package net.deterlab.abac;
import edu.uci.ics.jung.graph.*;
import edu.uci.ics.jung.graph.util.*;
import java.io.*;
import java.util.*;
import java.util.zip.*;
import java.security.*;
import java.security.cert.*;
import org.bouncycastle.asn1.*;
import org.bouncycastle.asn1.x509.*;
import org.bouncycastle.x509.*;
import org.bouncycastle.openssl.*;
/**
* Represents a global graph of credentials in the form of principals and
* attributes. Contains the identities and credentials that can be used in a
* proof.
* @author ISI ABAC team
* @version 1.3
*/
public class Context {
/** Certificate imported successfully */
public static final int ABAC_CERT_SUCCESS = 0;
/** Certificate import failed, invalid certificate */
public static final int ABAC_CERT_INVALID = -1;
/** Certificate import failed, signature filed */
public static final int ABAC_CERT_BAD_SIG = -2;
/** Certificate import failed, unknown issuer */
public static final int ABAC_CERT_MISSING_ISSUER = -3;
/** Internal graph representation */
protected Graph g;
/** Set of edges in the graph that were added by the logic. */
protected Set derived_edges;
/** Internal persistent query object */
protected Query pq;
/** True when the graph has been changed since the last set of implied
* edges were calculated. */
protected boolean dirty;
/** Set of identities known to this Context. */
protected Set m_identities;
/** Translation from issuer CN to issuer pubkey identifier */
protected Map nicknames;
/** Translation from issuer pubkey identifier to issuer CN */
protected Map keys;
/**
* The result of a query on this context. The credentials form a partial
* or total proof, and success indicates whether the proof succeeded.
* @author ISI ABAC team
* @version 1.3
*/
public class QueryResult {
/** Credentials returned */
protected Collection creds;
/** True if the proof succeeded. */
protected boolean success;
/**
* Construct a result from components.
* @param c the collection of credentials in the proof
* @param s a boolean, true if the query succeeded.
*/
QueryResult(Collection c, boolean s) {
creds = c;
success = s;
}
/**
* Empty constructor
*/
public QueryResult() {
creds = new TreeSet();
success = false;
}
/**
* Return the credentials in the proof.
* @return the collection of credentials
*/
public Collection getCredentials() { return creds; }
/**
* Return the success in the proof.
* @return the boolean, true on success
*/
public boolean getSuccess() { return success; }
}
/**
* Create an empty Context.
*/
public Context() {
/* create the graph */
g = Graphs.synchronizedDirectedGraph(
new DirectedSparseGraph());
derived_edges = new HashSet();
pq = new Query(g);
dirty = false;
m_identities = new TreeSet();
nicknames = new TreeMap();
keys = new TreeMap();
}
/**
* Create a context from another context.
* @param c the Context to copy
*/
public Context(Context c) {
this();
for (Identity i: c.m_identities)
load_id_chunk(i);
for (Credential cr: c.credentials())
load_attribute_chunk(cr);
derive_implied_edges();
}
/**
* Create a Context from a collection of Credentials. A jabac extension.
* @param creds the collection of credentials
*/
public Context(Collection creds) {
this();
for (Credential c: creds) {
Identity i = c.issuer();
if (i != null ) load_id_chunk(i);
load_attribute_chunk(c);
}
}
/**
* Load an Identity from a file.
* @param fn a String containing the file name.
* @return one of the static int return codes.
*/
public int load_id_file(String fn) { return load_id_chunk(new File(fn)); }
/**
* Load an Identity from a file.
* @param fn a File containing the file name.
* @return one of the static int return codes.
*/
public int load_id_file(File fn) { return load_id_chunk(fn); }
/**
* Load an Identity from an object. Supported objects are an Identity, a
* String, a File, or a java.security.cert.X509Certificate. A string
* creates an new identity, and the others are derived from the contents of
* the data or file.
* @param c an object convertable to an identity as above.
* @return one of the static int return codes.
*/
public int load_id_chunk(Object c) {
try {
if (c instanceof Identity)
addIdentity((Identity) c);
else if (c instanceof String)
addIdentity(new Identity((String) c));
else if (c instanceof File)
addIdentity(new Identity((File) c));
else if (c instanceof X509Certificate)
addIdentity(new Identity((X509Certificate) c));
else
return ABAC_CERT_INVALID;
}
catch (SignatureException sig) {
return ABAC_CERT_BAD_SIG;
}
catch (Exception e) {
return ABAC_CERT_INVALID;
}
return ABAC_CERT_SUCCESS;
}
/**
* Load an attribute certificate from a file.
