Emeric Vigier | 2f62582 | 2012-08-06 11:09:52 -0400 | [diff] [blame] | 1 | /* |
| 2 | Copyright (c) 2010 Werner Dittmann |
| 3 | |
| 4 | Permission is hereby granted, free of charge, to any person |
| 5 | obtaining a copy of this software and associated documentation |
| 6 | files (the "Software"), to deal in the Software without |
| 7 | restriction, including without limitation the rights to use, |
| 8 | copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 9 | copies of the Software, and to permit persons to whom the |
| 10 | Software is furnished to do so, subject to the following |
| 11 | conditions: |
| 12 | |
| 13 | The above copyright notice and this permission notice shall be |
| 14 | included in all copies or substantial portions of the Software. |
| 15 | |
| 16 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| 17 | EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES |
| 18 | OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND |
| 19 | NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT |
| 20 | HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, |
| 21 | WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| 22 | FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR |
| 23 | OTHER DEALINGS IN THE SOFTWARE. |
| 24 | |
| 25 | */ |
| 26 | |
| 27 | #define SKEIN_ERR_CHECK 1 |
| 28 | #include <ccrtp/crypto/skeinApi.h> |
| 29 | #include <string.h> |
| 30 | #include <stdio.h> |
| 31 | |
| 32 | int skeinCtxPrepare(SkeinCtx_t* ctx, SkeinSize_t size) |
| 33 | { |
| 34 | Skein_Assert(ctx && size, SKEIN_FAIL); |
| 35 | |
| 36 | memset(ctx ,0, sizeof(SkeinCtx_t)); |
| 37 | ctx->skeinSize = size; |
| 38 | |
| 39 | return SKEIN_SUCCESS; |
| 40 | } |
| 41 | |
| 42 | int skeinInit(SkeinCtx_t* ctx, size_t hashBitLen) |
| 43 | { |
| 44 | int ret = SKEIN_FAIL; |
| 45 | size_t Xlen = 0; |
| 46 | u64b_t* X = NULL; |
| 47 | uint64_t treeInfo = SKEIN_CFG_TREE_INFO_SEQUENTIAL; |
| 48 | |
| 49 | Skein_Assert(ctx, SKEIN_FAIL); |
| 50 | /* |
| 51 | * The following two lines rely of the fact that the real Skein contexts are |
| 52 | * a union in out context and thus have tha maximum memory available. |
| 53 | * The beauty of C :-) . |
| 54 | */ |
| 55 | X = ctx->m.s256.X; |
| 56 | Xlen = ctx->skeinSize/8; |
| 57 | /* |
| 58 | * If size is the same and hash bit length is zero then reuse |
| 59 | * the save chaining variables. |
| 60 | */ |
| 61 | switch (ctx->skeinSize) { |
| 62 | case Skein256: |
| 63 | ret = Skein_256_InitExt(&ctx->m.s256, hashBitLen, |
| 64 | treeInfo, NULL, 0); |
| 65 | break; |
| 66 | case Skein512: |
| 67 | ret = Skein_512_InitExt(&ctx->m.s512, hashBitLen, |
| 68 | treeInfo, NULL, 0); |
| 69 | break; |
| 70 | case Skein1024: |
| 71 | ret = Skein1024_InitExt(&ctx->m.s1024, hashBitLen, |
| 72 | treeInfo, NULL, 0); |
| 73 | break; |
| 74 | } |
| 75 | |
| 76 | if (ret == SKEIN_SUCCESS) { |
| 77 | /* Save chaining variables for this combination of size and hashBitLen */ |
| 78 | memcpy(ctx->XSave, X, Xlen); |
| 79 | } |
| 80 | return ret; |
| 81 | } |
| 82 | |
| 83 | int skeinMacInit(SkeinCtx_t* ctx, const uint8_t *key, size_t keyLen, |
| 84 | size_t hashBitLen) |
| 85 | { |
| 86 | int ret = SKEIN_FAIL; |
| 87 | u64b_t* X = NULL; |
| 88 | size_t Xlen = 0; |
| 89 | uint64_t treeInfo = SKEIN_CFG_TREE_INFO_SEQUENTIAL; |
| 90 | |
| 91 | Skein_Assert(ctx, SKEIN_FAIL); |
| 92 | |
| 93 | X = ctx->m.s256.X; |
| 94 | Xlen = ctx->skeinSize/8; |
| 95 | |
| 96 | Skein_Assert(hashBitLen, SKEIN_BAD_HASHLEN); |
| 97 | |
| 98 | switch (ctx->skeinSize) { |
| 99 | case Skein256: |
| 100 | ret = Skein_256_InitExt(&ctx->m.s256, hashBitLen, |
| 101 | treeInfo, |
| 102 | (const u08b_t*)key, keyLen); |
| 103 | |
| 104 | break; |
| 105 | case Skein512: |
| 106 | ret = Skein_512_InitExt(&ctx->m.s512, hashBitLen, |
| 107 | treeInfo, |
| 108 | (const u08b_t*)key, keyLen); |
| 109 | break; |
| 110 | case Skein1024: |
| 111 | ret = Skein1024_InitExt(&ctx->m.s1024, hashBitLen, |
| 112 | treeInfo, |
| 113 | (const u08b_t*)key, keyLen); |
| 114 | |
| 115 | break; |
| 116 | } |
