go - 如何在 GO 中创建带有扩展名和属性值的证书签名请求？

Question

我正在尝试使用 crypto/x509 包来创建证书请求 (csr)，但我不知道如何添加扩展和属性参数。

在CertificateRequest struct我们可以看到扩展是 pkix.Extension 类型。这是 pki.Extension 的结构:

type Extension struct {
        Id       asn1.ObjectIdentifier
        Critical bool `asn1:"optional"`
        Value    []byte
}

在代码中搜索，我在 https://golang.org/src/crypto/x509/x509.go 中找到了以下常量:

var (
    oidExtKeyUsageAny                            = asn1.ObjectIdentifier{2, 5, 29, 37, 0}
    oidExtKeyUsageServerAuth                     = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 1}
    oidExtKeyUsageClientAuth                     = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 2}
    oidExtKeyUsageCodeSigning                    = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 3}
    oidExtKeyUsageEmailProtection                = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 4}
    oidExtKeyUsageIPSECEndSystem                 = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 5}
    oidExtKeyUsageIPSECTunnel                    = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 6}
    oidExtKeyUsageIPSECUser                      = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 7}
    oidExtKeyUsageTimeStamping                   = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 8}
    oidExtKeyUsageOCSPSigning                    = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 3, 9}
    oidExtKeyUsageMicrosoftServerGatedCrypto     = asn1.ObjectIdentifier{1, 3, 6, 1, 4, 1, 311, 10, 3, 3}
    oidExtKeyUsageNetscapeServerGatedCrypto      = asn1.ObjectIdentifier{2, 16, 840, 1, 113730, 4, 1}
    oidExtKeyUsageMicrosoftCommercialCodeSigning = asn1.ObjectIdentifier{1, 3, 6, 1, 4, 1, 311, 2, 1, 22}
    oidExtKeyUsageMicrosoftKernelCodeSigning     = asn1.ObjectIdentifier{1, 3, 6, 1, 4, 1, 311, 61, 1, 1}
)

好的，现在我有了参数的Id。就我而言，我想将 KeyUsage 扩展设置为 serverAuth。我有 ID，但值是多少？

不知道我的做法对不对。有人可以帮我解决这个问题吗？

Answer 1

Attributes 字段被认为已弃用，无法正常工作。

当我必须向 csr 添加属性时，我将 x509.CreateCertificateRequest 所需的功能复制到内部文件并修复了 CreateCertificateRequest，在编码 certificateRequest 的 tbsCSR 字段之前以原始格式添加我的属性。注意:certificateRequest 结构不是 x509.CertifiacteRequest，该结构用于编码。以下是 passwordChallengeAttribute 的代码示例:

var oidChallengePassword = asn1.ObjectIdentifier{1, 2, 840, 113549, 1, 9, 7}

type passwordChallengeAttribute struct {
    Type  asn1.ObjectIdentifier
    Value []string `asn1:"set"`
}

passwordAttribute := passwordChallengeAttribute{
    Type:  oidChallengePassword,
    Value: []string{challenge},
}

b, err := asn1.Marshal(passwordAttribute)
if err != nil {
    //
}

var rawAttribute asn1.RawValue
asn1.Unmarshal(b, &rawAttribute)
tbsCSR.RawAttributes = append(tbsCSR.RawAttributes, rawAttribute)

但是使用扩展更好，也更受支持，所以你只需要实现代表所需扩展的数据结构，编码它并添加到扩展列表中。例如，添加 BasicConstraints 扩展:

type basicConstraints struct {
    IsCA       bool `asn1:"optional"`
    MaxPathLen int  `asn1:"optional,default:-1"`
}   
var extensions []pkix.Extension
basicCon := basicConstraints{IsCA: true, MaxPathLen: -1} 
bitstr, err := asn1.Marshal(basicCon)
if err != nil {
    //  
}   
var oidExtensionBasicConstraints = []int{2, 5, 29, 19} //export from x509 package
bcExt := pkix.Extension{Id: oidExtensionBasicConstraints, Value: bitstr}
extensions = append(extensions, bcExt)
csrTmpl := &x509.CertificateRequest{
    Extensions:    extensions,
}