* @param fn a String containing the file name.
* @return one of the static int return codes.
*/
public int load_attribute_file(String fn) {
return load_attribute_chunk(new File(fn));
}
/**
* Load an attribute certificate from a file.
* @param fn a File containing the file name.
* @return one of the static int return codes.
*/
public int load_attribute_file(File fn) { return load_attribute_chunk(fn); }
/**
* Load an Identity from an object. Supported objects are a Credential, a
* String, a File, or an org.bouncycastle.x509.X509V2AttributeCertificate.
* A string creates an new Credential, and the others are derived from the
* contents of the data or file.
* @param c an object convertable to a Credential as above.
* @return one of the static int return codes.
*/
public int load_attribute_chunk(Object c) {
try {
if (c instanceof Credential)
add_credential((Credential) c);
else if (c instanceof String)
add_credential(new Credential((String) c, m_identities));
else if (c instanceof File)
add_credential(new Credential((File) c, m_identities));
else if ( c instanceof X509V2AttributeCertificate)
add_credential(new Credential((X509V2AttributeCertificate)c,
m_identities));
else
return ABAC_CERT_INVALID;
}
catch (InvalidKeyException sig) {
return ABAC_CERT_MISSING_ISSUER ;
}
catch (SignatureException sig) {
return ABAC_CERT_BAD_SIG;
}
catch (Exception e) {
return ABAC_CERT_INVALID;
}
return ABAC_CERT_SUCCESS;
}
/**
* Determine if prinicpal possesses role in the current context. If so,
* return a proof of that, otherwise return a partial proof of it.
* @param role a String encoding the role to check for.
* @param principal a String with the principal ID in it.
* @return a Context.QueryResult containing the result.
*/
public QueryResult query(String role, String principal) {
derive_implied_edges();
Query q = new Query(g);
Graph rg = q.run(role, principal);
return new QueryResult(rg.getEdges(), q.successful());
}
/**
* Return a collection of the credentials in the graph.s
* @return a collection of the credentials in the graph.
*/
public Collection credentials() {
Collection creds = new HashSet();
// only return creds with a cert: all others are derived edges
for (Credential cred : g.getEdges())
if (cred.cert() != null)
creds.add(cred);
return creds;
}
/**
* Return all the Identities known in this context. A jabac extension.
* @return all the Identities known in this context.
*/
public Collection identities() {
return m_identities;
}
/**
* Returns true if the given Identity is known in this Context. A jabac
* extension.
* @param i the Identity to look for
* @return a boolean, true if the Identity is known.
*/
public boolean knowsIdentity(Identity i) { return m_identities.contains(i); }
/**
* Returns true if an Identity with the given string representation is
* known in this Context. A jabac extension.
* @param k the string representing the Identity to look for
* @return a boolean, true if the Identity is known.
*/
public boolean knowsKeyID(String k) {
boolean known = false;
for (Identity i: m_identities)
if (k.equals(i.getKeyID())) return true;
return false;
}
/**
* Add a credential to the graph.
* @param cred the Credential to add
*/
protected void add_credential(Credential cred) {
Role tail = cred.tail();
Role head = cred.head();
// explicitly add the vertices, to avoid a null pointer exception
if ( !g.containsVertex(head))
g.addVertex(head);
if ( !g.containsVertex(tail))
g.addVertex(tail);
if (!g.containsEdge(cred))
g.addEdge(cred, tail, head);
// add the prereqs of an intersection to the graph
if (tail.is_intersection())
for (Role prereq : tail.prereqs())
g.addVertex(prereq);
dirty = true;
}
/**
* Remove a credential from the graph.
* @param cred the Credential to remove
*/
protected void remove_credential(Credential cred) {
if (g.containsEdge(cred))
g.removeEdge(cred);
dirty = true;
}
/**
* Add a role w/o an edge
* @param v the Role to add
*/
protected void add_vertex(Role v) {
if (!g.containsVertex(v)) {
g.addVertex(v);
dirty = true;
}
}
/**
* Remove a role and connected edges.
* @param v the Role to remove
*/
protected void remove_vertex(Role v) {
if (g.containsVertex(v)) {
g.removeVertex(v);
dirty = true;
}
}
/**
* Derive the implied edges in the graph, according to RT0 derivation rules.
