java - SHA1withRSA NoSuchAlgorithmException

Question

您好，我有以下函数可以在我的应用程序中将字符串转换为私钥:

public static PrivateKey main() throws Exception {
    // Read in the key into a String
    StringBuilder pkcs8Lines = new StringBuilder();
    BufferedReader rdr = new BufferedReader(new StringReader(PRIVATE_KEY));
    String line;
    while ((line = rdr.readLine()) != null) {
        pkcs8Lines.append(line);
    }

    // Remove the "BEGIN" and "END" lines, as well as any whitespace

    String pkcs8Pem = pkcs8Lines.toString();
    pkcs8Pem = pkcs8Pem.replaceAll("\\n+","");

    // Base64 decode the result

    byte [] pkcs8EncodedBytes = Base64.decode(pkcs8Pem, Base64.DEFAULT);

    // extract the private key

    PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(pkcs8EncodedBytes);
    KeyFactory kf = KeyFactory.getInstance("SHA1WITHRSA");
    PrivateKey privKey = kf.generatePrivate(keySpec);
    return privKey;
}

我得到以下异常:

W/System.err: java.security.NoSuchAlgorithmException: SHA1withRSA KeyFactory not available W/System.err: at java.security.KeyFactory.(KeyFactory.java:161) at java.security.KeyFactory.getInstance(KeyFactory.java:195)

所以我尝试找到可以通过此代码使用的所有算法:

        TreeSet<String> algorithms = new TreeSet<>();
    for (Provider provider : Security.getProviders())
        for (Provider.Service service : provider.getServices())
            if (service.getType().equals("Signature"))
                algorithms.add(service.getAlgorithm());
    for (String algorithm : algorithms)
        System.out.println(algorithm);

响应中包含“SHA1withRSA”，您知道问题出在哪里吗？

Answer 1

SHA1withRSA 是一种签名类型，您会在列表中看到它，因为您有

if (service.getType().equals("Signature"))

如果您将其编辑为

if (service.getType().equals("KeyFactory"))

您应该看到一个类似这样的列表

DSA
EC
RSA
RSASSA-PSS
X25519
X448
XDH