--- /dev/null
+/* fides.c - Light-weight, decentralised trust and authorisation management
+ Copyright (C) 2008-2009 Guus Sliepen <guus@tinc-vpn.org>
+
+ Fides is free software; you can redistribute it and/or modify
+ it under the terms of the GNU Lesser General Public License as
+ published by the Free Software Foundation; either version 2.1 of
+ the License, or (at your option) any later version.
+
+ Fides 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 Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with this program; if not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <cstdio>
+#include <cstring>
+#include <cstdlib>
+#include <stdint.h>
+#include <getopt.h>
+#include <sysexits.h>
+#include <iostream>
+#include <fstream>
+#include <botan/types.h>
+#include <botan/botan.h>
+#include <botan/ecdsa.h>
+#include <botan/look_pk.h>
+#include <botan/lookup.h>
+#include <botan/filters.h>
+#include <botan/sha2_32.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <list>
+
+#include "fides.h"
+
+using namespace std;
+
+// Global state
+
+Botan::LibraryInitializer libinit;
+Botan::AutoSeeded_RNG fides::rng;
+
+// Public key functions
+
+fides::publickey::publickey(): pub(0), trust(0) {
+}
+
+fides::publickey::~publickey() {
+ delete pub;
+}
+
+void fides::publickey::load(istream &in) {
+ try {
+ Botan::DataSource_Stream source(in);
+ pub = dynamic_cast<Botan::ECDSA_PublicKey *>(Botan::X509::load_key(source));
+ } catch(Botan::Exception &e) {
+ throw exception(e.what());
+ }
+}
+
+void fides::publickey::load(const std::string &filename) {
+ ifstream in(filename.c_str());
+ load(in);
+}
+
+void fides::publickey::save(ostream &out) {
+ out << to_string();
+}
+
+void fides::publickey::save(const std::string &filename) {
+ ofstream out(filename.c_str());
+ save(out);
+}
+
+void fides::publickey::from_string(const std::string &in) {
+ try {
+ Botan::DataSource_Memory source(in);
+ pub = dynamic_cast<Botan::ECDSA_PublicKey *>(Botan::X509::load_key(source));
+ } catch(Botan::Exception &e) {
+ throw exception(e.what());
+ }
+}
+
+string fides::publickey::to_string() {
+ return Botan::X509::PEM_encode(*pub);
+}
+
+string fides::publickey::fingerprint(unsigned int bits) {
+ // TODO: find out if there is a standard way to get a hash of an ECDSA public key
+ Botan::SHA_256 sha256;
+ Botan::SecureVector<Botan::byte> hash = sha256.process(Botan::X509::PEM_encode(*pub));
+ return string((const char *)hash.begin(), bits / 8);
+}
+
+bool fides::publickey::verify(const std::string &statement, const std::string &signature) {
+ auto_ptr<Botan::PK_Verifier> verifier(Botan::get_pk_verifier(*pub, "EMSA1(SHA-512)"));
+ verifier->update((const Botan::byte *)statement.data(), statement.size());
+ Botan::SecureVector<Botan::byte> sig;
+ sig.set((const Botan::byte *)signature.data(), signature.size());
+ return verifier->check_signature(sig);
+}
+
+// Private key functions
+
+fides::privatekey::privatekey(): priv(0) {
+}
+
+fides::privatekey::~privatekey() {
+ delete priv;
+ pub = 0;
+}
+
+void fides::privatekey::generate(const std::string &field) {
+ Botan::EC_Domain_Params domain = Botan::get_EC_Dom_Pars_by_oid(field);
+ pub = priv = new Botan::ECDSA_PrivateKey(rng, domain);
+}
+
+void fides::privatekey::generate(unsigned int bits) {
+ switch(bits) {
+ case 112: return generate("1.3.132.0.6");
+ case 128: return generate("1.3.132.0.28");
+ case 160: return generate("1.3.132.0.9");
+ case 192: return generate("1.3.132.0.31");
+ case 224: return generate("1.3.132.0.32");
+ case 256: return generate("1.3.132.0.10");
+ case 384: return generate("1.3.132.0.34");
+ case 521: return generate("1.3.132.0.35");
+ default: throw exception("Unsupported number of bits for private key");
+ }
+}
+
+void fides::privatekey::load_private(istream &in) {
+ try {
+ Botan::DataSource_Stream stream(in);
+ pub = priv = dynamic_cast<Botan::ECDSA_PrivateKey *>(Botan::PKCS8::load_key(stream, rng, ""));
