sodium-javascript/crypto_sign.js

320 lines
6.8 KiB
JavaScript
Raw Normal View History

Split library into modules (#20) * crypto_stream: signature change needed to modularise * move ed25519 arithmetic to separate module * module: poly1305 * module: crypto_scalarmult * module: crypto_hash * module: crypto_sign * module: crypto_secretbox * move verify functions to crypto_verify module * leftover crypto_stream functions * module: crypto_onetimeauth * module: crypto_box * tidy up * require ed25519.js * update: crypto_hash * add chacha20; align API with PR#21 * update sha512 to wasm module * fix bugs in crypto_sign * be standard * add: crypto_box_seed_keypair; alias crypto_kx methods to crypto_box * scalarmult: import curve methods; be standard * correction: crypto_kx is not actually an alias of crypto_box * export _9 constant field element * add: crypto_box_seed_keypair * removed duplicate module.exports declaraion * declare constants about exports * rename memzero -> sodium-memzero * update sodium_memzero function to arr.fill(0) * tidy: remove legacy functions * added: crypto_aead_chacha20poly1305_ietf methods * listen to linter * add assertions * chacha: readUint32Le generalised for uint8array; aead: standard fix * add null check on ad param * added: sodium_memcmp * export sodium_memcmp * export crypto_verify module * sodium_memcmp returns boolean * added: sodium_is_zero * catch syntax error * throw if crypto_aead cannot validate, fix typo in crypto_verify * move chacha20 alg to external module * use Uint8Arrays instead of buffers * change checks to assertions * bump to chacha 1.0.3 - remove Buffer dependency * reduce code branching, align return values with sodium-native * add sha-wasm deps to package.json * standard fixes * bump chacha20 to 1.0.4: remove Buffer dep * move crypto_hash_sha256 to module to uncouple wasm dependencies * add endian check: all other modules require members of this set * correct filename: crypto_hash_sha256 * export constant: crypto_hash_sha512_BYTES
2020-06-18 15:09:03 +00:00
const { crypto_verify_32 } = require('./crypto_verify')
const { crypto_hash } = require('./crypto_hash')
const {
gf, gf0, gf1, D, D2,
X, Y, I, A, Z, M, S,
sel25519, pack25519,
inv25519, unpack25519
} = require('./ed25519')
const { randombytes } = require('./randombytes')
const crypto_sign_BYTES = 64,
crypto_sign_PUBLICKEYBYTES = 32,
crypto_sign_SECRETKEYBYTES = 64,
crypto_sign_SEEDBYTES = 32
module.exports = {
crypto_sign_keypair,
crypto_sign_seed_keypair,
crypto_sign,
crypto_sign_detached,
crypto_sign_open,
crypto_sign_verify_detached,
crypto_sign_BYTES,
crypto_sign_PUBLICKEYBYTES,
crypto_sign_SECRETKEYBYTES,
crypto_sign_SEEDBYTES
}
function set25519(r, a) {
var i;
for (i = 0; i < 16; i++) r[i] = a[i]|0;
}
function pow2523(o, i) {
var c = gf();
var a;
for (a = 0; a < 16; a++) c[a] = i[a];
for (a = 250; a >= 0; a--) {
S(c, c);
if(a !== 1) M(c, c, i);
}
for (a = 0; a < 16; a++) o[a] = c[a];
}
function add(p, q) {
var a = gf(), b = gf(), c = gf(),
d = gf(), e = gf(), f = gf(),
g = gf(), h = gf(), t = gf();
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);
}
function cswap(p, q, b) {
var i;
for (i = 0; i < 4; i++) {
sel25519(p[i], q[i], b);
}
}
function pack(r, p) {
var tx = gf(), ty = gf(), zi = gf();
inv25519(zi, p[2]);
M(tx, p[0], zi);
M(ty, p[1], zi);
pack25519(r, ty);
r[31] ^= par25519(tx) << 7;
}
function scalarmult(p, q, s) {
var b, i;
set25519(p[0], gf0);
set25519(p[1], gf1);
set25519(p[2], gf1);
set25519(p[3], gf0);
for (i = 255; i >= 0; --i) {
