sha.c

00001 /* sha.c
00002  *
00003  * Copyright (C) 2006-2012 Sawtooth Consulting Ltd.
00004  *
00005  * This file is part of CyaSSL.
00006  *
00007  * CyaSSL is free software; you can redistribute it and/or modify
00008  * it under the terms of the GNU General Public License as published by
00009  * the Free Software Foundation; either version 2 of the License, or
00010  * (at your option) any later version.
00011  *
00012  * CyaSSL is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00015  * GNU General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU General Public License
00018  * along with this program; if not, write to the Free Software
00019  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
00020  */
00021 
00022 #ifdef HAVE_CONFIG_H
00023     #include <config.h>
00024 #endif
00025 
00026 #include <cyassl/ctaocrypt/sha.h>
00027 #ifdef NO_INLINE
00028     #include <cyassl/ctaocrypt/misc.h>
00029 #else
00030     #include <ctaocrypt/src/misc.c>
00031 #endif
00032 
00033 
00034 #ifdef STM32F2_CRYPTO
00035     /*
00036      * STM32F2 hardware SHA1 support through the STM32F2 standard peripheral
00037      * library. Documentation located in STM32F2xx Standard Peripheral Library
00038      * document (See note in README).
00039      */
00040     #include "stm32f2xx.h"
00041 
00042     void InitSha(Sha* sha)
00043     {
00044         /* STM32F2 struct notes:
00045          * sha->buffer  = first 4 bytes used to hold partial block if needed 
00046          * sha->buffLen = num bytes currently stored in sha->buffer
00047          * sha->loLen   = num bytes that have been written to STM32 FIFO
00048          */
00049         XMEMSET(sha->buffer, 0, SHA_REG_SIZE);
00050         sha->buffLen = 0;
00051         sha->loLen = 0;
00052 
00053         /* initialize HASH peripheral */
00054         HASH_DeInit();
00055 
00056         /* configure algo used, algo mode, datatype */
00057         HASH->CR &= ~ (HASH_CR_ALGO | HASH_CR_DATATYPE | HASH_CR_MODE);
00058         HASH->CR |= (HASH_AlgoSelection_SHA1 | HASH_AlgoMode_HASH 
00059                  | HASH_DataType_8b);
00060 
00061         /* reset HASH processor */
00062         HASH->CR |= HASH_CR_INIT;
00063     }
00064 
00065     void ShaUpdate(Sha* sha, const byte* data, word32 len)
00066     {
00067         word32 i = 0;
00068         word32 fill = 0;
00069         word32 diff = 0;
00070 
00071         /* if saved partial block is available */
00072         if (sha->buffLen) {
00073             fill = 4 - sha->buffLen;
00074 
00075             /* if enough data to fill, fill and push to FIFO */
00076             if (fill <= len) {
00077                 XMEMCPY((byte*)sha->buffer + sha->buffLen, data, fill);
00078                 HASH_DataIn(*(uint32_t*)sha->buffer);
00079 
00080                 data += fill;
00081                 len -= fill;
00082                 sha->loLen += 4;
00083                 sha->buffLen = 0;
00084             } else {
00085                 /* append partial to existing stored block */
00086                 XMEMCPY((byte*)sha->buffer + sha->buffLen, data, len);
00087                 sha->buffLen += len;
00088                 return;
00089             }