+ } catch(Botan::Exception &e) {
+ throw exception(e.what());
+ }
+}
+
+void fides::privatekey::load_private(const std::string &filename) {
+ ifstream in(filename.c_str());
+ load_private(in);
+}
+
+void fides::privatekey::save_private(ostream &out) {
+ out << Botan::PKCS8::PEM_encode(*priv);
+}
+
+void fides::privatekey::save_private(const std::string &filename) {
+ ofstream out(filename.c_str());
+ save_private(out);
+}
+
+string fides::privatekey::sign(const std::string &statement) {
+ auto_ptr<Botan::PK_Signer> signer(Botan::get_pk_signer(*priv, "EMSA1(SHA-512)"));
+ Botan::SecureVector<Botan::byte> sig = signer->sign_message((const Botan::byte *)statement.data(), statement.size(), rng);
+ return string((const char *)sig.begin(), (size_t)sig.size());
+}
+
+// Base64 and hex encoding/decoding functions
+
+string fides::hexencode(const string &in) {
+ Botan::Pipe pipe(new Botan::Hex_Encoder);
+ pipe.process_msg((Botan::byte *)in.data(), in.size());
+ return pipe.read_all_as_string();
+}
+
+string fides::hexdecode(const string &in) {
+ Botan::Pipe pipe(new Botan::Hex_Decoder);
+ pipe.process_msg((Botan::byte *)in.data(), in.size());
+ return pipe.read_all_as_string();
+}
+
+string fides::b64encode(const string &in) {
+ Botan::Pipe pipe(new Botan::Base64_Encoder);
+ pipe.process_msg((Botan::byte *)in.data(), in.size());
+ return pipe.read_all_as_string();
+}
+
+string fides::b64decode(const string &in) {
+ Botan::Pipe pipe(new Botan::Base64_Decoder);
+ pipe.process_msg((Botan::byte *)in.data(), in.size());
+ return pipe.read_all_as_string();
+}
+
+// Certificate functions
+
+fides::certificate::certificate(publickey *key, struct timeval timestamp, const std::string &statement, const std::string &signature): signer(key), timestamp(timestamp), statement(statement), signature(signature) {}
+
+bool fides::certificate::validate() {
+ string data = signer->fingerprint(256);
+ data += string((const char *)×tamp, sizeof timestamp);
+ data += statement;
+ return signer->verify(data, signature);
+}
+
+fides::certificate::certificate(privatekey *key, struct timeval timestamp, const std::string &statement): signer(key), timestamp(timestamp), statement(statement) {
+ string data = signer->fingerprint(256);
+ data += string((const char *)×tamp, sizeof timestamp);
+ data += statement;
+ signature = key->sign(data);
+}
+
+string fides::certificate::fingerprint(unsigned int bits) {
+ return signature.substr(signature.size() - bits / 8);
+}
+
+string fides::certificate::to_string() const {
+ string data = fides::hexencode(signer->fingerprint());
+ data += ' ';
+ char ts[100];
+ snprintf(ts, sizeof ts, "%lu.%06lu", timestamp.tv_sec, timestamp.tv_usec);
+ data += ts;
+ data += ' ';
+ data += fides::b64encode(signature);
+ data += ' ';
+ data += statement;
+ return data;
+}
+
+static void help(ostream &out, const string &argv0) {
+ out << "Usage: " << argv0 << "<command> [arguments]\n"
+ "\n"
+ "Available commands are:\n"
+ "\n"
+ " init Initialise fides, generate a public/private keypair.\n"
+ " version Show version and copyright information.\n"
+ " help Show this help message.\n"
+ "\n"
+ " trust <keyid>\n"
+ " Trust allow/deny packets signed by the specified key.\n"
+ " distrust <keyid>\n"
+ " Distrust allow/deny packets signed by the specified key.\n"
+ " dctrust <keyid>\n"
+ " Don't care about allow/deny packets signed by the specified key.\n"
+ " is_trusted <keyid>\n"
+ " Returns 0 if key is trusted, 1 otherwise\n"
+ " is_distrusted <keyid>\n"
+ " Returns 0 if key is distrusted, 1 otherwise\n"
+ "\n"
+ " sign <stuff ...>\n"
+ " Sign stuff.\n"
+ " allow <stuff ...>\n"
+ " Allow stuff.\n"
+ " deny <stuff ...> \n"
+ " Deny stuff.\n"
+ " dontcare <stuff ...> \n"
+ " Don't care about stuff.\n"
+ " is_allowed <stuff ...>\n"
+ " Returns 0 if stuff is allowed, 1 otherwise\n"
+ " is_denied <stuff ...>\n"
+ " Returns 0 if stuff is denied, 1 otherwise\n"
+ "\n"
