diff options
Diffstat (limited to 'arduino/libraries/BLEHomekit/src/crypto/tweetnacl-modified/tweetnacl.c')
-rwxr-xr-x | arduino/libraries/BLEHomekit/src/crypto/tweetnacl-modified/tweetnacl.c | 841 |
1 files changed, 841 insertions, 0 deletions
diff --git a/arduino/libraries/BLEHomekit/src/crypto/tweetnacl-modified/tweetnacl.c b/arduino/libraries/BLEHomekit/src/crypto/tweetnacl-modified/tweetnacl.c new file mode 100755 index 0000000..ed2f0a2 --- /dev/null +++ b/arduino/libraries/BLEHomekit/src/crypto/tweetnacl-modified/tweetnacl.c @@ -0,0 +1,841 @@ +/* + * tweetnacl.c + * + * Modified version of the amazing NaCL in 100 Tweets: http://tweetnacl.cr.yp.to/software.html + * + * 1. Replaced salsa20 with chacha20 + * 2. Improved performance, especially around multiply routines. No assembly yet (it would probably help a great deal). + * + * Created on: Jun 21, 2015 + * Modified: tim + */ + +#include <string.h> +#include <stdint.h> + +#include "../crypto.h" + +#define FOR(i,n) for (i = 0;i < n;++i) + +typedef unsigned char u8; +typedef unsigned short u16; +typedef short i16; +typedef unsigned long u32; +typedef unsigned long long u64; +typedef long i32; +typedef long long i64; +typedef i64 gf[16]; +extern void randombytes(u8 *,u64); + +static const u8 + _0[16], + _9[32] = {9}; +static const gf + gf0, + gf1 = {1}, + _121665 = {0xDB41,1}, + D = {0x78a3, 0x1359, 0x4dca, 0x75eb, 0xd8ab, 0x4141, 0x0a4d, 0x0070, 0xe898, 0x7779, 0x4079, 0x8cc7, 0xfe73, 0x2b6f, 0x6cee, 0x5203}, + D2 = {0xf159, 0x26b2, 0x9b94, 0xebd6, 0xb156, 0x8283, 0x149a, 0x00e0, 0xd130, 0xeef3, 0x80f2, 0x198e, 0xfce7, 0x56df, 0xd9dc, 0x2406}, + X = {0xd51a, 0x8f25, 0x2d60, 0xc956, 0xa7b2, 0x9525, 0xc760, 0x692c, 0xdc5c, 0xfdd6, 0xe231, 0xc0a4, 0x53fe, 0xcd6e, 0x36d3, 0x2169}, + Y = {0x6658, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666, 0x6666}, + I = {0xa0b0, 0x4a0e, 0x1b27, 0xc4ee, 0xe478, 0xad2f, 0x1806, 0x2f43, 0xd7a7, 0x3dfb, 0x0099, 0x2b4d, 0xdf0b, 0x4fc1, 0x2480, 0x2b83}; + +static inline u32 L32(u32 x,int c) { return (x << c) | ((x&0xffffffff) >> (32 - c)); } + +static u32 ld32(const u8 *x) +{ + u32 u = x[3]; + u = (u<<8)|x[2]; + u = (u<<8)|x[1]; + return (u<<8)|x[0]; +} + +static u64 dl64(const u8 *x) +{ + u64 i,u=0; + FOR(i,8) u=(u<<8)|x[i]; + return u; +} + +static void st32(u8 *x,u32 u) +{ + int i; + FOR(i,4) { x[i] = u; u >>= 8; } +} + +static void ts64(u8 *x,u64 u) +{ + int i; + for (i = 7;i >= 0;--i) { x[i] = u; u >>= 8; } +} + +static inline int vn(const u8 *x,const u8 *y,int n) +{ + return memcmp(x,y,n); +} + +int inline crypto_verify_16(const u8 *x,const u8 *y) +{ + return vn(x,y,16); +} + +int inline crypto_verify_32(const u8 *x,const u8 *y) +{ + return vn(x,y,32); +} + +static void crypto_core_chacha20(u8 *out,const u8 *in,const u8 *k,const u8 *c) +{ + u32 x[16],y[16],t[4]; + int i,j,m; + + FOR(i,4) { + x[i] = ld32(c+4*i); + x[4+i] = ld32(k+4*i); + x[8+i] = ld32(k+16+4*i); + x[12+(2+i)%4] = ld32(in+4*i); + } + + FOR(i,16) y[i] = x[i]; + + FOR(i,10) { + FOR(j,4) { + FOR(m,4) t[m] = x[(j+4*m)%16]; + t[3] = L32(t[3] ^ (t[0] += t[1]), 16); + t[1] = L32(t[1] ^ (t[2] += t[3]), 12); + t[3] = L32(t[3] ^ (t[0] += t[1]), 8); + t[1] = L32(t[1] ^ (t[2] += t[3]), 7); + FOR(m,4) x[(j+4*m)%16] = t[m]; + } + FOR(j,4) { + FOR(m,4) t[m] = x[(4*m+(j+m)%4)%16]; + t[3] = L32(t[3] ^ (t[0] += t[1]), 16); + t[1] = L32(t[1] ^ (t[2] += t[3]), 12); + t[3] = L32(t[3] ^ (t[0] += t[1]), 8); + t[1] = L32(t[1] ^ (t[2] += t[3]), 7); + FOR(m,4) x[(4*m+(j+m)%4)%16] = t[m]; + } + } + FOR(i,16) st32(out + 4 * i,x[i] + y[i]); +} + +static const u8 sigma[16] = "expand 32-byte k"; + +int crypto_stream_chacha20_xor(u8 *c,const u8 *m,u64 b,const u8 *n,const u8 *k,const u8 v) +{ + u8 z[16],x[64]; + u32 u,i; + if (!b) return 0; + FOR(i,16) z[i] = 0; + FOR(i,8) z[i] = n[i]; + z[8] = v; + while (b >= 64) { + crypto_core_chacha20(x,z,k,sigma); + FOR(i,64) c[i] = (m?m[i]:0) ^ x[i]; + u = 1; + for (i = 8;i < 16;++i) { + u += (u32) z[i]; + z[i] = u; + u >>= 8; + } + b -= 64; + c += 64; + if (m) m += 64; + } + if (b) { + crypto_core_chacha20(x,z,k,sigma); + FOR(i,b) c[i] = (m?m[i]:0) ^ x[i]; + } + return 0; +} + +static void add1305(u32 *h,const u32 *c) +{ + u32 j,u = 0; + FOR(j,17) { + u += h[j] + c[j]; + h[j] = u & 255; + u >>= 8; + } +} + +static const u32 minusp[17] = { + 5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 252 +} ; + +int crypto_onetimeauth_poly1305(u8 *out,const u8 *m,u32 n,const u8 *k) +{ + u32 s,i,j,u,x[17],r[17],h[17],c[17],g[17]; + + FOR(j,17) r[j]=h[j]=0; + FOR(j,16) r[j]=k[j]; + r[3]&=15; + r[4]&=252; + r[7]&=15; + r[8]&=252; + r[11]&=15; + r[12]&=252; + r[15]&=15; + + while (n > 0) { + FOR(j,17) c[j] = 0; + for (j = 0;(j < 16) && (j < n);++j) c[j] = m[j]; + c[j] = 1; + m += j; n -= j; + add1305(h,c); + FOR(i,17) { + x[i] = 0; + for(j=0;j<=i;j++) x[i] += h[j] * r[i - j]; + for(;j<17;j++) x[i] += h[j] * 320 * r[i + 17 - j]; + } + FOR(i,17) h[i] = x[i]; + u = 0; + FOR(j,16) { + u += h[j]; + h[j] = u & 255; + u >>= 8; + } + u += h[16]; h[16] = u & 3; + u = 5 * (u >> 2); + FOR(j,16) { + u += h[j]; + h[j] = u & 255; + u >>= 8; + } + u += h[16]; h[16] = u; + } + + FOR(j,17) g[j] = h[j]; + add1305(h,minusp); + s = -(h[16] >> 7); + FOR(j,17) h[j] ^= s & (g[j] ^ h[j]); + + FOR(j,16) c[j] = k[j + 16]; + c[16] = 0; + add1305(h,c); + FOR(j,16) out[j] = h[j]; + return 0; +} + +int crypto_onetimeauth_poly1305_verify(const u8 *h,const u8 *m,u32 n,const u8 *k) +{ + u8 x[16]; + crypto_onetimeauth_poly1305(x,m,n,k); + return crypto_verify_16(h,x); +} + +static inline void set25519(gf r, const gf a) +{ + int i; + FOR(i,16) r[i]=a[i]; +} + +//#define MUL38(V) ((v)*38) +#define MUL38(V) ((((((V) << 3) + (V)) << 1) + (V)) << 1) + +static void car25519(gf o) +{ + i64 c=0; + unsigned i; + FOR(i,16) { + i64 v=o[i]+c; + o[i]=v&0xFFFF; + c=v>>16; + } + while (c) { + c=MUL38(c); + for(i = 0; c && i < 16; i++) { + i64 v=o[i]+c; + o[i]=v&0xFFFF; + c=v>>16; + } + } +} + +static inline void sel25519(gf p,gf q) +{ + gf t; + memcpy(t,p,sizeof(t)); + memcpy(p,q,sizeof(t)); + memcpy(q,t,sizeof(t)); +} + +static void pack25519(u8 *o,const gf n) +{ + int i,j,b; + gf m,t; + FOR(i,16) t[i]=n[i]; + car25519(t); + FOR(j,2) { + m[0]=t[0]-0xffed; + for(i=1;i<15;i++) { + m[i]=t[i]-0xffff-((m[i-1]>>16)&1); + m[i-1]&=0xffff; + } + m[15]=t[15]-0x7fff-((m[14]>>16)&1); + b=(m[15]>>16)&1; + m[14]&=0xffff; + if (!b) sel25519(t,m); + } + FOR(i,16) { + o[2*i]=t[i]&0xff; + o[2*i+1]=t[i]>>8; + } +} + +static int neq25519(const gf a, const gf b) +{ + u8 c[32],d[32]; + pack25519(c,a); + pack25519(d,b); + return crypto_verify_32(c,d); +} + +static u8 par25519(const gf a) +{ + u8 d[32]; + pack25519(d,a); + return d[0]&1; +} + +static void unpack25519(gf o, const u8 *n) +{ + unsigned i; + FOR(i,16) o[i]=(i64)(n[2*i]|((u32)n[2*i+1]<<8)); + o[15]&=0x7fff; +} + +static inline void A(gf o,const gf a,const gf b) +{ + unsigned i; + FOR(i,16) o[i]=a[i]+b[i]; +} + +static inline void Z(gf o,const gf a,const gf b) +{ + unsigned i; + FOR(i,16) o[i]=a[i]-b[i]; +} + +static inline void CS(u16 s[16], const gf o) +{ + i64 c=0; + unsigned i; + FOR(i,16) { + i64 v=o[i]+c; + s[i]=(u16)v; + c=v>>16; + } + while (c) { + c=MUL38(c); + for(i = 0; c && i < 16; i++) { + i64 v=s[i]+c; + s[i]=(u16)v; + c=v>>16; + } + } +} + +#if defined(USE_UNACL_SCALARMULT) + +extern void fe25519_mul(u16 o[16], u16 x[16], u16 y[16]); +extern void fe25519_square(u16 o[16], u16 x[16]); + +static void M(gf o, const gf a, const gf b) +{ + unsigned i; + u16 as[16]; + u16 bs[16]; + u16 