1/*
2The Keccak sponge function, designed by Guido Bertoni, Joan Daemen,
3Michaƫl Peeters and Gilles Van Assche. For more information, feedback or
4questions, please refer to our website: http://keccak.noekeon.org/
5
6Implementation by the designers,
7hereby denoted as "the implementer".
8
9To the extent possible under law, the implementer has waived all copyright
10and related or neighboring rights to the source code in this file.
11http://creativecommons.org/publicdomain/zero/1.0/
12*/
13
14#include <string.h>
15#include "KeccakSponge.h"
16#include "KeccakF-1600-interface.h"
17#ifdef KeccakReference
18#include "displayIntermediateValues.h"
19#endif
20
21static int InitSponge(spongeState *state, unsigned int rate, unsigned int capacity)
22{
23 if (rate+capacity != 1600)
24 return 1;
25 if ((rate <= 0) || (rate >= 1600) || ((rate % 64) != 0))
26 return 1;
27 KeccakInitialize();
28 state->rate = rate;
29 state->capacity = capacity;
30 state->fixedOutputLength = 0;
31 KeccakInitializeState(state->state);
32 memset(state->dataQueue, 0, KeccakMaximumRateInBytes);
33 state->bitsInQueue = 0;
34 state->squeezing = 0;
35 state->bitsAvailableForSqueezing = 0;
36
37 return 0;
38}
39
40static void AbsorbQueue(spongeState *state)
41{
42 // state->bitsInQueue is assumed to be equal to state->rate
43 #ifdef KeccakReference
44 displayBytes(1, "Block to be absorbed", state->dataQueue, state->rate/8);
45 #endif
46#ifdef ProvideFast576
47 if (state->rate == 576)
48 KeccakAbsorb576bits(state->state, state->dataQueue);
49 else
50#endif
51#ifdef ProvideFast832
52 if (state->rate == 832)
53 KeccakAbsorb832bits(state->state, state->dataQueue);
54 else
55#endif
56#ifdef ProvideFast1024
57 if (state->rate == 1024)
58 KeccakAbsorb1024bits(state->state, state->dataQueue);
59 else
60#endif
61#ifdef ProvideFast1088
62 if (state->rate == 1088)
63 KeccakAbsorb1088bits(state->state, state->dataQueue);
64 else
65#endif
66#ifdef ProvideFast1152
67 if (state->rate == 1152)
68 KeccakAbsorb1152bits(state->state, state->dataQueue);
69 else
70#endif
71#ifdef ProvideFast1344
72 if (state->rate == 1344)
73 KeccakAbsorb1344bits(state->state, state->dataQueue);
74 else
75#endif
76 KeccakAbsorb(state->state, state->dataQueue, state->rate/64);
77 state->bitsInQueue = 0;
78}
79
80static int Absorb(spongeState *state, const unsigned char *data, unsigned long long databitlen)
81{
82 unsigned long long i, j, wholeBlocks;
83 unsigned int partialBlock, partialByte;
84 const unsigned char *curData;
85
86 if ((state->bitsInQueue % 8) != 0)
87 return 1; // Only the last call may contain a partial byte
88 if (state->squeezing)
89 return 1; // Too late for additional input
90
91 i = 0;
92 while(i < databitlen) {
93 if ((state->bitsInQueue == 0) && (databitlen >= state->rate) && (i <= (databitlen-state->rate))) {
94 wholeBlocks = (databitlen-i)/state->rate;
95 curData = data+i/8;
96#ifdef ProvideFast576
97 if (state->rate == 576) {
98 for(j=0; j<wholeBlocks; j++, curData+=576/8) {
99 #ifdef KeccakReference
100 displayBytes(1, "Block to be absorbed", curData, state->rate/8);
101 #endif
102 KeccakAbsorb576bits(state->state, curData);
103 }
104 }
105 else
106#endif
107#ifdef ProvideFast832
108 if (state->rate == 832) {
109 for(j=0; j<wholeBlocks; j++, curData+=832/8) {
110 #ifdef KeccakReference
111 displayBytes(1, "Block to be absorbed", curData, state->rate/8);
112 #endif
113 KeccakAbsorb832bits(state->state, curData);
114 }
115 }
116 else
117#endif
118#ifdef ProvideFast1024
119 if (state->rate == 1024) {
120 for(j=0; j<wholeBlocks; j++, curData+=1024/8) {
121 #ifdef KeccakReference
122 displayBytes(1, "Block to be absorbed", curData, state->rate/8);
123 #endif
124 KeccakAbsorb1024bits(state->state, curData);
125 }
126 }
127 else
128#endif
129#ifdef ProvideFast1088
130 if (state->rate == 1088) {
131 for(j=0; j<wholeBlocks; j++, curData+=1088/8) {
132 #ifdef KeccakReference
133 displayBytes(1, "Block to be absorbed", curData, state->rate/8);
134 #endif
135 KeccakAbsorb1088bits(state->state, curData);
136 }
137 }
138 else
139#endif
140#ifdef ProvideFast1152
