X-Git-Url: https://tinc-vpn.org/git/browse?p=fides;a=blobdiff_plain;f=lib%2Ffides.cc;h=0e367aa7a9888f201c08f55dd003bbe7681c266f;hp=b13e6562d49fac1f0e998a611afbd62820c0fca8;hb=401e0b5e1d97ded0e2c7415c6dd0f94ee6bfb470;hpb=0f3083b8693bfaddc4bf3fd6ce7174ac06afa958 diff --git a/lib/fides.cc b/lib/fides.cc index b13e656..0e367aa 100644 --- a/lib/fides.cc +++ b/lib/fides.cc @@ -22,13 +22,6 @@ #include #include #include -#include -#include -#include -#include -#include -#include -#include #include #include "fides.h" @@ -41,799 +34,497 @@ using namespace std; -// Global state - -Botan::AutoSeeded_RNG fides::rng; - -/// \class fides::publickey -/// -/// \brief Representation of a public key. -/// -/// A public key is the counterpart of a private key that is held by some entity. -/// If we have a public key, we can verify signatures made by the corresponding private key. -/// Thus, we can ascertain if a statement, if it has been properly signed, -/// was indeed made by that entity. - -fides::publickey::publickey(): pub(0), trust(0) { -} - -fides::publickey::~publickey() { - delete pub; -} - -/// Loads a public key from a stream. -// -/// @param in Stream to read from. -void fides::publickey::load(std::istream &in) { - try { - Botan::DataSource_Stream source(in); - pub = dynamic_cast(Botan::X509::load_key(source)); - } catch(Botan::Exception &e) { - throw exception(e.what()); - } -} - -/// Loads a public key from a file. -// -/// @param filename Name of the file to read the key from. -void fides::publickey::load(const std::string &filename) { - ifstream in(filename.c_str()); - load(in); -} - -/// Saves the public key to a stream. -// -/// @param out Stream to write to. -void fides::publickey::save(std::ostream &out) const { - out << to_string(); -} - -/// Saves the public key to a file. -// -/// @param filename Name of the file to save the key to. -void fides::publickey::save(const std::string &filename) const { - ofstream out(filename.c_str()); - save(out); -} - -/// Loads a public key from a string. -// -/// @param in String containing a public key in textual format. -void fides::publickey::from_string(const std::string &in) { - try { - Botan::DataSource_Memory source(in); - pub = dynamic_cast(Botan::X509::load_key(source)); - } catch(Botan::Exception &e) { - throw exception(e.what()); +namespace fides { + /// Saves a certificate to a file. + // + /// @param cert Certificate to save. + /// @param filename File to save the certificate to. + void fides::certificate_save(const certificate *cert, const std::string &filename) const { + ofstream file(filename.c_str()); + file << cert->to_string() << '\n'; } -} - -/// Write the public key to a string. -// -/// @return String containing the public key in textual format. -string fides::publickey::to_string() const { - return Botan::X509::PEM_encode(*pub); -} - -/// Get the fingerprint of the public key. -// -/// @param bits Number of bits from the fingerprint to return. -/// The number will be rounded down to the nearest multiple of 8. -/// @return String containing the fingerprint. -string fides::publickey::fingerprint(unsigned int bits) const { - // TODO: find out if there is a standard way to get a hash of an ECDSA public key - Botan::SHA_256 sha256; - Botan::SecureVector hash = sha256.process(Botan::X509::PEM_encode(*pub)); - return string((const char *)hash.begin(), bits / 8); -} - -/// Verify the signature of a statement. -// -/// @param statement The statement. This is the data that has been signed. -/// @param signature The signature of the statement. -/// @return Returns true if the signature is indeed a valid signature, made by this public key, of the statement. -/// Return false otherwise. -bool fides::publickey::verify(const std::string &statement, const std::string &signature) const { - auto_ptr verifier(Botan::get_pk_verifier(*pub, "EMSA1(SHA-512)")); - verifier->update((const Botan::byte *)statement.data(), statement.size()); - Botan::SecureVector sig; - sig.set((const Botan::byte *)signature.data(), signature.size()); - return verifier->check_signature(sig); -} - -/// \class fides::privatekey -/// -/// \brief Representation of a public/private keypair. -/// -/// With a private key we can create a signature of a statement, -/// so that others who have the corresponding public key -/// can ascertain that the statement was really made by us. - -fides::privatekey::privatekey(): priv(0) { -} - -fides::privatekey::~privatekey() { - delete priv; - pub = 0; -} -/// Generates a new public/private keypair. -// -/// @param field OID of the field to generate a key in. -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); -} - -/// Generates a new public/private keypair. -// -/// This function uses standard NIST fields. -/// @param bits Desired size of the keys. -/// Allowed values are 112, 128, 160, 192, 224, 256, 384 and 521. -/// Keys less than 160 bits are considered