os[16]; + + CS(as, a); + CS(bs, b); + + fe25519_mul(os, as, bs); + + FOR(i,16) o[i] = os[i]; +} + +static void S(gf o, const gf a) +{ + unsigned i; + u16 as[16]; + u16 os[16]; + + CS(as, a); + + fe25519_square(os, as); + + FOR(i,16) o[i] = os[i]; +} + +#else + +static void M(gf o,const gf a,const gf b) +{ + unsigned i,j; + u16 as[16]; + u16 bs[16]; + + CS(as, a); + CS(bs, b); + + i64 t[31],v; + FOR(i,31) t[i]=0; + i64* pt = &t[15]; + for (u16* asp = &as[15]; asp >= as; asp--, pt--) { + u32 asi = *asp; + i64* ppt = pt + 15; + for (u16* bsp = &bs[15]; bsp >= bs; bsp--, ppt--) { + v=*ppt; + v+=(i64)(asi * (u32)*bsp); + *ppt=v; + } + } + FOR(i,15) { v=t[i+16]; v=MUL38(v); o[i]=t[i]+v; } + o[15]=t[15]; +} + +static void S(gf o,const gf a) +{ + unsigned i,j; + u16 as[16]; + + CS(as, a); + + i64 t[31],v; + FOR(i,31) t[i]=0; + FOR(i,16) { + u32 ai = (u32)as[i]; + t[i<<1]+=(u32)(ai*ai); + for(j=i+1;j<16;j++) { + v=t[i+j]; + v+=((i64)(ai*(u32)as[j]))<<1; + t[i+j]=v; + } + } + FOR(i,15) { v=t[i+16]; v=MUL38(v); o[i]=t[i]+v; } + o[15]=t[15]; +} + +#endif + +static void inv25519(gf o,const gf i) +{ + gf c; + int a; + FOR(a,16) c[a]=i[a]; + for(a=249;a;a--) { + S(c,c); + M(c,c,i); + } + S(c,c); + S(c,c); + M(c,c,i); + S(c,c); + S(c,c); + M(c,c,i); + S(c,c); + M(c,c,i); + FOR(a,16) o[a]=c[a]; +} + +static void pow2523(gf o,const gf i) +{ + gf c; + int a; + FOR(a,16) c[a]=i[a]; + for(a=249;a;a--) { + S(c,c); + M(c,c,i); + } + S(c,c); + S(c,c); + M(c,c,i); + FOR(a,16) o[a]=c[a]; +} + +#if defined(USE_TWEETNACL_SCALARMULT) + +int crypto_scalarmult_curve25519(u8 *q,const u8 *n,const u8 *p) +{ + u8 z[32],r; + i64 x[80]; + int i,j; + gf a,b,c,d,e,f; + FOR(i,31) z[i]=n[i]; + z[31]=(n[31]&127)|64; + z[0]&=248; + unpack25519(x,p); + FOR(i,16) { + b[i]=x[i]; + d[i]=a[i]=c[i]=0; + } + a[0]=d[0]=1; + for(i=254;i>=0;--i) { + r=(z[i>>3]>>(i&7))&1; + if(r) { + sel25519(a,b); + sel25519(c,d); + } + A(e,a,c); + Z(a,a,c); + A(c,b,d); + Z(b,b,d); + S(d,e); + S(f,a); + M(a,c,a); + M(c,b,e); + A(e,a,c); + Z(a,a,c); + S(b,a); + Z(c,d,f); + M(a,c,_121665); + A(a,a,d); + M(c,c,a); + M(a,d,f); + M(d,b,x); + S(b,e); + if(r) { + sel25519(a,b); + sel25519(c,d); + } + } + FOR(i,16) { + x[i+16]=a[i]; + x[i+32]=c[i]; + x[i+48]=b[i]; + x[i+64]=d[i]; + } + inv25519(x+32,x+32); + M(x+16,x+16,x+32); + pack25519(q,x+16); + return 0; +} + +int crypto_scalarmult_curve25519_base(u8 *q,const u8 *n) +{ + return crypto_scalarmult_curve25519(q,n,_9); +} + +#endif + +static u64 R(u64 x,int c) { return (x >> c) | (x << (64 - c)); } +static u64 Ch(u64 x,u64 