b = (s[(i/8)|0] >> (i&7)) & 1;
cswap(p, q, b);
add(q, p);
add(p, p);
cswap(p, q, b);
}
}
function scalarbase(p, s) {
var q = [gf(), gf(), gf(), gf()];
set25519(q[0], X);
set25519(q[1], Y);
set25519(q[2], gf1);
M(q[3], X, Y);
scalarmult(p, q, s);
}
function crypto_sign_keypair(pk, sk, seeded) {
check(pk, crypto_sign_PUBLICKEYBYTES)
check(sk, crypto_sign_SECRETKEYBYTES)
var d = new Uint8Array(64);
var p = [gf(), gf(), gf(), gf()];
var i;
if (!seeded) randombytes(sk, 32);
crypto_hash(d, sk, 32);
d[0] &= 248;
d[31] &= 127;
d[31] |= 64;
scalarbase(p, d);
pack(pk, p);
for (i = 0; i < 32; i++) sk[i+32] = pk[i];
return 0;
}
function crypto_sign_seed_keypair (pk, sk, seed) {
check(seed, crypto_sign_SEEDBYTES)
2020-06-18 15:12:00 +00:00
sk.set(seed)
Split library into modules (#20) * crypto_stream: signature change needed to modularise * move ed25519 arithmetic to separate module * module: poly1305 * module: crypto_scalarmult * module: crypto_hash * module: crypto_sign * module: crypto_secretbox * move verify functions to crypto_verify module * leftover crypto_stream functions * module: crypto_onetimeauth * module: crypto_box * tidy up * require ed25519.js * update: crypto_hash * add chacha20; align API with PR#21 * update sha512 to wasm module * fix bugs in crypto_sign * be standard * add: crypto_box_seed_keypair; alias crypto_kx methods to crypto_box * scalarmult: import curve methods; be standard * correction: crypto_kx is not actually an alias of crypto_box * export _9 constant field element * add: crypto_box_seed_keypair * removed duplicate module.exports declaraion * declare constants about exports * rename memzero -> sodium-memzero * update sodium_memzero function to arr.fill(0) * tidy: remove legacy functions * added: crypto_aead_chacha20poly1305_ietf methods * listen to linter * add assertions * chacha: readUint32Le generalised for uint8array; aead: standard fix * add null check on ad param * added: sodium_memcmp * export sodium_memcmp * export crypto_verify module * sodium_memcmp returns boolean * added: sodium_is_zero * catch syntax error * throw if crypto_aead cannot validate, fix typo in crypto_verify * move chacha20 alg to external module * use Uint8Arrays instead of buffers * change checks to assertions * bump to chacha 1.0.3 - remove Buffer dependency * reduce code branching, align return values with sodium-native * add sha-wasm deps to package.json * standard fixes * bump chacha20 to 1.0.4: remove Buffer dep * move crypto_hash_sha256 to module to uncouple wasm dependencies * add endian check: all other modules require members of this set * correct filename: crypto_hash_sha256 * export constant: crypto_hash_sha512_BYTES
2020-06-18 15:09:03 +00:00
return crypto_sign_keypair(pk, sk, true)
}
var L = new Float64Array([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]);
function modL(r, x) {
var carry, i, j, k;
for (i = 63; i >= 32; --i) {
carry = 0;
for (j = i - 32, k = i - 12; j < k; ++j) {
x[j] += carry - 16 * x[i] * L[j - (i - 32)];
carry = (x[j] + 128) >> 8;
x[j] -= carry * 256;
}
x[j] += carry;
x[i] = 0;
}
carry = 0;
for (j = 0; j < 32; j++) {
x[j] += carry - (x[31] >> 4) * L[j];
carry = x[j] >> 8;
x[j] &= 255;
}
for (j = 0; j < 32; j++) x[j] -= carry * L[j];
for (i = 0; i < 32; i++) {
x[i+1] += x[i] >> 8;
r[i] = x[i] & 255;
}
}
function reduce(r) {
var x = new Float64Array(64), i;
for (i = 0; i < 64; i++) x[i] = r[i];
for (i = 0; i < 64; i++) r[i] = 0;
modL(r, x);
}
// Note: difference from C - smlen returned, not passed as argument.
