != NULL); + log_assert(len != NULL); + + *len = 0; switch (packet->data[0]) { case 2: case 3: + md5_init(&md5_context); + /* - * 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. - * - * We need to ensure it's an RSA key. + * MD5 the modulus and exponent. */ - if (packet->data[7] == 1) { - 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++]; - } - } else { - fputs("Type 2 or 3 key, but not RSA.\n", stderr); - } + 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]); + + *len = 16; + md5_digest(&md5_context, *len, fingerprint); + break; + case 4: - /* - * For a type 4 key the keyid is the last 64 bits of the - * fingerprint, which is the 160 bit SHA-1 hash of the packet - * tag, 2 octet packet length and the public key packet - * including version field. - */ 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_write(&sha_ctx, &c, sizeof(c)); + sha1_update(&sha_ctx, sizeof(c), &c); c = packet->length >> 8; - sha1_write(&sha_ctx, &c, sizeof(c)); + sha1_update(&sha_ctx, sizeof(c), &c); c = packet->length & 0xFF; - sha1_write(&sha_ctx, &c, sizeof(c)); - sha1_write(&sha_ctx, packet->data, - packet->length); - sha1_final(&sha_ctx); - buff = sha1_read(&sha_ctx); + sha1_update(&sha_ctx, sizeof(c), &c); + sha1_update(&sha_ctx, packet->length, + packet->data); + *len = 20; + sha1_digest(&sha_ctx, *len, fingerprint); + + break; + default: + logthing(LOGTHING_ERROR, "Unknown key type: %d", + packet->data[0]); + } + + return fingerprint; +} + + +/** + * get_packetid - Given a PGP packet returns the keyid. + * @packet: The packet to calculate the id for. + */ +uint64_t get_packetid(struct openpgp_packet *packet) +{ + uint64_t keyid = 0; + int offset = 0; + int i = 0; + size_t length = 0; + unsigned char buff[20]; + + log_assert(packet != NULL); + + switch (packet->data[0]) { + case 2: + case 3: + /* + * 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; - assert(buff != NULL); + for (keyid = 0, i = 0; i < 8; i++) { + keyid <<= 8; + keyid += packet->data[offset++]; + } + /* + * Check for an RSA key; if not then log but accept anyway. + * 1 == RSA + * 2 == RSA Encrypt-Only + * 3 == RSA Sign-Only + */ + if (packet->data[7] < 1 || packet->data[7] > 3) { + logthing(LOGTHING_NOTICE, + "Type 2 or 3 key, but not RSA: %llx (type %d)", + keyid, + packet->data[7]); + } + break; + case 4: + get_fingerprint(packet, buff, &length); for (keyid = 0, i = 12; i < 20; i++) { keyid <<= 8; @@ -93,9 +172,94 @@ uint64_t get_packetid(struct openpgp_packet *packet) break; default: - fprintf(stderr, "Unknown key type: %d\n", + logthing(LOGTHING_ERROR, "Unknown key type: %d", packet->data[0]); } return keyid; } + +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; +} + +void 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); +} + +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; +}