1 /* This file is derived from "Keccak-more-compact.c", which has been downloaded from <https://github.com/gvanas/KeccakCodePackage/blob/10856bc1922a1ee2c4d2822a88b9ef8fb5059932/Standalone/CompactFIPS202/Keccak-more-compact.c>. The original file "Keccak-more-compact.c" has, according to <https://github.com/gvanas/KeccakCodePackage/blob/10856bc1922a1ee2c4d2822a88b9ef8fb5059932/README.markdown>, been put into the public domain. */

2

3 #include <stdint.h>

4

5 #if defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__)

6 #include <sys/endian.h>

7 #if defined(_BYTE_ORDER) && defined(_LITTLE_ENDIAN) && _BYTE_ORDER == _LITTLE_ENDIAN

8 #define MOONHASH_LITTLE_ENDIAN

9 #endif

10 #elif defined(__linux__)

11 #include <endian.h>

12 #if defined(__BYTE_ORDER) && defined(__LITTLE_ENDIAN) && __BYTE_ORDER == __LITTLE_ENDIAN

13 #define MOONHASH_LITTLE_ENDIAN

14 #endif

15 #else

16 #warning Could not determine endianess, revert to fail safe.

17 #endif

18

19 #define FOR(i,n) for(i=0; i<n; ++i)

20 typedef uint8_t u8;

21 typedef uint64_t u64;

22 typedef unsigned int ui;

23

24 static void Keccak(ui r, ui c, const u8 *in, u64 inLen, u8 sfx, u8 *out, u64 outLen);

25 void FIPS202_SHAKE128(const u8 *in, u64 inLen, u8 *out, u64 outLen) { Keccak(1344, 256, in, inLen, 0x1F, out, outLen); }

26 void FIPS202_SHAKE256(const u8 *in, u64 inLen, u8 *out, u64 outLen) { Keccak(1088, 512, in, inLen, 0x1F, out, outLen); }

27 void FIPS202_SHA3_224(const u8 *in, u64 inLen, u8 *out) { Keccak(1152, 448, in, inLen, 0x06, out, 28); }

28 void FIPS202_SHA3_256(const u8 *in, u64 inLen, u8 *out) { Keccak(1088, 512, in, inLen, 0x06, out, 32); }

29 void FIPS202_SHA3_384(const u8 *in, u64 inLen, u8 *out) { Keccak(832, 768, in, inLen, 0x06, out, 48); }

30 void FIPS202_SHA3_512(const u8 *in, u64 inLen, u8 *out) { Keccak(576, 1024, in, inLen, 0x06, out, 64); }

31

32 static int LFSR86540(u8 *R) { (*R)=((*R)<<1)^(((*R)&0x80)?0x71:0); return ((*R)&2)>>1; }

33 #define ROL(a,o) ((((u64)a)<<o)^(((u64)a)>>(64-o)))

34 #ifdef MOONHASH_LITTLE_ENDIAN

35 #define load64(src) (*(uint64_t *)(src))

36 #define store64(dst, src) do { *(uint64_t *)(dst) = src; } while (0)

37 #define xor64(dst, src) do { *(uint64_t *)(dst) ^= src; } while (0)

38 #else

39 static u64 load64(const u8 *x) { ui i; u64 u=0; FOR(i,8) { u<<=8; u|=x[7-i]; } return u; }

40 static void store64(u8 *x, u64 u) { ui i; FOR(i,8) { x[i]=u; u>>=8; } }

41 static void xor64(u8 *x, u64 u) { ui i; FOR(i,8) { x[i]^=u; u>>=8; } }

42 #endif

43 #define rL(x,y) load64((u8*)s+8*(x+5*y))

44 #define wL(x,y,l) store64((u8*)s+8*(x+5*y),l)

45 #define XL(x,y,l) xor64((u8*)s+8*(x+5*y),l)

46 static void KeccakF1600(void *s)

47 {

48 ui r,x,y,i,j,Y; u8 R=0x01; u64 C[5],D;

49 for(i=0; i<24; i++) {

50 /*θ*/ FOR(x,5) C[x]=rL(x,0)^rL(x,1)^rL(x,2)^rL(x,3)^rL(x,4); FOR(x,5) { D=C[(x+4)%5]^ROL(C[(x+1)%5],1); FOR(y,5) XL(x,y,D); }

51 /*ρπ*/ x=1; y=r=0; D=rL(x,y); FOR(j,24) { r+=j+1; Y=(2*x+3*y)%5; x=y; y=Y; C[0]=rL(x,y); wL(x,y,ROL(D,r%64)); D=C[0]; }

52 /*χ*/ FOR(y,5) { FOR(x,5) C[x]=rL(x,y); FOR(x,5) wL(x,y,C[x]^((~C[(x+1)%5])&C[(x+2)%5])); }

53 /*ι*/ FOR(j,7) if (LFSR86540(&R)) XL(0,0,(u64)1<<((1<<j)-1));

54 }

55 }

56 static void Keccak(ui r, ui c, const u8 *in, u64 inLen, u8 sfx, u8 *out, u64 outLen)

57 {

58 /*initialize*/ u8 s[200]; ui R=r/8; ui i,b=0; FOR(i,200) s[i]=0;

59 /*absorb*/ while(inLen>0) { b=(inLen<R)?inLen:R; FOR(i,b) s[i]^=in[i]; in+=b; inLen-=b; if (b==R) { KeccakF1600(s); b=0; } }

60 /*pad*/ s[b]^=sfx; if((sfx&0x80)&&(b==(R-1))) KeccakF1600(s); s[R-1]^=0x80; KeccakF1600(s);

61 /*squeeze*/ while(outLen>0) { b=(outLen<R)?outLen:R; FOR(i,b) out[i]=s[i]; out+=b; outLen-=b; if(outLen>0) KeccakF1600(s); }

62 }