如何将私钥从 .der 文件加载到 java 私钥对象中
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how to load the private key from a .der file into java private key object
提问by monim
I'm writing a java program to import private keys from files within the file system and make a private key object, using java...
I could do it for files in .pemformat but, with .der format, I had no idea what to do, since I couldnt firstly detect the algorithm used to generate the keys.
within .pemfiles I could determine the algorithm from the header for PKCS#1which have a header like-----BEGIN RSA PRIVATE KEY----
formats and used the bouncycastle pemreader for those in PKCS#8 which have a header-----BEGIN PRIVATE KEY-----but with those in .der format no idea :(
also if anyone have an idea about .keyformat tell me
thanx
我正在编写一个 java 程序来从文件系统中的文件中导入私钥并使用 java 创建一个私钥对象...我可以对.pem格式的文件执行此操作，但是使用 .der 格式，我不知道该做什么做，因为我无法首先检测用于生成密钥的算法。在.pem文件中，我可以从PKCS#1具有标题-----BEGIN RSA PRIVATE KEY----
格式的标题中确定算法，并使用 bouncycastlepem阅读器用于 PKCS#8 中的那些有标题-----BEGIN PRIVATE KEY-----但 .der 格式的人不知道:(
如果有人知道.key格式告诉我
thanx
采纳答案by gtrig
If your DER files are in PKCS#8 format, you can use the Java KeyFactoryand do something like this:
如果您的 DER 文件是 PKCS#8 格式，您可以使用 Java KeyFactory并执行以下操作：
// Read file to a byte array.
String privateKeyFileName = "C:\myPrivateKey.der";
Path path = Paths.get(privateKeyFileName);
byte[] privKeyByteArray = Files.readAllBytes(path);
PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(privKeyByteArray);
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
PrivateKey myPrivKey = keyFactory.generatePrivate(keySpec);
System.out.println("Algorithm: " + myPrivKey.getAlgorithm());
You mentioned that you may not know what algorithm the key is using. I'm sure there is a more elegant solution than this, but you could create several KeyFactoryobjects (one for each possible algorithm) and try to generatePrivate()on each one until you do not get an InvalidKeySpecException.
您提到您可能不知道密钥使用的是什么算法。我确信有比这更优雅的解决方案，但是您可以创建多个KeyFactory对象（每个可能的算法一个）并尝试generatePrivate()对每个对象进行操作，直到您没有得到InvalidKeySpecException.
回答by monim
thanks @gtrig using ur idea and editing the code like this :
感谢@gtrig 使用你的想法并像这样编辑代码：
PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(KeyBytes);
try
KeyFactory keyFactory = KeyFactory.getInstance("RSA");
privateKey = keyFactory.generatePrivate(keySpec);
algorithm = keyFactory.getAlgorithm();
//algorithm = "RSA";
//publicKey = keyFactory.generatePublic(keySpec);
} catch (InvalidKeySpecException excep1) {
try {
KeyFactory keyFactory = KeyFactory.getInstance("DSA");
privateKey = keyFactory.generatePrivate(keySpec);
algorithm = keyFactory.getAlgorithm();
//publicKey = keyFactory.generatePublic(keySpec);
} catch (InvalidKeySpecException excep2) {
KeyFactory keyFactory = KeyFactory.getInstance("EC");
privateKey = keyFactory.generatePrivate(keySpec);
} // inner catch
}
the code is working well now
代码现在运行良好
