将webcrypto键导出为PEM格式

Question

我正在使用WebCrypto和RSASSA-PKCS1-v1_5(https://github.com/diafygi/webcrypto-examples#rsassa-pkcs1-v1_5---sign),我需要使用javascript代码将公钥导出为PEM格式.

文档说可以通过这种方式导出密钥:https: //github.com/diafygi/webcrypto-examples#rsassa-pkcs1-v1_5---exportkey 但我需要不同的格式.

任何的想法？

提前致谢.

问候

Answer 1

将公钥导出到 spki

window.crypto.subtle.exportKey("spki",keys.publicKey);

并将生成的数组缓冲区转换为base64,添加PEM头-----BEGIN PUBLIC KEY-----和-----END PUBLIC KEY-----.下面我提供spkiToPEM一个完整的例子

crypto.subtle.generateKey(
    {
        name: "RSASSA-PKCS1-v1_5",
        modulusLength: 2048, 
        publicExponent: new Uint8Array([0x01, 0x00, 0x01]),
        hash: {name: "SHA-256"}, 
    },
    false, 
    ["sign", "verify"] 
).then(function(keys){     
    return window.crypto.subtle.exportKey("spki",keys.publicKey);
}).then (function(keydata){
    var pem = spkiToPEM(keydata);
    console.log(pem);
}).catch(function(err){
    console.error(err);
});

function spkiToPEM(keydata){
    var keydataS = arrayBufferToString(keydata);
    var keydataB64 = window.btoa(keydataS);
    var keydataB64Pem = formatAsPem(keydataB64);
    return keydataB64Pem;
}

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;
}


function formatAsPem(str) {
    var finalString = '-----BEGIN PUBLIC KEY-----\n';

    while(str.length > 0) {
        finalString += str.substring(0, 64) + '\n';
        str = str.substring(64);
    }

    finalString = finalString + "-----END PUBLIC KEY-----";

    return finalString;
}