/**
* \file cipher.h
*
* \brief Generic cipher wrapper.
*
* \author Adriaan de Jong <dejong@fox-it.com>
*
* Copyright (C) 2006-2012, Brainspark B.V.
*
* This file is part of PolarSSL (http://www.polarssl.org)
* Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
*
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef POLARSSL_CIPHER_H
#define POLARSSL_CIPHER_H
#include <string.h>
#if defined(_MSC_VER) && !defined(inline)
#define inline _inline
#else
#if defined(__ARMCC_VERSION) && !defined(inline)
#define inline __inline
#endif /* __ARMCC_VERSION */
#endif /*_MSC_VER */
#define POLARSSL_ERR_CIPHER_FEATURE_UNAVAILABLE -0x6080 /**< The selected feature is not available. */
#define POLARSSL_ERR_CIPHER_BAD_INPUT_DATA -0x6100 /**< Bad input parameters to function. */
#define POLARSSL_ERR_CIPHER_ALLOC_FAILED -0x6180 /**< Failed to allocate memory. */
#define POLARSSL_ERR_CIPHER_INVALID_PADDING -0x6200 /**< Input data contains invalid padding and is rejected. */
#define POLARSSL_ERR_CIPHER_FULL_BLOCK_EXPECTED -0x6280 /**< Decryption of block requires a full block. */
typedef enum {
POLARSSL_CIPHER_ID_NONE = 0,
POLARSSL_CIPHER_ID_NULL,
POLARSSL_CIPHER_ID_AES,
POLARSSL_CIPHER_ID_DES,
POLARSSL_CIPHER_ID_3DES,
POLARSSL_CIPHER_ID_CAMELLIA,
POLARSSL_CIPHER_ID_BLOWFISH,
} cipher_id_t;
typedef enum {
POLARSSL_CIPHER_NONE = 0,
POLARSSL_CIPHER_NULL,
POLARSSL_CIPHER_AES_128_CBC,
POLARSSL_CIPHER_AES_192_CBC,
POLARSSL_CIPHER_AES_256_CBC,
POLARSSL_CIPHER_AES_128_CFB128,
POLARSSL_CIPHER_AES_192_CFB128,
POLARSSL_CIPHER_AES_256_CFB128,
POLARSSL_CIPHER_AES_128_CTR,
POLARSSL_CIPHER_AES_192_CTR,
POLARSSL_CIPHER_AES_256_CTR,
POLARSSL_CIPHER_CAMELLIA_128_CBC,
POLARSSL_CIPHER_CAMELLIA_192_CBC,
POLARSSL_CIPHER_CAMELLIA_256_CBC,
POLARSSL_CIPHER_CAMELLIA_128_CFB128,
POLARSSL_CIPHER_CAMELLIA_192_CFB128,
POLARSSL_CIPHER_CAMELLIA_256_CFB128,
POLARSSL_CIPHER_CAMELLIA_128_CTR,
POLARSSL_CIPHER_CAMELLIA_192_CTR,
POLARSSL_CIPHER_CAMELLIA_256_CTR,
POLARSSL_CIPHER_DES_CBC,
POLARSSL_CIPHER_DES_EDE_CBC,
POLARSSL_CIPHER_DES_EDE3_CBC,
POLARSSL_CIPHER_BLOWFISH_CBC,
POLARSSL_CIPHER_BLOWFISH_CFB64,
POLARSSL_CIPHER_BLOWFISH_CTR,
} cipher_type_t;
typedef enum {
POLARSSL_MODE_NONE = 0,
POLARSSL_MODE_NULL,
POLARSSL_MODE_CBC,
POLARSSL_MODE_CFB,
POLARSSL_MODE_OFB,
POLARSSL_MODE_CTR,
} cipher_mode_t;
typedef enum {
POLARSSL_OPERATION_NONE = -1,
POLARSSL_DECRYPT = 0,
POLARSSL_ENCRYPT,
} operation_t;
enum {
/** Undefined key length */
POLARSSL_KEY_LENGTH_NONE = 0,
/** Key length, in bits (including parity), for DES keys */
POLARSSL_KEY_LENGTH_DES = 64,
/** Key length, in bits (including parity), for DES in two key EDE */
POLARSSL_KEY_LENGTH_DES_EDE = 128,
/** Key length, in bits (including parity), for DES in three-key EDE */
POLARSSL_KEY_LENGTH_DES_EDE3 = 192,
/** Maximum length of any IV, in bytes */
POLARSSL_MAX_IV_LENGTH = 16,
};
/**
* Base cipher information. The non-mode specific functions and values.