function crypto_sign(sm, m, sk) {
check(sm, crypto_sign_BYTES + m.length)
check(m, 0)
check(sk, crypto_sign_SECRETKEYBYTES)
var n = m.length
var d = new Uint8Array(64), h = new Uint8Array(64), r = new Uint8Array(64);
var i, j, x = new Float64Array(64);
var p = [gf(), gf(), gf(), gf()];
crypto_hash(d, sk, 32);
d[0] &= 248;
d[31] &= 127;
d[31] |= 64;
var smlen = n + 64;
for (i = 0; i < n; i++) sm[64 + i] = m[i];
for (i = 0; i < 32; i++) sm[32 + i] = d[32 + i];
crypto_hash(r, sm.subarray(32), n+32);
reduce(r);
scalarbase(p, r);
pack(sm, p);
for (i = 32; i < 64; i++) sm[i] = sk[i];
crypto_hash(h, sm, n + 64);
reduce(h);
for (i = 0; i < 64; i++) x[i] = 0;
for (i = 0; i < 32; i++) x[i] = r[i];
for (i = 0; i < 32; i++) {
for (j = 0; j < 32; j++) {
x[i+j] += h[i] * d[j];
}
}
modL(sm.subarray(32), x);
return smlen
}
function crypto_sign_detached(sig, m, sk) {
var sm = new Uint8Array(m.length + crypto_sign_BYTES)
crypto_sign(sm, m, sk)
for (var i = 0; i < crypto_sign_BYTES; i++) sig[i] = sm[i]
}
function unpackneg(r, p) {
var t = gf(), chk = gf(), num = gf(),
den = gf(), den2 = gf(), den4 = gf(),
den6 = gf();
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;
}
function crypto_sign_open(msg, sm, pk) {
check(msg, sm.length - crypto_sign_BYTES)
check(sm, crypto_sign_BYTES)
check(pk, crypto_sign_PUBLICKEYBYTES)
var n = sm.length
var m = new Uint8Array(sm.length)
var i, mlen;
var t = new Uint8Array(32), h = new Uint8Array(64);
var p = [gf(), gf(), gf(), gf()],
q = [gf(), gf(), gf(), gf()];
mlen = -1;
if (n < 64) return false;
if (unpackneg(q, pk)) return false;
for (i = 0; i < n; i++) m[i] = sm[i];
for (i = 0; i < 32; i++) m[i+32] = pk[i];
crypto_hash(h, m, n);
reduce(h);
scalarmult(p, q, h);
scalarbase(q, sm.subarray(32));
add(p, q);
pack(t, p);
n -= 64;
if (crypto_verify_32(sm, 0, t, 0)) {
for (i = 0; i < n; i++) m[i] = 0;
return false;
}
for (i = 0; i < n; i++) msg[i] = sm[i + 64];
mlen = n;
return true;
}
function crypto_sign_verify_detached (sig, m, pk) {
check(sig, crypto_sign_BYTES)
var sm = new Uint8Array(m.length + crypto_sign_BYTES)
var i = 0
for (i = 0; i < crypto_sign_BYTES; i++) sm[i] = sig[i]
for (i = 0; i < m.length; i++) sm[i + crypto_sign_BYTES] = m[i]
return crypto_sign_open(m, sm, pk)
}
function par25519(a) {
var d = new Uint8Array(32);
pack25519(d, a);
return d[0] & 1;
}
function neq25519(a, b) {
var c = new Uint8Array(32), d = new Uint8Array(32);
pack25519(c, a);
pack25519(d, b);
return crypto_verify_32(c, 0, d, 0);
}
function check (buf, len) {
if (!buf || (len && buf.length < len)) throw new Error('Argument must be a buffer' + (len ? ' of length ' + len : ''))
}