It's likely that other FPE methods will be desirable once they are

standardized by NIST; the FPE currently included is just a random one
that was relatively easy to implement. Move the header to fpe_fe1.h,
and rename the function. Update the example and add some documentation
for it.

3 files changed, 17 insertions, 9 deletions

diff --git a/src/constructs/fpe/fpe.cpp b/src/constructs/fpe_fe1/fpe_fe1.cpp
index 5491af133..91d328c17 100644
--- a/src/constructs/fpe/fpe.cpp
+++ b/src/constructs/fpe_fe1/fpe_fe1.cpp
@@ -8,7 +8,7 @@
 * Distributed under the terms of the Botan license
 */
 
-#include <botan/fpe.h>
+#include <botan/fpe_fe1.h>
 #include <botan/numthry.h>
 #include <botan/hmac.h>
 #include <botan/sha2_32.h>
@@ -16,6 +16,8 @@
 
 namespace Botan {
 
+namespace FPE {
+
 namespace {
 
 // Normally FPE is for SSNs, CC#s, etc, nothing too big
@@ -133,7 +135,7 @@ BigInt FPE_Encryptor::operator()(size_t round_no, const BigInt& R)
 /*
 * Generic Z_n FPE encryption, FE1 scheme
 */
-BigInt fpe_encrypt(const BigInt& n, const BigInt& X0,
+BigInt fe1_encrypt(const BigInt& n, const BigInt& X0,
                    const SymmetricKey& key,
                    const MemoryRegion<byte>& tweak)
    {
@@ -161,7 +163,7 @@ BigInt fpe_encrypt(const BigInt& n, const BigInt& X0,
 /*
 * Generic Z_n FPE decryption, FD1 scheme
 */
-BigInt fpe_decrypt(const BigInt& n, const BigInt& X0,
+BigInt fe1_decrypt(const BigInt& n, const BigInt& X0,
                    const SymmetricKey& key,
                    const MemoryRegion<byte>& tweak)
    {
@@ -187,3 +189,5 @@ BigInt fpe_decrypt(const BigInt& n, const BigInt& X0,
    }
 
 }
+
+}
diff --git a/src/constructs/fpe/fpe.h b/src/constructs/fpe_fe1/fpe_fe1.h
index 7a4a7861a..da9a6bcb6 100644
--- a/src/constructs/fpe/fpe.h
+++ b/src/constructs/fpe_fe1/fpe_fe1.h
@@ -1,18 +1,20 @@
 /*
-* Format Preserving Encryption
+* Format Preserving Encryption (FE1 scheme)
 * (C) 2009 Jack Lloyd
 *
 * Distributed under the terms of the Botan license
 */
 
-#ifndef BOTAN_FORMAT_PRESERVING_ENCRYPTION_H__
-#define BOTAN_FORMAT_PRESERVING_ENCRYPTION_H__
+#ifndef BOTAN_FPE_FE1_H__
+#define BOTAN_FPE_FE1_H__
 
 #include <botan/bigint.h>
 #include <botan/symkey.h>
 
 namespace Botan {
 
+namespace FPE {
+
 /**
 * Encrypt X from and onto the group Z_n using key and tweak
 * @param n the modulus
@@ -20,7 +22,7 @@ namespace Botan {
 * @param key a random key
 * @param tweak will modify the ciphertext (think of as an IV)
 */
-BigInt BOTAN_DLL fpe_encrypt(const BigInt& n, const BigInt& X,
+BigInt BOTAN_DLL fe1_encrypt(const BigInt& n, const BigInt& X,
                              const SymmetricKey& key,
                              const MemoryRegion<byte>& tweak);
 
@@ -31,10 +33,12 @@ BigInt BOTAN_DLL fpe_encrypt(const BigInt& n, const BigInt& X,
 * @param key is the key used for encryption
 * @param tweak the same tweak used for encryption
 */
-BigInt BOTAN_DLL fpe_decrypt(const BigInt& n, const BigInt& X,
+BigInt BOTAN_DLL fe1_decrypt(const BigInt& n, const BigInt& X,
                              const SymmetricKey& key,
                              const MemoryRegion<byte>& tweak);
 
 }
 
+}
+
 #endif
diff --git a/src/constructs/fpe/info.txt b/src/constructs/fpe_fe1/info.txt
index 078eb2135..33b5a1c80 100644
--- a/src/constructs/fpe/info.txt
+++ b/src/constructs/fpe_fe1/info.txt
@@ -1,4 +1,4 @@
-define FORMAT_PRESERVING_ENCRYPTION
+define FPE_FE1
 
 <requires>
 hmac