00090         }
00091        
00092         /* write input block in the IN FIFO */
00093         for(i = 0; i < len; i += 4)
00094         {
00095             diff = len - i;
00096             if ( diff < 4) {
00097                 /* store incomplete last block, not yet in FIFO */
00098                 XMEMSET(sha->buffer, 0, SHA_REG_SIZE);
00099                 XMEMCPY((byte*)sha->buffer, data, diff);
00100                 sha->buffLen = diff;
00101             } else {
00102                 HASH_DataIn(*(uint32_t*)data);
00103                 data+=4;
00104             }
00105         }
00106 
00107         /* keep track of total data length thus far */ 
00108         sha->loLen += (len - sha->buffLen);
00109     }
00110 
00111     void ShaFinal(Sha* sha, byte* hash)
00112     {
00113         __IO uint16_t nbvalidbitsdata = 0;
00114         
00115         /* finish reading any trailing bytes into FIFO */
00116         if (sha->buffLen) {
00117             HASH_DataIn(*(uint32_t*)sha->buffer);
00118             sha->loLen += sha->buffLen;
00119         }
00120 
00121         /* calculate number of valid bits in last word of input data */
00122         nbvalidbitsdata = 8 * (sha->loLen % SHA_REG_SIZE);
00123 
00124         /* configure number of valid bits in last word of the data */
00125         HASH_SetLastWordValidBitsNbr(nbvalidbitsdata);
00126 
00127         /* start HASH processor */
00128         HASH_StartDigest();
00129 
00130         /* wait until Busy flag == RESET */
00131         while (HASH_GetFlagStatus(HASH_FLAG_BUSY) != RESET) {}
00132 
00133         /* read message digest */
00134         sha->digest[0] = HASH->HR[0];
00135         sha->digest[1] = HASH->HR[1];
00136         sha->digest[2] = HASH->HR[2];
00137         sha->digest[3] = HASH->HR[3];
00138         sha->digest[4] = HASH->HR[4];
00139         
00140         ByteReverseWords(sha->digest, sha->digest, SHA_DIGEST_SIZE);
00141 
00142         XMEMCPY(hash, sha->digest, SHA_DIGEST_SIZE);
00143 
00144         InitSha(sha);  /* reset state */
00145     }
00146 
00147 #else /* CTaoCrypt software implementation */
00148 
00149 #ifndef min
00150 
00151     static INLINE word32 min(word32 a, word32 b)
00152     {
00153         return a > b ? b : a;
00154     }
00155 
00156 #endif /* min */
00157 
00158 
00159 void InitSha(Sha* sha)
00160 {
00161     sha->digest[0] = 0x67452301L;
00162     sha->digest[1] = 0xEFCDAB89L;
00163     sha->digest[2] = 0x98BADCFEL;
00164     sha->digest[3] = 0x10325476L;
00165     sha->digest[4] = 0xC3D2E1F0L;
00166 
00167     sha->buffLen = 0;
00168     sha->loLen   = 0;
00169     sha->hiLen   = 0;
00170 }
00171 
00172 #define blk0(i) (W[i] = sha->buffer[i])
00173 #define blk1(i) (W[i&15] = \
00174                    rotlFixed(W[(i+13)&15]^W[(i+8)&15]^W[(i+2)&15]^W[i&15],1))
00175 
00176 #define f1(x,y,z) (z^(x &(y^z)))
00177 #define f2(x,y,z) (x^y^z)
00178 #define f3(x,y,z) ((x&y)|(z&(x|y)))
00179 #define f4(x,y,z) (x^y^z)
00180 
00181 /* (R0+R1), R2, R3, R4 are the different operations used in SHA1 */
00182 #define R0(v,w,x,y,z,i) z+= f1(w,x,y) + blk0(i) + 0x5A827999+ \
00183                         rotlFixed(v,5); w = rotlFixed(w,30);
