使用 Node.js/crypto 生成 ECDSA 签名

问题描述

我的代码使用 jsrsasign 和 JWK 格式的密钥为 ECDSA 签名生成串联 (r-s) 签名:

I have code that generates a concatenated (r-s) signature for the ECDSA signature using jsrsasign and a key in JWK format:

const sig = new Signature({ alg: 'SHA256withECDSA' });
sig.init(KEYUTIL.getKey(key));
sig.updateHex(dataBuffer.toString('hex'));
const asn1hexSig = sig.sign();
const concatSig = ECDSA.asn1SigToConcatSig(asn1hexSig);
return new Buffer(concatSig, 'hex');

似乎有效.我也有使用 SubtleCrypto 来实现相同目的的代码:

Seems to work. I also have code that uses SubtleCrypto to achieve the same thing:

importEcdsaKey(key, 'sign') // importKey JWK -> raw
.then((privateKey) => subtle.sign(
    { name: 'ECDSA', hash: {name: 'SHA-256'} },
    privateKey,
    dataBuffer
))

它们都返回 128 字节的缓冲区；他们交叉验证(即我可以用 SubtleCrypto 验证 jsrsasign 签名，反之亦然).但是，当我在 Node.js crypto 模块中使用 Sign 类时，我似乎得到了完全不同的东西.

These both return 128-byte buffers; and they cross-verify (i.e. I can verify jsrsasign signatures with SubtleCrypto and vice versa). However, when I use the Sign class in the Node.js crypto module, I seem to get something quite different.

key = require('jwk-to-pem')(key, {'private': true});
const sign = require('crypto').createSign('sha256');
sign.update(dataBuffer);
return sign.sign(key);

这里我得到一个可变长度的缓冲区，大约 70 个字节；它不会与 jsrsa 进行交叉验证(它会抱怨 r-s 签名的长度无效).

Here I get a buffer of variable length, roughly 70 bytes; it does not cross-verify with jsrsa (which bails complaining about an invalid length for an r-s signature).

如何使用 Node crypto 获得由 jsrsasign 和 SubtleCrypto 生成的 r-s 签名?

How can I get an r-s signature, as generated by jsrsasign and SubtleCrypto, using Node crypto?

推荐答案

答案原来是 Node crypto 模块生成 ASN.1/DER 签名，而其他 API 如 jsrsasign 和 SubtleCrypto 产生一个串联"签名.在这两种情况下，签名都是 (r, s) 的串联.不同之处在于 ASN.1 使用最少的字节数，加上一些有效载荷长度数据；而 P1363 格式使用两个 32 位十六进制编码的整数，必要时补零.

The answer turns out to be that the Node crypto module generates ASN.1/DER signatures, while other APIs like jsrsasign and SubtleCrypto produce a "concatenated" signature. In both cases, the signature is a concatenation of (r, s). The difference is that ASN.1 does so with the minimum number of bytes, plus some payload length data; while the P1363 format uses two 32-bit hex encoded integers, zero-padding them if necessary.

以下解决方案假定规范"格式是 SubtleCrypto 使用的连接样式.

The below solution assumes that the "canonical" format is the concatenated style used by SubtleCrypto.

const asn1 = require('asn1.js');
const BN = require('bn.js');
const crypto = require('crypto');

const EcdsaDerSig = asn1.define('ECPrivateKey', function() {
    return this.seq().obj(
        this.key('r').int(),
        this.key('s').int()
    );
});

function asn1SigSigToConcatSig(asn1SigBuffer) {
    const rsSig = EcdsaDerSig.decode(asn1SigBuffer, 'der');
    return Buffer.concat([
        rsSig.r.toArrayLike(Buffer, 'be', 32),
        rsSig.s.toArrayLike(Buffer, 'be', 32)
    ]);
}

function concatSigToAsn1SigSig(concatSigBuffer) {
    const r = new BN(concatSigBuffer.slice(0, 32).toString('hex'), 16, 'be');
    const s = new BN(concatSigBuffer.slice(32).toString('hex'), 16, 'be');
    return EcdsaDerSig.encode({r, s}, 'der');
}

function ecdsaSign(hashBuffer, key) {
    const sign = crypto.createSign('sha256');
    sign.update(asBuffer(hashBuffer));
    const asn1SigBuffer = sign.sign(key, 'buffer');
    return asn1SigSigToConcatSig(asn1SigBuffer);
}

function ecdsaVerify(data, signature, key) {
    const verify = crypto.createVerify('SHA256');
    verify.update(data);
    const asn1sig = concatSigToAsn1Sig(signature);
    return verify.verify(key, new Buffer(asn1sig, 'hex'));
}

感谢

• https://crypto.stackexchange.com/questions/1795/how-can-i-convert-a-der-ecdsa-signature-to-asn-1
• ECDSA 签名在 Node.js 和WebCrypto 似乎不兼容?

这篇关于使用 Node.js/crypto 生成 ECDSA 签名的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！