weak. -/// Keys greater than 224 bits are considered very strong. -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"); + /// Loads a certificate from a file. + // + /// @param filename File to save the certificate to. + /// @return The certificate. + certificate *fides::certificate_load(const std::string &filename) { + ifstream file(filename.c_str()); + string data; + getline(file, data); + return certificate_from_string(data); } -} -/// Loads a private key from a stream. -// -/// @param in Stream to read from. -void fides::privatekey::load_private(std::istream &in) { - try { - Botan::DataSource_Stream stream(in); - pub = priv = dynamic_cast(Botan::PKCS8::load_key(stream, rng, "")); - } catch(Botan::Exception &e) { - throw exception(e.what()); + /// Loads a certificate from a string. + // + /// @param data String containing the certificate in textual form. + /// @return The certificate. + certificate *fides::certificate_from_string(const std::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)); + const 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 = b64decode(data.substr(b, e - b)); + b = e + 1; + string statement = data.substr(b); + + return new certificate(signer, timestamp, statement, signature); } -} - -/// Loads a private key from a file. -// -/// @param filename Name of the file to read from. -void fides::privatekey::load_private(const std::string &filename) { - ifstream in(filename.c_str()); - load_private(in); -} - -/// Saves the private key to a stream. -// -/// @param out Stream to write to. -void fides::privatekey::save_private(std::ostream &out) const { - out << Botan::PKCS8::PEM_encode(*priv); -} - -/// Saves the private key to a file. -// -/// @param filename Name of the file to write to. -void fides::privatekey::save_private(const std::string &filename) const { - ofstream out(filename.c_str()); - save_private(out); -} - -/// Signs a statement with this private key. -// -/// @param statement The statement that is to be signed. -/// @return A string containing the signature. -string fides::privatekey::sign(const std::string &statement) const { - auto_ptr signer(Botan::get_pk_signer(*priv, "EMSA1(SHA-512)")); - Botan::SecureVector 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 - -/// Hexadecimal encode data. -// -/// @param in A string containing raw data. -/// @return A string containing the hexadecimal encoded data. -string fides::hexencode(const std::string &in) { - Botan::Pipe pipe(new Botan::Hex_Encoder); - pipe.process_msg((Botan::byte *)in.data(), in.size()); - return pipe.read_all_as_string(); -} - -/// Decode hexadecimal data. -// -/// @param in A string containing hexadecimal encoded data. -/// @return A string containing the raw data. -string fides::hexdecode(const std::string &in) { - Botan::Pipe pipe(new Botan::Hex_Decoder); - pipe.process_msg((Botan::byte *)in.data(), in.size()); - return pipe.read_all_as_string(); -} - -/// Base-64 encode data. -// -/// @param in A string containing raw data. -/// @return A string containing the base-64 encoded data. -string fides::b64encode(const std::string &in) { - Botan::Pipe pipe(new Botan::Base64_Encoder); - pipe.process_msg((Botan::byte *)in.data(), in.size()); - return pipe.read_all_as_string(); -} -/// Decode base-64 data. -// -/// @param in A string containing base-64 encoded data. -/// @return A string containing the raw data. -string fides::b64decode(const std::string &in) { - Botan::Pipe pipe(new Botan::Base64_Decoder); - pipe.process_msg((Botan::byte *)in.data(), in.size()); - return pipe.read_all_as_string(); -} - -/// \class fides::certificate -/// -/// \brief Representation of a certificate. - -/// Construct a certificate from elements of an already existing certificate. -// -/// @param key Public key used to sign the certificate. -/// @param timestamp Timestamp of the certificate. -/// @param statement Statement of the certificate. -/// @param signature Signature of the certificate. -fides::certificate::certificate(const publickey *key, struct timeval timestamp, const std::string &statement, const std::string &signature): signer(key), timestamp(timestamp), statement(statement), signature(signature) {} - -/// Verifies the signature of the certificate. -// -/// @return True if the signature is valid, false otherwise. -bool fides::certificate::validate() const { - string data = signer->fingerprint(256); - data += string((const char *)×tamp, sizeof timestamp); - data += statement; - return signer->verify(data, signature); -} + /// \class fides + /// + /// \brief Interaction with a Fides database. + /// + /// A fides object manages a database of public keys and certificates. + /// New certificates can be created, certificates can be imported and exported, + /// and queries can be done on the database. + + + /// Creates a new handle on a Fides database. + // + /// Will load the private key, known public keys and