令我惊讶的是，那里没有明显的东西。我很好奇，并实现了一种解码
authorized_keys文件的方法。这取决于用于base64解码的Apache
Commons Codec。
import java.io.File;import java.math.BigInteger;import java.security.KeyFactory;import java.security.PublicKey;import java.security.spec.DSAPublicKeySpec;import java.security.spec.RSAPublicKeySpec;import java.util.Scanner;import org.apache.commons.prec.binary.base64;public class AuthorizedKeysDeprer { private byte[] bytes; private int pos; public PublicKey deprePublicKey(String keyLine) throws Exception { bytes = null; pos = 0; // look for the base64 enpred part of the line to depre // both ssh-rsa and ssh-dss begin with "AAAA" due to the length bytes for (String part : keyLine.split(" ")) { if (part.startsWith("AAAA")) { bytes = base64.deprebase64(part); break; } } if (bytes == null) { throw new IllegalArgumentException("no base64 part to depre"); } String type = depreType(); if (type.equals("ssh-rsa")) { BigInteger e = depreBigInt(); BigInteger m = depreBigInt(); RSAPublicKeySpec spec = new RSAPublicKeySpec(m, e); return KeyFactory.getInstance("RSA").generatePublic(spec); } else if (type.equals("ssh-dss")) { BigInteger p = depreBigInt(); BigInteger q = depreBigInt(); BigInteger g = depreBigInt(); BigInteger y = depreBigInt(); DSAPublicKeySpec spec = new DSAPublicKeySpec(y, p, q, g); return KeyFactory.getInstance("DSA").generatePublic(spec); } else { throw new IllegalArgumentException("unknown type " + type); } } private String depreType() { int len = depreInt(); String type = new String(bytes, pos, len); pos += len; return type; } private int depreInt() { return ((bytes[pos++] & 0xFF) << 24) | ((bytes[pos++] & 0xFF) << 16) | ((bytes[pos++] & 0xFF) << 8) | (bytes[pos++] & 0xFF); } private BigInteger depreBigInt() { int len = depreInt(); byte[] bigIntBytes = new byte[len]; System.arraycopy(bytes, pos, bigIntBytes, 0, len); pos += len; return new BigInteger(bigIntBytes); } public static void main(String[] args) throws Exception { AuthorizedKeysDeprer deprer = new AuthorizedKeysDeprer(); File file = new File("authorized_keys"); Scanner scanner = new Scanner(file).useDelimiter("n"); while (scanner.hasNext()) { System.out.println(deprer.deprePublicKey(scanner.next())); } scanner.close(); }}
