text: /* $Id: sph_echo.h 216 2010-06-08 09:46:57Z tp $ */
  /**
   * ECHO interface. ECHO is a family of functions which differ by
   * their output size; this implementation defines ECHO for output
   * sizes 224, 256, 384 and 512 bits.
   *
   * ==========================(LICENSE BEGIN)============================
   *
   * Copyright (c) 2007-2010  Projet RNRT SAPHIR
   * 
   * Permission is hereby granted, free of charge, to any person obtaining
   * a copy of this software and associated documentation files (the
   * "Software"), to deal in the Software without restriction, including
   * without limitation the rights to use, copy, modify, merge, publish,
   * distribute, sublicense, and/or sell copies of the Software, and to
   * permit persons to whom the Software is furnished to do so, subject to
   * the following conditions:
   * 
   * The above copyright notice and this permission notice shall be
   * included in all copies or substantial portions of the Software.
   * 
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
   * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
   * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
   * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
   * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
   *
   * ===========================(LICENSE END)=============================
   *
   * @file     sph_echo.h
   * @author   Thomas Pornin <thomas.pornin@cryptolog.com>
   */
  
  #ifndef SPH_ECHO_H__
  #define SPH_ECHO_H__
  
  #ifdef __cplusplus
  extern "C"{
  #endif
  
  #include <stddef.h>
  #include "sph_types.h"
  
  /**
   * Output size (in bits) for ECHO-224.
   */
  #define SPH_SIZE_echo224   224
  
  /**
   * Output size (in bits) for ECHO-256.
   */
  #define SPH_SIZE_echo256   256
  
  /**
   * Output size (in bits) for ECHO-384.
   */
  #define SPH_SIZE_echo384   384
  
  /**
   * Output size (in bits) for ECHO-512.
   */
  #define SPH_SIZE_echo512   512
  
  /**
   * This structure is a context for ECHO computations: it contains the
   * intermediate values and some data from the last entered block. Once
   * an ECHO computation has been performed, the context can be reused for
   * another computation. This specific structure is used for ECHO-224
   * and ECHO-256.
   *
   * The contents of this structure are private. A running ECHO computation
   * can be cloned by copying the context (e.g. with a simple
   * <code>memcpy()</code>).
   */
  typedef struct {
  #ifndef DOXYGEN_IGNORE
  	unsigned char buf[192];    /* first field, for alignment */
  	size_t ptr;
  	union {
  		sph_u32 Vs[4][4];
  #if SPH_64
  		sph_u64 Vb[4][2];
  #endif
  	} u;
  	sph_u32 C0, C1, C2, C3;
  #endif
  } sph_echo_small_context;
  
  /**
   * This structure is a context for ECHO computations: it contains the
   * intermediate values and some data from the last entered block. Once
   * an ECHO computation has been performed, the context can be reused for
   * another computation. This specific structure is used for ECHO-384
   * and ECHO-512.
   *
   * The contents of this structure are private. A running ECHO computation
   * can be cloned by copying the context (e.g. with a simple
   * <code>memcpy()</code>).
   */
  typedef struct {
  #ifndef DOXYGEN_IGNORE
  	unsigned char buf[128];    /* first field, for alignment */
  	size_t ptr;
  	union {
  		sph_u32 Vs[8][4];
  #if SPH_64
  		sph_u64 Vb[8][2];
  #endif
  	} u;
  	sph_u32 C0, C1, C2, C3;
  #endif
  } sph_echo_big_context;
  
  /**
   * Type for a ECHO-224 context (identical to the common "small" context).
   */
  typedef sph_echo_small_context sph_echo224_context;
  
  /**
   * Type for a ECHO-256 context (identical to the common "small" context).
   */
  typedef sph_echo_small_context sph_echo256_context;
  
  /**
   * Type for a ECHO-384 context (identical to the common "big" context).
   */
  typedef sph_echo_big_context sph_echo384_context;
  
  /**
   * Type for a ECHO-512 context (identical to the common "big" context).
   */
  typedef sph_echo_big_context sph_echo512_context;
  
  /**
   * Initialize an ECHO-224 context. This process performs no memory allocation.
   *
   * @param cc   the ECHO-224 context (pointer to a
   *             <code>sph_echo224_context</code>)
   */
  void sph_echo224_init(void *cc);
  
  /**
   * Process some data bytes. It is acceptable that <code>len</code> is zero
   * (in which case this function does nothing).
   *
   * @param cc     the ECHO-224 context
   * @param data   the input data
   * @param len    the input data length (in bytes)
   */
  void sph_echo224(void *cc, const void *data, size_t len);
  
  /**
   * Terminate the current ECHO-224 computation and output the result into
   * the provided buffer. The destination buffer must be wide enough to
   * accomodate the result (28 bytes). The context is automatically
   * reinitialized.
   *
   * @param cc    the ECHO-224 context
   * @param dst   the destination buffer
   */
  void sph_echo224_close(void *cc, void *dst);
  