certificates. + /// After that it will calculate the trust value of all keys. + /// + /// @param dir Directory where Fides stores the keys and certificates. + /// If no directory is specified, the following environment variables + /// are used, in the given order: + /// - \$FIDES_HOME + /// - \$HOME/.fides + /// - \$WPD/.fides + fides::fides(const std::string &dir): homedir(dir) { + debug 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"; + } -/// Construct a new certificate and sign it with the private key. -// -/// @param key Private key to sign the certificate with. -/// @param timestamp Timestamp of the certificate. -/// @param statement Statement of the certificate. -fides::certificate::certificate(const 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); -} + // 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 files = dirlist(keydir); + for(size_t i = 0; i < files.size(); ++i) { + debug cerr << "Loading key " << files[i] << '\n'; -/// Get the fingerprint of this certificate. -// -/// @param bits Number of bits from the fingerprint to return. -/// The number will be rounded down to the nearest multiple of 8. -/// @return String containing the fingerprint. -string fides::certificate::fingerprint(unsigned int bits) const { - return signature.substr(signature.size() - bits / 8); -} + publickey *key = new publickey(); + key->load(keydir + files[i]); + keys[hexdecode(files[i])] = key; + } -/// Write the certificate to a string. -// -/// @return String containing the certificate in textual format. -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; -} + keys[mykey.fingerprint()] = &mykey; -// Utility functions - -/// Return the names of all the files in a directory. -// -/// @param path Directory to search for files. -/// @return A vector of strings with the name of each file in the directory. -/// The filename does not contain the leading path. -static vector dirlist(const std::string &path) { - vector 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)) + files = dirlist(certdir); + for(size_t i = 0; i < files.size(); ++i) { + debug cerr << "Loading certificate " << files[i] << '\n'; + certificate *cert = certificate_load(certdir + files[i]); + if(false && !cert->validate()) { + cerr << "Bad certificate in database: " << cert->to_string() << '\n'; 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); + } + certs[hexdecode(files[i])] = cert; } - } - closedir(dir); + // TODO: save and load this value + latest.tv_sec = 0; + latest.tv_usec = 0; - return files; -} + update_trust(); + } -/// Saves a certificate to a file. -// -/// @param cert Certificate to save. -/// @param filename File to save the certificate to. -void fides::certificate_save(const certificate *cert, const std::string &filename) const { - ofstream file(filename.c_str()); - file << cert->to_string() << '\n'; -} + fides::~fides() { + debug cerr << "Fides exitting\n"; + for(map::const_iterator i = certs.begin(); i != certs.end(); ++i) + delete i->second; + for(map::const_iterator i = keys.begin(); i != keys.end(); ++i) + if(i->second != &mykey) + delete i->second; + } -/// Loads a certificate from a file. -// -/// @param filename File to save the certificate to. -/// @return The certificate. -fides::certificate *fides::certificate_load(const std::string &filename) { - ifstream file(filename.c_str()); - string data; - getline(file, data); - return certificate_from_string(data); -} + /// Checks the validaty of all certificates. + // + /// @return True if all known certificates are valid, false otherwise. + bool fides::fsck() const { + int errors = 0; -/// Loads a certificate from a string. -// -/// @param data String containing the certificate in textual form. -/// @return The certificate. -fides::certificate *fides::certificate_from_string(const std::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)); - const 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); -} + for(map::const_iterator i = certs.begin(); i != certs.end(); ++i) { + if(!i->second->validate()) { + cerr << "Validation of certificate failed: " << i->second->to_string() << '\n'; + errors++; + } + } -/// \class fides -/// -/// \brief Interaction with a Fides database. -/// -/// A fides object manages a database of public keys and certificates. -/// New certificates can be created, certificates can be imported and exported, -/// and queries can be done on the database. - - -/// Creates a new handle on a Fides database. -// -/// Will load the private key, known public keys and certificates. -/// After that it will calculate the trust value of all keys. -/// -/// @param dir Directory where Fides stores the keys and certificates. -/// If no directory is specified, the following environment variables -/// are used, in the given order: -/// - \$FIDES_HOME -/// - \$HOME/.fides -/// - \$WPD/.fides -fides::fides(const std::string &dir): homedir(dir) { - debug 