/*http://sea-to-sky.net/~sreid/sha1.c@(#) Sep 21 2004, 15:03:04SHA-1 in CBy Steve Reid <sreid@sea-to-sky.net>100% Public DomainWARNING!! The update functions destroys the buffer! (RW)-----------------Modified 7/98 By James H. Brown <jbrown@burgoyne.com>Still 100% Public DomainCorrected a problem which generated improper hash values on 16 bit machinesRoutine SHA1Update changed from	void SHA1Update(SHA1_CTX* context,			unsigned char* data, unsigned int len)to	void SHA1Update(SHA1_CTX* context,			unsigned char* data, unsigned long len)The 'len' parameter was declared an int which works fine on 32 bitmachines. However, on 16 bit machines an int is too small for the shiftsbeing done against it.  This caused the hash function to generateincorrect values if len was greater than 8191 (8K - 1) due to the 'len<< 3' on line 3 of SHA1Update().Since the file IO in main() reads 16K at a time, any file 8K or largerwould be guaranteed to generate the wrong hash (e.g. Test Vector #3, amillion "a"s).I also changed the declaration of variables i & j in SHA1Update tounsigned long from unsigned int for the same reason.These changes should make no difference to any 32 bit implementationssince an int and a long are the same size in those environments.--I also corrected a few compiler warnings generated by Borland C.1. Added #include <process.h> for exit() prototype2. Removed unused variable 'j' in SHA1Final3. Changed exit(0) to return(0) at end of main.ALL changes I made can be located by searching for comments containing 'JHB'-----------------Modified 8/98By Steve Reid <sreid@sea-to-sky.net>Still 100% public domain1- Removed #include <process.h> and used return() instead of exit()2- Fixed overwriting of finalcount in SHA1Final() (discovered by Chris Hall)3- Changed email address from steve@edmweb.com to sreid@sea-to-sky.net-----------------Modified 4/01By Saul Kravitz <Saul.Kravitz@celera.com>Still 100% PDModified to run on Compaq Alpha hardware.  -----------------Modified 8/04By Reinhard Wobst (RW, r.wobst@gmx.de) - removing unrolled loopin SHA1Transform() for reducing code sizeStill 100% PD*//*Test Vectors (from FIPS PUB 180-1)"abc"  A9993E36 4706816A BA3E2571 7850C26C 9CD0D89D"abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq"  84983E44 1C3BD26E BAAE4AA1 F95129E5 E54670F1A million repetitions of "a"  34AA973C D4C4DAA4 F61EEB2B DBAD2731 6534016F*//* #define SHA1HANDSOFF  */#include <string.h>#include "sha1.h"#ifdef EL#define LITTLE_ENDIAN#endif#define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))/* blk0() and blk() perform the initial expand. *//* I got the idea of expanding during the round function from SSLeay */#ifdef LITTLE_ENDIAN#define blk0(i) (block->l[i] = (rol(block->l[i],24)&0xFF00FF00) \		 |(rol(block->l[i],8)&0x00FF00FF))#else#define blk0(i) block->l[i]#endif#define blk(i) (block->l[i&15] = rol(block->l[(i+13)&15]^block->l[(i+8)&15] \				     ^block->l[(i+2)&15]^block->l[i&15],1))/* (R0+R1), R2, R3, R4 are the different operations used in SHA1 */#define R0(v,w,x,y,z,i) \  z+=((w&(x^y))^y)+blk0(i)+0x5A827999+rol(v,5);w=rol(w,30);#define R1(v,w,x,y,z,i) \  z+=((w&(x^y))^y)+blk(i)+0x5A827999+rol(v,5);w=rol(w,30);#define R2(v,w,x,y,z,i) \  z+=(w^x^y)+blk(i)+0x6ED9EBA1+rol(v,5);w=rol(w,30);#define R3(v,w,x,y,z,i) \  z+=(((w|x)&y)|(w&x))+blk(i)+0x8F1BBCDC+rol(v,5);w=rol(w,30);#define R4(v,w,x,y,z,i) \  z+=(w^x^y)+blk(i)+0xCA62C1D6+rol(v,5);w=rol(w,30);/* Hash a single 512-bit block. This is the core of the algorithm. */#define RW_NOT_UNROLL_THE_LOOPS_BECAUSE_OF_SMALLER_CODESZEstatic void SHA1Transform(uint32 state[5], unsigned char buffer[64]){#ifdef RW_NOT_UNROLL_THE_LOOPS_BECAUSE_OF_SMALLER_CODESZE    uint32 a[5];    register int n, N;#else    uint32 a, b, c, d, e;#endif    typedef union {	unsigned char c[64];	uint32 l[16];    } CHAR64LONG16;#if 0    CHAR64LONG16 *block;    block = (CHAR64LONG16 *) buffer;#else    /* AMD CHANGE:     * \par     * This fixes the problem with unaligned      * Int32 accesses on MIPS M4K     * If the address of buffer is not a      * valid 32 bit addr, the cpu raises a      * exception.      */    CHAR64LONG16 blkinstance;    CHAR64LONG16 *block;    memcpy(&blkinstance, buffer, 64);    block = &blkinstance;#endif    /* Copy context->state[] to working vars */#ifdef RW_NOT_UNROLL_THE_LOOPS_BECAUSE_OF_SMALLER_CODESZE    for (n = 5; n--;)	a[n] = state[n];#else    a = state[0];    b = state[1];    c = state[2];    d = state[3];    e = state[4];#endif    /* 4 rounds of 20 operations each. Loop unrolled. */    /* *** RW: Though I am a mathematician, I can count. It is 5 rounds of     * 16, 4, 20, 20, 20 operations each.     */#ifdef RW_NOT_UNROLL_THE_LOOPS_BECAUSE_OF_SMALLER_CODESZE    N = 80;    for (n = 0; n < 16; ++n, --N) {	R0(a[N % 5], a[(N + 1) % 5], a[(N + 2) % 5], a[(N + 3) % 5],	   a[(N + 4) % 5], n);    }    for (n = 0; n < 4; ++n, --N) {	R1(a[N % 5], a[(N + 1) % 5], a[(N + 2) % 5], a[(N + 3) % 5],	   a[(N + 4) % 5], (n + 16));    }    for (n = 0; n < 20; ++n, --N) {	R2(a[N % 5], a[(N + 1) % 5], a[(N + 2) % 5], a[(N + 3) % 5],	   a[(N + 4) % 5], (n + 20));    }    for (n = 0; n < 20; ++n, --N) {	R3(a[N % 5], a[(N + 1) % 5], a[(N + 2) % 5], a[(N + 3) % 5],	   a[(N + 4) % 5], (n + 40));    }    for (n = 0; n < 20; ++n, --N) {	R4(a[N % 5], a[(N + 1) % 5], a[(N + 2) % 5], a[(N + 3) % 5],	   a[(N + 4) % 5], (n + 60));    }#else    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);    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);    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);    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);    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);    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);    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);    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);    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);    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);    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);    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);    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);    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);    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);    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);    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);    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);    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);    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);#endif    /* Add the working vars back into context.state[] */#ifdef RW_NOT_UNROLL_THE_LOOPS_BECAUSE_OF_SMALLER_CODESZE    for (n = 5; n--;) {	state[n] += a[n];	a[n] = 0;    }#else    state[0] += a;    state[1] += b;    state[2] += c;    state[3] += d;    state[4] += e;    /* Wipe variables */    a = b = c = d = e = 0;#endif}/* SHA1Init - Initialize new context */void SHA1Init(SHA1_CTX * context){    /* SHA1 initialization constants */    context->state[0] = 0x67452301;    context->state[1] = 0xEFCDAB89;    context->state[2] = 0x98BADCFE;    context->state[3] = 0x10325476;    context->state[4] = 0xC3D2E1F0;    context->count[0] = context->count[1] = 0;}/* Run your data through this. */void SHA1Update(SHA1_CTX * context, unsigned char *data, uint32 len){    uint32 i, j;    j = (context->count[0] >> 3) & 63;    if ((context->count[0] += len << 3) < (len << 3))	context->count[1]++;    context->count[1] += (len >> 29);    if ((j + len) > 63) {	memcpy(&context->buffer[j], data, (i = 64 - j));	SHA1Transform(context->state, context->buffer);	for (; i + 63 < len; i += 64) {	    SHA1Transform(context->state, &data[i]);	}	j = 0;    } else	i = 0;    memcpy(&context->buffer[j], &data[i], len - i);}/* Add padding and return the message digest. */void SHA1Final(unsigned char digest[20], SHA1_CTX * context){    uint32 i;    unsigned char finalcount[8];    for (i = 0; i < 8; i++) {	finalcount[i] = (unsigned char) ((context->count[(i >= 4 ? 0 : 1)]					  >> ((3 - (i & 3)) * 8)) & 255);	/* Endian independent */    }    SHA1Update(context, (unsigned char *) "\200", 1);    while ((context->count[0] & 504) != 448) {	SHA1Update(context, (unsigned char *) "\0", 1);    }    SHA1Update(context, finalcount, 8);	/* Should cause a SHA1Transform() */    for (i = 0; i < 20; i++) {	digest[i] = (unsigned char)	    ((context->state[i >> 2] >> ((3 - (i & 3)) * 8)) & 255);    }    /* Wipe variables */    i = 0;			/* JHB */    memset(context->buffer, 0, 64);    memset(context->state, 0, 20);    memset(context->count, 0, 8);    memset(finalcount, 0, 8);	/* SWR */}