* They are added to this graph. See "Distributed Credential Chain Discovery
* in Trust Management" by Ninghui Li et al. for details. Note that a
* derived linking edge can imply a new intersection edge and vice versa.
* Therefore we iteratively derive edges, giving up when an iteration
* produces 0 new edges.
*/
protected synchronized void derive_implied_edges() {
// nothing to do on a clean graph
if (!dirty)
return;
clear_old_edges();
// iteratively derive links. continue as long as new links are added
while (derive_links_iter() > 0)
;
dirty = false;
}
/**
* Single iteration of deriving implied edges. Returns the number of new
* links added.
* @return the number of new links added.
*/
protected int derive_links_iter() {
int count = 0;
/* for every node in the graph.. */
for (Role vertex : g.getVertices()) {
if (vertex.is_intersection()) {
// for each prereq edge:
// find set of principals that have the prereq
// find the intersection of all sets (i.e., principals
// that satisfy all prereqs)
// for each principal in intersection:
// add derived edge
Set principals = null;
for (Role prereq : vertex.prereqs()) {
Set cur_principals = pq.find_principals(prereq);
if (principals == null)
principals = cur_principals;
else
// no, they couldn't just call it "intersection"
principals.retainAll(cur_principals);
if (principals.size() == 0)
break;
}
// add em
for (Role principal : principals)
if (add_derived_edge(vertex, principal))
++count;
}
else if (vertex.is_linking()) {
// make the rest of the code a bit clearer
Role A_r1_r2 = vertex;
Role A_r1 = new Role(A_r1_r2.A_r1());
String r2 = A_r1_r2.r2();
/* locate the node A.r1 */
if (!g.containsVertex(A_r1)) continue;
/* for each B that satisfies A_r1 */
for (Role principal : pq.find_principals(A_r1)) {
Role B_r2 = new Role(principal + "." + r2);
if (!g.containsVertex(B_r2)) continue;
if (add_derived_edge(A_r1_r2, B_r2))
++count;
}
}
}
return count;
}
/**
* Add a derived edge in the graph. Returns true only if the edge does not
* exist.
* @return a boolean, true if an edge has been added
*/
protected boolean add_derived_edge(Role head, Role tail) {
// edge exists: return false
if (g.findEdge(tail, head) != null)
return false;
// add the new edge
Credential derived_edge = new Credential(head, tail);
derived_edges.add(derived_edge);
g.addEdge(derived_edge, tail, head);
return true;
}
/**
* Clear the derived edges that currently exist in the graph. This is done
* before the edges are rederived. The derived edges in filtered graphs are
* also cleared.
*/
protected void clear_old_edges() {
for (Credential i: derived_edges)
g.removeEdge(i);
derived_edges = new HashSet();
}
/**
* Put the Identity into the set of ids used to validate certificates.
* Also put the keyID and name into the translation mappings used by Roles
* to pretty print. In the role mapping, if multiple ids use the same
* common name they are disambiguated. Only one entry for keyid is
* allowed.
* @param id the Identity to add
*/
protected void addIdentity(Identity id) {
m_identities.add(id);
if (id.getName() != null && id.getKeyID() != null) {
if ( !keys.containsKey(id.getKeyID()) ) {
String name = id.getName();
int n= 1;
while (nicknames.containsKey(name)) {
name = id.getName() + n++;
}
nicknames.put(name, id.getKeyID());
keys.put(id.getKeyID(), name);
}
}
}
/**
* Translate either keys to nicknames or vice versa. Break the string into
* space separated tokens and then each of them into period separated
* strings. If any of the smallest strings is in the map, replace it with
* the value.
* @param is the string to manipulate
* @param m the Map containing translations
* @return the string after modification
*/
protected String replace(String is, Map m) {
String rv = "";
for (String tok: is.split(" ")) {
String term = "";
for (String s: tok.split("\\.")) {
String next = m.containsKey(s) ? m.get(s) : s;
if (term.isEmpty()) term = next;
else term += "." + next;
}
if (rv.isEmpty()) rv = term;
else rv += " " + term;
}
return rv;
}
/**
* Expand menmonic names in a Role string, e.g. the CN of the issuer
* certificate, into the full key ID. Used internally by Roles to provide
* transparent use of mnemonics
* @param s the string to expand
* @return the String after expansion.
*/
String expandKeyID(String s) { return replace(s, nicknames); }
/**
* Convert key IDs to menmonic names in a Role string. The inverse of
* expandKeyID.