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"; + cerr << errors << " errors in " << certs.size() << " certificates\n"; + return !errors; } - // 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; + /// Returns the base directory used by Fides. + // + /// @return The home directory. + string fides::get_homedir() const { + return homedir; } - vector files = dirlist(keydir); - for(size_t i = 0; i < files.size(); ++i) { - debug cerr << "Loading key " << files[i] << '\n'; - publickey *key = new publickey(); - key->load(keydir + files[i]); - keys[hexdecode(files[i])] = key; + /// Tests whether this is the first time Fides has run and has generated new keys. + // + /// @return True if this is the first time, false otherwise. + bool fides::is_firstrun() const { + return firstrun; } - keys[mykey.fingerprint()] = &mykey; - - files = dirlist(certdir); - for(size_t i = 0; i < files.size(); ++i) { - debug cerr << "Loading certificate " << files[i] << '\n'; - certificate *cert = certificate_load(certdir + files[i]); - if(false && !cert->validate()) { - cerr << "Bad certificate in database: " << cert->to_string() << '\n'; - continue; - } - certs[hexdecode(files[i])] = cert; + /// Find the public key corresponding to a given fingerprint. + // + /// @param fingerprint String containing a fingerprint. + /// @return Pointer to the public key corresponding to the fingerprint, or NULL if it was not found. + publickey *fides::find_key(const std::string &fingerprint) const { + map::const_iterator i; + i = keys.find(fingerprint); + if(i != keys.end()) + return i->second; + else + return 0; } - // TODO: save and load this value - latest.tv_sec = 0; - latest.tv_usec = 0; - - update_trust(); -} - -fides::~fides() { - debug cerr << "Fides exitting\n"; - for(map::const_iterator i = certs.begin(); i != certs.end(); ++i) - delete i->second; - for(map::const_iterator i = keys.begin(); i != keys.end(); ++i) - if(i->second != &mykey) - delete i->second; -} - -/// Checks the validaty of all certificates. -// -/// @return True if all known certificates are valid, false otherwise. -bool fides::fsck() const { - int errors = 0; - - for(map::const_iterator i = certs.begin(); i != certs.end(); ++i) { - if(!i->second->validate()) { - cerr << "Validation of certificate failed: " << i->second->to_string() << '\n'; - errors++; + /// Find all certificates from a give public key and that match a regular expression. + // + /// @param signer Public key to match certificates to. + /// @param regex Regular expression to match the statement of each certificate to. + /// @return A vector of certificates that match the criteria. + vector fides::find_certificates(const publickey *signer, const std::string ®ex) const { + vector found; + map::const_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; } - cerr << errors << " errors in " << certs.size() << " certificates\n"; - return !errors; -} - -/// Returns the base directory used by Fides. -// -/// @return The home directory. -string fides::get_homedir() const { - return homedir; -} - -/// Tests whether this is the first time Fides has run and has generated new keys. -// -/// @return True if this is the first time, false otherwise. -bool fides::is_firstrun() const { - return firstrun; -} - -/// Find the public key corresponding to a given fingerprint. -// -/// @param fingerprint String containing a fingerprint. -/// @return Pointer to the public key corresponding to the fingerprint, or NULL if it was not found. -fides::publickey *fides::find_key(const std::string &fingerprint) const { - map::const_iterator i; - i = keys.find(fingerprint); - if(i != keys.end()) - return i->second; - else - return 0; -} - -/// Find all certificates from a give public key and that match a regular expression. -// -/// @param signer Public key to match certificates to. -/// @param regex Regular expression to match the statement of each certificate to. -/// @return A vector of certificates that match the criteria. -vector fides::find_certificates(const publickey *signer, const std::string ®ex) const { - vector found; - map::const_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) + /// Find all certificates that match a regular expression. + // + /// @param regex Regular expression to match the statement of each certificate to. + /// @return A vector of certificates that match the criteria. + vector fides::find_certificates(const std::string ®ex) const { + vector found; + map::const_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; } - return found; -} -/// Find all certificates that match a regular expression. -// -/// @param regex Regular expression to match the statement of each certificate to. -/// @return A vector of certificates that match the criteria. -vector fides::find_certificates(const std::string ®ex) const { - vector found; - map::const_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; -} + /// Find all