CryptoKey ArrayBuffer 到 base64 并返回-前端问题

CryptoKey ArrayBuffer to base64 and Back(CryptoKey ArrayBuffer 到 base64 并返回)

本文介绍了CryptoKey ArrayBuffer 到 base64 并返回的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

我想知道如何解决这个问题.我使用 WebCrypto API 生成 RSA-OAEP 密钥对，然后从导出为 ArrayBuffer 的密钥对中导出 pkcs8 中的私钥，我想将此 ArrayBuffer 编码为 base64，以便将其存储为 PEM.

I was wondering how do I solve this problem. I generate RSA-OAEP keypair using WebCrypto API, then I export private key in pkcs8 from the keypair which exports as ArrayBuffer and I want to encode this ArrayBuffer into base64 so I can store it as a PEM.

在此测试示例中，我将密钥导出为 pkcs8 并将此 pkcs8 导入回 CryptoKey.问题是有时有效，有时无效.

In this testing example I am exporting key as pkcs8 and importing this pkcs8 back to CryptoKey. The problem is that sometimes it works and sometimes it does not.

这些是代码的结果:注意:只发生这些状态之一，而不是同时发生.NOTE2:本例不包含 -----BEGIN PRIVATE KEY----- 前缀和后缀，我只是对密钥进行编码.

These are results of the code: NOTE: Only happens one of these states not all at once. NOTE2: This example does not contain -----BEGIN PRIVATE KEY----- prefix and suffix I am only encoding the key.

Case1: Uncaught (in promise) URIError: URI malformed(...)b64DecodeUnicode @ try.php:20b64toab @ try.php:70wayBack @ try.php:66(anonymous function) @ try.php:56

Case1: Uncaught (in promise) URIError: URI malformed(…)b64DecodeUnicode @ try.php:20b64toab @ try.php:70wayBack @ try.php:66(anonymous function) @ try.php:56

Case2: undefined:1 Uncaught (in promise) DOMException

案例 3:好的 - 一直有效.

Case3: OK - works all the way back.

我不知道是什么导致了错误，但我认为这与 base64 编码有关.正如我所说，有时私钥会生成 OK，有时则不会.

I don't know what causes the errors but I think it has something to do with base64 encoding. As I said sometimes private key generates OK and sometimes not.

非常感谢您提前提供的每一个帮助.

Thank you very much for every help in advance.

function b64EncodeUnicode(str) {
    return btoa(encodeURIComponent(str).replace(/%([0-9A-F]{2})/g, function(match, p1) {
        return String.fromCharCode('0x' + p1);
    }));
}

function b64DecodeUnicode(str) {
    return decodeURIComponent(Array.prototype.map.call(atob(str), function(c) {
        return '%' + ('00' + c.charCodeAt(0).toString(16)).slice(-2);
    }).join(''));
}

function addNewLines(str) {
    var finalString = '';
    for(var i=0; i < str.length; i++) {
        finalString += str.substring(0, 64) + '
';
        str = str.substring(64);
    }

     return finalString;
}

window.crypto.subtle.generateKey(
    {
        name: "RSA-OAEP",
        modulusLength: 2048,
        publicExponent: new Uint8Array([0x01, 0x00, 0x01]),
        hash: {name: "SHA-256"}
    },
    true,
    ["encrypt", "decrypt"]
).then(function(keyPair) {
    window.crypto.subtle.exportKey(
        "pkcs8",
        keyPair.privateKey
    ).then(function(exportedPrivateKey) {
        var byteArray = new Uint8Array(exportedPrivateKey);
        console.log(byteArray);
        var byteString = '';
        for(var i=0; i < byteArray.byteLength; i++) {
            byteString += String.fromCodePoint(byteArray[i]);
        }

        wayBack(addNewLines(b64EncodeUnicode(byteString)));
    });
});

function wayBack(pem) {
    var lines = pem.split('
');
    var encodedString = '';
    for(var i=0; i < lines.length; i++) {
        encodedString += lines[i].trim();
    }
    b64toab(encodedString);
}

function b64toab(b64) {
    var byteString = b64DecodeUnicode(b64);
    console.log(byteString);
    var byteArray = new Uint8Array(byteString.length);
    for(var i=0; i < byteString.length; i++) {
        byteArray[i] = byteString.codePointAt(i);
    }
    console.log(byteArray);

    window.crypto.subtle.importKey(
        "pkcs8",
        byteArray,
        {
            name: "RSA-OAEP",
            hash: {name: "SHA-256"}
        },
        true,
        ["decrypt"]
    ).then(function(importedPrivateKey) {
        console.log(importedPrivateKey);
    });
}

