(Android / Java) 创建RSA私钥实例

Question

我正在尝试从 pem 文件在 Android 应用程序中创建一个 PrivateKey 实例来解密一些数据，但我收到以下错误：

java.lang.RuntimeException: error:0c0890ba:ASN.1 encoding routines:asn1_check_tlen:WRONG_TAG

代码：

// Read private key.
InputStream is = context.getResources().openRawResource(R.raw.private_key);
br = new BufferedReader(new InputStreamReader(is));
List<String> lines = new ArrayList<String>();
line = null;
while ((line = br.readLine()) != null)
    lines.add(line);

// Removes the first and last lines of the file (comments).
if (lines.size() > 1 && lines.get(0).startsWith("-----") &&
        lines.get(lines.size()-1).startsWith("-----")) {
    lines.remove(0);
    lines.remove(lines.size()-1);
}

// Concats the remaining lines to a single String.
StringBuilder sb = new StringBuilder();
for (String aLine: lines)
    sb.append(aLine);
String keyString = sb.toString();

// Converts the String to a PublicKey instance
byte[] keyBytes = Base64.decode(keyString, Base64.DEFAULT);
PKCS8EncodedKeySpec spec = new PKCS8EncodedKeySpec(keyBytes);
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
mKey = keyFactory.generatePrivate(spec);

有什么帮助吗？

Answer 1

您的密钥似乎不是 PKCS8 格式。 Java 不支持加载 PKCS#1 格式的密钥。检查您的密钥是否为 PKCS#8 格式，验证它是否以 -----BEGIN PRIVATE KEY----- 开头如果它以 ----BEGIN RSA PRIVATE KEY----- 开头，则您需要将其转换为 PKCS#8。参见 Convert PEM traditional private key to PKCS8 private key

Answer 2

使用这一行：

    if (privateKeyString.contains("-----BEGIN PRIVATE KEY-----") || privateKeyString.contains("-----END PRIVATE KEY-----"))
        privateKeyString = privateKeyString.replace("-----BEGIN PRIVATE KEY-----", "").replace("-----END PRIVATE KEY-----", "");


    if (privateKeyString.contains("-----BEGIN RSA PRIVATE KEY-----") || privateKeyString.contains("-----END RSA PRIVATE KEY-----"))
        privateKeyString = privateKeyString.replace("-----BEGIN RSA PRIVATE KEY-----", "").replace("-----END RSA PRIVATE KEY-----", "");

(Android / Java) 创建RSA私钥实例

(Android / Java) Create a RSA private key instance

java

android

encryption

rsa

private-key