+ " import [filename]\n"
+ " Import keys and certificates from file, or stdin if unspecified.\n"
+ " export [filename]\n"
+ " Export keys and certificates to file, or stdout if unspecified.\n"
+ " test <stuff ...>\n"
+ " Tell whether stuff is allowed or not by counting relevant certificates\n"
+ " find <regexp>\n"
+ " Find all certificates matching regexp\n"
+ " fsck Verify the signature on all information collected.\n";
+}
+
+static void version(ostream &out = cout) {
+ out << "fides version 0.1\n"
+ "Copyright (c) 2008-2009 Guus Sliepen <guus@tinc-vpn.org>\n"
+ "\n"
+ "This program is free software; you can redistribute it and/or modify\n"
+ "it under the terms of the GNU General Public License as published by\n"
+ "the Free Software Foundation; either version 2 of the License, or\n"
+ "(at your option) any later version.\n";
+}
+
+// Utility functions
+
+static vector<string> dirlist(const string &path) {
+ vector<string> files;
+
+ DIR *dir = opendir(path.c_str());
+ if(!dir)
+ return files;
+
+ struct dirent entry, *result = &entry;
+
+ while(result) {
+ readdir_r(dir, &entry, &result);
+ if(!result)
+ break;
+ struct stat st;
+ if(result->d_type == DT_UNKNOWN) {
+ if(stat((path + "/" + result->d_name).c_str(), &st))
+ continue;
+ if(S_ISREG(st.st_mode))
+ files.push_back(result->d_name);
+ } else if(result->d_type == DT_REG) {
+ files.push_back(result->d_name);
+ }
+ }
+
+ closedir(dir);
+
+ return files;
+}
+
+void fides::certificate_save(const certificate *cert, const string &filename) {
+ ofstream file(filename.c_str());
+ file << cert->to_string() << '\n';
+}
+
+fides::certificate *fides::certificate_load(const string &filename) {
+ ifstream file(filename.c_str());
+ string data;
+ getline(file, data);
+ return certificate_from_string(data);
+}
+
+fides::certificate *fides::certificate_from_string(const string &data) {
+ size_t b, e;
+ e = data.find(' ', 0);
+ if(e == string::npos)
+ throw exception("Invalid certificate");
+ string fingerprint = hexdecode(data.substr(0, e));
+ publickey *signer = find_key(fingerprint);
+ if(!signer)
+ throw exception("Unknown public key");
+ b = e + 1;
+ e = data.find('.', b);
+ if(e == string::npos)
+ throw exception("Invalid certificate");
+ struct timeval timestamp;
+ timestamp.tv_sec = atol(data.c_str() + b);
+ b = e + 1;
+ timestamp.tv_usec = atol(data.c_str() + b);
+ e = data.find(' ', b);
+ if(e == string::npos)
+ throw exception("Invalid certificate");
+ b = e + 1;
+ e = data.find(' ', b);
+ if(e == string::npos)
+ throw exception("Invalid certificate");
+ string signature = fides::b64decode(data.substr(b, e - b));
+ b = e + 1;
+ string statement = data.substr(b);
+
+ return new certificate(signer, timestamp, statement, signature);
+}
+
+// Fides main functions
+
+fides::fides(const string &dir): homedir(dir) {
+ cerr << "Fides initialising\n";
+
+ // Set homedir to provided directory, or $FIDES_HOME, or $HOME/.fides, or as a last resort $PWD/.fides
+ if(homedir.empty())
+ homedir = getenv("FIDES_HOME") ?: "";
+ if(homedir.empty()) {
+ char cwd[PATH_MAX];
+ homedir = getenv("HOME") ?: getcwd(cwd, sizeof cwd);
+ homedir += "/.fides";
+ }
+
+ // Derived directories
+ homedir += '/';
+ certdir = homedir + "certs/";
+ keydir = homedir + "keys/";
+ obsoletedir = homedir + ".obsolete_certs/";
+
+ // Ensure the homedir and its subdirectories exist
+ mkdir(homedir.c_str(), 0700);
+ mkdir(certdir.c_str(), 0700);
+ mkdir(keydir.c_str(), 0700);
+ mkdir(obsoletedir.c_str(), 0700);
+
+ try {
+ mykey.load_private(homedir + "priv");
+ firstrun = false;
+ } catch(fides::exception &e) {
+ cerr << "Fides generating keypair\n";
+ mykey.generate();
+ mykey.save_private(homedir + "priv");
+ mykey.save(keydir + hexencode(mykey.fingerprint()));
+ firstrun = true;
+ }
+ vector<string> files = dirlist(keydir);
+ for(size_t i = 0; i < files.size(); ++i) {
+ cerr << "Loading key " << files[i] << '\n';
+
+ publickey *key = new publickey();