00184 #define R1(v,w,x,y,z,i) z+= f1(w,x,y) + blk1(i) + 0x5A827999+ \
00185                         rotlFixed(v,5); w = rotlFixed(w,30);
00186 #define R2(v,w,x,y,z,i) z+= f2(w,x,y) + blk1(i) + 0x6ED9EBA1+ \
00187                         rotlFixed(v,5); w = rotlFixed(w,30);
00188 #define R3(v,w,x,y,z,i) z+= f3(w,x,y) + blk1(i) + 0x8F1BBCDC+ \
00189                         rotlFixed(v,5); w = rotlFixed(w,30);
00190 #define R4(v,w,x,y,z,i) z+= f4(w,x,y) + blk1(i) + 0xCA62C1D6+ \
00191                         rotlFixed(v,5); w = rotlFixed(w,30);
00192 
00193 
00194 static void Transform(Sha* sha)
00195 {
00196     word32 W[SHA_BLOCK_SIZE / sizeof(word32)];
00197 
00198     /* Copy context->state[] to working vars */ 
00199     word32 a = sha->digest[0];
00200     word32 b = sha->digest[1];
00201     word32 c = sha->digest[2];
00202     word32 d = sha->digest[3];
00203     word32 e = sha->digest[4];
00204 
00205 #ifdef USE_SLOW_SHA
00206     word32 t, i;
00207 
00208     for (i = 0; i < 16; i++) {
00209         R0(a, b, c, d, e, i);
00210         t = e; e = d; d = c; c = b; b = a; a = t;
00211     }
00212 
00213     for (; i < 20; i++) {
00214         R1(a, b, c, d, e, i);
00215         t = e; e = d; d = c; c = b; b = a; a = t;
00216     }
00217 
00218     for (; i < 40; i++) {
00219         R2(a, b, c, d, e, i);
00220         t = e; e = d; d = c; c = b; b = a; a = t;
00221     }
00222 
00223     for (; i < 60; i++) {
00224         R3(a, b, c, d, e, i);
00225         t = e; e = d; d = c; c = b; b = a; a = t;
00226     }
00227 
00228     for (; i < 80; i++) {
00229         R4(a, b, c, d, e, i);
00230         t = e; e = d; d = c; c = b; b = a; a = t;
00231     }
00232 #else
00233     /* nearly 1 K bigger in code size but 25% faster  */
00234     /* 4 rounds of 20 operations each. Loop unrolled. */
00235     R0(a,b,c,d,e, 0); R0(e,a,b,c,d, 1); R0(d,e,a,b,c, 2); R0(c,d,e,a,b, 3);
00236     R0(b,c,d,e,a, 4); R0(a,b,c,d,e, 5); R0(e,a,b,c,d, 6); R0(d,e,a,b,c, 7);
00237     R0(c,d,e,a,b, 8); R0(b,c,d,e,a, 9); R0(a,b,c,d,e,10); R0(e,a,b,c,d,11);
00238     R0(d,e,a,b,c,12); R0(c,d,e,a,b,13); R0(b,c,d,e,a,14); R0(a,b,c,d,e,15);
00239 
00240     R1(e,a,b,c,d,16); R1(d,e,a,b,c,17); R1(c,d,e,a,b,18); R1(b,c,d,e,a,19);
00241 
00242     R2(a,b,c,d,e,20); R2(e,a,b,c,d,21); R2(d,e,a,b,c,22); R2(c,d,e,a,b,23);
00243     R2(b,c,d,e,a,24); R2(a,b,c,d,e,25); R2(e,a,b,c,d,26); R2(d,e,a,b,c,27);
00244     R2(c,d,e,a,b,28); R2(b,c,d,e,a,29); R2(a,b,c,d,e,30); R2(e,a,b,c,d,31);
00245     R2(d,e,a,b,c,32); R2(c,d,e,a,b,33); R2(b,c,d,e,a,34); R2(a,b,c,d,e,35);
00246     R2(e,a,b,c,d,36); R2(d,e,a,b,c,37); R2(c,d,e,a,b,38); R2(b,c,d,e,a,39);
00247 
00248     R3(a,b,c,d,e,40); R3(e,a,b,c,d,41); R3(d,e,a,b,c,42); R3(c,d,e,a,b,43);
00249     R3(b,c,d,e,a,44); R3(a,b,c,d,e,45); R3(e,a,b,c,d,46); R3(d,e,a,b,c,47);
00250     R3(c,d,e,a,b,48); R3(b,c,d,e,a,49); R3(a,b,c,d,e,50); R3(e,a,b,c,d,51);
00251     R3(d,e,a,b,c,52); R3(c,d,e,a,b,53); R3(b,c,d,e,a,54); R3(a,b,c,d,e,55);
00252     R3(e,a,b,c,d,56); R3(d,e,a,b,c,57); R3(c,d,e,a,b,58); R3(b,c,d,e,a,59);
00253 
00254     R4(a,b,c,d,e,60); R4(e,a,b,c,d,61); R4(d,e,a,b,c,62); R4(c,d,e,a,b,63);
00255     R4(b,c,d,e,a,64); R4(a,b,c,d,e,65); R4(e,a,b,c,d,66); R4(d,e,a,b,c,67);
