ConnectAuth.java

package org.libvirt;

import org.libvirt.jna.Libvirt;
import org.libvirt.jna.virConnectCredential;

import com.sun.jna.Pointer;

/**
 * We diverge from the C implementation There is no explicit cbdata field, you
 * should just add any extra data to the child class's instance.
 * 
 * @author stoty
 * 
 */
public abstract class ConnectAuth implements Libvirt.VirConnectAuthCallback {
  public class Credential {

    /**
     * One of virConnectCredentialType constants
     */
    public CredentialType type;
    /**
     * Prompt to show to user
     */
    public String         prompt;
    /**
     * Additional challenge to show
     */
    public String         challenge;
    /**
     * Optional default result
     */
    public String         defresult;
    /**
     * Result to be filled with user response (or defresult)
     */
    public String         result;

    /**
     * Convenience constructor to be called from the JNI side
     * 
     * @param type
     * @param prompt
     * @param challenge
     * @param defresult
     */
    Credential(int type, String prompt, String challenge, String defresult) {
      switch (type) {
        case 1:
          this.type = CredentialType.VIR_CRED_USERNAME;
          break;
        case 2:
          this.type = CredentialType.VIR_CRED_AUTHNAME;
          break;
        case 3:
          this.type = CredentialType.VIR_CRED_LANGUAGE;
          break;
        case 4:
          this.type = CredentialType.VIR_CRED_CNONCE;
          break;
        case 5:
          this.type = CredentialType.VIR_CRED_PASSPHRASE;
          break;
        case 6:
          this.type = CredentialType.VIR_CRED_ECHOPROMPT;
          break;
        case 7:
          this.type = CredentialType.VIR_CRED_NOECHOPROMPT;
          break;
        case 8:
          this.type = CredentialType.VIR_CRED_REALM;
          break;
        case 9:
          this.type = CredentialType.VIR_CRED_EXTERNAL;
          break;
        default:
          assert (false);
      }
      this.prompt = prompt;
      this.challenge = challenge;
      this.defresult = defresult;
    }

  }

  /**
   * @author stoty
   * 
   */
  public static enum CredentialType {

    /**
     * Fake credential so that the ordinal value equls the c value.
     */
    VIR_CRED_NONE,
    /**
     * Identity to act as
     */
    VIR_CRED_USERNAME,
    /**
     * Identify to authorize as
     */
    VIR_CRED_AUTHNAME,
    /**
     * RFC 1766 languages, comma separated
     */
    VIR_CRED_LANGUAGE,
    /**
     * client supplies a nonce
     */
    VIR_CRED_CNONCE,
    /**
     * Passphrase secret
     */
    VIR_CRED_PASSPHRASE,
    /**
     * Challenge response
     */
    VIR_CRED_ECHOPROMPT,
    /**
     * Challenge response
     */
    VIR_CRED_NOECHOPROMPT,
    /**
     * Authentication realm
     */
    VIR_CRED_REALM,
    /**
     * Externally managed credential More may be added - expect the unexpected
     */
    VIR_CRED_EXTERNAL;

    /**
     * Maps the java CredentialType Enum to libvirt's integer constant
     * 
     * @return The integer equivalent
     */
    @SuppressWarnings("all")
    public int mapToInt() {
      switch (this) {
        case VIR_CRED_USERNAME:
          return 1;
        case VIR_CRED_AUTHNAME:
          return 2;
        case VIR_CRED_LANGUAGE:
          return 3;
        case VIR_CRED_CNONCE:
          return 4;
        case VIR_CRED_PASSPHRASE:
          return 5;
        case VIR_CRED_ECHOPROMPT:
          return 6;
        case VIR_CRED_NOECHOPROMPT:
          return 7;
        case VIR_CRED_REALM:
          return 8;
        case VIR_CRED_EXTERNAL:
          return 9;
      }
      // We may never reach this point
      assert (false);
      return 0;
    }
  }

  /**
   * List of supported ConnectCredential.CredentialType values
   */
  public CredentialType credType[];

  @Override
  public int authCallback(virConnectCredential cred, int ncred, Pointer cbdata) {
    virConnectCredential[] nativeCreds = (virConnectCredential[]) cred.toArray(ncred);
    Credential[] creds = new Credential[ncred];
    for (int x = 0; x < ncred; x++) {
      virConnectCredential vCred = nativeCreds[x];
      creds[x] = new Credential(vCred.type, vCred.prompt, vCred.challenge, vCred.defresult);
    }
    int returnValue = callback(creds);
    for (int x = 0; x < ncred; x++) {
      virConnectCredential vCred = nativeCreds[x];
      String result = creds[x].result;
      vCred.result = result;
      vCred.resultlen = result.length();
      vCred.write();
    }

    return returnValue;
  }

  /**
   * The callback function that fills the credentials in
   * 
   * @param cred
   *          the array of credentials passed by libvirt
   * @return 0 if the defresult field contains a vailde response, -1 otherwise
   */
  public abstract int callback(Credential[] cred);
}