source: java/net/deterlab/abac/Identity.java @ 84f0e7a

package net.deterlab.abac;

import java.io.*;

import java.util.*;
import java.security.*;
import java.security.cert.*;
import javax.security.auth.x500.*;

import java.math.BigInteger;

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 implements Comparable {
    private X509Certificate m_cert;
    private String m_keyid;
    private String m_cn;
    private KeyPair kp;

    /**
     *  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 = null;

        while ( ( c= pr.readObject()) != null ){

            if (c instanceof X509Certificate) {
                if ( m_cn == null ) 
                    init((X509Certificate)c);
                else
                    throw new CertificateException("Two certs in one file");
            }
            else if (c instanceof KeyPair) setKeyPair((KeyPair)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(X509Certificate c) throws
        CertificateException, NoSuchAlgorithmException,InvalidKeyException,
        NoSuchProviderException, SignatureException, IOException {
            m_cert = (X509Certificate) 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, used as a CN
     */
    public Identity(String cn) throws
            CertificateException, NoSuchAlgorithmException,InvalidKeyException,
            NoSuchProviderException, SignatureException, IOException {
        X509V1CertificateGenerator gen = new X509V1CertificateGenerator();
        kp = KeyPairGenerator.getInstance("RSA").genKeyPair();

        gen.setIssuerDN(new X500Principal("CN=" + cn));
        gen.setSubjectDN(new X500Principal("CN=" + cn));
        gen.setNotAfter(new Date(System.currentTimeMillis() 
                    + 3600 * 1000 * 24 * 365));
        gen.setNotBefore(new Date(System.currentTimeMillis()));
        gen.setSerialNumber(BigInteger.valueOf(System.currentTimeMillis()));
        gen.setPublicKey(kp.getPublic());
        gen.setSignatureAlgorithm("SHA256WithRSAEncryption");
        X509Certificate a = (X509Certificate) gen.generate(kp.getPrivate());
        init(a);
    }



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

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

    /**
     * Construct from an X509Certificate, if you parsed one somewhere
     * else.
     */
    public Identity(X509Certificate cert) throws 
        CertificateException, NoSuchAlgorithmException,InvalidKeyException,
        NoSuchProviderException, SignatureException, FileNotFoundException,
        IOException { 
            kp = null;
            init(cert);
        }

    /**
     * Write the PEM key to the given writer.
     */
    public boolean writePrivateKey(Writer w) throws IOException {
        if (kp != null ) {
            PEMWriter pw = new PEMWriter(w);

            pw.writeObject(kp.getPrivate());
            pw.flush();
            return true;
        }
        else return false;
    }

    /**
     * Write the PEM key to a file with the given name.
     */
    public boolean writePrivateKey(String fn) 
            throws IOException, FileNotFoundException {
        return writePrivateKey(new FileWriter(fn));
    }

    /**
     * Write the PEM key to the given file.
     */
    public boolean writePrivateKey(File fn) 
            throws IOException, FileNotFoundException {
        return writePrivateKey(new FileWriter(fn));
    }

    /**
     * Write the PEM key to the given OutputStream.
     */
    public boolean writePrivateKey(OutputStream s) 
            throws IOException, FileNotFoundException {
        return writePrivateKey(new OutputStreamWriter(s));
    }


    /**
     * 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.flush();
    }

    /**
     * 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) {
        SubjectPublicKeyInfo ki = extractSubjectPublicKeyInfo(k);
        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();
    }

    /**
     * Extratct the SubjectPublicKeyInfo.  Useful for some other encryptions,
     * notably Certificate.make_cert().
     */
    public static SubjectPublicKeyInfo extractSubjectPublicKeyInfo(PublicKey k) {
        ASN1Sequence seq = null;
        try {
            seq = (ASN1Sequence) new ASN1InputStream(
                    k.getEncoded()).readObject();
        }
        catch (IOException ie) {
            // Badly formatted key??
            return null;
        }
        return new SubjectPublicKeyInfo(seq);
    }


    // Accessors
    public String getKeyID() { return m_keyid; }
    public String getName() { return m_cn; }
    public String toString() { 
        String s = m_keyid + " (" + m_cn ;

        if (m_keyid != null ) s += " [keyed]";
        s += ")";
        return s;
    }
    /**
     * Associate a keypair with this Identity.  If the ID has a certificate,
     * make sure that the keypair matches it.  If not throw an
     * IllegalArgumentException.
     */
    public void setKeyPair(KeyPair k) {
        if (m_keyid != null) {
            String kid = extractKeyID(k.getPublic());

            if ( kid != null && kid.equals(m_keyid)) kp = k;
            else 
                throw new IllegalArgumentException(
                        "Keypair does not match certificate");
        }
        else kp = k;
    }
    public KeyPair getKeyPair() { return kp; }
    public boolean equals(Object o) { 
        if ( o == null ) return false;
        else if ( ! (o instanceof Identity) ) return false;
        else return getKeyID().equals(((Identity)o).getKeyID());
    }
    public int compareTo(Object o) { 
        if ( ! (o instanceof Identity) ) return 1;
        else return getKeyID().compareTo(((Identity)o).getKeyID());
    }
    public X509Certificate getCertificate() { return m_cert; }

};