+ key->load(keydir + files[i]);
+ keys[hexdecode(files[i])] = key;
+ }
+
+ keys[mykey.fingerprint()] = &mykey;
+
+ files = dirlist(certdir);
+ for(size_t i = 0; i < files.size(); ++i) {
+ cerr << "Loading certificate " << files[i] << '\n';
+ certificate *cert = certificate_load(certdir + files[i]);
+ if(false && !cert->validate()) {
+ cerr << "Bad certificate!\n";
+ continue;
+ }
+ certs[hexdecode(files[i])] = cert;
+ }
+
+ // TODO: save and load this value
+ latest.tv_sec = 0;
+ latest.tv_usec = 0;
+
+ update_trust();
+}
+
+fides::~fides() {
+ cerr << "Fides exitting\n";
+ for(map<string, certificate *>::iterator i = certs.begin(); i != certs.end(); ++i)
+ delete i->second;
+ for(map<string, publickey *>::iterator i = keys.begin(); i != keys.end(); ++i)
+ if(i->second != &mykey)
+ delete i->second;
+}
+
+bool fides::fsck() {
+ int errors = 0;
+
+ for(map<string, certificate *>::iterator i = certs.begin(); i != certs.end(); ++i) {
+ if(!i->second->validate()) {
+ cerr << "Validation of certificate failed: " << i->second->to_string() << '\n';
+ errors++;
+ }
+ }
+
+ cerr << errors << " errors in " << certs.size() << " certificates\n";
+ return !errors;
+}
+
+string fides::get_homedir() {
+ return homedir;
+}
+
+bool fides::is_firstrun() {
+ return firstrun;
+}
+
+fides::publickey *fides::find_key(const string &fingerprint) {
+ map<string, publickey *>::iterator i;
+ i = keys.find(fingerprint);
+ if(i != keys.end())
+ return i->second;
+ else
+ return 0;
+}
+
+vector<fides::certificate *> fides::find_certificates(publickey *signer, const string ®ex) {
+ vector<certificate *> found;
+ map<string, certificate *>::iterator i;
+ regexp regexp(regex);
+ for(i = certs.begin(); i != certs.end(); ++i) {
+ if(!i->second) {
+ cerr << "No certificate for " << hexencode(i->first) << '\n';
+ continue;
+ }
+ if(i->second->signer == signer)
+ if(regexp.match(i->second->statement))
+ found.push_back(i->second);
+ }
+ return found;
+}
+
+vector<fides::certificate *> fides::find_certificates(const string ®ex) {
+ vector<certificate *> found;
+ map<string, certificate *>::iterator i;
+ regexp regexp(regex);
+ for(i = certs.begin(); i != certs.end(); ++i)
+ if(regexp.match(i->second->statement))
+ found.push_back(i->second);
+ return found;
+}
+
+vector<fides::certificate *> fides::find_certificates(publickey *signer) {
+ vector<certificate *> found;
+ map<string, certificate *>::iterator i;
+ for(i = certs.begin(); i != certs.end(); ++i)
+ if(i->second->signer == signer)
+ found.push_back(i->second);
+ return found;
+}
+
+void fides::import_all(istream &in) {
+ string line, pem;
+ bool is_pem = false;
+
+ while(getline(in, line)) {
+ if(line.empty())
+ continue;
+
+ if(is_pem || !line.compare(0, 11, "-----BEGIN ")) {
+ pem += line + '\n';
+ if(!line.compare(0, 9, "-----END ")) {
+ fides::publickey *key = new publickey();
+ key->from_string(pem);
+ cerr << "Imported key " << hexencode(key->fingerprint()) << '\n';
+ merge(key);
+ is_pem = false;
+ } else {
+ is_pem = true;
+ }
+ continue;
+ }
+
+ fides::certificate *cert = certificate_from_string(line);
+ cerr << "Importing certificate " << hexencode(cert->fingerprint()) << '\n';
+ merge(cert);
+ }
+}
+
+void fides::export_all(ostream &out) {
+ for(map<string, publickey *>::iterator i = keys.begin(); i != keys.end(); ++i)
+ out << i->second->to_string();
+ for(map<string, certificate *>::iterator i = certs.begin(); i != certs.end(); ++i)
+ out << i->second->to_string() << '\n';
+}
+
+static int init() {
+ fides fides;
+ if(fides.is_firstrun()) {
+ cout << "New keys generated in " << fides.get_homedir() << '\n';
+ } else {
+ cout << "Fides already initialised\n";
+ }
+ return 0;
+}
+
+void fides::trust(publickey *key) {
+ string full = "t+ " + hexencode(key->fingerprint());
+ sign(full);
+}
+
+void fides::distrust(publickey *key) {
+ string full = "t- " + hexencode(key->fingerprint());
+ sign(full);
+}
+