certificates from a give public key. + // + /// @param signer Public key to match certificates to. + /// @return A vector of certificates that match the criteria. + vector fides::find_certificates(const publickey *signer) const { + vector found; + map::const_iterator i; + for(i = certs.begin(); i != certs.end(); ++i) + if(i->second->signer == signer) + found.push_back(i->second); + return found; + } -/// Find all certificates from a give public key. -// -/// @param signer Public key to match certificates to. -/// @return A vector of certificates that match the criteria. -vector fides::find_certificates(const publickey *signer) const { - vector found; - map::const_iterator i; - for(i = certs.begin(); i != certs.end(); ++i) - if(i->second->signer == signer) - found.push_back(i->second); - return found; -} + /// Import public keys and certificates from a stream. + // + /// @param in Stream to read from. + void fides::import_all(std::istream &in) { + string line, pem; + bool is_pem = false; + + while(getline(in, line)) { + if(line.empty()) + continue; -/// Import public keys and certificates from a stream. -// -/// @param in Stream to read from. -void fides::import_all(std::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); - debug cerr << "Imported key " << hexencode(key->fingerprint()) << '\n'; - merge(key); - is_pem = false; - } else { - is_pem = true; + if(is_pem || !line.compare(0, 11, "-----BEGIN ")) { + pem += line + '\n'; + if(!line.compare(0, 9, "-----END ")) { + publickey *key = new publickey(); + key->from_string(pem); + debug cerr << "Imported key " << hexencode(key->fingerprint()) << '\n'; + merge(key); + is_pem = false; + } else { + is_pem = true; + } + continue; } - continue; - } - fides::certificate *cert = certificate_from_string(line); - debug cerr << "Importing certificate " << hexencode(cert->fingerprint()) << '\n'; - merge(cert); + certificate *cert = certificate_from_string(line); + debug cerr << "Importing certificate " << hexencode(cert->fingerprint()) << '\n'; + merge(cert); + } } -} -/// Export all public keys and certificates to a stream. -// -/// @param out Stream to write to. -void fides::export_all(std::ostream &out) const { - for(map::const_iterator i = keys.begin(); i != keys.end(); ++i) - out << i->second->to_string(); - for(map::const_iterator i = certs.begin(); i != certs.end(); ++i) - out << i->second->to_string() << '\n'; -} + /// Export all public keys and certificates to a stream. + // + /// @param out Stream to write to. + void fides::export_all(std::ostream &out) const { + for(map::const_iterator i = keys.begin(); i != keys.end(); ++i) + out << i->second->to_string(); + for(map::const_iterator i = certs.begin(); i != certs.end(); ++i) + out << i->second->to_string() << '\n'; + } -/// Trust a public key. -// -/// This creates a certificate that says that we trust the given public key. -/// If a key is trusted, then authorisation certificates from that key are taken into account -/// when calling functions such as fides::is_allowed(). -/// -/// @param key Public key to trust. -void fides::trust(const publickey *key) { - string full = "t+ " + hexencode(key->fingerprint()); - sign(full); -} + /// Trust a public key. + // + /// This creates a certificate that says that we trust the given public key. + /// If a key is trusted, then authorisation certificates from that key are taken into account + /// when calling functions such as fides::is_allowed(). + /// + /// @param key Public key to trust. + void fides::trust(const publickey *key) { + string full = "t+ " + hexencode(key->fingerprint()); + sign(full); + } -/// Distrust a public key. -// -/// This creates a certificate that says that we distrust the given public key. -/// If a key is distrusted, then authorisation certificates from that key are not taken into account -/// when calling functions such as fides::is_allowed(). -/// -/// @param key Public key to trust. -void fides::distrust(const publickey *key) { - string full = "t- " + hexencode(key->fingerprint()); - sign(full); -} + /// Distrust a public key. + // + /// This creates a certificate that says that we distrust the given public key. + /// If a key is distrusted, then authorisation certificates from that key are not taken into account + /// when calling functions such as fides::is_allowed(). + /// + /// @param key Public key to trust. + void fides::distrust(const publickey *key) { + string full = "t- " + hexencode(key->fingerprint()); + sign(full); + } -/// Don't care about a public key. -// -/// This creates a certificate that says that we neither trust nor distrust the given public key. -/// This key and certificates created by it are then treated as if we have never trusted nor distrusted this key. -/// -/// @param key Public key to trust. -void fides::dctrust(const publickey *key) { - string full = "t0 " + hexencode(key->fingerprint()); - sign(full); -} + /// Don't