1 /*
2 Implementation by the Keccak, Keyak and Ketje Teams, namely, Guido Bertoni,
3 Joan Daemen, Michaël Peeters, Gilles Van Assche and Ronny Van Keer, hereby
4 denoted as "the implementer".
5 
6 For more information, feedback or questions, please refer to our websites:
7 http://keccak.noekeon.org/
8 http://keyak.noekeon.org/
9 http://ketje.noekeon.org/
10 
11 To the extent possible under law, the implementer has waived all copyright
12 and related or neighboring rights to the source code in this file.
13 http://creativecommons.org/publicdomain/zero/1.0/
14 */
15 
16 #include <string.h>
17 #include "KeccakHash.h"
18 
19 /* ---------------------------------------------------------------- */
20 
21 HashReturn Keccak_HashInitialize(Keccak_HashInstance *instance, unsigned int rate, unsigned int capacity, unsigned int hashbitlen, unsigned char delimitedSuffix)
22 {
23     HashReturn result;
24 
25     if (delimitedSuffix == 0)
26         return FAIL;
27     result = (HashReturn)KeccakWidth1600_SpongeInitialize(&instance->sponge, rate, capacity);
28     if (result != SUCCESS)
29         return result;
30     instance->fixedOutputLength = hashbitlen;
31     instance->delimitedSuffix = delimitedSuffix;
32     return SUCCESS;
33 }
34 
35 /* ---------------------------------------------------------------- */
36 
37 HashReturn Keccak_HashUpdate(Keccak_HashInstance *instance, const BitSequence *data, DataLength databitlen)
38 {
39     if ((databitlen % 8) == 0)
40         return (HashReturn)KeccakWidth1600_SpongeAbsorb(&instance->sponge, data, databitlen/8);
41     else {
42         HashReturn ret = (HashReturn)KeccakWidth1600_SpongeAbsorb(&instance->sponge, data, databitlen/8);
43         if (ret == SUCCESS) {
44             /* The last partial byte is assumed to be aligned on the least significant bits */
45 
46             unsigned char lastByte = data[databitlen/8];
47             /* Concatenate the last few bits provided here with those of the suffix */
48 
49             unsigned short delimitedLastBytes = (unsigned short)((unsigned short)lastByte | ((unsigned short)instance->delimitedSuffix << (databitlen % 8)));
50             if ((delimitedLastBytes & 0xFF00) == 0x0000) {
51                 instance->delimitedSuffix = delimitedLastBytes & 0xFF;
52             }
53             else {
54                 unsigned char oneByte[1];
55                 oneByte[0] = delimitedLastBytes & 0xFF;
56                 ret = (HashReturn)KeccakWidth1600_SpongeAbsorb(&instance->sponge, oneByte, 1);
57                 instance->delimitedSuffix = (delimitedLastBytes >> 8) & 0xFF;
58             }
59         }
60         return ret;
61     }
62 }
63 
64 /* ---------------------------------------------------------------- */
65 
66 HashReturn Keccak_HashFinal(Keccak_HashInstance *instance, BitSequence *hashval)
67 {
68     HashReturn ret = (HashReturn)KeccakWidth1600_SpongeAbsorbLastFewBits(&instance->sponge, instance->delimitedSuffix);
69     if (ret == SUCCESS)
70         return (HashReturn)KeccakWidth1600_SpongeSqueeze(&instance->sponge, hashval, instance->fixedOutputLength/8);
71     else
72         return ret;
73 }
74 
75 /* ---------------------------------------------------------------- */
76 
77 HashReturn Keccak_HashSqueeze(Keccak_HashInstance *instance, BitSequence *data, DataLength databitlen)
78 {
79     if ((databitlen % 8) != 0)
80         return FAIL;
81     return (HashReturn)KeccakWidth1600_SpongeSqueeze(&instance->sponge, data, databitlen/8);
82 }
83