/* * (C) 2014,2015 Jack Lloyd * * Botan is released under the Simplified BSD License (see license.txt) */ #include "cli.h" #include <botan/hex.h> #if defined(BOTAN_HAS_FPE_FE1) && defined(BOTAN_HAS_PBKDF) #include <botan/fpe_fe1.h> #include <botan/pbkdf.h> namespace Botan_CLI { namespace { uint8_t luhn_checksum(uint64_t cc_number) { uint8_t sum = 0; bool alt = false; while(cc_number) { uint8_t digit = cc_number % 10; if(alt) { digit *= 2; if(digit > 9) digit -= 9; } sum += digit; cc_number /= 10; alt = !alt; } return (sum % 10); } bool luhn_check(uint64_t cc_number) { return (luhn_checksum(cc_number) == 0); } uint64_t cc_rank(uint64_t cc_number) { // Remove Luhn checksum return cc_number / 10; } uint64_t cc_derank(uint64_t cc_number) { for(size_t i = 0; i != 10; ++i) { if(luhn_check(cc_number * 10 + i)) { return (cc_number * 10 + i); } } return 0; } uint64_t encrypt_cc_number(uint64_t cc_number, const Botan::secure_vector<uint8_t>& key, const std::vector<uint8_t>& tweak) { const Botan::BigInt n = 1000000000000000; const uint64_t cc_ranked = cc_rank(cc_number); const Botan::BigInt c = Botan::FPE::fe1_encrypt(n, cc_ranked, key, tweak); if(c.bits() > 50) throw Botan::Internal_Error("FPE produced a number too large"); uint64_t enc_cc = 0; for(size_t i = 0; i != 7; ++i) enc_cc = (enc_cc << 8) | c.byte_at(6-i); return cc_derank(enc_cc); } uint64_t decrypt_cc_number(uint64_t enc_cc, const Botan::secure_vector<uint8_t>& key, const std::vector<uint8_t>& tweak) { const Botan::BigInt n = 1000000000000000; const uint64_t cc_ranked = cc_rank(enc_cc); const Botan::BigInt c = Botan::FPE::fe1_decrypt(n, cc_ranked, key, tweak); if(c.bits() > 50) throw CLI_Error("FPE produced a number too large"); uint64_t dec_cc = 0; for(size_t i = 0; i != 7; ++i) dec_cc = (dec_cc << 8) | c.byte_at(6-i); return cc_derank(dec_cc); } } class CC_Encrypt final : public Command { public: CC_Encrypt() : Command("cc_encrypt CC passphrase --tweak=") {} void go() { const uint64_t cc_number = std::stoull(get_arg("CC")); const std::vector<uint8_t> tweak = Botan::hex_decode(get_arg("tweak")); const std::string pass = get_arg("passphrase"); std::unique_ptr<Botan::PBKDF> pbkdf(Botan::PBKDF::create("PBKDF2(SHA-256)")); if(!pbkdf) throw CLI_Error_Unsupported("PBKDF", "PBKDF2(SHA-256)"); Botan::secure_vector<uint8_t> key = pbkdf->pbkdf_iterations(32, pass, tweak.data(), tweak.size(), 100000); output() << encrypt_cc_number(cc_number, key, tweak) << "\n"; } }; BOTAN_REGISTER_COMMAND("cc_encrypt", CC_Encrypt); class CC_Decrypt final : public Command { public: CC_Decrypt() : Command("cc_decrypt CC passphrase --tweak=") {} void go() override { const uint64_t cc_number = std::stoull(get_arg("CC")); const std::vector<uint8_t> tweak = Botan::hex_decode(get_arg("tweak")); const std::string pass = get_arg("passphrase"); std::unique_ptr<Botan::PBKDF> pbkdf(Botan::PBKDF::create("PBKDF2(SHA-256)")); if(!pbkdf) throw CLI_Error_Unsupported("PBKDF", "PBKDF2(SHA-256)"); Botan::secure_vector<uint8_t> key = pbkdf->pbkdf_iterations(32, pass, tweak.data(), tweak.size(), 100000); output() << decrypt_cc_number(cc_number, key, tweak) << "\n"; } }; BOTAN_REGISTER_COMMAND("cc_decrypt", CC_Decrypt); } #endif // FPE && PBKDF