y,u64 z) { return (x & y) ^ (~x & z); } +static u64 Maj(u64 x,u64 y,u64 z) { return (x & y) ^ (x & z) ^ (y & z); } +static u64 Sigma0(u64 x) { return R(x,28) ^ R(x,34) ^ R(x,39); } +static u64 Sigma1(u64 x) { return R(x,14) ^ R(x,18) ^ R(x,41); } +static u64 sigma0(u64 x) { return R(x, 1) ^ R(x, 8) ^ (x >> 7); } +static u64 sigma1(u64 x) { return R(x,19) ^ R(x,61) ^ (x >> 6); } + +static const u64 K[80] = +{ + 0x428a2f98d728ae22ULL, 0x7137449123ef65cdULL, 0xb5c0fbcfec4d3b2fULL, 0xe9b5dba58189dbbcULL, + 0x3956c25bf348b538ULL, 0x59f111f1b605d019ULL, 0x923f82a4af194f9bULL, 0xab1c5ed5da6d8118ULL, + 0xd807aa98a3030242ULL, 0x12835b0145706fbeULL, 0x243185be4ee4b28cULL, 0x550c7dc3d5ffb4e2ULL, + 0x72be5d74f27b896fULL, 0x80deb1fe3b1696b1ULL, 0x9bdc06a725c71235ULL, 0xc19bf174cf692694ULL, + 0xe49b69c19ef14ad2ULL, 0xefbe4786384f25e3ULL, 0x0fc19dc68b8cd5b5ULL, 0x240ca1cc77ac9c65ULL, + 0x2de92c6f592b0275ULL, 0x4a7484aa6ea6e483ULL, 0x5cb0a9dcbd41fbd4ULL, 0x76f988da831153b5ULL, + 0x983e5152ee66dfabULL, 0xa831c66d2db43210ULL, 0xb00327c898fb213fULL, 0xbf597fc7beef0ee4ULL, + 0xc6e00bf33da88fc2ULL, 0xd5a79147930aa725ULL, 0x06ca6351e003826fULL, 0x142929670a0e6e70ULL, + 0x27b70a8546d22ffcULL, 0x2e1b21385c26c926ULL, 0x4d2c6dfc5ac42aedULL, 0x53380d139d95b3dfULL, + 0x650a73548baf63deULL, 0x766a0abb3c77b2a8ULL, 0x81c2c92e47edaee6ULL, 0x92722c851482353bULL, + 0xa2bfe8a14cf10364ULL, 0xa81a664bbc423001ULL, 0xc24b8b70d0f89791ULL, 0xc76c51a30654be30ULL, + 0xd192e819d6ef5218ULL, 0xd69906245565a910ULL, 0xf40e35855771202aULL, 0x106aa07032bbd1b8ULL, + 0x19a4c116b8d2d0c8ULL, 0x1e376c085141ab53ULL, 0x2748774cdf8eeb99ULL, 0x34b0bcb5e19b48a8ULL, + 0x391c0cb3c5c95a63ULL, 0x4ed8aa4ae3418acbULL, 0x5b9cca4f7763e373ULL, 0x682e6ff3d6b2b8a3ULL, + 0x748f82ee5defb2fcULL, 0x78a5636f43172f60ULL, 0x84c87814a1f0ab72ULL, 0x8cc702081a6439ecULL, + 0x90befffa23631e28ULL, 0xa4506cebde82bde9ULL, 0xbef9a3f7b2c67915ULL, 0xc67178f2e372532bULL, + 0xca273eceea26619cULL, 0xd186b8c721c0c207ULL, 0xeada7dd6cde0eb1eULL, 0xf57d4f7fee6ed178ULL, + 0x06f067aa72176fbaULL, 0x0a637dc5a2c898a6ULL, 0x113f9804bef90daeULL, 0x1b710b35131c471bULL, + 0x28db77f523047d84ULL, 0x32caab7b40c72493ULL, 0x3c9ebe0a15c9bebcULL, 0x431d67c49c100d4cULL, + 0x4cc5d4becb3e42b6ULL, 0x597f299cfc657e2aULL, 0x5fcb6fab3ad6faecULL, 0x6c44198c4a475817ULL +}; + +int crypto_hashblocks_sha512(u8 *x,const u8 *m,u64 n) +{ + u64 z[8],b[8],a[8],w[16],t; + int i,j; + + FOR(i,8) z[i] = a[i] = dl64(x + 8 * i); + + while (n >= 128) { + FOR(i,16) w[i] = dl64(m + 8 * i); + + FOR(i,80) { + FOR(j,8) b[j] = a[j]; + t = a[7] + Sigma1(a[4]) + Ch(a[4],a[5],a[6]) + K[i] + w[i%16]; + b[7] = t + Sigma0(a[0]) + Maj(a[0],a[1],a[2]); + b[3] += t; + FOR(j,8) a[(j+1)%8] = b[j]; + if (i%16 == 15) + FOR(j,16) + w[j] += w[(j+9)%16] + sigma0(w[(j+1)%16]) + sigma1(w[(j+14)%16]); + } + + FOR(i,8) { a[i] += z[i]; z[i] = a[i]; } + + m += 128; + n -= 128; + } + + FOR(i,8) ts64(x+8*i,z[i]); + + return n; +} + +static const u8 iv[64] = { + 0x6a,0x09,0xe6,0x67,0xf3,0xbc,0xc9,0x08, + 0xbb,0x67,0xae,0x85,0x84,0xca,0xa7,0x3b, + 0x3c,0x6e,0xf3,0x72,0xfe,0x94,0xf8,0x2b, + 0xa5,0x4f,0xf5,0x3a,0x5f,0x1d,0x36,0xf1, + 0x51,0x0e,0x52,0x7f,0xad,0xe6,0x82,0xd1, + 0x9b,0x05,0x68,0x8c,0x2b,0x3e,0x6c,0x1f, + 0x1f,0x83,0xd9,0xab,0xfb,0x41,0xbd,0x6b, + 0x5b,0xe0,0xcd,0x19,0x13,0x7e,0x21,0x79 +} ; + +int crypto_hash_sha512(u8 *out,const u8 *m,u64 n) +{ + u8 h[64],x[256]; + u64 i,b = n; + + FOR(i,64) h[i] = iv[i]; + + crypto_hashblocks_sha512(h,m,n); + m += n; + n &= 127; + m -= n; + + FOR(i,256) x[i] = 0; + FOR(i,n) x[i] = m[i]; + x[n] = 128; + + n = 256-128*(n<112); + x[n-9] = b >> 61; + ts64(x+n-8,b<<3); + crypto_hashblocks_sha512(h,x,n); + + FOR(i,64) out[i] = h[i]; + + return 0; +} + +static void add(gf p[4],gf q[4]) +{ + gf a,b,c,d,t,e,f,g,h; + + Z(a, p[1], p[0]); + Z(t, q[1], q[0]); + M(a, a, t); + A(b, p[0], p[1]); + A(t, q[0], q[1]); + M(b, b, t); + M(c, p[3], q[3]); + M(c, c, D2); + M(d, p[2], q[2]); + A(d, d, d); + Z(e, b, a); + Z(f, d, c); + A(g, d, c); + A(h, b, a); + M(p[0], e, f); + M(p[1], h, g); + M(p[2], g, f); + M(p[3], e, h); +} + +static void pack(u8 *r,gf p[4]) +{ + gf tx, ty, zi; + inv25519(zi, p[2]); + M(tx, p[0], zi); + M(ty, p[1], zi); + pack25519(r, ty); + r[31] ^= par25519(tx) << 7; +} + +static void scalarmult(gf p[4],gf q[4],const u8 *s) +{ + set25519(p[0],gf0); + set25519(p[1],gf1); + set25519(p[2],gf1); + set25519(p[3],gf0); + for (const u8* sp = &s[31]; sp >= s; --sp) { + const u8 si = *sp; + for (u8 j = 0x80; j; j>>=1) { + if (si & j) { + add(p,q); + add(q,q); + } else { + add(q,p); + add(p,p); + } + } + } +} + +static void scalarbase(gf p[4],const u8 *s) +{ + gf q[4]; + set25519(q[0],X); + set25519(q[1],Y); + set25519(q[2],gf1); + M(q[3],X,Y); + scalarmult(p,q,s); +} + +int crypto_sign_ed25519_keypair(u8 *pk, u8 *sk) +{ + u8 d[64]; + gf p[4]; + int i; + + randombytes(sk, 32); + crypto_hash_sha512(d, sk, 32); + d[0] &= 248; + d[31] &= 127; + d[31] |= 64; + + scalarbase(p,d); + pack(pk,p); + + FOR(i,32) sk[32 + i] = pk[i]; + return 0; +} + +static