141 if (state->rate == 1152) {
142 for(j=0; j<wholeBlocks; j++, curData+=1152/8) {
143 #ifdef KeccakReference
144 displayBytes(1, "Block to be absorbed", curData, state->rate/8);
145 #endif
146 KeccakAbsorb1152bits(state->state, curData);
147 }
148 }
149 else
150#endif
151#ifdef ProvideFast1344
152 if (state->rate == 1344) {
153 for(j=0; j<wholeBlocks; j++, curData+=1344/8) {
154 #ifdef KeccakReference
155 displayBytes(1, "Block to be absorbed", curData, state->rate/8);
156 #endif
157 KeccakAbsorb1344bits(state->state, curData);
158 }
159 }
160 else
161#endif
162 {
163 for(j=0; j<wholeBlocks; j++, curData+=state->rate/8) {
164 #ifdef KeccakReference
165 displayBytes(1, "Block to be absorbed", curData, state->rate/8);
166 #endif
167 KeccakAbsorb(state->state, curData, state->rate/64);
168 }
169 }
170 i += wholeBlocks*state->rate;
171 }
172 else {
173 partialBlock = (unsigned int)(databitlen - i);
174 if (partialBlock+state->bitsInQueue > state->rate)
175 partialBlock = state->rate-state->bitsInQueue;
176 partialByte = partialBlock % 8;
177 partialBlock -= partialByte;
178 memcpy(state->dataQueue+state->bitsInQueue/8, data+i/8, partialBlock/8);
179 state->bitsInQueue += partialBlock;
180 i += partialBlock;
181 if (state->bitsInQueue == state->rate)
182 AbsorbQueue(state);
183 if (partialByte > 0) {
184 unsigned char mask = (1 << partialByte)-1;
185 state->dataQueue[state->bitsInQueue/8] = data[i/8] & mask;
186 state->bitsInQueue += partialByte;
187 i += partialByte;
188 }
189 }
190 }
191 return 0;
192}
193
194static void PadAndSwitchToSqueezingPhase(spongeState *state)
195{
196 // Note: the bits are numbered from 0=LSB to 7=MSB
197 if (state->bitsInQueue + 1 == state->rate) {
198 state->dataQueue[state->bitsInQueue/8 ] |= 1 << (state->bitsInQueue % 8);
199 AbsorbQueue(state);
200 memset(state->dataQueue, 0, state->rate/8);
201 }
202 else {
203 memset(state->dataQueue + (state->bitsInQueue+7)/8, 0, state->rate/8 - (state->bitsInQueue+7)/8);
204 state->dataQueue[state->bitsInQueue/8 ] |= 1 << (state->bitsInQueue % 8);
205 }
206 state->dataQueue[(state->rate-1)/8] |= 1 << ((state->rate-1) % 8);
207 AbsorbQueue(state);
208
209 #ifdef KeccakReference
210 displayText(1, "--- Switching to squeezing phase ---");
211 #endif
212#ifdef ProvideFast1024
213 if (state->rate == 1024) {
214 KeccakExtract1024bits(state->state, state->dataQueue);
215 state->bitsAvailableForSqueezing = 1024;
216 }
217 else
218#endif
219 {
220 KeccakExtract(state->state, state->dataQueue, state->rate/64);
221 state->bitsAvailableForSqueezing = state->rate;
222 }
223 #ifdef KeccakReference
224 displayBytes(1, "Block available for squeezing", state->dataQueue, state->bitsAvailableForSqueezing/8);
225 #endif
226 state->squeezing = 1;
227}
228
229static int Squeeze(spongeState *state, unsigned char *output, unsigned long long outputLength)
230{
231 unsigned long long i;
232 unsigned int partialBlock;
233
234 if (!state->squeezing)
235 PadAndSwitchToSqueezingPhase(state);
236 if ((outputLength % 8) != 0)
237 return 1; // Only multiple of 8 bits are allowed, truncation can be done at user level
238
239 i = 0;
240 while(i < outputLength) {
241 if (state->bitsAvailableForSqueezing == 0) {
242 KeccakPermutation(state->state);
243#ifdef ProvideFast1024
244 if (state->rate == 1024) {
245 KeccakExtract1024bits(state->state, state->dataQueue);
246 state->bitsAvailableForSqueezing = 1024;
247 }
248 else
249#endif
250 {
251 KeccakExtract(state->state, state->dataQueue, state->rate/64);
252 state->bitsAvailableForSqueezing = state->rate;
253 }
254 #ifdef KeccakReference
255 displayBytes(1, "Block available for squeezing", state->dataQueue, state->bitsAvailableForSqueezing/8);
256 #endif
257 }
258 partialBlock = state->bitsAvailableForSqueezing;
259 if ((unsigned long long)partialBlock > outputLength - i)
260 partialBlock = (unsigned int)(outputLength - i);
261 memcpy(output+i/8, state->dataQueue+(state->rate-state->bitsAvailableForSqueezing)/8, partialBlock/8);
262 state->bitsAvailableForSqueezing -= partialBlock;
263 i += partialBlock;
264 }
265 return 0;
266}
267