*/
typedef struct {
/** Base Cipher type (e.g. POLARSSL_CIPHER_ID_AES) */
cipher_id_t cipher;
/** Encrypt using CBC */
int (*cbc_func)( void *ctx, operation_t mode, size_t length, unsigned char *iv,
const unsigned char *input, unsigned char *output );
/** Encrypt using CFB (Full length) */
int (*cfb_func)( void *ctx, operation_t mode, size_t length, size_t *iv_off,
unsigned char *iv, const unsigned char *input, unsigned char *output );
/** Encrypt using CTR */
int (*ctr_func)( void *ctx, size_t length, size_t *nc_off, unsigned char *nonce_counter,
unsigned char *stream_block, const unsigned char *input, unsigned char *output );
/** Set key for encryption purposes */
int (*setkey_enc_func)( void *ctx, const unsigned char *key, unsigned int key_length);
/** Set key for decryption purposes */
int (*setkey_dec_func)( void *ctx, const unsigned char *key, unsigned int key_length);
/** Allocate a new context */
void * (*ctx_alloc_func)( void );
/** Free the given context */
void (*ctx_free_func)( void *ctx );
} cipher_base_t;
/**
* Cipher information. Allows cipher functions to be called in a generic way.
*/
typedef struct {
/** Full cipher identifier (e.g. POLARSSL_CIPHER_AES_256_CBC) */
cipher_type_t type;
/** Cipher mode (e.g. POLARSSL_MODE_CBC) */
cipher_mode_t mode;
/** Cipher key length, in bits (default length for variable sized ciphers)
* (Includes parity bits for ciphers like DES) */
unsigned int key_length;
/** Name of the cipher */
const char * name;
/** IV size, in bytes */
unsigned int iv_size;
/** block size, in bytes */
unsigned int block_size;
/** Base cipher information and functions */
const cipher_base_t *base;
} cipher_info_t;
/**
* Generic cipher context.
*/
typedef struct {
/** Information about the associated cipher */
const cipher_info_t *cipher_info;
/** Key length to use */
int key_length;
/** Operation that the context's key has been initialised for */
operation_t operation;
/** Buffer for data that hasn't been encrypted yet */
unsigned char unprocessed_data[POLARSSL_MAX_IV_LENGTH];
/** Number of bytes that still need processing */
size_t unprocessed_len;
/** Current IV or NONCE_COUNTER for CTR-mode */
unsigned char iv[POLARSSL_MAX_IV_LENGTH];
/** Cipher-specific context */
void *cipher_ctx;
} cipher_context_t;
#ifdef __cplusplus
extern "C" {
#endif
/**
* \brief Returns the list of ciphers supported by the generic cipher module.
*
* \return a statically allocated array of ciphers, the last entry
* is 0.
*/
const int *cipher_list( void );
/**
* \brief Returns the cipher information structure associated
* with the given cipher name.
*
* \param cipher_name Name of the cipher to search for.
*
* \return the cipher information structure associated with the
* given cipher_name, or NULL if not found.
*/
const cipher_info_t *cipher_info_from_string( const char *cipher_name );
/**
* \brief Returns the cipher information structure associated
* with the given cipher type.
*
* \param cipher_type Type of the cipher to search for.
*
* \return the cipher information structure associated with the
* given cipher_type, or NULL if not found.
*/
const cipher_info_t *cipher_info_from_type( const cipher_type_t cipher_type );
/**
* \brief Initialises and fills the cipher context structure with
* the appropriate values.
*
* \param ctx context to initialise. May not be NULL.
* \param cipher_info cipher to use.
*
* \return \c 0 on success,
* \c POLARSSL_ERR_CIPHER_BAD_INPUT_DATA on parameter failure,
* \c POLARSSL_ERR_CIPHER_ALLOC_FAILED if allocation of the
* cipher-specific context failed.
*/
int cipher_init_ctx( cipher_context_t *ctx, const cipher_info_t *cipher_info );
/**
* \brief Free the cipher-specific context of ctx. Freeing ctx
* itself remains the responsibility of the caller.
*
* \param ctx Free the cipher-specific context
*
* \returns 0 on success, POLARSSL_ERR_CIPHER_BAD_INPUT_DATA if
* parameter verification fails.
*/
int cipher_free_ctx( cipher_context_t *ctx );
/**
* \brief Returns the block size of the given cipher.
*
* \param ctx cipher's context. Must have been initialised.
*
* \return size of the cipher's blocks, or 0 if ctx has not been
* initialised.
*/
static inline unsigned int cipher_get_block_size( const cipher_context_t *ctx )
{
if( NULL == ctx || NULL == ctx->cipher_info )
return 0;
return ctx->cipher_info->block_size;
}
/**
* \brief Returns the mode of operation for the cipher.
* (e.g. POLARSSL_MODE_CBC)
*
* \param ctx cipher's context. Must have been initialised.
*
* \return mode of operation, or POLARSSL_MODE_NONE if ctx
* has not been initialised.
*/
static inline cipher_mode_t cipher_get_cipher_mode( const cipher_context_t *ctx )
{
if( NULL == ctx || NULL == ctx->cipher_info )
return POLARSSL_MODE_NONE;
return ctx->cipher_info->mode;
}
/**
* \brief Returns the size of the cipher's IV.
*
* \param ctx cipher's context. Must have been initialised.
*
* \return size of the cipher's IV, or 0 if ctx has not been
* initialised.
