diff options
Diffstat (limited to 'src')
-rw-r--r-- | src/main/java/de/pixart/messenger/utils/PRNGFixes.java | 124 |
1 files changed, 62 insertions, 62 deletions
diff --git a/src/main/java/de/pixart/messenger/utils/PRNGFixes.java b/src/main/java/de/pixart/messenger/utils/PRNGFixes.java index 211ebca8e..c26fe9f13 100644 --- a/src/main/java/de/pixart/messenger/utils/PRNGFixes.java +++ b/src/main/java/de/pixart/messenger/utils/PRNGFixes.java @@ -133,6 +133,58 @@ public final class PRNGFixes { } /** + * Generates a device- and invocation-specific seed to be mixed into the + * Linux PRNG. + */ + private static byte[] generateSeed() { + try { + ByteArrayOutputStream seedBuffer = new ByteArrayOutputStream(); + DataOutputStream seedBufferOut = new DataOutputStream(seedBuffer); + seedBufferOut.writeLong(System.currentTimeMillis()); + seedBufferOut.writeLong(System.nanoTime()); + seedBufferOut.writeInt(Process.myPid()); + seedBufferOut.writeInt(Process.myUid()); + seedBufferOut.write(BUILD_FINGERPRINT_AND_DEVICE_SERIAL); + seedBufferOut.close(); + return seedBuffer.toByteArray(); + } catch (IOException e) { + throw new SecurityException("Failed to generate seed", e); + } + } + + /** + * Gets the hardware serial number of this device. + * + * @return serial number or {@code null} if not available. + */ + private static String getDeviceSerialNumber() { + // We're using the Reflection API because Build.SERIAL is only available + // since API Level 9 (Gingerbread, Android 2.3). + try { + return (String) Build.class.getField("SERIAL").get(null); + } catch (Exception ignored) { + return null; + } + } + + private static byte[] getBuildFingerprintAndDeviceSerial() { + StringBuilder result = new StringBuilder(); + String fingerprint = Build.FINGERPRINT; + if (fingerprint != null) { + result.append(fingerprint); + } + String serial = getDeviceSerialNumber(); + if (serial != null) { + result.append(serial); + } + try { + return result.toString().getBytes("UTF-8"); + } catch (UnsupportedEncodingException e) { + throw new RuntimeException("UTF-8 encoding not supported"); + } + } + + /** * {@code Provider} of {@code SecureRandom} engines which pass through all * requests to the Linux PRNG. */ @@ -157,17 +209,17 @@ public final class PRNGFixes { */ public static class LinuxPRNGSecureRandom extends SecureRandomSpi { - /* + /* * IMPLEMENTATION NOTE: Requests to generate bytes and to mix in a seed - * are passed through to the Linux PRNG (/dev/urandom). Instances of - * this class seed themselves by mixing in the current time, PID, UID, - * build fingerprint, and hardware serial number (where available) into - * Linux PRNG. - * - * Concurrency: Read requests to the underlying Linux PRNG are - * serialized (on sLock) to ensure that multiple threads do not get - * duplicated PRNG output. - */ + * are passed through to the Linux PRNG (/dev/urandom). Instances of + * this class seed themselves by mixing in the current time, PID, UID, + * build fingerprint, and hardware serial number (where available) into + * Linux PRNG. + * + * Concurrency: Read requests to the underlying Linux PRNG are + * serialized (on sLock) to ensure that multiple threads do not get + * duplicated PRNG output. + */ private static final File URANDOM_FILE = new File("/dev/urandom"); @@ -271,56 +323,4 @@ public final class PRNGFixes { } } } - - /** - * Generates a device- and invocation-specific seed to be mixed into the - * Linux PRNG. - */ - private static byte[] generateSeed() { - try { - ByteArrayOutputStream seedBuffer = new ByteArrayOutputStream(); - DataOutputStream seedBufferOut = new DataOutputStream(seedBuffer); - seedBufferOut.writeLong(System.currentTimeMillis()); - seedBufferOut.writeLong(System.nanoTime()); - seedBufferOut.writeInt(Process.myPid()); - seedBufferOut.writeInt(Process.myUid()); - seedBufferOut.write(BUILD_FINGERPRINT_AND_DEVICE_SERIAL); - seedBufferOut.close(); - return seedBuffer.toByteArray(); - } catch (IOException e) { - throw new SecurityException("Failed to generate seed", e); - } - } - - /** - * Gets the hardware serial number of this device. - * - * @return serial number or {@code null} if not available. - */ - private static String getDeviceSerialNumber() { - // We're using the Reflection API because Build.SERIAL is only available - // since API Level 9 (Gingerbread, Android 2.3). - try { - return (String) Build.class.getField("SERIAL").get(null); - } catch (Exception ignored) { - return null; - } - } - - private static byte[] getBuildFingerprintAndDeviceSerial() { - StringBuilder result = new StringBuilder(); - String fingerprint = Build.FINGERPRINT; - if (fingerprint != null) { - result.append(fingerprint); - } - String serial = getDeviceSerialNumber(); - if (serial != null) { - result.append(serial); - } - try { - return result.toString().getBytes("UTF-8"); - } catch (UnsupportedEncodingException e) { - throw new RuntimeException("UTF-8 encoding not supported"); - } - } }
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