diff -r 000000000000 -r 6474c204b198 mobile/android/base/browserid/MockMyIDTokenFactory.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mobile/android/base/browserid/MockMyIDTokenFactory.java	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,128 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.browserid;
+
+import java.math.BigInteger;
+import java.security.NoSuchAlgorithmException;
+import java.security.spec.InvalidKeySpecException;
+
+/**
+ * Generate certificates and assertions backed by mockmyid.com's private key.
+ * <p>
+ * These artifacts are for testing only.
+ */
+public class MockMyIDTokenFactory {
+  public static final BigInteger MOCKMYID_x = new BigInteger("385cb3509f086e110c5e24bdd395a84b335a09ae", 16);
+  public static final BigInteger MOCKMYID_y = new BigInteger("738ec929b559b604a232a9b55a5295afc368063bb9c20fac4e53a74970a4db7956d48e4c7ed523405f629b4cc83062f13029c4d615bbacb8b97f5e56f0c7ac9bc1d4e23809889fa061425c984061fca1826040c399715ce7ed385c4dd0d402256912451e03452d3c961614eb458f188e3e8d2782916c43dbe2e571251ce38262", 16);
+  public static final BigInteger MOCKMYID_p = new BigInteger("ff600483db6abfc5b45eab78594b3533d550d9f1bf2a992a7a8daa6dc34f8045ad4e6e0c429d334eeeaaefd7e23d4810be00e4cc1492cba325ba81ff2d5a5b305a8d17eb3bf4a06a349d392e00d329744a5179380344e82a18c47933438f891e22aeef812d69c8f75e326cb70ea000c3f776dfdbd604638c2ef717fc26d02e17", 16);
+  public static final BigInteger MOCKMYID_q = new BigInteger("e21e04f911d1ed7991008ecaab3bf775984309c3", 16);
+  public static final BigInteger MOCKMYID_g = new BigInteger("c52a4a0ff3b7e61fdf1867ce84138369a6154f4afa92966e3c827e25cfa6cf508b90e5de419e1337e07a2e9e2a3cd5dea704d175f8ebf6af397d69e110b96afb17c7a03259329e4829b0d03bbc7896b15b4ade53e130858cc34d96269aa89041f409136c7242a38895c9d5bccad4f389af1d7a4bd1398bd072dffa896233397a", 16);
+
+  // Computed lazily by static <code>getMockMyIDPrivateKey</code>.
+  protected static SigningPrivateKey cachedMockMyIDPrivateKey = null;
+
+  public static SigningPrivateKey getMockMyIDPrivateKey() throws NoSuchAlgorithmException, InvalidKeySpecException {
+    if (cachedMockMyIDPrivateKey == null) {
+      cachedMockMyIDPrivateKey = DSACryptoImplementation.createPrivateKey(MOCKMYID_x, MOCKMYID_p, MOCKMYID_q, MOCKMYID_g);
+    }
+    return cachedMockMyIDPrivateKey;
+  }
+
+  /**
+   * Sign a public key asserting ownership of username@mockmyid.com with
+   * mockmyid.com's private key.
+   *
+   * @param publicKeyToSign
+   *          public key to sign.
+   * @param username
+   *          sign username@mockmyid.com
+   * @param issuedAt
+   *          timestamp for certificate, in milliseconds since the epoch.
+   * @param expiresAt
+   *          expiration timestamp for certificate, in milliseconds since the epoch.
+   * @return encoded certificate string.
+   * @throws Exception
+   */
+  public String createMockMyIDCertificate(final VerifyingPublicKey publicKeyToSign, String username,
+      final long issuedAt, final long expiresAt)
+          throws Exception {
+    if (!username.endsWith("@mockmyid.com")) {
+      username = username + "@mockmyid.com";
+    }
+    SigningPrivateKey mockMyIdPrivateKey = getMockMyIDPrivateKey();
+    return JSONWebTokenUtils.createCertificate(publicKeyToSign, username, "mockmyid.com", issuedAt, expiresAt, mockMyIdPrivateKey);
+  }
+
+  /**
+   * Sign a public key asserting ownership of username@mockmyid.com with
+   * mockmyid.com's private key.
+   *
+   * @param publicKeyToSign
+   *          public key to sign.
+   * @param username
+   *          sign username@mockmyid.com
+   * @return encoded certificate string.
+   * @throws Exception
+   */
+  public String createMockMyIDCertificate(final VerifyingPublicKey publicKeyToSign, final String username)
+      throws Exception {
+    long ciat = System.currentTimeMillis();
+    long cexp = ciat + JSONWebTokenUtils.DEFAULT_CERTIFICATE_DURATION_IN_MILLISECONDS;
+    return createMockMyIDCertificate(publicKeyToSign, username, ciat, cexp);
+  }
+
+  /**
+   * Generate an assertion asserting ownership of username@mockmyid.com to a
+   * relying party. The underlying certificate is signed by mockymid.com's
+   * private key.
+   *
+   * @param keyPair
+   *          to sign with.
+   * @param username
+   *          sign username@mockmyid.com.
+   * @param certificateIssuedAt
+   *          timestamp for certificate, in milliseconds since the epoch.
+   * @param certificateExpiresAt
+   *          expiration timestamp for certificate, in milliseconds since the epoch.
+   * @param assertionIssuedAt
+   *          timestamp for assertion, in milliseconds since the epoch; if null,
+   *          no timestamp is included.
+   * @param assertionExpiresAt
+   *          expiration timestamp for assertion, in milliseconds since the epoch.
+   * @return encoded assertion string.
+   * @throws Exception
+   */
+  public String createMockMyIDAssertion(BrowserIDKeyPair keyPair, String username, String audience,
+      long certificateIssuedAt, long certificateExpiresAt,
+      Long assertionIssuedAt, long assertionExpiresAt)
+          throws Exception {
+    String certificate = createMockMyIDCertificate(keyPair.getPublic(), username,
+        certificateIssuedAt, certificateExpiresAt);
+    return JSONWebTokenUtils.createAssertion(keyPair.getPrivate(), certificate, audience,
+        JSONWebTokenUtils.DEFAULT_ASSERTION_ISSUER, assertionIssuedAt, assertionExpiresAt);
+  }
+
+  /**
+   * Generate an assertion asserting ownership of username@mockmyid.com to a
+   * relying party. The underlying certificate is signed by mockymid.com's
+   * private key.
+   *
+   * @param keyPair
+   *          to sign with.
+   * @param username
+   *          sign username@mockmyid.com.
+   * @return encoded assertion string.
+   * @throws Exception
+   */
+  public String createMockMyIDAssertion(BrowserIDKeyPair keyPair, String username, String audience)
+      throws Exception {
+    long ciat = System.currentTimeMillis();
+    long cexp = ciat + JSONWebTokenUtils.DEFAULT_CERTIFICATE_DURATION_IN_MILLISECONDS;
+    long aiat = ciat + 1;
+    long aexp = aiat + JSONWebTokenUtils.DEFAULT_ASSERTION_DURATION_IN_MILLISECONDS;
+    return createMockMyIDAssertion(keyPair, username, audience,
+        ciat, cexp, aiat, aexp);
+  }
+}