*/
static inline int cipher_get_iv_size( const cipher_context_t *ctx )
{
if( NULL == ctx || NULL == ctx->cipher_info )
return 0;
return ctx->cipher_info->iv_size;
}
/**
* \brief Returns the type of the given cipher.
*
* \param ctx cipher's context. Must have been initialised.
*
* \return type of the cipher, or POLARSSL_CIPHER_NONE if ctx has
* not been initialised.
*/
static inline cipher_type_t cipher_get_type( const cipher_context_t *ctx )
{
if( NULL == ctx || NULL == ctx->cipher_info )
return POLARSSL_CIPHER_NONE;
return ctx->cipher_info->type;
}
/**
* \brief Returns the name of the given cipher, as a string.
*
* \param ctx cipher's context. Must have been initialised.
*
* \return name of the cipher, or NULL if ctx was not initialised.
*/
static inline const char *cipher_get_name( const cipher_context_t *ctx )
{
if( NULL == ctx || NULL == ctx->cipher_info )
return 0;
return ctx->cipher_info->name;
}
/**
* \brief Returns the key length of the cipher.
*
* \param ctx cipher's context. Must have been initialised.
*
* \return cipher's key length, in bits, or
* POLARSSL_KEY_LENGTH_NONE if ctx has not been
* initialised.
*/
static inline int cipher_get_key_size ( const cipher_context_t *ctx )
{
if( NULL == ctx )
return POLARSSL_KEY_LENGTH_NONE;
return ctx->key_length;
}
/**
* \brief Returns the operation of the given cipher.
*
* \param ctx cipher's context. Must have been initialised.
*
* \return operation (POLARSSL_ENCRYPT or POLARSSL_DECRYPT),
* or POLARSSL_OPERATION_NONE if ctx has not been
* initialised.
*/
static inline operation_t cipher_get_operation( const cipher_context_t *ctx )
{
if( NULL == ctx || NULL == ctx->cipher_info )
return POLARSSL_OPERATION_NONE;
return ctx->operation;
}
/**
* \brief Set the key to use with the given context.
*
* \param ctx generic cipher context. May not be NULL. Must have been
* initialised using cipher_context_from_type or
* cipher_context_from_string.
* \param key The key to use.
* \param key_length key length to use, in bits.
* \param operation Operation that the key will be used for, either
* POLARSSL_ENCRYPT or POLARSSL_DECRYPT.
*
* \returns 0 on success, POLARSSL_ERR_CIPHER_BAD_INPUT_DATA if
* parameter verification fails or a cipher specific
* error code.
*/
int cipher_setkey( cipher_context_t *ctx, const unsigned char *key, int key_length,
const operation_t operation );
/**
* \brief Reset the given context, setting the IV to iv
*
* \param ctx generic cipher context
* \param iv IV to use or NONCE_COUNTER in the case of a CTR-mode cipher
*
* \returns 0 on success, POLARSSL_ERR_CIPHER_BAD_INPUT_DATA
* if parameter verification fails.
*/
int cipher_reset( cipher_context_t *ctx, const unsigned char *iv );
/**
* \brief Generic cipher update function. Encrypts/decrypts
* using the given cipher context. Writes as many block
* size'd blocks of data as possible to output. Any data
* that cannot be written immediately will either be added
* to the next block, or flushed when cipher_final is
* called.
*
* \param ctx generic cipher context
* \param input buffer holding the input data
* \param ilen length of the input data
* \param output buffer for the output data. Should be able to hold at
* least ilen + block_size. Cannot be the same buffer as
* input!
* \param olen length of the output data, will be filled with the
* actual number of bytes written.
*
* \returns 0 on success, POLARSSL_ERR_CIPHER_BAD_INPUT_DATA if
* parameter verification fails,
* POLARSSL_ERR_CIPHER_FEATURE_UNAVAILABLE on an
* unsupported mode for a cipher or a cipher specific
* error code.
*/
int cipher_update( cipher_context_t *ctx, const unsigned char *input, size_t ilen,
unsigned char *output, size_t *olen );
/**
* \brief Generic cipher finalisation function. If data still
* needs to be flushed from an incomplete block, data
* contained within it will be padded with the size of
* the last block, and written to the output buffer.
*
* \param ctx Generic cipher context
* \param output buffer to write data to. Needs block_size data available.
* \param olen length of the data written to the output buffer.
*
* \returns 0 on success, POLARSSL_ERR_CIPHER_BAD_INPUT_DATA if
* parameter verification fails,
* POLARSSL_ERR_CIPHER_FULL_BLOCK_EXPECTED if decryption
* expected a full block but was not provided one,
* POLARSSL_ERR_CIPHER_INVALID_PADDING on invalid padding
* while decrypting or a cipher specific error code.
*/
int cipher_finish( cipher_context_t *ctx, unsigned char *output, size_t *olen);
/**
* \brief Checkup routine
*
* \return 0 if successful, or 1 if the test failed
*/
int cipher_self_test( int verbose );
#ifdef __cplusplus
}
#endif
#endif /* POLARSSL_MD_H */