node-rsa 密钥对生成

第一方案为
window.crypto.subtle.generateKey

但是某些情况下，在http链接无法获取 window.crypto.subtle对象，只能在https请求和localHost的时候能够获取到window.crypto.subtle对象。
为了解决任何时候都能生成密钥对，因此我选择了node-rsa来生成。

第二方案：使用node-rsa 库。
使用：

public static CreateAesAPair(func: Function) {
       try {
            const key = new NodeRSA({ b: 512 }); //生成512, 1024, 2048位的密钥
            var publicDer = key.exportKey("pkcs8-public-pem"); //公钥
            var privateDer = key.exportKey('pkcs8-private-pem');//私钥
            // 'pkcs1' — public key starts from '-----BEGIN RSA PUBLIC KEY-----' header and private key starts from '-----BEGIN RSA PRIVATE KEY-----' header
            // 'pkcs8' — public key starts from '-----BEGIN PUBLIC KEY-----' header and private key starts from '-----BEGIN PRIVATE KEY-----' header
            // 'pem'— 带有页眉和页脚的 Base64 编码字符串。默认使用。
            // 'der' — 二进制编码的密钥数据。

            return func(privateDer, publicDer);
       } catch(e) {
            console.error("------e: ", e);
            return func(null, null);
       }
}

生成密钥如下所示：

this.model.privateKey = 
        "-----BEGIN PRIVATE KEY-----" + 
        'MIICdwIBADANBgkqhkiG9w0BAQEFAASCAmEwggJdAgEAAoGBAIXawhnxuqzgnwam' + 
        'IHZ94tpqTsQtmWIUIVidPCkRN+vJXk8k7o2dUDHSY5w0Ls6MeNUPDxW2ED90yrop' + 
        'YPhXTlT1caRaeINa4bOB6zaKymXNvpZdDbf+CR1dKWSAfTkUgKm+Pxi3EKRidP9D' + 
        'lLRkKQEgLdUMQmmbSDXW3bmfWjiJAgMBAAECgYEAg/o/q6kGMHKBGeMu2uYgiM6M' + 
        'vy1esK+8eUz/Blbt1lQD4vE9LPBRI+6XPGrPQ+SJNznT28pZltenE4q9C9+5YOM3' + 
        '9Z+UU2tpAKaymOR8L/3VTeFrfd2iRi+gM7TWpXeM7jdEUfyY3dAQVDjZkHSrBnKC' + 
        'n51u9YA4fI/DyiI1XAECQQDhjo+nastsDCu6c9Hcj4KAtt39+mou/Hz4ZnTP5Avc' + 
        '8K5nERTy1LoyML+VUYu7hSFH5V2BNsOHSMCYmVuXl9zBAkEAl+uywk53HKdqWj57' + 
        'ATNVvWFN5o2/mfosZuxMrwcxbHM8fp7pWppGJRYDmaNqhppWiFrHFDLl46QQu5dr' + 
        '9bYlyQJBALpoaUyBNBDdlh4Hrf7ME5xwhNJra+nc/SME+bD91NgJiPjg4yE0sZTd' + 
        'ONgchpC5G6Ihar9pFPrvI0x6IXoNJYECQBGFvwWIVVa5vJuSD0/xIteIDJsmCE5z' + 
        'O4HXiXS6qKmwlO6p15J6rtKCOoITBitmS8rIZaPfxwI9nyxz56DclHkCQEH04rGr' + 
        'qeIBSDAzuJt7+KhplTSeHsuTZfkw0RZBx6+rrEn9wsEuj9rB+j78LPU1665VNF5z' + 
        'jZIkl4lnJi0Ij6k=' + 
        "-----END PRIVATE KEY-----";
this.model.publicKey = 
        '-----BEGIN PUBLIC KEY-----' + 
        'MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCF2sIZ8bqs4J8GpiB2feLaak7E' + 
        'LZliFCFYnTwpETfryV5PJO6NnVAx0mOcNC7OjHjVDw8VthA/dMq6KWD4V05U9XGk' + 
        'WniDWuGzges2isplzb6WXQ23/gkdXSlkgH05FICpvj8YtxCkYnT/Q5S0ZCkBIC3V' + 
        'DEJpm0g11t25n1o4iQIDAQAB' + 
        '-----END PUBLIC KEY-----';