JavaScript 导出 RSA-OAEP 公钥

Question

我正在尝试使用描述为 here 的导出 key 来访问公钥。 。我有以下代码:

window.crypto.subtle.generateKey(
            {
                name: "RSA-OAEP",
                modulusLength: 2048, //can be 1024, 2048, or 4096
                publicExponent: new Uint8Array([0x01, 0x00, 0x01]),
                hash: {name: "SHA-256"}, //can be "SHA-1", "SHA-256", "SHA-384", or "SHA-512"
            },
            true, //whether the key is extractable (i.e. can be used in exportKey)
            ["encrypt", "decrypt"] //must be ["encrypt", "decrypt"] or ["wrapKey", "unwrapKey"]
        )
            .then(function(key){
                //returns a keypair object
                console.log(key);
                console.log(key.publicKey);
                console.log(key.privateKey);

        window.crypto.subtle.exportKey("spki",key.publicKey)
            .then(function(keydata){
                //returns the exported key data
                console.log(keydata);
                document.getElementById("key").innerHTML = String(key.publicKey)
            })
            .catch(function(err){
                console.error(err);
            });
    })

我想查看公钥，例如将其设置为 HTML 元素，目前 HTML 元素被设置为 [object CryptoKey]。如何直接获取公钥？

谢谢

编辑:

window.crypto.subtle.generateKey(
            {
                name: "RSA-OAEP",
                modulusLength: 2048, //can be 1024, 2048, or 4096
                publicExponent: new Uint8Array([0x01, 0x00, 0x01]),
                hash: {name: "SHA-256"}, //can be "SHA-1", "SHA-256", "SHA-384", or "SHA-512"
            },
            true, //whether the key is extractable (i.e. can be used in exportKey)
            ["encrypt", "decrypt"] //must be ["encrypt", "decrypt"] or ["wrapKey", "unwrapKey"]
        )
            .then(function(key){
                //returns a keypair object
                console.log(key);
                console.log(key.publicKey);
                console.log(key.privateKey);

                window.crypto.subtle.exportKey("spki",key.publicKey)
                    .then(function(keydata){
                        //returns the exported key data
                        console.log(keydata);
                        var  publicKeyB64 = ab2str(keydata);
                        document.getElementById("key").innerHTML = publicKeyB64;

                    })
                    .catch(function(err){
                        console.error(err);
                    });
            })




        function ab2str( 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 window.btoa( binary );
        }

Answer 1

keydata 是一个 ArrayBuffer，其中包含导出为 DER 格式的公钥。由于 DER 是二进制的，因此需要将结果编码为文本，例如使用 base64

选择您喜欢的函数，将 Converting between strings and ArrayBuffers 中的 ArrayBuffer 转换为字符串

var  publicKeyB64 = btoa(ab2str(keydata));
document.getElementById("key").innerHTML = publicKeyB64;