00256     R4(c,d,e,a,b,68); R4(b,c,d,e,a,69); R4(a,b,c,d,e,70); R4(e,a,b,c,d,71);
00257     R4(d,e,a,b,c,72); R4(c,d,e,a,b,73); R4(b,c,d,e,a,74); R4(a,b,c,d,e,75);
00258     R4(e,a,b,c,d,76); R4(d,e,a,b,c,77); R4(c,d,e,a,b,78); R4(b,c,d,e,a,79);
00259 #endif
00260 
00261     /* Add the working vars back into digest state[] */
00262     sha->digest[0] += a;
00263     sha->digest[1] += b;
00264     sha->digest[2] += c;
00265     sha->digest[3] += d;
00266     sha->digest[4] += e;
00267 }
00268 
00269 
00270 static INLINE void AddLength(Sha* sha, word32 len)
00271 {
00272     word32 tmp = sha->loLen;
00273     if ( (sha->loLen += len) < tmp)
00274         sha->hiLen++;                       /* carry low to high */
00275 }
00276 
00277 
00278 void ShaUpdate(Sha* sha, const byte* data, word32 len)
00279 {
00280     /* do block size increments */
00281     byte* local = (byte*)sha->buffer;
00282 
00283     while (len) {
00284         word32 add = min(len, SHA_BLOCK_SIZE - sha->buffLen);
00285         XMEMCPY(&local[sha->buffLen], data, add);
00286 
00287         sha->buffLen += add;
00288         data         += add;
00289         len          -= add;
00290 
00291         if (sha->buffLen == SHA_BLOCK_SIZE) {
00292             #ifdef LITTLE_ENDIAN_ORDER
00293                 ByteReverseBytes(local, local, SHA_BLOCK_SIZE);
00294             #endif
00295             Transform(sha);
00296             AddLength(sha, SHA_BLOCK_SIZE);
00297             sha->buffLen = 0;
00298         }
00299     }
00300 }
00301 
00302 
00303 void ShaFinal(Sha* sha, byte* hash)
00304 {
00305     byte* local = (byte*)sha->buffer;
00306 
00307     AddLength(sha, sha->buffLen);               /* before adding pads */
00308 
00309     local[sha->buffLen++] = 0x80;  /* add 1 */
00310 
00311     /* pad with zeros */
00312     if (sha->buffLen > SHA_PAD_SIZE) {
00313         XMEMSET(&local[sha->buffLen], 0, SHA_BLOCK_SIZE - sha->buffLen);
00314         sha->buffLen += SHA_BLOCK_SIZE - sha->buffLen;
00315 
00316         #ifdef LITTLE_ENDIAN_ORDER
00317             ByteReverseBytes(local, local, SHA_BLOCK_SIZE);
00318         #endif
00319         Transform(sha);
00320         sha->buffLen = 0;
00321     }
00322     XMEMSET(&local[sha->buffLen], 0, SHA_PAD_SIZE - sha->buffLen);
00323    
00324     /* put lengths in bits */
00325     sha->hiLen = (sha->loLen >> (8*sizeof(sha->loLen) - 3)) + 
00326                  (sha->hiLen << 3);
00327     sha->loLen = sha->loLen << 3;
00328 
00329     /* store lengths */
00330     #ifdef LITTLE_ENDIAN_ORDER
00331         ByteReverseBytes(local, local, SHA_BLOCK_SIZE);
00332     #endif
00333     /* ! length ordering dependent on digest endian type ! */
00334     XMEMCPY(&local[SHA_PAD_SIZE], &sha->hiLen, sizeof(word32));
00335     XMEMCPY(&local[SHA_PAD_SIZE + sizeof(word32)], &sha->loLen, sizeof(word32));
00336 
00337     Transform(sha);
00338     #ifdef LITTLE_ENDIAN_ORDER
00339         ByteReverseWords(sha->digest, sha->digest, SHA_DIGEST_SIZE);
00340     #endif
00341     XMEMCPY(hash, sha->digest, SHA_DIGEST_SIZE);
00342 
00343     InitSha(sha);  /* reset state */
00344 }
00345 
00346 #endif /* STM32F2_CRYPTO */
00347