英文:
sign a SHA-256 hash with DSA in Go
问题
我想用DSA对SHA-256哈希进行签名。
使用Java，我可以这样写：
Signature sig = Signature.getInstance("SHA256withDSA");
sig.initSign(priKey);
sig.update(new byte[]{1});
byte[] sign = sig.sign();
System.out.println(HexUtil.encodeHexStr(sign));
使用Go语言，我找不到任何解决方法。
英文:
I want to sign a SHA-256 hash with DSA.
Using Java I can write:
Signature sig = Signature.getInstance("SHA256withDSA");
sig.initSign(priKey);
sig.update(new byte[]{1});
byte[] sign = sig.sign();
System.out.println(HexUtil.encodeHexStr(sign));
Using the Go language, I couldn't find any way to resolve it
答案1
得分: 2
在Go语言中，对DSAWithSHA256签名的唯一检查实例出现在github.com/avast/apkverifier中的代码中。
case x509.DSAWithSHA256:
hash := sha256.Sum256(signed)
pub := cert.PublicKey.(*dsa.PublicKey)
reqLen := pub.Q.BitLen() / 8
if reqLen > len(hash) {
return fmt.Errorf("给定的DSA参数对应的摘要算法太短。")
}
digest := hash[:reqLen]
dsaSig := new(dsaSignature)
if rest, err := asn1.Unmarshal(signature, dsaSig); err != nil {
return err
} else if len(rest) != 0 {
return errors.New("x509: DSA签名后存在多余数据")
}
if dsaSig.R.Sign() <= 0 || dsaSig.S.Sign() <= 0 {
return errors.New("x509: DSA签名包含零值或负值")
}
if !dsa.Verify(pub, digest, dsaSig.R, dsaSig.S) {
return errors.New("x509: DSA验证失败")
}
但实际上，在github.com/grantae/certinfo中有说明，确实不支持使用该签名算法。
> ## 问题：
>
> 1. 不幸的是，OpenSSL对DSA和ECDSA证书请求使用非确定性签名，因此运行make-certs.sh将无法生成相同的CSR，尽管密钥是静态的。
这些文件必须手动保持同步。
>
> 2. x509包目前不会为DSA CSR设置CertificateRequest.SignatureAlgorithm。
因此，'leaf2.csr.text'文件中包含的行是'Signature Algorithm: 0'，而不是'Signature Algorithm: DSAWithSHA256'，以便测试通过并指示问题出现在x509而不是该包中。
因此，在Go的crypto/x509包中，该签名算法是不支持的。
英文:
The only instance of checking a DSAWithSHA256 signature in go is in github.com/avast/apkverifier
case x509.DSAWithSHA256:
hash := sha256.Sum256(signed)
pub := cert.PublicKey.(*dsa.PublicKey)
reqLen := pub.Q.BitLen() / 8
if reqLen > len(hash) {
return fmt.Errorf("Digest algorithm is too short for given DSA parameters.")
}
digest := hash[:reqLen]
dsaSig := new(dsaSignature)
if rest, err := asn1.Unmarshal(signature, dsaSig); err != nil {
return err
} else if len(rest) != 0 {
return errors.New("x509: trailing data after DSA signature")
}
if dsaSig.R.Sign() <= 0 || dsaSig.S.Sign() <= 0 {
return errors.New("x509: DSA signature contained zero or negative values")
}
if !dsa.Verify(pub, digest, dsaSig.R, dsaSig.S) {
return errors.New("x509: DSA verification failure")
}
But actually using the signature algorithm is indeed unsupported, for reason illustrated in github.com/grantae/certinfo
> ## Issues:
>
> 1. Unfortunately, OpenSSL uses non-deterministic signing for DSA and ECDSA certificate requests, so running make-certs.sh will not reproduce the same CSRs despite having static keys.
These files have to be kept in-sync manually.
>
> 2. The x509 package does not currently set CertificateRequest.SignatureAlgorithm for DSA CSRs.
Therefore the 'leaf2.csr.text' contains the line 'Signature Algorithm: 0'
instead of 'Signature Algorithm: DSAWithSHA256' to allow the test to pass and indicate that the problem is with x509 and not this package.
Hence its unsupported status in Go crypto/x509 package.
专注分享java语言的经验与见解，让所有开发者获益！
评论