+void fides::dctrust(publickey *key) {
+ string full = "t0 " + hexencode(key->fingerprint());
+ sign(full);
+}
+
+static int is_trusted(int argc, char *const argv[]) {
+ if(argc < 1)
+ return EX_USAGE;
+
+ fides fides;
+ fides::publickey *key = fides.find_key(fides::hexdecode(argv[0]));
+ if(!key) {
+ cerr << "Unknown key!\n";
+ return 1;
+ }
+ return fides.is_trusted(key) ? 0 : 1;
+}
+
+static int is_distrusted(int argc, char *const argv[]) {
+ if(argc < 1)
+ return EX_USAGE;
+
+ fides fides;
+ fides::publickey *key = fides.find_key(fides::hexdecode(argv[0]));
+ if(!key) {
+ cerr << "Unknown key!\n";
+ return 1;
+ }
+ return fides.is_distrusted(key) ? 0 : 1;
+}
+
+static int trust(int argc, char *const argv[]) {
+ if(argc < 1)
+ return EX_USAGE;
+
+ fides fides;
+ fides::publickey *key = fides.find_key(fides::hexdecode(argv[0]));
+ if(key)
+ fides.trust(key);
+ else {
+ cerr << "Unknown key!\n";
+ return -1;
+ }
+ return 0;
+}
+
+static int dctrust(int argc, char *const argv[]) {
+ if(argc < 1)
+ return EX_USAGE;
+
+ fides fides;
+ fides::publickey *key = fides.find_key(fides::hexdecode(argv[0]));
+ if(key)
+ fides.dctrust(key);
+ else {
+ cerr << "Unknown key!\n";
+ return -1;
+ }
+ return 0;
+}
+
+static int distrust(int argc, char *const argv[]) {
+ if(argc < 1)
+ return EX_USAGE;
+
+ fides fides;
+ fides::publickey *key = fides.find_key(fides::hexdecode(argv[0]));
+ if(key)
+ fides.distrust(key);
+ else {
+ cerr << "Unknown key!\n";
+ return -1;
+ }
+ return 0;
+}
+
+void fides::update_trust() {
+ // clear trust on all keys
+ for(map<string, publickey *>::iterator i = keys.begin(); i != keys.end(); ++i)
+ i->second->trust = 0;
+
+ // Start by checking all trust certificates from ourself.
+ // If another key is positively or negatively trusted, update its trust score
+ // and add it to the the list of new keys to check.
+ // Then add our own key to the list of already checked keys.
+ // Then check all the trust certificates of those on the tocheck list, etc.
+ // Already checked keys are never updated anymore (TODO: is that smart?)
+ // Certificates of keys with a zero or negative trust score are not processed.
+
+ set<publickey *> checked;
+ set<publickey *> tocheck;
+ set<publickey *> newkeys;
+ set<publickey *>::iterator i;
+
+ mykey.trust = 3;
+ tocheck.insert(&mykey);
+
+ while(tocheck.size()) {
+ // add
+ checked.insert(tocheck.begin(), tocheck.end());
+ newkeys.clear();
+
+ // loop over all keys whose certificates need to be checked
+
+ for(i = tocheck.begin(); i != tocheck.end(); ++i) {
+ cerr << "Trust for key " << hexencode((*i)->fingerprint()) << " set to " << (*i)->trust << '\n';
+
+ // except if this key is not trusted
+
+ if((*i)->trust <= 0)
+ continue;
+
+ // find all non-zero trust certificates of this key
+
+ vector<certificate *> matches = find_certificates(*i, "^t[+-] ");
+
+ // update trust value of those keys
+
+ for(size_t j = 0; j < matches.size(); j++) {
+ publickey *other = find_key(hexdecode(matches[j]->statement.substr(3)));
+
+ if(!other) {
+ cerr << "Trust certificate for unknown key: " << matches[j]->to_string() << '\n';
+ continue;
+ }
+
+ // except for keys we already checked
+
+ if(checked.find(other) != checked.end()) {
+ cerr << "Skipping trust certificate for already checked key: " << matches[j]->to_string() << '\n';
+ continue;
+ }
+
+ // update trust
+
+ if(matches[j]->statement[1] == '+')
+ other->trust++;
+ else
+ other->trust--;
+
+ newkeys.insert(other);
+ }
+ }
+
+ tocheck = newkeys;
+ }
+}
+
+void fides::merge(publickey *key) {
+ if(keys.find(key->fingerprint()) != keys.end()) {
+ cerr << "Key already known\n";
+ return;
+ }
+
+ keys[key->fingerprint()] = key;
+ key->save(keydir + hexencode(key->fingerprint()));
+}
+
+void fides::merge(certificate *cert) {
+ // TODO: check if cert is already in database
+ // TODO: check if cert obsoletes other certs
+
+ // If we already know this certificate, drop it.