care about a public key. + // + /// This creates a certificate that says that we neither trust nor distrust the given public key. + /// This key and certificates created by it are then treated as if we have never trusted nor distrusted this key. + /// + /// @param key Public key to trust. + void fides::dctrust(const publickey *key) { + string full = "t0 " + hexencode(key->fingerprint()); + sign(full); + } -/// Recalculate the trust value of all known public keys. -void fides::update_trust() { - // clear trust on all keys - for(map::const_iterator i = keys.begin(); i != keys.end(); ++i) - i->second->trust = 0; + /// Recalculate the trust value of all known public keys. + void fides::update_trust() { + // clear trust on all keys + for(map::const_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. + // 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 checked; - set tocheck; - set newkeys; - set::iterator i; + set checked; + set tocheck; + set newkeys; + set::iterator i; - mykey.trust = 3; - tocheck.insert(&mykey); + mykey.trust = 3; + tocheck.insert(&mykey); - while(tocheck.size()) { - // add - checked.insert(tocheck.begin(), tocheck.end()); - newkeys.clear(); + while(tocheck.size()) { + // add + checked.insert(tocheck.begin(), tocheck.end()); + newkeys.clear(); - // loop over all keys whose certificates need to be checked + // loop over all keys whose certificates need to be checked - for(i = tocheck.begin(); i != tocheck.end(); ++i) { - debug cerr << "Trust for key " << hexencode((*i)->fingerprint()) << " set to " << (*i)->trust << '\n'; + for(i = tocheck.begin(); i != tocheck.end(); ++i) { + debug cerr << "Trust for key " << hexencode((*i)->fingerprint()) << " set to " << (*i)->trust << '\n'; - // except if this key is not trusted + // except if this key is not trusted - if((*i)->trust <= 0) - continue; + if((*i)->trust <= 0) + continue; - // find all non-zero trust certificates of this key + // find all non-zero trust certificates of this key - vector matches = find_certificates(*i, "^t[+-] "); + vector matches = find_certificates(*i, "^t[+-] "); - // update trust value of those keys + // 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))); + 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; - } + if(!other) { + cerr << "Trust certificate for unknown key: " << matches[j]->to_string() << '\n'; + continue; + } - // except for keys we already checked + // except for keys we already checked - if(checked.find(other) != checked.end()) { - debug cerr << "Skipping trust certificate for already checked key: " << matches[j]->to_string() << '\n'; - continue; - } + if(checked.find(other) != checked.end()) { + debug cerr << "Skipping trust certificate for already checked key: " << matches[j]->to_string() << '\n'; + continue; + } - // update trust + // update trust - if(matches[j]->statement[1] == '+') - other->trust++; - else - other->trust--; + if(matches[j]->statement[1] == '+') + other->trust++; + else + other->trust--; - newkeys.insert(other); + newkeys.insert(other); + } } - } - tocheck = newkeys; + tocheck = newkeys; + } } -} - -/// Merges a public key into the database. -// -/// @param key The public key to merge. -void fides::merge(publickey *key) { - if(keys.find(key->fingerprint()) != keys.end()) { - debug cerr << "Key already known\n"; - return; - } - keys[key->fingerprint()] = key; - key->save(keydir + hexencode(key->fingerprint())); -} + /// Merges a public key into the database. + // + /// @param key The public key to merge. + void fides::merge(publickey *key) { + if(keys.find(key->fingerprint()) != keys.end()) { + debug cerr << "Key already known\n"; + return; + } -/// Merges a certificate into the database. -// -/// The database is searched to find if there are certificates from the same signer -/// with similar statements. -/// If the given certificate is similar to another one in our database, -/// then the certificate with the newer timestamp wins and will be allowed in the database, -/// the older certificate will be removed. -/// -/// @param cert The certificate to merge. -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()) { - debug cerr << "Certificate already known\n"; - return; + keys[key->fingerprint()] = key; + key->save(keydir + hexencode(key->fingerprint())); } - // If the certificate does not validate, drop it. - if(!cert->validate()) { - // TODO: this should not happen, be wary of DoS attacks - cerr << "Trying to merge invalid certificate: " << cert->to_string() << '\n'; - return; - } + /// Merges a certificate into the database. + // + /// The database is searched to find if there are certificates from the same signer + /// with similar statements. + /// If the given certificate is similar to another one in our database, + /// then the certificate with the newer timestamp wins and will be allowed in the database, + /// the older certificate will be