使用Node.js / crypto生成ECDSA签名

问题描述

我有使用 c> c>

解决方案 / code>模块生成ASN.1 / DER签名，而其他API如 jsrsasign 和 SubtleCrypto 连接签名。在这两种情况下，签名是（r，s）的级联。不同之处在于ASN.1使用最小字节数加上一些有效载荷长度数据;

下面的解决方案假定规范格式是使用的连接样式 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）
]）; 
} 
 
函数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）; 
} 
 
函数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

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');

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
))

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);

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).

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

解决方案

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.

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'));
}

Figured it out thanks to

• http://crypto.stackexchange.com/questions/1795/how-can-i-convert-a-der-ecdsa-signature-to-asn-1
• ECDSA signatures between Node.js and WebCrypto appear to be incompatible?

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！