source: java/net/deterlab/abac/GENICredentialv1_1.java

package net.deterlab.abac;

import java.io.*;
import java.math.*;
import java.text.*;

import java.util.*;

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

import javax.xml.parsers.*;
import javax.xml.transform.*;
import javax.xml.transform.dom.*;
import javax.xml.transform.stream.*;

import javax.xml.crypto.*;
import javax.xml.crypto.dsig.*;
import javax.xml.crypto.dsig.dom.*;
import javax.xml.crypto.dsig.keyinfo.*;
import javax.xml.crypto.dsig.spec.*;

import org.xml.sax.*;
import org.w3c.dom.*;

/**
 * An ABAC credential formatted as an abac-type GENI credential, version 1.1.
 * @author <a href="http://abac.deterlab.net">ISI ABAC team</a>
 * @version 1.5
 */
public class GENICredentialv1_1 extends GENICredential 
    implements Comparable, MapsKeyIDs {

    protected KeyIDMap keyMap;
    /**
     * Create an empty Credential.
     */
    public GENICredentialv1_1() {
        super();
        keyMap = new KeyIDMap();
    }
    /**
     * Create a credential from a head and tail role.  This credential has no
     * underlying certificate, and cannot be exported or used in real proofs.
     * make_cert can create a certificate for a credential initialized this
     * way.
     * @param head the Role at the head of the credential
     * @param tail the Role at the tail of the credential
     */
    public GENICredentialv1_1(Role head, Role tail) {
        super(head, tail);
        keyMap = new KeyIDMap();
    }

    /**
     * Create a credential from a head and tail role.  This credential has no
     * underlying certificate, and cannot be exported or used in real proofs.
     * make_cert can create a certificate for a credential initialized this
     * way.  The keymap will be used to annotate the names.
     * @param head the Role at the head of the credential
     * @param tail the Role at the tail of the credential
     * @param km a KeyIDmap used to map nicknames to actual roles if one is
     *          already in use.
     */
    public GENICredentialv1_1(Role head, Role tail, KeyIDMap km) {
        super(head, tail);
        keyMap = new KeyIDMap(km);
    }
    /**
     * Create a credential from an attribute cert in a file. Throws an
     * exception if the cert file can't be opened or if there's a format
     * problem with the cert.  Note that catching
     * java.security.GeneralSecurityException catches most of the exceptions
     * this throws.
     * @param filename a String containing the filename to read
     * @param ids a Collection of Identities to use in validating the cert
     * @throws CertInvalidException if the stream is unparsable
     * @throws MissingIssuerException if none of the Identities can validate the
     *                              certificate
     * @throws BadSignatureException if the signature check fails
     */
    GENICredentialv1_1(String filename, Collection<Identity> ids) 
        throws ABACException { 
        super(filename, ids);
        /* Parsers should create a keyMap in load_roles(), but create one here
         * if not */
        if ( keyMap == null ) keyMap = new KeyIDMap();
    }

    /**
     * Create a credential from an attribute cert in a file. Throws an
     * exception if the cert file can't be opened or if there's a format
     * problem with the cert.  Note that catching
     * java.security.GeneralSecurityException catches most of the exceptions
     * this throws.
     * @param file the File to read
     * @param ids a Collection of Identities to use in validating the cert
     * @throws CertInvalidException if the stream is unparsable
     * @throws MissingIssuerException if none of the Identities can validate the
     *                              certificate
     * @throws BadSignatureException if the signature check fails
     */
    GENICredentialv1_1(File file, Collection<Identity> ids) 
            throws ABACException {
        super(file, ids);
        /* Parsers should create a keyMap in load_roles(), but create one here
         * if not */
        if ( keyMap == null ) keyMap = new KeyIDMap();
    }

    /**
     * Create a credential from an InputStream.  Throws an exception if the
     * stream can't be parsed or if there's a format problem with the cert.
     * Note that catching java.security.GeneralSecurityException catches most
     * of the exceptions this throws.
     * @param s the InputStream to read
     * @param ids a Collection of Identities to use in validating the cert
     * @throws CertInvalidException if the stream is unparsable
     * @throws MissingIssuerException if none of the Identities can validate the
     *                              certificate
     * @throws BadSignatureException if the signature check fails
     */
    GENICredentialv1_1(InputStream s, Collection<Identity> ids) 
            throws ABACException { 
        super(s, ids);
        /* Parsers should create a keyMap in load_roles(), but create one here
         * if not */
        if ( keyMap == null ) keyMap = new KeyIDMap();
    }

    protected void add_structured_role(Role r, Node top) {
        if ( r.is_principal()) {
            Element p = doc.createElement("ABACprincipal");
            Element k = doc.createElement("keyid");
            String ms = keyMap.keyToNickname(r.principal());
            Element m = (ms != null ) ? doc.createElement("mnemonic") : null;

            k.appendChild(doc.createTextNode(r.principal()));
            p.appendChild(k);

