如何使用Javascript WebCrypto API加载PKCS#12数字证书

我试图使用WebCrypto API签署数据,但是不是创建一个私有/公共密钥并将其导出到pkcs#1或8,我真的想使用用户的PKCS#12签署数据.我已经阅读了W3C规范,但不能做太多的事情,也找不到任何有关如何做到这一点的好材料.现在我想把ActiveX和 Java Applet放在一边.有没有办法调整以下内容：

var buffer = encode(prompt("Please enter your password"));
    //Todo:
    //implement a prompt for a pfx or cert

  return crypto.subtle.importKey("raw",buffer,"PBKDF2",false,usages);
    //Todo:
    //instead of importing it,ask for the certificate's pass to sign data
    //with crypto.subtle.sign

任何指针？

UPDATE
这是我一直在工作的代码

<script src="forge.min.js"></script>

<script>
    var errorsReportedByVerifier;
    errorsReportedByVerifier = checkStorage() && checkbrowserAPIs();
    if (!errorsReportedByVerifier){
        console.log("adding click event");
        document.getElementById('btnPfx').addEventListener('click',handlePFXFile,false);
        storeVariables();
        getvariables();
    }


    function handlePFXFile(evnt) {
        console.log("handling pfx")
        //alert(document.getElementById('pfx').value);

        //error happens in 1st line
        //error object does not accept property replace
        //forge.min.js Line 1,Column: 17823
        var p12Der = forge.util.decode64(document.getElementById('pfx').valueOf());
        //var pkcs12Asn1 = forge.asn1.fromDer(p12Der);
        //var pkcs12 = forge.pkcs12.pkcs12FromAsn1(pkcs12Asn1,'pss');
        console.log("pkcs12");
    }
</script>

解决方法

Web加密api不支持PKCS#12.您可以使用第三方库将p12解码为forge https://github.com/digitalbazaar/forge#pkcs12,并在webcrypto中加载privateKey

阅读PKCS#12证书

PKCS#12存储在DER中,因此首先从文件读取它或使用预存的base64

//Reading certificate from a 'file' form field
var reader = new FileReader();
reader.onload = function(e) {               
    var contents = e.target.result;
    var pkcs12Der = arrayBufferToString(contents)
    var pkcs12B64 = forge.util.encode64(pkcs12Der);     
    //do something else...

}   
reader.readAsArrayBuffer(file);

function arrayBufferToString( buffer ) {
    var binary = '';
    var bytes = new Uint8Array( buffer );
    var len = bytes.byteLength;
    for (var i = 0; i < len; i++) {
        binary += String.fromCharCode( bytes[ i ] );
    }
    return binary;
}

//p12 certificate stored in Base64 format
var pkcs12Der= forge.util.decode64(pkcs12B64);

解密PKCS#12,伪造并提取私钥

然后将DER格式解码为ASN1,并使伪造读取内容

var pkcs12Asn1 = forge.asn1.fromDer(pkcs12Der);
var pkcs12 = forge.pkcs12.pkcs12FromAsn1(pkcs12Asn1,password);

然后从pkcs12获取所需证书的私钥(参见forge doc)并转换为PKCS#8以使用webcrypto导入

// load keypair and cert chain from safe content(s) 
for(var sci = 0; sci < pkcs12.safeContents.length; ++sci) {
    var safeContents = pkcs12.safeContents[sci];

    for(var sbi = 0; sbi < safeContents.safeBags.length; ++sbi) {
        var safeBag = safeContents.safeBags[sbi];

        // this bag has a private key
        if(safeBag.type === forge.pki.oids.keyBag) {
            //Found plain private key
            privateKey = safeBag.key;
        } else if(safeBag.type === forge.pki.oids.pkcs8ShroudedKeyBag) {
            // found encrypted private key
            privateKey = safeBag.key;
        } else if(safeBag.type === forge.pki.oids.certBag) {
            // this bag has a certificate...        
        }   
    }
}

转换为PKCS#8

_privateKeyToPkcs8 function (privateKey) {
     var rsaPrivateKey = forge.pki.privateKeyToAsn1(privateKey);
     var privateKeyInfo = forge.pki.wrapRsaPrivateKey(rsaPrivateKey);
     var privateKeyInfoDer = forge.asn1.toDer(privateKeyInfo).getBytes();
     var privateKeyInfoDerBuff = stringToArrayBuffer(privateKeyInfoDer);
     return privateKeyInfoDerBuff;
 }
 function stringToArrayBuffer(data){
     var arrBuff = new ArrayBuffer(data.length);
     var writer = new Uint8Array(arrBuff);
     for (var i = 0,len = data.length; i < len; i++) {
         writer[i] = data.charCodeAt(i);
     }
     return arrBuff;
  }

导入密钥在Webcrypto

最后导入webcrypto的密钥

function _importCryptoKeyPkcs8(privateKey,extractable) {
    var privateKeyInfoDerBuff = _privateKeyToPkcs8(privateKey);

    //Importa la clave en la webcrypto
    return crypto.subtle.importKey(
            'pkcs8',privateKeyInfoDerBuff,{ name: "RSASSA-PKCS1-v1_5",hash:{name:"SHA-256"}},extractable,["sign"]);        

}
_importCryptoKeyPkcs8(entry.privateKey,extractable).    
        then(function(cryptoKey) {
            //your cryptokey is here!!!
        }

电子签名

使用从上述方法返回的导入的cryptoKey,您可以使用webcrypto进行签名.

var digestToSign = forge.util.decode64(digestToSignB64);
var digestToSignBuf = stringToArrayBuffer(digestToSign);

crypto.subtle.sign(
            {name: "RSASSA-PKCS1-v1_5"},cryptoKey,digestToSignBuf)
.then(function(signature){
    signatureB64 = forge.util.encode64(arrayBufferToString(signature))
}

我包括来自base64的编码,因为数据转换不是微不足道的

在pkc12中,如果您需要构建像AdES这样的高级格式,您也可以拥有认证链