1  /*
 2  The Keccak sponge function, designed by Guido Bertoni, Joan Daemen,
 3  Michaël Peeters and Gilles Van Assche. For more information, feedback or
 4  questions, please refer to our website: http://keccak.noekeon.org/
 5  
 6  Implementation by the designers,
 7  hereby denoted as "the implementer".
 8  
 9  To the extent possible under law, the implementer has waived all copyright
10  and related or neighboring rights to the source code in this file.
11  http://creativecommons.org/publicdomain/zero/1.0/
12  */
13  
14  #ifndef _KeccakSponge_h_
15  #define _KeccakSponge_h_
16  
17  #define KeccakPermutationSize 1600
18  #define KeccakPermutationSizeInBytes (KeccakPermutationSize/8)
19  #define KeccakMaximumRate 1536
20  #define KeccakMaximumRateInBytes (KeccakMaximumRate/8)
21  
22  #if defined(__GNUC__)
23  #define ALIGN __attribute__ ((aligned(32)))
24  #elif defined(_MSC_VER)
25  #define ALIGN __declspec(align(32))
26  #else
27  #define ALIGN
28  #endif
29  
30  ALIGN typedef struct spongeStateStruct {
31      ALIGN unsigned char state[KeccakPermutationSizeInBytes];
32      ALIGN unsigned char dataQueue[KeccakMaximumRateInBytes];
33      unsigned int rate;
34      unsigned int capacity;
35      unsigned int bitsInQueue;
36      unsigned int fixedOutputLength;
37      int squeezing;
38      unsigned int bitsAvailableForSqueezing;
39  } spongeState;
40  
41  /**
42    * Function to initialize the state of the Keccak[r, c] sponge function.
43    * The sponge function is set to the absorbing phase.
44    * @param  state       Pointer to the state of the sponge function to be initialized.
45    * @param  rate        The value of the rate r.
46    * @param  capacity    The value of the capacity c.
47    * @pre    One must have r+c=1600 and the rate a multiple of 64 bits in this implementation.
48    * @return Zero if successful, 1 otherwise.
49    */
50  int InitSponge(spongeState *state, unsigned int rate, unsigned int capacity);
51  /**
52    * Function to give input data for the sponge function to absorb.
53    * @param  state       Pointer to the state of the sponge function initialized by InitSponge().
54    * @param  data        Pointer to the input data. 
55    *                     When @a databitLen is not a multiple of 8, the last bits of data must be
56    *                     in the least significant bits of the last byte.
57    * @param  databitLen  The number of input bits provided in the input data.
58    * @pre    In the previous call to Absorb(), databitLen was a multiple of 8.
59    * @pre    The sponge function must be in the absorbing phase,
60    *         i.e., Squeeze() must not have been called before.
61    * @return Zero if successful, 1 otherwise.
62    */
63  int Absorb(spongeState *state, const unsigned char *data, unsigned long long databitlen);
64  /**
65    * Function to squeeze output data from the sponge function.
66    * If the sponge function was in the absorbing phase, this function 
67    * switches it to the squeezing phase.
68    * @param  state       Pointer to the state of the sponge function initialized by InitSponge().
69    * @param  output      Pointer to the buffer where to store the output data.
70    * @param  outputLength    The number of output bits desired.
71    *                     It must be a multiple of 8.
72    * @return Zero if successful, 1 otherwise.
73    */
74  int Squeeze(spongeState *state, unsigned char *output, unsigned long long outputLength);
75  
76  #endif