1 #include "gnutls-helpers.h"
3 #include <gnutls/openpgp.h>
4 #include <gnutls/x509.h>
11 Author: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
12 Date: Tue, 08 Apr 2008
13 License: GPL v3 or later
15 monkeysphere public key translator: execute this with an GPG
16 certificate (public key(s) + userid(s)) on stdin. It currently
17 only works with RSA keys.
19 It will spit out a version of the first key capable of being used
20 for authentication on stdout. The output format should be suitable
21 for appending a known_hosts file.
23 Requirements: I've only built this so far with GnuTLS v2.3.4 --
24 version 2.2.0 does not contain the appropriate pieces.
28 int main(int argc, char* argv[]) {
31 gnutls_openpgp_crt_t openpgp_crt;
32 gnutls_openpgp_keyid_t keyid;
33 printable_keyid p_keyid;
35 unsigned int usage, bits;
36 gnutls_pk_algorithm_t algo;
38 gnutls_datum_t m, e, p, q, g, y;
40 char output_data[10240];
41 size_t ods = sizeof(output_data);
56 /* slurp in the private key from stdin */
57 if (ret = set_datum_fd(&data, 0), ret) {
58 err("didn't read file descriptor 0\n");
63 if (ret = gnutls_openpgp_crt_init(&openpgp_crt), ret) {
64 err("Failed to initialize OpenPGP certificate (error: %d)\n", ret);
68 /* format could be either: GNUTLS_OPENPGP_FMT_RAW,
69 GNUTLS_OPENPGP_FMT_BASE64; if MONKEYSPHERE_RAW is set, use RAW,
70 otherwise, use BASE64: */
72 if (getenv("MONKEYSPHERE_RAW")) {
73 err("assuming RAW formatted certificate\n");
74 if (ret = gnutls_openpgp_crt_import(openpgp_crt, &data, GNUTLS_OPENPGP_FMT_RAW), ret) {
75 err("failed to import the OpenPGP certificate in RAW format (error: %d)\n", ret);
79 err("assuming BASE64 formatted certificate\n");
80 if (ret = gnutls_openpgp_crt_import (openpgp_crt, &data, GNUTLS_OPENPGP_FMT_BASE64), ret) {
81 err("failed to import the OpenPGP certificate in BASE64 format (error: %d)\n", ret);
86 if (gnutls_openpgp_crt_get_revoked_status(openpgp_crt)) {
87 err("the primary key was revoked!\n");
91 if (ret = gnutls_openpgp_crt_get_key_usage(openpgp_crt, &usage), ret) {
92 err("failed to get the usage flags for the primary key (error: %d)\n", ret);
95 if (usage & GNUTLS_KEY_KEY_AGREEMENT) {
96 err("the primary key can be used for authentication\n");
98 algo = gnutls_openpgp_crt_get_pk_algorithm(openpgp_crt, &bits);
100 err("failed to get the algorithm of the OpenPGP public key (error: %d)\n", algo);
102 } else if (algo == GNUTLS_PK_RSA) {
104 err("OpenPGP RSA certificate, with %d bits\n", bits);
105 ret = gnutls_openpgp_crt_get_pk_rsa_raw(openpgp_crt, &m, &e);
106 if (GNUTLS_E_SUCCESS != ret) {
107 err ("failed to export RSA key parameters (error: %d)\n", ret);
110 } else if (algo == GNUTLS_PK_DSA) {
111 err("OpenPGP DSA Key, with %d bits\n", bits);
112 ret = gnutls_openpgp_crt_get_pk_dsa_raw(openpgp_crt, &p, &q, &g, &y);
113 if (GNUTLS_E_SUCCESS != ret) {
114 err ("failed to export DSA key parameters (error: %d)\n", ret);
118 err("OpenPGP Key was not RSA or DSA -- can't deal! (actual algorithm was: %d)\n", algo);
123 err("primary key is only good for: 0x%08x. Trying subkeys...\n", usage);
125 if (ret = gnutls_openpgp_crt_get_auth_subkey(openpgp_crt, keyid), ret) {
126 err("failed to find a subkey capable of authentication (error: %d)\n", ret);
129 make_keyid_printable(p_keyid, keyid);
130 err("found authentication subkey %.16s\n", p_keyid);
132 ret = gnutls_openpgp_crt_get_subkey_idx(openpgp_crt, keyid);
134 err("could not get the index of subkey %.16s (error: %d)\n", ret);
139 if (gnutls_openpgp_crt_get_subkey_revoked_status(openpgp_crt, keyidx)) {
140 err("The authentication subkey was revoked!\n");
144 if (ret = gnutls_openpgp_crt_get_subkey_usage(openpgp_crt, keyidx, &usage), ret) {
145 err("could not figure out usage of subkey %.16s (error: %d)\n", p_keyid, ret);
148 if ((usage & GNUTLS_KEY_KEY_AGREEMENT) == 0) {
149 err("could not find a subkey with authentication privileges.\n");
153 /* switch, based on the algorithm in question, to extract the MPI
156 algo = gnutls_openpgp_crt_get_subkey_pk_algorithm(openpgp_crt, keyidx, &bits);
158 err("failed to get the algorithm of the authentication subkey (error: %d)\n", algo);
160 } else if (algo == GNUTLS_PK_RSA) {
162 err("OpenPGP RSA subkey, with %d bits\n", bits);
163 ret = gnutls_openpgp_crt_get_subkey_pk_rsa_raw(openpgp_crt, keyidx, &m, &e);
164 if (GNUTLS_E_SUCCESS != ret) {
165 err ("failed to export RSA subkey parameters (error: %d)\n", ret);
168 } else if (algo == GNUTLS_PK_DSA) {
169 err("OpenPGP DSA subkey, with %d bits\n", bits);
170 ret = gnutls_openpgp_crt_get_subkey_pk_dsa_raw(openpgp_crt, keyidx, &p, &q, &g, &y);
171 if (GNUTLS_E_SUCCESS != ret) {
172 err ("failed to export DSA subkey parameters (error: %d)\n", ret);
176 err("OpenPGP subkey was not RSA or DSA -- can't deal! (actual algorithm was: %d)\n", algo);
181 /* now we have algo, and the various MPI data set. Can we export
186 gnutls_openpgp_crt_deinit(openpgp_crt);
187 gnutls_global_deinit();