            if (m != null ) {
                m.appendChild(doc.createTextNode(ms));
                p.appendChild(m);
            }
            top.appendChild(p);
        } else if ( r.is_role() ) {
            Element p = doc.createElement("ABACprincipal");
            Element k = doc.createElement("keyid");
            String ms = keyMap.keyToNickname(r.principal());
            Element m = (ms != null ) ? doc.createElement("mnemonic") : null;
            Element rr = doc.createElement("role");

            k.appendChild(doc.createTextNode(r.principal()));
            rr.appendChild(doc.createTextNode(r.role_name()));
            p.appendChild(k);
            if (m != null ) {
                m.appendChild(doc.createTextNode(ms));
                p.appendChild(m);
            }
            top.appendChild(p);
            top.appendChild(rr);
        } else {
            Element p = doc.createElement("ABACprincipal");
            Element k = doc.createElement("keyid");
            String ms = keyMap.keyToNickname(r.principal());
            Element m = (ms != null ) ? doc.createElement("mnemonic") : null;
            Element rr = doc.createElement("role");
            Element lr = doc.createElement("linking_role");

            k.appendChild(doc.createTextNode(r.principal()));
            rr.appendChild(doc.createTextNode(r.role_name()));
            lr.appendChild(doc.createTextNode(r.linking_role()));
            p.appendChild(k);
            if (m != null ) {
                m.appendChild(doc.createTextNode(ms));
                p.appendChild(m);
            }
            top.appendChild(p);
            top.appendChild(rr);
            top.appendChild(lr);
        }
    }

    protected Node make_structured_rt0() {
        Element a = doc.createElement("rt0");
        Element v = doc.createElement("version");
        Element n = doc.createElement("head");
        Role[] tailRoles = null;

        v.appendChild(doc.createTextNode("1.1"));
        a.appendChild(v);
        add_structured_role(head(), n);
        a.appendChild(n);
        
        if (tail().is_intersection()) {
            try { 
                tailRoles = tail().prereqs();
            } catch (ABACException ignored ) { }
        } else {
            tailRoles = new Role[] { tail() };
        }

        for ( Role tr: tailRoles ) {
            n = doc.createElement("tail");
            add_structured_role(tr, n);
            a.appendChild(n);
        }
        return a;
    }

    /**
     * Encode the abac credential's XML and set the validity.  This is straight
     * line code that directly builds the credential.
     * @param validity a long holding the number of seconds that the credential
     * is valid for.
     * @return a Node, the place to attach signatures
     * @throws ABACException if any of the XML construction fails
     */
    protected Node make_rt0_content(long validity) throws ABACException {
        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
        DocumentBuilder db = null;
        SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'");
        StringBuffer expBuf = new StringBuffer();

        /* This is a weirdness to cope with the GENI format.  They have a naked
         * xml:id specifier without any namespace declarations in the
         * credential.  Notice that this is the opposite of the setting used in
         * init to read a credential. */
        dbf.setNamespaceAware(false);

        if ( dbf == null ) 
            throw new ABACException("Cannot get DocumentBuilderFactory!?");

        try {
            db = dbf.newDocumentBuilder();
        }
        catch (ParserConfigurationException pe) {
            throw new ABACException("Cannot get DocumentBuilder!?" + 
                    pe.getMessage(), pe);
        }

        doc = db.newDocument();
        if ( doc == null ) 
            throw new ABACException("No Document");

        Element root = doc.createElement("signed-credential"); 
        Element cred = doc.createElement("credential");
        Element serial = doc.createElement("serial");
        Element owner_gid = doc.createElement("owner_gid");
        Element target_gid = doc.createElement("target_gid");
        Element uuid = doc.createElement("uuid");
        Element sig = doc.createElement("signatures");
        Element e = doc.createElement("type");
        Node text = doc.createTextNode("abac");

        doc.appendChild(root);

        cred.setAttribute("xml:id", "ref0");
        /* So that the signing code can find the section to sign */
        cred.setIdAttribute("xml:id", true);

        root.appendChild(cred);
        e.appendChild(text);
        for (Element ele : new Element[] 
                {serial, owner_gid, target_gid, uuid, sig, e })
            cred.appendChild(ele);

        m_expiration = new Date(System.currentTimeMillis() + 
                (1000L * validity ));
        df.setTimeZone(new SimpleTimeZone(0, "Z"));
        df.format(m_expiration, expBuf, new FieldPosition(0));
        e = doc.createElement("expires");
        text = doc.createTextNode(expBuf.toString());
        e.appendChild(text);
        cred.appendChild(e);

        e = doc.createElement("abac");
        e.appendChild(make_structured_rt0());
        cred.appendChild(e);

