* Jonathan McDowell <noodles@earth.li>
*
* Copyright 2002 Project Purple
+ *
+ * $Id: keyid.c,v 1.7 2003/06/04 20:57:09 noodles Exp $
*/
#include <sys/types.h>
#include "keyid.h"
#include "keystructs.h"
+#include "log.h"
#include "md5.h"
#include "sha.h"
+
/**
* get_keyid - Given a public key returns the keyid.
- * @publickey: The key to calculate the fingerprint for.
+ * @publickey: The key to calculate the id for.
*/
uint64_t get_keyid(struct openpgp_publickey *publickey)
+{
+ return (get_packetid(publickey->publickey));
+}
+
+/**
+ * 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.
+ */
+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;
+ MD5_CONTEXT md5_ctx;
unsigned char c;
unsigned char *buff = NULL;
+ size_t modlen, explen;
- assert(publickey != NULL);
+ assert(fingerprint != NULL);
+ assert(len != NULL);
- switch (publickey->publickey->data[0]) {
+ *len = 0;
+
+ switch (packet->data[0]) {
case 2:
case 3:
+ md5_init(&md5_ctx);
+
/*
- * 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 (publickey->publickey->data[7] == 1) {
- offset = (publickey->publickey->data[8] << 8) +
- publickey->publickey->data[9];
- offset = ((offset + 7) / 8) + 2;
+ modlen = ((packet->data[8] << 8) +
+ packet->data[9] + 7) >> 3;
+ md5_write(&md5_ctx, &packet->data[10], modlen);
+
+ explen = ((packet->data[10+modlen] << 8) +
+ packet->data[11+modlen] + 7) >> 3;
+ md5_write(&md5_ctx, &packet->data[12 + modlen], explen);
+
+ md5_final(&md5_ctx);
+ buff = md5_read(&md5_ctx);
+
+ *len = 16;
+ memcpy(fingerprint, buff, *len);
- for (keyid = 0, i = 0; i < 8; i++) {
- keyid <<= 8;
- keyid += publickey->publickey->data[offset++];
- }
- } else {
- fputs("Type 2 or 3 key, but not RSA.\n", stderr);
- }
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
*/
c = 0x99;
sha1_write(&sha_ctx, &c, sizeof(c));
- c = publickey->publickey->length >> 8;
+ c = packet->length >> 8;
sha1_write(&sha_ctx, &c, sizeof(c));
- c = publickey->publickey->length & 0xFF;
+ c = packet->length & 0xFF;
sha1_write(&sha_ctx, &c, sizeof(c));
- sha1_write(&sha_ctx, publickey->publickey->data,
- publickey->publickey->length);
+ sha1_write(&sha_ctx, packet->data,
+ packet->length);
sha1_final(&sha_ctx);
buff = sha1_read(&sha_ctx);
- assert(buff != NULL);
+ *len = 20;
+ memcpy(fingerprint, buff, *len);
+ 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];
+
+ 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.
+ *
+ * We need to ensure it's an RSA key.
+ */
+ 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 {
+ logthing(LOGTHING_ERROR,
+ "Type 2 or 3 key, but not RSA.");
+ }
+ break;
+ case 4:
+ get_fingerprint(packet, buff, &length);
for (keyid = 0, i = 12; i < 20; i++) {
keyid <<= 8;
break;
default:
- fprintf(stderr, "Unknown key type: %d\n",
- publickey->publickey->data[0]);
+ logthing(LOGTHING_ERROR, "Unknown key type: %d",
+ packet->data[0]);
}
return keyid;
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