ffi_fpe.cpp File Reference

#include <botan/ffi.h>
#include <botan/assert.h>
#include <botan/internal/ffi_mp.h>
#include <botan/internal/ffi_util.h>
#include <memory>

Go to the source code of this file.

Functions
int	botan_fpe_decrypt (botan_fpe_t fpe, botan_mp_t x, const uint8_t tweak[], size_t tweak_len)
int	botan_fpe_destroy (botan_fpe_t fpe)
int	botan_fpe_encrypt (botan_fpe_t fpe, botan_mp_t x, const uint8_t tweak[], size_t tweak_len)
int	botan_fpe_fe1_init (botan_fpe_t *fpe, botan_mp_t n, const uint8_t key[], size_t key_len, size_t rounds, uint32_t flags)

Function Documentation

botan_fpe_decrypt()

int botan_fpe_decrypt	(	botan_fpe_t	fpe,
		botan_mp_t	x,
		const uint8_t	tweak[],
		size_t	tweak_len )

Decrypt an integer, replacing it with the result

Parameters

fpe	the FPE object
x	the value to decrypt, modified in place; must be less than n
tweak	the tweak, may be NULL if tweak_len is 0
tweak_len	length of tweak in bytes

Returns

0 on success, a negative value on failure

Definition at line 82 of file ffi_fpe.cpp.

                                                                                              {
   if(tweak_len > 0 && tweak == nullptr) {
      return BOTAN_FFI_ERROR_NULL_POINTER;
   }
 
#if defined(BOTAN_HAS_FPE_FE1)
   return ffi_guard_thunk(__func__, [=]() {
      const Botan::BigInt r = safe_get(fpe).decrypt(safe_get(x), tweak, tweak_len);
      safe_get(x) = r;
      return BOTAN_FFI_SUCCESS;
   });
 
#else
   BOTAN_UNUSED(fpe, x, tweak, tweak_len);
   return BOTAN_FFI_ERROR_NOT_IMPLEMENTED;
#endif
}

References BOTAN_FFI_ERROR_NOT_IMPLEMENTED, BOTAN_FFI_ERROR_NULL_POINTER, BOTAN_FFI_SUCCESS, BOTAN_UNUSED, Botan_FFI::ffi_guard_thunk(), and Botan_FFI::safe_get().

botan_fpe_destroy()

int botan_fpe_destroy

(

botan_fpe_t

fpe

)

Frees all resources of the FPE object

Parameters

fpe	the FPE object to destroy

Returns

0 if success, error if invalid object handle

Definition at line 56 of file ffi_fpe.cpp.

                                       {
#if defined(BOTAN_HAS_FPE_FE1)
   return BOTAN_FFI_CHECKED_DELETE(fpe);
#else
   BOTAN_UNUSED(fpe);
   return BOTAN_FFI_ERROR_NOT_IMPLEMENTED;
#endif
}

References BOTAN_FFI_CHECKED_DELETE, BOTAN_FFI_ERROR_NOT_IMPLEMENTED, and BOTAN_UNUSED.

botan_fpe_encrypt()

int botan_fpe_encrypt	(	botan_fpe_t	fpe,
		botan_mp_t	x,
		const uint8_t	tweak[],
		size_t	tweak_len )

Encrypt an integer, replacing it with the result

Parameters

fpe	the FPE object
x	the value to encrypt, modified in place; must be less than n
tweak	the tweak, may be NULL if tweak_len is 0
tweak_len	length of tweak in bytes

Returns

0 on success, a negative value on failure

Definition at line 65 of file ffi_fpe.cpp.

                                                                                              {
   if(tweak_len > 0 && tweak == nullptr) {
      return BOTAN_FFI_ERROR_NULL_POINTER;
   }
 
#if defined(BOTAN_HAS_FPE_FE1)
   return ffi_guard_thunk(__func__, [=]() {
      const Botan::BigInt r = safe_get(fpe).encrypt(safe_get(x), tweak, tweak_len);
      safe_get(x) = r;
      return BOTAN_FFI_SUCCESS;
   });
#else
   BOTAN_UNUSED(fpe, x, tweak, tweak_len);
   return BOTAN_FFI_ERROR_NOT_IMPLEMENTED;
#endif
}

References BOTAN_FFI_ERROR_NOT_IMPLEMENTED, BOTAN_FFI_ERROR_NULL_POINTER, BOTAN_FFI_SUCCESS, BOTAN_UNUSED, Botan_FFI::ffi_guard_thunk(), and Botan_FFI::safe_get().

botan_fpe_fe1_init()

int botan_fpe_fe1_init	(	botan_fpe_t *	fpe,
		botan_mp_t	n,
		const uint8_t	key[],
		size_t	key_len,
		size_t	rounds,
		uint32_t	flags )

Initialize an FE1 format preserving encryption object, which encrypts integers in the range [0, n)

Parameters

fpe	the new object will be placed here
n	the modulus defining the range of the permutation
key	the key
key_len	length of key in bytes
rounds	the number of Feistel rounds; at least 16 is recommended
flags	0, or BOTAN_FPE_FLAG_FE1_COMPAT_MODE to match the encoding used by Botan versions prior to 2.5

Returns

0 on success, a negative value on failure

Definition at line 28 of file ffi_fpe.cpp.

                                                                                                       {
#if defined(BOTAN_HAS_FPE_FE1)
   return ffi_guard_thunk(__func__, [=]() {
      if(any_null_pointers(fpe, key)) {
         return BOTAN_FFI_ERROR_NULL_POINTER;
      }
 
      *fpe = nullptr;
 
      if(flags != 0 && flags != BOTAN_FPE_FLAG_FE1_COMPAT_MODE) {
         return BOTAN_FFI_ERROR_BAD_FLAG;
      }
 
      const bool compat_mode = (flags & BOTAN_FPE_FLAG_FE1_COMPAT_MODE) != 0;
 
      auto fpe_obj = std::make_unique<Botan::FPE_FE1>(safe_get(n), rounds, compat_mode);
 
      fpe_obj->set_key(key, key_len);
 
      return ffi_new_object(fpe, std::move(fpe_obj));
   });
#else
   BOTAN_UNUSED(fpe, n, key, key_len, rounds, flags);
   return BOTAN_FFI_ERROR_NOT_IMPLEMENTED;
#endif
}

References Botan_FFI::any_null_pointers(), BOTAN_FFI_ERROR_BAD_FLAG, BOTAN_FFI_ERROR_NOT_IMPLEMENTED, BOTAN_FFI_ERROR_NULL_POINTER, BOTAN_FPE_FLAG_FE1_COMPAT_MODE, BOTAN_UNUSED, Botan_FFI::ffi_guard_thunk(), Botan_FFI::ffi_new_object(), and Botan_FFI::safe_get().