【问题】RSA私钥获取异常

问题描述

生成PKCS8编码的私钥时报algid parse error, not a sequence

PrivateKey getPrivateKey(String key) 
        throws NoSuchAlgorithmException, InvalidKeySpecException {
    byte[] keyBytes = Base64.getDecoder().decode(key);
    PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(keyBytes);
    KeyFactory keyFactory = KeyFactory.getInstance("RSA");
    return keyFactory.generatePrivate(keySpec);
}

错误：

java.security.spec.InvalidKeySpecException: java.security.InvalidKeyException: IOException : algid parse error, not a sequence
  at sun.security.rsa.RSAKeyFactory.engineGeneratePrivate(RSAKeyFactory.java:217)
  at java.security.KeyFactory.generatePrivate(KeyFactory.java:372)

解决办法

使用BouncyCastle

PrivateKey getPrivateKey(String key) 
        throws NoSuchAlgorithmException, InvalidKeySpecException {
    // 使用BouncyCastle
    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
    byte[] keyBytes = Base64.getDecoder().decode(key);
    PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(keyBytes);
    KeyFactory keyFactory = KeyFactory.getInstance("RSA");
    return keyFactory.generatePrivate(keySpec);
}

RSA密钥生成与使用详情见：https://www.cnblogs.com/yszr/p/8215075.html