From 7382e3af9769f76fe4e19934a59e45a3f9858332 Mon Sep 17 00:00:00 2001 From: steckbrief Date: Sun, 3 May 2015 22:25:46 +0200 Subject: renaming eu.siacs.conversations to de.thedevstack.conversationsplus "renaming eu.siacs.conversations to de.thedevstack.conversationsplus" package renaming completed --- .../conversationsplus/utils/CryptoHelper.java | 124 +++++++++++++++++++++ 1 file changed, 124 insertions(+) create mode 100644 src/main/java/de/thedevstack/conversationsplus/utils/CryptoHelper.java (limited to 'src/main/java/de/thedevstack/conversationsplus/utils/CryptoHelper.java') diff --git a/src/main/java/de/thedevstack/conversationsplus/utils/CryptoHelper.java b/src/main/java/de/thedevstack/conversationsplus/utils/CryptoHelper.java new file mode 100644 index 00000000..115ac190 --- /dev/null +++ b/src/main/java/de/thedevstack/conversationsplus/utils/CryptoHelper.java @@ -0,0 +1,124 @@ +package de.thedevstack.conversationsplus.utils; + +import java.security.SecureRandom; +import java.text.Normalizer; +import java.util.Arrays; +import java.util.Collection; +import java.util.Iterator; +import java.util.LinkedHashSet; +import java.util.List; + +import de.thedevstack.conversationsplus.Config; + +public final class CryptoHelper { + public static final String FILETRANSFER = "?FILETRANSFERv1:"; + private final static char[] hexArray = "0123456789abcdef".toCharArray(); + private final static char[] vowels = "aeiou".toCharArray(); + private final static char[] consonants = "bcdfghjklmnpqrstvwxyz".toCharArray(); + final public static byte[] ONE = new byte[] { 0, 0, 0, 1 }; + + public static String bytesToHex(byte[] bytes) { + char[] hexChars = new char[bytes.length * 2]; + for (int j = 0; j < bytes.length; j++) { + int v = bytes[j] & 0xFF; + hexChars[j * 2] = hexArray[v >>> 4]; + hexChars[j * 2 + 1] = hexArray[v & 0x0F]; + } + return new String(hexChars); + } + + public static byte[] hexToBytes(String hexString) { + int len = hexString.length(); + byte[] array = new byte[len / 2]; + for (int i = 0; i < len; i += 2) { + array[i / 2] = (byte) ((Character.digit(hexString.charAt(i), 16) << 4) + Character + .digit(hexString.charAt(i + 1), 16)); + } + return array; + } + + public static String hexToString(final String hexString) { + return new String(hexToBytes(hexString)); + } + + public static byte[] concatenateByteArrays(byte[] a, byte[] b) { + byte[] result = new byte[a.length + b.length]; + System.arraycopy(a, 0, result, 0, a.length); + System.arraycopy(b, 0, result, a.length, b.length); + return result; + } + + public static String randomMucName(SecureRandom random) { + return randomWord(3, random) + "." + randomWord(7, random); + } + + private static String randomWord(int lenght, SecureRandom random) { + StringBuilder builder = new StringBuilder(lenght); + for (int i = 0; i < lenght; ++i) { + if (i % 2 == 0) { + builder.append(consonants[random.nextInt(consonants.length)]); + } else { + builder.append(vowels[random.nextInt(vowels.length)]); + } + } + return builder.toString(); + } + + /** + * Escapes usernames or passwords for SASL. + */ + public static String saslEscape(final String s) { + final StringBuilder sb = new StringBuilder((int) (s.length() * 1.1)); + for (int i = 0; i < s.length(); i++) { + char c = s.charAt(i); + switch (c) { + case ',': + sb.append("=2C"); + break; + case '=': + sb.append("=3D"); + break; + default: + sb.append(c); + break; + } + } + return sb.toString(); + } + + public static String saslPrep(final String s) { + return Normalizer.normalize(s, Normalizer.Form.NFKC); + } + + public static String prettifyFingerprint(String fingerprint) { + StringBuilder builder = new StringBuilder(fingerprint); + builder.insert(8, " "); + builder.insert(17, " "); + builder.insert(26, " "); + builder.insert(35, " "); + return builder.toString(); + } + + public static String[] getOrderedCipherSuites(final String[] platformSupportedCipherSuites) { + final Collection cipherSuites = new LinkedHashSet<>(Arrays.asList(Config.ENABLED_CIPHERS)); + final List platformCiphers = Arrays.asList(platformSupportedCipherSuites); + cipherSuites.retainAll(platformCiphers); + cipherSuites.addAll(platformCiphers); + filterWeakCipherSuites(cipherSuites); + return cipherSuites.toArray(new String[cipherSuites.size()]); + } + + private static void filterWeakCipherSuites(final Collection cipherSuites) { + final Iterator it = cipherSuites.iterator(); + while (it.hasNext()) { + String cipherName = it.next(); + // remove all ciphers with no or very weak encryption or no authentication + for (String weakCipherPattern : Config.WEAK_CIPHER_PATTERNS) { + if (cipherName.contains(weakCipherPattern)) { + it.remove(); + break; + } + } + } + } +} -- cgit v1.2.3