        root.appendChild(sig);
        return sig;
    }

    protected Role parse_structured_rt0(Node srt)  throws CertInvalidException {
        Node p = getChildByName(srt, "ABACprincipal");
        Node k = null;
        Node mn = null;
        Node r = getChildByName(srt, "role");
        Node lr = getChildByName(srt, "linking_role");
        String ks = null;
        String mns = null;
        String rs = ( r != null ) ? r.getTextContent() : null;
        String lrs = ( lr!= null ) ? lr.getTextContent() : null;
        Role rv = null;

        if (p == null ) 
            throw new CertInvalidException("No principal!?");

        if ( (k = getChildByName(p, "keyid")) == null ) 
            throw new CertInvalidException("Principal w/o keyid");

        if ( (ks = k.getTextContent()) == null ) 
            throw new CertInvalidException("Empty keyid");

        if ( (mn = getChildByName(p, "mnemonic")) != null )
            mns = mn.getTextContent();

        if ( lrs != null ) {
            if ( rs == null ) {
                throw new CertInvalidException("Linking role without role");
            }
            rv = new Role(ks + "." + lrs + "." + rs);
        } else if ( rs == null ) {
            rv = new Role(ks);
        } else {
            rv = new Role(ks + "." + rs);
        }
        if ( mns != null ) keyMap.addNickname(ks, mns);
        return rv;
    }

    /**
     * Load the roles off the attribute cert.
     * @throws CertInvalidException if the certificate is badly formatted
     */
    protected void load_roles() throws CertInvalidException {
        if ( doc == null ) 
            throw new CertInvalidException("No credential");

        if ( keyMap == null ) keyMap = new KeyIDMap();

        NodeList nodes = doc.getElementsByTagName("credential");
        Node node = null;
        Node type = null;
        Node rt0 = null;
        Node v = null;
        String vs = null;

        if (nodes == null || nodes.getLength() != 1) 
            throw new CertInvalidException("More than one credential?");

        node = nodes.item(0);
        if ( node == null ) 
            throw new CertInvalidException("bad credential element?");

        if ( (type = getChildByName(node, "type")) == null ) {
            throw new CertInvalidException("No Type field");
        }

        if ( !"abac".equals(type.getTextContent()) ) 
            throw new CertInvalidException("Not an abac type credential");

        // Walk down to the abac and rt0 field using the rt0 variable.
        if ( (rt0 = getChildByName(node, "abac")) == null ) {
            throw new CertInvalidException("No abac field");
        }
        if ( (rt0 = getChildByName(rt0, "rt0")) == null ) {
            throw new CertInvalidException("No rt0 field");
        }

        if ( (v = getChildByName(rt0, "version")) == null ) {
            throw new CertInvalidException("No version field");
        }
        if ( (vs = v.getTextContent()) == null) {
            throw new CertInvalidException("empty version field");
        }
        if ( ! vs.trim().equals("1.1")) {
            throw new CertInvalidException("bad version: expected 1.1 got "+vs);
        }

        m_head = null;
        m_tail = null;

        for (Node n = rt0.getFirstChild(); n != null; n = n.getNextSibling()) {
            String nname = null;

            if ( n.getNodeType() != Node.ELEMENT_NODE) continue;
            nname = n.getNodeName();
            if (nname == null ) continue;

            if (nname.equals("head")) {
                if ( m_head != null ) 
                    throw new CertInvalidException("2 head elements");
                try {
                    m_head = parse_structured_rt0(n);
                } catch (CertInvalidException ce) {
                    throw new CertInvalidException("Error parsing head: " + 
                            ce.getMessage());
                }
            } else if (nname.equals("tail")) {
                Role t = null;

                try {
                    t = parse_structured_rt0(n);
                } catch (CertInvalidException ce) {
                    throw new CertInvalidException("Error parsing tail: " + 
                            ce.getMessage());
                }
                // This is a little wasteful in processing terms, but simply
                // appends the new tail entry to a new intersection role.
                if ( m_tail != null ) 
                    m_tail = new Role(m_tail.toString()  + " & " + 
                            t.toString());
                else m_tail = t;
            }
        }
    }
    /**
     * Return the keymap.
     * @return a KeyIDMap, this class's keymap
     */
    public KeyIDMap getMapping() { return keyMap; }
    /**
     * Return a CredentialCredentialFactorySpecialization for 
     * GENICredentialsv1_1.  Used by the CredentialFactory to parse and generate
     * these kind of credentials.  It basically wraps constuctor calls.
     * @return a CredentialFactorySpecialization for this kind of credential.
     */
    static public CredentialFactorySpecialization 
            getCredentialFactorySpecialization() {
        return new CredentialFactorySpecialization() {
            public Credential[] parseCredential(InputStream is, 
                    Collection<Identity> ids) throws ABACException {
                return new Credential[] { new GENICredentialv1_1(is, ids) }; 
            }
            public Credential generateCredential(Role head, Role tail,
                    KeyIDMap aliases) {
                return new GENICredentialv1_1(head, tail, aliases);
            }
        };
    }
}