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[/] [sha_core/] [tags/] [arelease/] [src/] [mrshs.c] - Rev 2
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/* * Implementation of the Secure Hashing Standard (SHS) * specified for use with the NIST Digital Signature Standard (DSS) * * Generates a 160 bit message digest. It should be impossible to come * come up with two messages that hash to the same value ("collision free"). * * For use with byte-oriented messages only. Could/Should be speeded * up by unwinding loops in shs_transform(), and assembly patches. */ #include <stdio.h> #include "miracl.h" /* for definition of mr_unsign32 & prototypes */ #define FIX /* Include this #define in order to implement the rather mysterious 'fix' to SHS With this definition in, SHA-1 is implemented Without this definition, SHA-0 is implemented */ #define H0 0x67452301L #define H1 0xefcdab89L #define H2 0x98badcfeL #define H3 0x10325476L #define H4 0xc3d2e1f0L #define K0 0x5a827999L #define K1 0x6ed9eba1L #define K2 0x8f1bbcdcL #define K3 0xca62c1d6L #define PAD 0x80 #define ZERO 0 /* functions */ #define S(n,x) (((x)<<n) | ((x)>>(32-n))) #define F0(x,y,z) (z^(x&(y^z))) #define F1(x,y,z) (x^y^z) #define F2(x,y,z) ((x&y) | (z&(x|y))) #define F3(x,y,z) (x^y^z) static void shs_transform(sha *sh) { /* basic transformation step */ mr_unsign32 a,b,c,d,e,temp; int t; #ifdef FIX for (t=16;t<80;t++) sh->w[t]=S(1,sh->w[t-3]^sh->w[t-8]^sh->w[t-14]^sh->w[t-16]); #else for (t=16;t<80;t++) sh->w[t]=sh->w[t-3]^sh->w[t-8]^sh->w[t-14]^sh->w[t-16]; #endif a=sh->h[0]; b=sh->h[1]; c=sh->h[2]; d=sh->h[3]; e=sh->h[4]; for (t=0;t<20;t++) { /* 20 times - mush it up */ temp=K0+F0(b,c,d)+S(5,a)+e+sh->w[t]; e=d; d=c; c=S(30,b); b=a; a=temp; } for (t=20;t<40;t++) { /* 20 more times - mush it up */ temp=K1+F1(b,c,d)+S(5,a)+e+sh->w[t]; e=d; d=c; c=S(30,b); b=a; a=temp; } for (t=40;t<60;t++) { /* 20 more times - mush it up */ temp=K2+F2(b,c,d)+S(5,a)+e+sh->w[t]; e=d; d=c; c=S(30,b); b=a; a=temp; } for (t=60;t<80;t++) { /* 20 more times - mush it up */ temp=K3+F3(b,c,d)+S(5,a)+e+sh->w[t]; e=d; d=c; c=S(30,b); b=a; a=temp; } sh->h[0]+=a; sh->h[1]+=b; sh->h[2]+=c; sh->h[3]+=d; sh->h[4]+=e; } void shs_init(sha *sh) { /* re-initialise */ int i; for (i=0;i<80;i++) sh->w[i]=0L; sh->length[0]=sh->length[1]=0L; sh->h[0]=H0; sh->h[1]=H1; sh->h[2]=H2; sh->h[3]=H3; sh->h[4]=H4; } void shs_process(sha *sh,int byte) { /* process the next message byte */ int cnt; cnt=(int)((sh->length[0]/32)%16); sh->w[cnt]<<=8; sh->w[cnt]|=(mr_unsign32)(byte&0xFF); sh->length[0]+=8; if (sh->length[0]==0L) { sh->length[1]++; sh->length[0]=0L; } if ((sh->length[0]%512)==0) shs_transform(sh); } void shs_hash(sha *sh,char hash[20]) { /* pad message and finish - supply digest */ int i; mr_unsign32 len0,len1; len0=sh->length[0]; len1=sh->length[1]; shs_process(sh,PAD); while ((sh->length[0]%512)!=448) shs_process(sh,ZERO); sh->w[14]=len1; sh->w[15]=len0; shs_transform(sh); for (i=0;i<20;i++) { /* convert to bytes */ hash[i]=((sh->h[i/4]>>(8*(3-i%4))) & 0xffL); } shs_init(sh); } /* test program: should produce digest 84983e44 1c3bd26e baae4aa1 f95129e5 e54670f1 #include <stdio.h> #include "miracl.h" char test[]="abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq"; int main() { char hash[20]; int i; sha sh; shs_init(&sh); for (i=0;test[i]!=0;i++) shs_process(&sh,test[i]); shs_hash(&sh,hash); for (i=0;i<20;i++) printf("%02x",(unsigned char)hash[i]); printf("\n"); return 0; } */
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