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92 lines
2.5 KiB
92 lines
2.5 KiB
import parseKeys from "../parse-asn1";
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import randomBytes from "../randombytes";
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import createHash from "../create-hash";
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import mgf from "./mgf";
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import xor from "./xor";
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import BN from "../bn.js";
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import withPublic from "./withPublic";
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import crt from "../browserify-rsa";
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function oaep(key, msg) {
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var k = key.modulus.byteLength();
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var mLen = msg.length;
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var iHash = createHash('sha1').update(Buffer.alloc(0)).digest();
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var hLen = iHash.length;
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var hLen2 = 2 * hLen;
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if (mLen > k - hLen2 - 2) {
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throw new Error('message too long');
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}
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var ps = Buffer.alloc(k - mLen - hLen2 - 2);
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var dblen = k - hLen - 1;
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var seed = randomBytes(hLen);
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var maskedDb = xor(Buffer.concat([iHash, ps, Buffer.alloc(1, 1), msg], dblen), mgf(seed, dblen));
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var maskedSeed = xor(seed, mgf(maskedDb, hLen));
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return new BN(Buffer.concat([Buffer.alloc(1), maskedSeed, maskedDb], k));
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}
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function pkcs1(key, msg, reverse) {
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var mLen = msg.length;
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var k = key.modulus.byteLength();
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if (mLen > k - 11) {
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throw new Error('message too long');
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}
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var ps;
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if (reverse) {
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ps = Buffer.alloc(k - mLen - 3, 0xff);
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}
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else {
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ps = nonZero(k - mLen - 3);
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}
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return new BN(Buffer.concat([Buffer.from([0, reverse ? 1 : 2]), ps, Buffer.alloc(1), msg], k));
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}
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function nonZero(len) {
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var out = Buffer.allocUnsafe(len);
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var i = 0;
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var cache = randomBytes(len * 2);
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var cur = 0;
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var num;
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while (i < len) {
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if (cur === cache.length) {
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cache = randomBytes(len * 2);
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cur = 0;
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}
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num = cache[cur++];
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if (num) {
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out[i++] = num;
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}
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}
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return out;
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}
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export default (function publicEncrypt(publicKey, msg, reverse) {
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var padding;
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if (publicKey.padding) {
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padding = publicKey.padding;
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}
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else if (reverse) {
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padding = 1;
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}
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else {
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padding = 4;
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}
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var key = parseKeys(publicKey);
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var paddedMsg;
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if (padding === 4) {
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paddedMsg = oaep(key, msg);
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}
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else if (padding === 1) {
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paddedMsg = pkcs1(key, msg, reverse);
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}
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else if (padding === 3) {
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paddedMsg = new BN(msg);
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if (paddedMsg.cmp(key.modulus) >= 0) {
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throw new Error('data too long for modulus');
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}
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}
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else {
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throw new Error('unknown padding');
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}
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if (reverse) {
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return crt(paddedMsg, key);
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}
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else {
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return withPublic(paddedMsg, key);
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}
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});
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