+ if(certs.find(cert->fingerprint()) != certs.end()) {
+ cerr << "Certificate already known\n";
+ return;
+ }
+
+ // If the certificate does not validate, drop it.
+ if(!cert->validate()) {
+ // TODO: this should not happen, be wary of DoS attacks
+ cerr << "Certificate invalid\n";
+ return;
+ }
+
+ // TODO: move these regexps to the class?
+ regexp authexp("^a[+0-] ");
+ regexp trustexp("^t[+0-] ");
+ vector<certificate *> others;
+
+ // Is this an authorisation cert?
+ if(authexp.match(cert->statement)) {
+ // Find certs identical except for the +/-/0
+ // TODO: escape statement in regexp
+ others = find_certificates(cert->signer, string("^a[+0-] ") + cert->statement.substr(3) + '$');
+ if(others.size()) {
+ if(timercmp(&others[0]->timestamp, &cert->timestamp, >)) {
+ cerr << "Certificate is overruled by a newer certificate\n";
+ return;
+ }
+ if(timercmp(&others[0]->timestamp, &cert->timestamp, ==)) {
+ // TODO: this should not happen, be wary of DoS attacks
+ cerr << "Certificate has same timestamp as another timestamp!\n";
+ return;
+ }
+ cerr << "Certificate overrules an older certificate!\n";
+ // save new cert first
+ certificate_save(cert, certdir + hexencode(cert->fingerprint()));
+ certs[cert->fingerprint()] = cert;
+
+ // delete old one
+ rename((certdir + hexencode(others[0]->fingerprint())).c_str(), (obsoletedir + hexencode(others[0]->fingerprint())).c_str());
+ certs.erase(others[0]->fingerprint());
+ delete others[0];
+ return;
+ }
+ }
+
+ // Is this a trust cert?
+ // TODO: it's just the same as above!
+ if(trustexp.match(cert->statement)) {
+ // Find certs identical except for the +/-/0
+ // TODO: escape statement in regexp
+ others = find_certificates(cert->signer, string("^t[+0-] ") + cert->statement.substr(3) + '$');
+ if(others.size()) {
+ if(timercmp(&others[0]->timestamp, &cert->timestamp, >)) {
+ cerr << "Certificate is overruled by a newer certificate\n";
+ return;
+ }
+ if(timercmp(&others[0]->timestamp, &cert->timestamp, ==)) {
+ // TODO: this should not happen, be wary of DoS attacks
+ cerr << "Certificate has same timestamp as another timestamp!\n";
+ return;
+ }
+ cerr << "Certificate overrules an older certificate!\n";
+ // delete old one
+ rename((certdir + hexencode(others[0]->fingerprint())).c_str(), (obsoletedir + hexencode(others[0]->fingerprint())).c_str());
+ certs.erase(others[0]->fingerprint());
+ delete others[0];
+ certs[cert->fingerprint()] = cert;
+ certificate_save(cert, certdir + hexencode(cert->fingerprint()));
+ return;
+ }
+ }
+
+ // Did somebody sign the exact same statement twice?
+ // Could happen if there is a different, conflicting statement between this new and the corresponding old one.
