namespace Crypto { public class SymmetricCipher { private GCrypt.Cipher.Cipher cipher; public static bool supports(string algo_name) { GCrypt.Cipher.Algorithm algo; GCrypt.Cipher.Mode mode; GCrypt.Cipher.Flag flags; return parse(algo_name, out algo, out mode, out flags); } private static unowned string mode_to_string(GCrypt.Cipher.Mode mode) { switch (mode) { case GCrypt.Cipher.Mode.ECB: return "ECB"; case GCrypt.Cipher.Mode.CFB: return "CFB"; case GCrypt.Cipher.Mode.CBC: return "CBC"; case GCrypt.Cipher.Mode.STREAM: return "STREAM"; case GCrypt.Cipher.Mode.OFB: return "OFB"; case GCrypt.Cipher.Mode.CTR: return "CTR"; case GCrypt.Cipher.Mode.AESWRAP: return "AESWRAP"; case GCrypt.Cipher.Mode.GCM: return "GCM"; case GCrypt.Cipher.Mode.POLY1305: return "POLY1305"; case GCrypt.Cipher.Mode.OCB: return "OCB"; case GCrypt.Cipher.Mode.CFB8: return "CFB8"; case GCrypt.Cipher.Mode.XTS: return "XTS"; } return "NONE"; } private static GCrypt.Cipher.Mode mode_from_string(string name) { switch (name) { case "ECB": return GCrypt.Cipher.Mode.ECB; case "CFB": return GCrypt.Cipher.Mode.CFB; case "CBC": return GCrypt.Cipher.Mode.CBC; case "STREAM": return GCrypt.Cipher.Mode.STREAM; case "OFB": return GCrypt.Cipher.Mode.OFB; case "CTR": return GCrypt.Cipher.Mode.CTR; case "AESWRAP": return GCrypt.Cipher.Mode.AESWRAP; case "GCM": return GCrypt.Cipher.Mode.GCM; case "POLY1305": return GCrypt.Cipher.Mode.POLY1305; case "OCB": return GCrypt.Cipher.Mode.OCB; case "CFB8": return GCrypt.Cipher.Mode.CFB8; case "XTS": return GCrypt.Cipher.Mode.XTS; } return GCrypt.Cipher.Mode.NONE; } private static string flags_to_string(GCrypt.Cipher.Flag flags) { string? s = null; if ((GCrypt.Cipher.Flag.CBC_MAC & flags) != 0) s = (s == null ? "" : @"$s-") + "MAC"; if ((GCrypt.Cipher.Flag.CBC_CTS & flags) != 0) s = (s == null ? "" : @"$s-") + "CTS"; if ((GCrypt.Cipher.Flag.ENABLE_SYNC & flags) != 0) s = (s == null ? "" : @"$s-") + "SYNC"; if ((GCrypt.Cipher.Flag.SECURE & flags) != 0) s = (s == null ? "" : @"$s-") + "SECURE"; return s ?? "NONE"; } private static GCrypt.Cipher.Flag flag_from_string(string flag_name) { if (flag_name == "SECURE") return GCrypt.Cipher.Flag.SECURE; if (flag_name == "SYNC") return GCrypt.Cipher.Flag.ENABLE_SYNC; if (flag_name == "CTS") return GCrypt.Cipher.Flag.CBC_CTS; if (flag_name == "MAC") return GCrypt.Cipher.Flag.CBC_MAC; return 0; } private static GCrypt.Cipher.Flag flags_from_string(string flag_names) { GCrypt.Cipher.Flag flags = 0; foreach(string flag in flag_names.split("-")) { flags |= flag_from_string(flag); } return flags; } private static bool parse(string algo_name, out GCrypt.Cipher.Algorithm algo, out GCrypt.Cipher.Mode mode, out GCrypt.Cipher.Flag flags) { algo = GCrypt.Cipher.Algorithm.NONE; mode = GCrypt.Cipher.Mode.NONE; flags = 0; string[] algo_parts = algo_name.split("-", 3); algo = GCrypt.Cipher.Algorithm.from_string(algo_parts[0]); if (algo_parts.length >= 2) { mode = mode_from_string(algo_parts[1]); } if (algo_parts.length == 3) { flags |= flags_from_string(algo_parts[2]); } return to_algo_name(algo, mode, flags) == algo_name; } private static string to_algo_name(GCrypt.Cipher.Algorithm algo = GCrypt.Cipher.Algorithm.NONE, GCrypt.Cipher.Mode mode = GCrypt.Cipher.Mode.NONE, GCrypt.Cipher.Flag flags = 0) { if (flags != 0) { return @"$algo-$(mode_to_string(mode))-$(flags_to_string(flags))"; } else if (mode != GCrypt.Cipher.Mode.NONE) { return @"$algo-$(mode_to_string(mode))"; } else { return algo.to_string(); } } public SymmetricCipher(string algo_name) throws Error { GCrypt.Cipher.Algorithm algo; GCrypt.Cipher.Mode mode; GCrypt.Cipher.Flag flags; if (parse(algo_name, out algo, out mode, out flags)) { this.gcrypt(algo, mode, flags); } else { throw new Error.ILLEGAL_ARGUMENTS(@"The algorithm $algo_name is not supported"); } } private SymmetricCipher.gcrypt(GCrypt.Cipher.Algorithm algo, GCrypt.Cipher.Mode mode, GCrypt.Cipher.Flag flags) throws Error { may_throw_gcrypt_error(GCrypt.Cipher.Cipher.open(out this.cipher, algo, mode, flags)); } public void set_key(uint8[] key) throws Error { may_throw_gcrypt_error(cipher.set_key(key)); } public void set_iv(uint8[] iv) throws Error { may_throw_gcrypt_error(cipher.set_iv(iv)); } public void set_counter_vector(uint8[] ctr) throws Error { may_throw_gcrypt_error(cipher.set_counter_vector(ctr)); } public void reset() throws Error { may_throw_gcrypt_error(cipher.reset()); } public uint8[] get_tag(size_t taglen) throws Error { uint8[] tag = new uint8[taglen]; may_throw_gcrypt_error(cipher.get_tag(tag)); return tag; } public void check_tag(uint8[] tag) throws Error { may_throw_gcrypt_error(cipher.check_tag(tag)); } public void encrypt(uint8[] output, uint8[] input) throws Error { may_throw_gcrypt_error(cipher.encrypt(output, input)); } public void decrypt(uint8[] output, uint8[] input) throws Error { may_throw_gcrypt_error(cipher.decrypt(output, input)); } public void sync() throws Error { may_throw_gcrypt_error(cipher.sync()); } } }