* @param s the string to expand
* @return the String after expansion.
*/
String expandNickname(String s) { return replace(s, keys); }
/**
* Import a zip file. First import all the identities
* (pem), then the credentials (der) into the credential graph then any
* alias files into the two maps. If keys is not null, any key pairs in
* PEM files are put in there. If errors is not null, errors reading files
* are added indexed by filename. This is a jabac extension.
* @param zf the File to read
* @param keys a Collection into which to insert unmatched keys
* @param errors a Map from entry name to generated exception
* @throws IOException if the file is unreadable. Per entry exceptions are
* returned in the errors parameter.
*/
public void load_zip_file(File zf, Collection keys,
Map errors) throws IOException {
Vector derEntries = new Vector();
Map ids = new TreeMap();
Map kps = new TreeMap();
ZipFile z = new ZipFile(zf);
for (Enumeration extends ZipEntry> ze = z.entries();
ze.hasMoreElements();) {
ZipEntry f = ze.nextElement();
try {
PEMReader r = new PEMReader(
new InputStreamReader(z.getInputStream(f)));
Object o = readPEM(r);
if ( o != null ) {
if (o instanceof Identity) {
Identity i = (Identity) o;
String kid = i.getKeyID();
if (kps.containsKey(kid) ) {
i.setKeyPair(kps.get(kid));
kps.remove(kid);
}
else if (i.getKeyPair() == null )
ids.put(i.getKeyID(), i);
load_id_chunk(i);
}
else if (o instanceof KeyPair ) {
KeyPair kp = (KeyPair) o;
String kid = extractKeyID(kp.getPublic());
if (ids.containsKey(kid)) {
Identity i = ids.get(kid);
i.setKeyPair(kp);
ids.remove(kid);
}
else {
kps.put(kid, kp);
}
}
}
else {
// Not a PEM file
derEntries.add(f);
continue;
}
}
catch (Exception e ) {
if (errors != null ) errors.put(f.getName(), e);
}
}
for ( ZipEntry f : derEntries ) {
try {
add_credential(new Credential(z.getInputStream(f),
m_identities));
}
catch (Exception e ) {
if (errors != null ) errors.put(f.getName(), e);
}
}
}
/**
* Equivalent to load_zip_file(d, null, null).
* @param d the File to read
* @throws IOException if the file is unreadable. To see per-entry
* exceptions use a signature with the errors parameter
*/
public void load_zip_file(File d)
throws IOException {
load_zip_file(d, null, null);
}
/**
* Equivalent to load_zip_file(d, null, errors).
* @param d the File to read
* @param errors a Map from entry name to generated exception
* @throws IOException if the file is unreadable. Per entry exceptions are
* returned in the errors parameter.
*/
public void load_zip_file(File d,
Map errors) throws IOException {
load_zip_file(d, null, errors);
}
/**
* Equivalent to load_zip_file(d, keys, null).
* @param d the File to read
* @param keys a Collection into which to insert unmatched keys
* @throws IOException if the file is unreadable. To see per-entry
* exceptions use a signature with the errors parameter
*/
public void load_zip_file(File d,
Collection keys) throws IOException {
load_zip_file(d, keys, null);
}
/**
* Read a PEM file that contains an X509 Certificate, a key pair, or both.
* If a cert is present it is converted into an Identity. A key pair is
* returned as a java.security.KeyPair and both are returned as an Identity
* with an associated key pair.
* @param r a PEMReader from which to read
* @return an object encoding the contents (as above)
* @throws IOException for an unreadable or badly formated input
*/
protected Object readPEM(PEMReader r) throws IOException {
Identity i = null;
KeyPair keys = null;
Object o = null;
while ( (o = r.readObject()) != null ) {
if (o instanceof X509Certificate) {
if ( i == null ) {
try {
i = new Identity((X509Certificate)o);
}
catch (Exception e) {
// Translate Idenitiy exceptions to IOException
throw new IOException(e);
}
if (keys != null ) {
i.setKeyPair(keys);
keys = null;
}
}
else throw new IOException("Two certificates");
}
else if (o instanceof KeyPair ) {
if ( i != null ) i.setKeyPair((KeyPair) o);
else keys = (KeyPair) o;
}
else {
throw new IOException("Unexpected PEM object: " +
o.getClass().getName());
}
}
if ( i != null ) return i;
else if ( keys != null) return keys;
else return null;
}
/**
* Import a directory full of files. First import all the identities
* (pem), then the credentials (der) into the credential graph then any
* alias files into the two maps. If keys is not null, any key pairs in
* PEM files are put in there. If errors is not null, errors reading files
* are added indexed by filename. This behaves slightly differently from
* the load_directory description in the general libabac documentation.