+ others = find_certificates(cert->signer, string("^") + cert->statement + '$');
+ if(others.size()) {
+ if(timercmp(&others[0]->timestamp, &cert->timestamp, >)) {
+ cerr << "Certificate is overruled by a newer certificate\n";
+ return;
+ }
+ if(timercmp(&others[0]->timestamp, &cert->timestamp, ==)) {
+ // TODO: this should not happen, be wary of DoS attacks
+ cerr << "Certificate has same timestamp as another timestamp!\n";
+ return;
+ }
+ cerr << "Certificate overrules an older certificate!\n";
+ // delete old one
+ rename((certdir + hexencode(others[0]->fingerprint())).c_str(), (obsoletedir + hexencode(others[0]->fingerprint())).c_str());
+ certs.erase(others[0]->fingerprint());
+ delete others[0];
+ certs[cert->fingerprint()] = cert;
+ certificate_save(cert, certdir + hexencode(cert->fingerprint()));
+ return;
+ }
+
+ cerr << "Certificate is new\n";
+ certs[cert->fingerprint()] = cert;
+ certificate_save(cert, certdir + hexencode(cert->fingerprint()));
+}
+
+void fides::auth_stats(const string &statement, int &self, int &trusted, int &all) {
+ self = trusted = all = 0;
+ vector<certificate *> matches = find_certificates(string("^a[+0-] ") + statement + '$');
+ for(size_t i = 0; i < matches.size(); ++i) {
+ char code = matches[i]->statement[1];
+ int diff = 0;
+ if(code == '+')
+ diff = 1;
+ else if(code == '-')
+ diff = -1;
+ if(matches[i]->signer == &mykey)
+ self += diff;
+ if(matches[i]->signer->trust > 0)
+ trusted += diff;
+ all += diff;
+ }
+}
+
+bool fides::is_trusted(publickey *key) {
+ return key->trust > 0;
+}
+
+bool fides::is_distrusted(publickey *key) {
+ return key->trust < 0;
+}
+
+bool fides::is_allowed(const string &statement, publickey *key) {
+ int self, trusted, all;
+
+ if(key)
+ auth_stats(hexencode(key->fingerprint()) + " " + statement, self, trusted, all);
+ else
+ auth_stats(statement, self, trusted, all);
+
+ if(self)
+ return self > 0;
+ else if(trusted)
+ return trusted > 0;
+ else
+ return false;
+}
+
+bool fides::is_denied(const string &statement, publickey *key) {
+ int self, trusted, all;
+
+ if(key)
+ auth_stats(hexencode(key->fingerprint()) + " " + statement, self, trusted, all);
+ else
+ auth_stats(statement, self, trusted, all);
+
+ if(self)
+ return self < 0;
+ else if(trusted)
+ return trusted < 0;
+ else
+ return false;
+}
+
+void fides::sign(const string &statement) {
+ // Try to set "latest" to now, but ensure monoticity
+ struct timeval now;
+ gettimeofday(&now, 0);
+ if(timercmp(&latest, &now, >=)) {
+ latest.tv_usec++;
+ if(latest.tv_usec >= 1000000) {
+ latest.tv_sec++;
+ latest.tv_usec -= 1000000;
+ }
+ } else {
+ latest = now;
+ }
+
+ // Create a new certificate and merge it with our database
+ merge(new certificate(&mykey, latest, statement));
+}
+
+void fides::allow(const string &statement, publickey *key) {
+ string full = "a+ ";
+ if(key)
+ full += hexencode(key->fingerprint()) + ' ';
+ full += statement;
+ sign(full);
+}
+
+void fides::dontcare(const string &statement, publickey *key) {
+ string full = "a0 ";
+ if(key)
+ full += hexencode(key->fingerprint()) + ' ';
+ full += statement;
+ sign(full);
+}
+
+void fides::deny(const string &statement, publickey *key) {
+ string full = "a- ";
+ if(key)
+ full += hexencode(key->fingerprint()) + ' ';
+ full += statement;
+ sign(full);
+}
+
+static int sign(int argc, char *const argv[]) {
+ if(argc < 1)
+ return EX_USAGE;
+
+ fides fides;
+ fides.sign(argv[0]);
+ return 0;
+}
+
+static int allow(int argc, char *const argv[]) {
+ if(argc < 1)
+ return EX_USAGE;
+
+ fides fides;
+ fides.allow(argv[0]);
+ return 0;
+}
+
+static int dontcare(int argc, char *const argv[]) {
+ if(argc < 1)
+ return EX_USAGE;
+
+ fides fides;
+ fides.dontcare(argv[0]);