推荐答案

当您将字符串拆分为 64 个字符的块时，您忘记包含 PEM 的最后一部分.只需将 finalString += str; 添加到 addNewLines

You forgot to include the last part of PEM when you split the string in blocks of 64 characters. Just add finalString += str; to addNewLines

function addNewLines(str) {
    var finalString = '';
    for(var i=0; i < str.length; i++) {
        finalString += str.substring(0, 64) + '
';
        str = str.substring(64);
    }
    finalString += str;

    return finalString;
}

我已经重构了您的示例以查看发生了什么.如果您认为它有用，请使用以下代码

I have refactorized your example to see what is happening. Use the below code if you consider it useful

function b64EncodeUnicode(str) {
    return btoa(encodeURIComponent(str).replace(/%([0-9A-F]{2})/g, function(match, p1) {
        return String.fromCharCode('0x' + p1);
    }));
}

function b64DecodeUnicode(str) {
    return decodeURIComponent(Array.prototype.map.call(atob(str), function(c) {
        return '%' + ('00' + c.charCodeAt(0).toString(16)).slice(-2);
    }).join(''));
}

function addNewLines(str) {
    var finalString = '';
    for(var i=0; i < str.length; i++) {
        finalString += str.substring(0, 64) + '
';
        str = str.substring(64);
    }
    finalString += str;

    return finalString;
}

function removeLines(pem) {
    var lines = pem.split('
');
    var encodedString = '';
    for(var i=0; i < lines.length; i++) {
        encodedString += lines[i].trim();
    }
    return encodedString;
}

function stringToArrayBuffer(byteString){
    var byteArray = new Uint8Array(byteString.length);
    for(var i=0; i < byteString.length; i++) {
        byteArray[i] = byteString.codePointAt(i);
    }
    return byteArray;
}

function  arrayBufferToString(exportedPrivateKey){
    var byteArray = new Uint8Array(exportedPrivateKey);
    var byteString = '';
    for(var i=0; i < byteArray.byteLength; i++) {
        byteString += String.fromCodePoint(byteArray[i]);
    }
    return byteString;
}

window.crypto.subtle.generateKey(
    {
        name: "RSA-OAEP",
        modulusLength: 2048,
        publicExponent: new Uint8Array([0x01, 0x00, 0x01]),
        hash: {name: "SHA-256"}
    },
    true,
    ["encrypt", "decrypt"]
).then(function(keyPair) {
    window.crypto.subtle.exportKey(
        "pkcs8",
        keyPair.privateKey
    ).then(function(exportedPrivateKey) {

        var privateKeyDer = arrayBufferToString(exportedPrivateKey); //pkcs#8 to DER
        var privateKeyB64 = b64EncodeUnicode(privateKeyDer); //btoa(privateKeyDer);
        var privateKeyPEMwithLines = addNewLines(privateKeyB64);  //split PEM into 64 character strings
        var privateKeyPEMwithoutLines = removeLines(privateKeyPEMwithLines);  //join PEM
        var privateKeyDerDecoded = b64DecodeUnicode(privateKeyPEMwithoutLines);  // atob(privateKeyB64);
        var privateKeyArrayBuffer = stringToArrayBuffer(privateKeyDerDecoded);  //DER to arrayBuffer
        window.crypto.subtle.importKey(  //importKEy
            "pkcs8",
            privateKeyArrayBuffer,
            {
                name: "RSA-OAEP",
                hash: {name: "SHA-256"}
            },
            true,
            ["decrypt"]
        ).then(function(importedPrivateKey) {
            console.log(importedPrivateKey);
        });
    });
});

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