1 files changed, 161 insertions, 0 deletions
diff --git a/src/cli/cc_enc.cpp b/src/cli/cc_enc.cpp
new file mode 100644
index 000000000..25c9b960b
--- /dev/null
+++ b/src/cli/cc_enc.cpp
@@ -0,0 +1,161 @@
+/*
+* (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 std::runtime_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 : 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);
+
+class CC_Decrypt : 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);
+
+}
+
+#endif // FPE && PBKDF