org.bouncycastle.jcajce.spec.OpenSSHPublicKeySpec Maven / Gradle / Ivy
package org.bouncycastle.jcajce.spec;
import java.security.spec.EncodedKeySpec;
import org.bouncycastle.util.Arrays;
import org.bouncycastle.util.Strings;
/**
* Holds an OpenSSH encoded public key.
*/
public class OpenSSHPublicKeySpec
extends EncodedKeySpec
{
private static final String[] allowedTypes = new String[]{"ssh-rsa", "ssh-ed25519", "ssh-dss"};
private final String type;
/**
* Construct and instance and determine the OpenSSH public key type.
* The current types are ssh-rsa, ssh-ed25519, ssh-dss and ecdsa-*
*
* It does not validate the key beyond identifying the type.
*
* @param encodedKey
*/
public OpenSSHPublicKeySpec(byte[] encodedKey)
{
super(encodedKey);
//
// The type is encoded at the start of the blob.
//
int pos = 0;
int i = (encodedKey[pos++] & 0xFF) << 24;
i |= (encodedKey[pos++] & 0xFF) << 16;
i |= (encodedKey[pos++] & 0xFF) << 8;
i |= (encodedKey[pos++] & 0xFF);
if ((pos + i) >= encodedKey.length)
{
throw new IllegalArgumentException("invalid public key blob: type field longer than blob");
}
this.type = Strings.fromByteArray(Arrays.copyOfRange(encodedKey, pos, pos + i));
if (type.startsWith("ecdsa"))
{
return; // These have a curve name and digest in them and can't be compared exactly.
}
for (int t = 0; t < allowedTypes.length; t++)
{
if (allowedTypes[t].equals(this.type))
{
return;
}
}
throw new IllegalArgumentException("unrecognised public key type " + type);
}
public String getFormat()
{
return "OpenSSH";
}
/**
* The type of OpenSSH public key.
*
* @return the type.
*/
public String getType()
{
return type;
}
}