| 117 | if (ret == SKEIN_SUCCESS) { |
| 118 | /* Save chaining variables for this combination of key, keyLen, hashBitLen */ |
| 119 | memcpy(ctx->XSave, X, Xlen); |
| 120 | } |
| 121 | return ret; |
| 122 | } |
| 123 | |
| 124 | void skeinReset(SkeinCtx_t* ctx) |
| 125 | { |
| 126 | size_t Xlen = 0; |
| 127 | u64b_t* X = NULL; |
| 128 | |
| 129 | /* |
| 130 | * The following two lines rely of the fact that the real Skein contexts are |
| 131 | * a union in out context and thus have tha maximum memory available. |
| 132 | * The beautiy of C :-) . |
| 133 | */ |
| 134 | X = ctx->m.s256.X; |
| 135 | Xlen = ctx->skeinSize/8; |
| 136 | /* |
| 137 | * If size is the same and hash bit length is zero then reuse |
| 138 | * the save chaining variables. |
| 139 | */ |
| 140 | /* Restore the chaing variable, reset byte counter */ |
| 141 | memcpy(X, ctx->XSave, Xlen); |
| 142 | |
| 143 | /* Setup context to process the message */ |
| 144 | Skein_Start_New_Type(&ctx->m, MSG); |
| 145 | } |
| 146 | |
| 147 | int skeinUpdate(SkeinCtx_t *ctx, const uint8_t *msg, |
| 148 | size_t msgByteCnt) |
| 149 | { |
| 150 | int ret = SKEIN_FAIL; |
| 151 | Skein_Assert(ctx, SKEIN_FAIL); |
| 152 | |
| 153 | switch (ctx->skeinSize) { |
| 154 | case Skein256: |
| 155 | ret = Skein_256_Update(&ctx->m.s256, (const u08b_t*)msg, msgByteCnt); |
| 156 | break; |
| 157 | case Skein512: |
| 158 | ret = Skein_512_Update(&ctx->m.s512, (const u08b_t*)msg, msgByteCnt); |
| 159 | break; |
| 160 | case Skein1024: |
| 161 | ret = Skein1024_Update(&ctx->m.s1024, (const u08b_t*)msg, msgByteCnt); |
| 162 | break; |
| 163 | } |
| 164 | return ret; |
| 165 | |
| 166 | } |
| 167 | |
| 168 | int skeinUpdateBits(SkeinCtx_t *ctx, const uint8_t *msg, |
| 169 | size_t msgBitCnt) |
| 170 | { |
| 171 | /* |
| 172 | * I've used the bit pad implementation from skein_test.c (see NIST CD) |
| 173 | * and modified it to use the convenience functions and added some pointer |
| 174 | * arithmetic. |
| 175 | */ |
| 176 | size_t length; |
| 177 | uint8_t mask; |
| 178 | uint8_t* up; |
| 179 | |
| 180 | /* only the final Update() call is allowed do partial bytes, else assert an error */ |
| 181 | Skein_Assert((ctx->m.h.T[1] & SKEIN_T1_FLAG_BIT_PAD) == 0 || msgBitCnt == 0, SKEIN_FAIL); |
| 182 | |
| 183 | /* if number of bits is a multiple of bytes - that's easy */ |
| 184 | if ((msgBitCnt & 0x7) == 0) { |
| 185 | return skeinUpdate(ctx, msg, msgBitCnt >> 3); |
| 186 | } |
| 187 | skeinUpdate(ctx, msg, (msgBitCnt >> 3) + 1); |
| 188 | |
| 189 | /* |
| 190 | * The next line rely on the fact that the real Skein contexts |
| 191 | * are a union in our context. After the addition the pointer points to |
| 192 | * Skein's real partial block buffer. |
| 193 | * If this layout ever changes we have to adapt this as well. |
| 194 | */ |
| 195 | up = (uint8_t*)ctx->m.s256.X + ctx->skeinSize / 8; |
| 196 | |
| 197 | Skein_Set_Bit_Pad_Flag(ctx->m.h); /* set tweak flag for the skeinFinal call */ |
| 198 | |
| 199 | /* now "pad" the final partial byte the way NIST likes */ |
| 200 | length = ctx->m.h.bCnt; /* get the bCnt value (same location for all block sizes) */ |
| 201 | Skein_assert(length != 0); /* internal sanity check: there IS a partial byte in the buffer! */ |
| 202 | mask = (uint8_t) (1u << (7 - (msgBitCnt & 7))); /* partial byte bit mask */ |
| 203 | up[length-1] = (uint8_t)((up[length-1] & (0-mask))|mask); /* apply bit padding on final byte (in the buffer) */ |
| 204 | |
| 205 | return SKEIN_SUCCESS; |
| 206 | } |
| 207 | |
| 208 | int skeinFinal(SkeinCtx_t* ctx, uint8_t* hash) |
| 209 | { |
| 210 | int ret = SKEIN_FAIL; |
| 211 | Skein_Assert(ctx, SKEIN_FAIL); |
| 212 | |
| 213 | switch (ctx->skeinSize) { |
| 214 | case Skein256: |
| 215 | ret = Skein_256_Final(&ctx->m.s256, (u08b_t*)hash); |
| 216 | break; |
| 217 | case Skein512: |
| 218 | ret = Skein_512_Final(&ctx->m.s512, (u08b_t*)hash); |
| 219 | break; |
| 220 | case Skein1024: |
| 221 | ret = Skein1024_Final(&ctx->m.s1024, (u08b_t*)hash); |
| 222 | break; |
| 223 | } |
| 224 | return ret; |
| 225 | } |