removed. + /// + /// @param cert The certificate to merge. + 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()) { + debug cerr << "Certificate already known\n"; + return; + } - // TODO: move these regexps to the class? - regexp authexp("^a[+0-] "); - regexp trustexp("^t[+0-] "); - vector others; + // If the certificate does not validate, drop it. + if(!cert->validate()) { + // TODO: this should not happen, be wary of DoS attacks + cerr << "Trying to merge invalid certificate: " << cert->to_string() << '\n'; + return; + } - // 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, >)) { - debug cerr << "Certificate is overruled by a newer certificate\n"; + // TODO: move these regexps to the class? + regexp authexp("^a[+0-] "); + regexp trustexp("^t[+0-] "); + vector 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) + '$'); + if(others.size()) { + if(timercmp(&others[0]->timestamp, &cert->timestamp, >)) { + debug cerr << "Certificate is overruled by a newer certificate\n"; + return; + } + if(timercmp(&others[0]->timestamp, &cert->timestamp, ==)) { + // TODO: this should not happen, be wary of DoS attacks + debug cerr << "Certificate has same timestamp as another timestamp!\n"; + return; + } + debug cerr << "Certificate overrules an older certificate!\n"; + // save new cert first + certificate_save(cert, certdir + hexencode(cert->fingerprint())); + certs[cert->fingerprint()] = cert; + + // delete old one + rename((certdir + hexencode(others[0]->fingerprint())).c_str(), (obsoletedir + hexencode(others[0]->fingerprint())).c_str()); + certs.erase(others[0]->fingerprint()); + delete others[0]; return; } - if(timercmp(&others[0]->timestamp, &cert->timestamp, ==)) { - // TODO: this should not happen, be wary of DoS attacks - debug cerr << "Certificate has same timestamp as another timestamp!\n"; + } + + // Is this a trust cert? + // TODO: it's just the same as above! + if(trustexp.match(cert->statement)) { + // Find certs identical except for the +/-/0 + // TODO: escape statement in regexp + others = find_certificates(cert->signer, string("^t[+0-] ") + cert->statement.substr(3) + '$'); + if(others.size()) { + if(timercmp(&others[0]->timestamp, &cert->timestamp, >)) { + debug 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 + debug cerr << "Certificate has same timestamp as another timestamp!\n"; + return; + } + debug 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; } - debug 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) + '$'); + // Did somebody sign the exact same statement twice? + // Could happen if there is a different, conflicting statement between this new and the corresponding old one. + others = find_certificates(cert->signer, string("^") + cert->statement + '$'); if(others.size()) { if(timercmp(&others[0]->timestamp, &cert->timestamp, >)) { debug cerr << "Certificate is overruled by a newer certificate\n"; @@ -853,164 +544,140 @@ void fides::merge(certificate *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 + '$'); - if(others.size()) { - if(timercmp(&others[0]->timestamp, &cert->timestamp, >)) { - debug cerr << "Certificate is overruled by a newer certificate\n"; - return; - } - if(timercmp(&others[0]->timestamp, &cert->timestamp, ==)) { - // TODO: this should not happen, be wary of DoS attacks - debug cerr << "Certificate has same timestamp as another timestamp!\n"; - return; - } - debug cerr << "Certificate overrules an older certificate!\n"; - // delete old one - rename((certdir + hexencode(others[0]->fingerprint())).c_str(), (obsoletedir + hexencode(others[0]->fingerprint())).c_str()); - certs.erase(others[0]->fingerprint()); - delete others[0]; + debug cerr << "Certificate is new\n"; certs[cert->fingerprint()] = cert; certificate_save(cert, certdir + hexencode(cert->fingerprint())); - return; } - debug cerr << "Certificate is new\n"; - certs[cert->fingerprint()] = cert; - certificate_save(cert, certdir + hexencode(cert->fingerprint())); -} - -/// Calculates whether a statement is allowed or denied. -// -/// @param statement The statement to calculate the authorisation values for. -/// @param self Will be set to 1 if we allow the statement, -/// 0 if we neither allowed nor denied it, -/// or -1 if we denied it. -/// @param trusted Will be positive if the majority of the trusted public keys -/// gave a positive authorisation, 0 if there is a tie, -/// or negative if the majority gave a negative authorisation. -/// @param all Same as trusted but for all public keys. -void fides::auth_stats(const std::string &statement, int &self, int &trusted, int &all) const { - self = trusted = all = 0; - vector matches = find_certificates(string("^a[+0-] ") + statement + '$'); - 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; + /// Calculates whether a statement is allowed or denied. + // + /// @param statement The statement to calculate the authorisation values for. + /// @param self Will