+ return 0;
+}
+
+static int deny(int argc, char *const argv[]) {
+ if(argc < 1)
+ return EX_USAGE;
+
+ fides fides;
+ fides.deny(argv[0]);
+ return 0;
+}
+
+static int import(int argc, char *const argv[]) {
+ fides fides;
+
+ if(argc) {
+ ifstream in(argv[0]);
+ fides.import_all(in);
+ } else
+ fides.import_all(cin);
+ return 0;
+}
+
+static int exprt(int argc, char *const argv[]) {
+ fides fides;
+
+ if(argc) {
+ ofstream out(argv[0]);
+ fides.export_all(out);
+ } else
+ fides.export_all(cout);
+ return 0;
+}
+
+static int find(int argc, char *const argv[]) {
+ if(argc < 1)
+ return EX_USAGE;
+
+ // Find certificates matching statement
+ fides fides;
+ const vector<fides::certificate *> &certs = fides.find_certificates(argv[0]);
+ for(size_t i = 0; i < certs.size(); ++i)
+ cout << i << ' ' << certs[i]->to_string() << '\n';
+ return 0;
+}
+
+static int is_allowed(int argc, char *const argv[]) {
+ if(argc < 1)
+ return EX_USAGE;
+
+ fides fides;
+ return fides.is_allowed(argv[0]) ? 0 : 1;
+}
+
+static int is_denied(int argc, char *const argv[]) {
+ if(argc < 1)
+ return EX_USAGE;
+
+ fides fides;
+ return fides.is_denied(argv[0]) ? 0 : 1;
+}
+
+static int test(int argc, char *const argv[]) {
+ if(argc < 1)
+ return EX_USAGE;
+
+ fides fides;
+ int self, trusted, all;
+ fides.auth_stats(argv[0], self, trusted, all);
+ cout << "Self: " << self << ", trusted: " << trusted << ", all: " << all << '\n';
+ return 0;
+}
+
+static int fsck() {
+ fides fides;
+ if(fides.fsck()) {
+ cout << "Everything OK\n";
+ return 0;
+ } else {
+ cout << "Integrity failure!\n";
+ return 1;
+ }
+}
+
+int main(int argc, char *const argv[]) {
+ int r;
+ int option_index;
+
+ static struct option const long_options[] = {
+ {"homedir", required_argument, NULL, 2},
+ {"help", no_argument, NULL, 'h'},
+ {"version", no_argument, NULL, 3},
+ {NULL, 0, NULL, 0}
+ };
+
+ while((r = getopt_long(argc, argv, "h", long_options, &option_index)) != EOF) {
+ switch (r) {
+ case 0: /* long option */
+ break;
+ case 1: /* non-option */
+ break;
+ case 2:
+ //homedir = strdup(optarg);
+ break;
+ case 3:
+ version();
+ return 0;
+ case 'h':
+ help(cout, argv[0]);
+ return 0;
+ }
+ }
+
+ if(argc < 2) {
+ help(cerr, argv[0]);
+ return EX_USAGE;
+ }
+
+ if(!strcmp(argv[1], "help")) {
+ help(cout, argv[0]);
+ return 0;
+ }
+
+ if(!strcmp(argv[1], "version")) {
+ version();
+ return 0;
+ }
+
+ if(!strcmp(argv[1], "init"))
+ return init();
+
+ if(!strcmp(argv[1], "trust"))
+ return trust(argc - 2, argv + 2);
+
+ if(!strcmp(argv[1], "dctrust"))
+ return dctrust(argc - 2, argv + 2);
+
+ if(!strcmp(argv[1], "distrust"))
+ return distrust(argc - 2, argv + 2);
+
+ if(!strcmp(argv[1], "is_trusted"))
+ return is_trusted(argc - 2, argv + 2);
+
+ if(!strcmp(argv[1], "is_distrusted"))
+ return is_distrusted(argc - 2, argv + 2);
+
+ if(!strcmp(argv[1], "is_allowed"))
+ return is_allowed(argc - 2, argv + 2);
+
+ if(!strcmp(argv[1], "is_denied"))
+ return is_denied(argc - 2, argv + 2);
+
+ if(!strcmp(argv[1], "allow"))
+ return allow(argc - 2, argv + 2);
+
+ if(!strcmp(argv[1], "dontcare"))
+ return dontcare(argc - 2, argv + 2);
+
+ if(!strcmp(argv[1], "deny"))
+ return deny(argc - 2, argv + 2);
+
+ if(!strcmp(argv[1], "sign"))
+ return sign(argc - 2, argv + 2);
+
+ if(!strcmp(argv[1], "import"))
+ return import(argc - 2, argv + 2);
+
+ if(!strcmp(argv[1], "export"))
+ return exprt(argc - 2, argv + 2);
+
+ if(!strcmp(argv[1], "test"))
+ return test(argc - 2, argv + 2);
+
+ if(!strcmp(argv[1], "find"))
+ return find(argc - 2, argv + 2);
+
+ if(!strcmp(argv[1], "fsck"))
+ return fsck();
+
+ cerr << "Unknown command: " << argv[1] << '\n';
+ return EX_USAGE;
+}
+
projects / fides / commitdiff