source: java/net/deterlab/abac/Identity.java @ 7ad0076

package net.deterlab.abac;

import java.io.*;

import java.util.*;
import java.security.*;
import java.security.cert.*;


import org.bouncycastle.asn1.*;
import org.bouncycastle.asn1.util.*;
import org.bouncycastle.asn1.x509.*;
import org.bouncycastle.x509.*;
import org.bouncycastle.jce.provider.X509AttrCertParser;
import org.bouncycastle.jce.provider.X509CertificateObject;
import org.bouncycastle.openssl.PEMReader;
import org.bouncycastle.openssl.PEMWriter;

public class Identity {
    private X509CertificateObject m_cert;
    private String m_keyid;
    private String m_cn;

    /**
     *  Initialize internals from PEM cert in a reader.  Use a PEMReader to get
     *  the certificate, and call init(cert) on it.
     */
    protected void init(Reader r) throws 
        CertificateException, NoSuchAlgorithmException,InvalidKeyException,
        NoSuchProviderException, SignatureException, IOException {
            PEMReader pr = new PEMReader(r);
            Object c = pr.readObject();

            if (c instanceof X509CertificateObject) 
                init((X509CertificateObject)c);
            else 
                throw new CertificateException("Not an identity certificate");
    }

    /**
     *  Initialize internals from cert.  Confirm it is self signed,  and then
     *  the keyid and common name.  There's some work to get this stuff, but
     *  it's all an incantation of getting the right classes to get the right
     *  data.  Looks more complex than it is.
     */
    protected void init(X509CertificateObject c) throws
        CertificateException, NoSuchAlgorithmException,InvalidKeyException,
        NoSuchProviderException, SignatureException, IOException {
            m_cert = (X509CertificateObject) c;
            m_cert.verify(m_cert.getPublicKey());
            // Cert is valid, fill in the CN and keyid
            m_keyid = extractKeyID(m_cert.getPublicKey());
            m_cn = m_cert.getSubjectDN().getName();
            /// XXX: better parse
            if (m_cn.startsWith("CN=")) m_cn = m_cn.substring(3);
    }

    /**
     * Construct from a string, which is a filename, containing a PEM format
     * self signed certificate.
     */
    public Identity(String filename) throws 
        CertificateException, NoSuchAlgorithmException,InvalidKeyException,
        NoSuchProviderException, SignatureException, FileNotFoundException,
        IOException { init(new FileReader(filename)); }


    /**
     * Construct from a file, containing a self-signed PEM certificate.
     */
    public Identity(File file) throws 
        CertificateException, NoSuchAlgorithmException,InvalidKeyException,
        NoSuchProviderException, SignatureException, FileNotFoundException,
        IOException { init(new FileReader(file)); }

    /**
     * Construct from a reader, containing a self-signed PEM certificate.
     */
    public Identity(Reader r) throws 
        CertificateException, NoSuchAlgorithmException,InvalidKeyException,
        NoSuchProviderException, SignatureException, IOException { init(r); }

    /**
     * Construct from an InputStream, containing a self-signed PEM certificate.
     */
    public Identity(InputStream s) throws 
        CertificateException, NoSuchAlgorithmException,InvalidKeyException,
        NoSuchProviderException, SignatureException, IOException { 
            init(new InputStreamReader(s));
        }

    /**
     * Construct from an X509CertificateObject, if you parsed one somewhere
     * else.
     */
    public Identity(X509CertificateObject cert) throws 
        CertificateException, NoSuchAlgorithmException,InvalidKeyException,
        NoSuchProviderException, SignatureException, FileNotFoundException,
        IOException { init(cert); }


    /**
     * Write the PEM cert to the given writer.
     */
    public void write(Writer w) throws IOException {
        PEMWriter pw = new PEMWriter(w);

        pw.writeObject(m_cert);
        pw.close();
    }

    /**
     * Write the PEM cert to a file with the given name.
     */
    public void write(String fn) throws IOException, FileNotFoundException {
        write(new FileWriter(fn));
    }

    /**
     * Write the PEM cert to the given file.
     */
    public void write(File fn) throws IOException, FileNotFoundException {
        write(new FileWriter(fn));
    }

    /**
     * Write the PEM cert to the given OutputStream.
     */
    public void write(OutputStream s) 
        throws IOException, FileNotFoundException {
        write(new OutputStreamWriter(s));
    }

    /**
     * Get to the SHA1 hash of the key.
     */
    public static String extractKeyID(PublicKey k) {
        ASN1Sequence seq = null;
        try {
            seq = (ASN1Sequence) new ASN1InputStream(
                    k.getEncoded()).readObject();
        }
        catch (IOException ie) {
            // Badly formatted key??
            return null;
        }
        SubjectPublicKeyInfo ki = new SubjectPublicKeyInfo(seq);
        SubjectKeyIdentifier id = 
            SubjectKeyIdentifier.createSHA1KeyIdentifier(ki);

        // Now format it into a string for keeps
        Formatter fmt = new Formatter(new StringWriter());
        for (byte b: id.getKeyIdentifier())
            fmt.format("%02x", b);
        return fmt.out().toString();
    }

    // Accessors
    public String getKeyID() { return m_keyid; }
    public String getName() { return m_cn; }
    public String toString() { return m_keyid + " (" + m_cn + ")"; }
    public X509CertificateObject getCertificate() { return m_cert; }

};