be set to 1 if we allow the statement, + /// 0 if we neither allowed nor denied it, + /// or -1 if we denied it. + /// @param trusted Will be positive if the majority of the trusted public keys + /// gave a positive authorisation, 0 if there is a tie, + /// or negative if the majority gave a negative authorisation. + /// @param all Same as trusted but for all public keys. + void fides::auth_stats(const std::string &statement, int &self, int &trusted, int &all) const { + self = trusted = all = 0; + vector 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; + } } -} -/// Tests whether the given public key is trusted. -// -/// @param key The public key to test. -/// @return True if the key is explicitly trusted, false otherwise. -bool fides::is_trusted(const publickey *key) const { - return key->trust > 0; -} + /// Tests whether the given public key is trusted. + // + /// @param key The public key to test. + /// @return True if the key is explicitly trusted, false otherwise. + bool fides::is_trusted(const publickey *key) const { + return key->trust > 0; + } -/// Tests whether the given public key is distrusted. -// -/// @param key The public key to test. -/// @return True if the key is explicitly distrusted, false otherwise. -bool fides::is_distrusted(const publickey *key) const { - return key->trust < 0; -} + /// Tests whether the given public key is distrusted. + // + /// @param key The public key to test. + /// @return True if the key is explicitly distrusted, false otherwise. + bool fides::is_distrusted(const publickey *key) const { + return key->trust < 0; + } -/// Tests whether the given statement is allowed. -// -/// @param statement The statement to test. -/// @param key The public key to test. -/// @return True if the statement is allowed for the given key, false otherwise. -bool fides::is_allowed(const std::string &statement, const publickey *key) const { - 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; -} + /// Tests whether the given statement is allowed. + // + /// @param statement The statement to test. + /// @param key The public key to test. + /// @return True if the statement is allowed for the given key, false otherwise. + bool fides::is_allowed(const std::string &statement, const publickey *key) const { + 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; + } -/// Tests whether the given statement is denied. -// -/// @param statement The statement to test. -/// @param key The public key to test. -/// @return True if the statement is denied for the given key, false otherwise. -bool fides::is_denied(const std::string &statement, const publickey *key) const { - 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; -} + /// Tests whether the given statement is denied. + // + /// @param statement The statement to test. + /// @param key The public key to test. + /// @return True if the statement is denied for the given key, false otherwise. + bool fides::is_denied(const std::string &statement, const publickey *key) const { + 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; + } -/// Creates a certificate for the given statement. -// -/// @param statement The statement to create a certificate for. -void fides::sign(const std::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; + /// Creates a certificate for the given statement. + // + /// @param statement The statement to create a certificate for. + void fides::sign(const std::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; } - } else { - latest = now; - } - // Create a new certificate and merge it with our database - merge(new certificate(&mykey, latest, statement)); -} + // Create a new certificate and merge it with our database + merge(new certificate(&mykey, latest, statement)); + } -void fides::allow(const std::string &statement, const publickey *key) { - string full = "a+ "; - if(key) - full += hexencode(key->fingerprint()) + ' '; - full += statement; - sign(full); -} + void fides::allow(const std::string &statement, const publickey *key) { + string full = "a+ "; + if(key) + full += hexencode(key->fingerprint()) + ' '; + full += statement; + sign(full); + } -void fides::dontcare(const std::string &statement, const publickey *key) { - string full = "a0 "; - if(key) - full += hexencode(key->fingerprint()) + ' '; - full += statement; - sign(full); -} + void fides::dontcare(const std::string &statement, const publickey *key) { + string full = "a0 "; + if(key) + full += hexencode(key->fingerprint()) + ' '; + full += statement; + sign(full); + } -void fides::deny(const std::string &statement, const publickey *key) { - string full = "a- "; - if(key) - full += hexencode(key->fingerprint()) + ' '; - full += statement; - sign(full); + void fides::deny(const std::string &statement, const publickey *key) { + string full = "a- "; + if(key) + full += hexencode(key->fingerprint()) + ' '; + full += statement; + sign(full); + } } -