const u64 L[32] = {0xed, 0xd3, 0xf5, 0x5c, 0x1a, 0x63, 0x12, 0x58, 0xd6, 0x9c, 0xf7, 0xa2, 0xde, 0xf9, 0xde, 0x14, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x10}; + +static void modL(u8 *r,i64 x[64]) +{ + i64 carry,i,j; + for (i = 63;i >= 32;--i) { + carry = 0; + for (j = i - 32;j < i - 12;++j) { + x[j] += carry - 16 * x[i] * L[j - (i - 32)]; + carry = (x[j] + 128) >> 8; + x[j] -= carry << 8; + } + x[j] += carry; + x[i] = 0; + } + carry = 0; + FOR(j,32) { + x[j] += carry - (x[31] >> 4) * L[j]; + carry = x[j] >> 8; + x[j] &= 255; + } + FOR(j,32) x[j] -= carry * L[j]; + FOR(i,32) { + x[i+1] += x[i] >> 8; + r[i] = x[i] & 255; + } +} + +static void reduce(u8 *r) +{ + i64 x[64],i; + FOR(i,64) x[i] = (u64) r[i]; + FOR(i,64) r[i] = 0; + modL(r,x); +} + +int crypto_sign_ed25519(u8 *sm,u64 *smlen,const u8 *m,u64 n,const u8 *sk) +{ + u8 d[64],h[64],r[64]; + i64 i,j,x[64]; + gf p[4]; + + crypto_hash_sha512(d, sk, 32); + d[0] &= 248; + d[31] &= 127; + d[31] |= 64; + + *smlen = n+64; + FOR(i,n) sm[64 + i] = m[i]; + FOR(i,32) sm[32 + i] = d[32 + i]; + + crypto_hash_sha512(r, sm+32, n+32); + reduce(r); + scalarbase(p,r); + pack(sm,p); + + FOR(i,32) sm[i+32] = sk[i+32]; + crypto_hash_sha512(h,sm,n + 64); + reduce(h); + + FOR(i,64) x[i] = 0; + FOR(i,32) x[i] = (u64) r[i]; + FOR(i,32) FOR(j,32) x[i+j] += h[i] * (u64) d[j]; + modL(sm + 32,x); + + return 0; +} + +static int unpackneg(gf r[4],const u8 p[32]) +{ + gf t, chk, num, den, den2, den4, den6; + set25519(r[2],gf1); + unpack25519(r[1],p); + S(num,r[1]); + M(den,num,D); + Z(num,num,r[2]); + A(den,r[2],den); + + S(den2,den); + S(den4,den2); + M(den6,den4,den2); + M(t,den6,num); + M(t,t,den); + + pow2523(t,t); + M(t,t,num); + M(t,t,den); + M(t,t,den); + M(r[0],t,den); + + S(chk,r[0]); + M(chk,chk,den); + if (neq25519(chk, num)) M(r[0],r[0],I); + + S(chk,r[0]); + M(chk,chk,den); + if (neq25519(chk, num)) return -1; + + if (par25519(r[0]) == (p[31]>>7)) Z(r[0],gf0,r[0]); + + M(r[3],r[0],r[1]); + return 0; +} + +int crypto_sign_ed25519_open(u8 *m,u64 *mlen,const u8 *sm,u64 n,const u8 *pk) +{ + int i; + u8 t[32],h[64]; + gf p[4],q[4]; + + *mlen = -1; + if (n < 64) return -1; + + if (unpackneg(q,pk)) return -1; + + FOR(i,n) m[i] = sm[i]; + FOR(i,32) m[i+32] = pk[i]; + crypto_hash_sha512(h,m,n); + reduce(h); + scalarmult(p,q,h); + + scalarbase(q,sm + 32); + add(p,q); + pack(t,p); + + n -= 64; + if (crypto_verify_32(sm, t)) { + FOR(i,n) m[i] = 0; + return -1; + } + + FOR(i,n) m[i] = sm[i + 64]; + *mlen = n; + return 0; +} |