  /**
   * Add a few additional bits (0 to 7) to the current computation, then
   * terminate it and output the result in the provided buffer, which must
   * be wide enough to accomodate the result (28 bytes). If bit number i
   * in <code>ub</code> has value 2^i, then the extra bits are those
   * numbered 7 downto 8-n (this is the big-endian convention at the byte
   * level). The context is automatically reinitialized.
   *
   * @param cc    the ECHO-224 context
   * @param ub    the extra bits
   * @param n     the number of extra bits (0 to 7)
   * @param dst   the destination buffer
   */
  void sph_echo224_addbits_and_close(
  	void *cc, unsigned ub, unsigned n, void *dst);
  
  /**
   * Initialize an ECHO-256 context. This process performs no memory allocation.
   *
   * @param cc   the ECHO-256 context (pointer to a
   *             <code>sph_echo256_context</code>)
   */
  void sph_echo256_init(void *cc);
  
  /**
   * Process some data bytes. It is acceptable that <code>len</code> is zero
   * (in which case this function does nothing).
   *
   * @param cc     the ECHO-256 context
   * @param data   the input data
   * @param len    the input data length (in bytes)
   */
  void sph_echo256(void *cc, const void *data, size_t len);
  
  /**
   * Terminate the current ECHO-256 computation and output the result into
   * the provided buffer. The destination buffer must be wide enough to
   * accomodate the result (32 bytes). The context is automatically
   * reinitialized.
   *
   * @param cc    the ECHO-256 context
   * @param dst   the destination buffer
   */
  void sph_echo256_close(void *cc, void *dst);
  
  /**
   * Add a few additional bits (0 to 7) to the current computation, then
   * terminate it and output the result in the provided buffer, which must
   * be wide enough to accomodate the result (32 bytes). If bit number i
   * in <code>ub</code> has value 2^i, then the extra bits are those
   * numbered 7 downto 8-n (this is the big-endian convention at the byte
   * level). The context is automatically reinitialized.
   *
   * @param cc    the ECHO-256 context
   * @param ub    the extra bits
   * @param n     the number of extra bits (0 to 7)
   * @param dst   the destination buffer
   */
  void sph_echo256_addbits_and_close(
  	void *cc, unsigned ub, unsigned n, void *dst);
  
  /**
   * Initialize an ECHO-384 context. This process performs no memory allocation.
   *
   * @param cc   the ECHO-384 context (pointer to a
   *             <code>sph_echo384_context</code>)
   */
  void sph_echo384_init(void *cc);
  
  /**
   * Process some data bytes. It is acceptable that <code>len</code> is zero
   * (in which case this function does nothing).
   *
   * @param cc     the ECHO-384 context
   * @param data   the input data
   * @param len    the input data length (in bytes)
   */
  void sph_echo384(void *cc, const void *data, size_t len);
  
  /**
   * Terminate the current ECHO-384 computation and output the result into
   * the provided buffer. The destination buffer must be wide enough to
   * accomodate the result (48 bytes). The context is automatically
   * reinitialized.
   *
   * @param cc    the ECHO-384 context
   * @param dst   the destination buffer
   */
  void sph_echo384_close(void *cc, void *dst);
  
  /**
   * Add a few additional bits (0 to 7) to the current computation, then
   * terminate it and output the result in the provided buffer, which must
   * be wide enough to accomodate the result (48 bytes). If bit number i
   * in <code>ub</code> has value 2^i, then the extra bits are those
   * numbered 7 downto 8-n (this is the big-endian convention at the byte
   * level). The context is automatically reinitialized.
   *
   * @param cc    the ECHO-384 context
   * @param ub    the extra bits
   * @param n     the number of extra bits (0 to 7)
   * @param dst   the destination buffer
   */
  void sph_echo384_addbits_and_close(
  	void *cc, unsigned ub, unsigned n, void *dst);
  
  /**
   * Initialize an ECHO-512 context. This process performs no memory allocation.
   *
   * @param cc   the ECHO-512 context (pointer to a
   *             <code>sph_echo512_context</code>)
   */
  void sph_echo512_init(void *cc);
  
  /**
   * Process some data bytes. It is acceptable that <code>len</code> is zero
   * (in which case this function does nothing).
   *
   * @param cc     the ECHO-512 context
   * @param data   the input data
   * @param len    the input data length (in bytes)
   */
  void sph_echo512(void *cc, const void *data, size_t len);
  
  /**
   * Terminate the current ECHO-512 computation and output the result into
   * the provided buffer. The destination buffer must be wide enough to
   * accomodate the result (64 bytes). The context is automatically
   * reinitialized.
   *
   * @param cc    the ECHO-512 context
   * @param dst   the destination buffer
   */
  void sph_echo512_close(void *cc, void *dst);
  
  /**
   * Add a few additional bits (0 to 7) to the current computation, then
   * terminate it and output the result in the provided buffer, which must
   * be wide enough to accomodate the result (64 bytes). If bit number i
   * in <code>ub</code> has value 2^i, then the extra bits are those
   * numbered 7 downto 8-n (this is the big-endian convention at the byte
   * level). The context is automatically reinitialized.
   *
   * @param cc    the ECHO-512 context
   * @param ub    the extra bits
   * @param n     the number of extra bits (0 to 7)
   * @param dst   the destination buffer
   */
  void sph_echo512_addbits_and_close(
  	void *cc, unsigned ub, unsigned n, void *dst);
  	
  #ifdef __cplusplus
  }
  #endif
  
  #endif
  