* @param d the File to read. If it is a directory its contents are read
* @param keys a Collection into which to insert unmatched keys
* @param errors a Map from entry name to generated exception
* @throws IOException if the file is unreadable. Per file exceptions are
* returned in the errors parameter.
*/
public void load_directory(File d, Collection keys,
Map errors) {
Vector derFiles = new Vector();
Collection files = new Vector();
Map ids = new TreeMap();
Map kps = new TreeMap();
if (d.isDirectory() )
for (File f : d.listFiles())
files.add(f);
else files.add(d);
for (File f: files ) {
try {
PEMReader r = new PEMReader(new FileReader(f));
Object o = readPEM(r);
if ( o != null ) {
if (o instanceof Identity) {
Identity i = (Identity) o;
String kid = i.getKeyID();
if (kps.containsKey(kid) ) {
i.setKeyPair(kps.get(kid));
kps.remove(kid);
}
else if (i.getKeyPair() == null )
ids.put(i.getKeyID(), i);
load_id_chunk(i);
}
else if (o instanceof KeyPair ) {
KeyPair kp = (KeyPair) o;
String kid = extractKeyID(kp.getPublic());
if (ids.containsKey(kid)) {
Identity i = ids.get(kid);
i.setKeyPair(kp);
ids.remove(kid);
}
else {
kps.put(kid, kp);
}
}
}
else {
// Not a PEM file
derFiles.add(f);
continue;
}
}
catch (Exception e ) {
if (errors != null ) errors.put(f.getName(), e);
}
}
for ( File f : derFiles ) {
try {
add_credential(new Credential(f, m_identities));
}
catch (Exception e ) {
if (errors != null ) errors.put(f.getName(), e);
}
}
}
/**
* Equivalent to load_directory(d, null, null).
* @param d the File to read. If it is a directory its contents are read
* @throws IOException if the file is unreadable. To see per-file
* exceptions use a signature with the errors parameter.
*/
public void load_directory(File d) {
load_directory(d, null, null);
}
/**
* Equivalent to load_directory(d, null, null).
* @param d the File to read. If it is a directory its contents are read
* @param errors a Map from entry name to generated exception
* @throws IOException if the file is unreadable. Per file exceptions are
* returned in the errors parameter.
*/
public void load_directory(File d, Map errors) {
load_directory(d, null, errors);
}
/**
* Equivalent to load_directory(d, null, null).
* @param d the File to read. If it is a directory its contents are read
* @param keys a Collection into which to insert unmatched keys
* @throws IOException if the file is unreadable. To see per-file
* exceptions use a signature with the errors parameter.
*/
public void load_directory(File d, Collection keys) {
load_directory(d, keys, null);
}
/**
* Write the certificates that make up the context as a zip file, with an
* entry for each credential or identity.
* @param f the File to write
* @param allIDs a boolean, if true write certificates for all Identities,
* whether used in signing a credential or not.
* @param withPrivateKeys a boolean, if true write the Identities as PEM
* file containing both the certificate and the private keys.
* @throws IOException if there is a problem writhing the file.
*/
public void write_zip_file(File f, boolean allIDs, boolean withPrivateKeys)
throws IOException {
ZipOutputStream z = new ZipOutputStream(new FileOutputStream(f));
Set ids = allIDs ? m_identities : new TreeSet();
int n = 0;
for (Credential c: credentials()) {
z.putNextEntry(new ZipEntry("attr" + n++ + ".der"));
c.write(z);
z.closeEntry();
if ( c.issuer() != null && !allIDs) ids.add(c.issuer());
}
for (Identity i: ids) {
z.putNextEntry(new ZipEntry(i.getName() + ".pem"));
i.write(z);
if (withPrivateKeys)
i.writePrivateKey(z);
z.closeEntry();
}
z.close();
}
/**
* Get to the SHA1 hash of the key. Used by Roles and Identities to get a
* key ID.
* @param k the PublicKey to get the ID from.
* @return a String with the key identifier
*/
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().
* @param k the PublicKey to get the ID from.
* @return a String with the key identifier
*/
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);
}
}