1package eu.siacs.conversations.utils;
2
3import android.os.Bundle;
4import android.util.Base64;
5import android.util.Pair;
6
7import org.bouncycastle.asn1.x500.X500Name;
8import org.bouncycastle.asn1.x500.style.BCStyle;
9import org.bouncycastle.asn1.x500.style.IETFUtils;
10import org.bouncycastle.cert.jcajce.JcaX509CertificateHolder;
11
12import java.io.InputStream;
13import java.io.IOException;
14import java.nio.charset.StandardCharsets;
15import java.security.MessageDigest;
16import java.security.NoSuchAlgorithmException;
17import java.security.SecureRandom;
18import java.security.cert.CertificateEncodingException;
19import java.security.cert.CertificateParsingException;
20import java.security.cert.X509Certificate;
21import java.text.Normalizer;
22import java.util.ArrayList;
23import java.util.Arrays;
24import java.util.Collection;
25import java.util.Iterator;
26import java.util.LinkedHashSet;
27import java.util.List;
28import java.util.regex.Pattern;
29
30import io.ipfs.cid.Cid;
31import io.ipfs.multihash.Multihash;
32
33import eu.siacs.conversations.Config;
34import eu.siacs.conversations.R;
35import eu.siacs.conversations.entities.Account;
36import eu.siacs.conversations.entities.Message;
37import eu.siacs.conversations.xmpp.Jid;
38
39public final class CryptoHelper {
40
41 public static final Pattern UUID_PATTERN = Pattern.compile("[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}");
42 final public static byte[] ONE = new byte[]{0, 0, 0, 1};
43 private static final char[] CHARS = "ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz123456789+-/#$!?".toCharArray();
44 private static final int PW_LENGTH = 12;
45 private static final char[] VOWELS = "aeiou".toCharArray();
46 private static final char[] CONSONANTS = "bcfghjklmnpqrstvwxyz".toCharArray();
47 private final static char[] hexArray = "0123456789abcdef".toCharArray();
48
49 public static String bytesToHex(byte[] bytes) {
50 char[] hexChars = new char[bytes.length * 2];
51 for (int j = 0; j < bytes.length; j++) {
52 int v = bytes[j] & 0xFF;
53 hexChars[j * 2] = hexArray[v >>> 4];
54 hexChars[j * 2 + 1] = hexArray[v & 0x0F];
55 }
56 return new String(hexChars);
57 }
58
59 public static String createPassword(SecureRandom random) {
60 StringBuilder builder = new StringBuilder(PW_LENGTH);
61 for (int i = 0; i < PW_LENGTH; ++i) {
62 builder.append(CHARS[random.nextInt(CHARS.length - 1)]);
63 }
64 return builder.toString();
65 }
66
67 public static String pronounceable(SecureRandom random) {
68 final int rand = random.nextInt(4);
69 char[] output = new char[rand * 2 + (5 - rand)];
70 boolean vowel = random.nextBoolean();
71 for (int i = 0; i < output.length; ++i) {
72 output[i] = vowel ? VOWELS[random.nextInt(VOWELS.length)] : CONSONANTS[random.nextInt(CONSONANTS.length)];
73 vowel = !vowel;
74 }
75 return String.valueOf(output);
76 }
77
78 public static byte[] hexToBytes(String hexString) {
79 int len = hexString.length();
80 byte[] array = new byte[len / 2];
81 for (int i = 0; i < len; i += 2) {
82 array[i / 2] = (byte) ((Character.digit(hexString.charAt(i), 16) << 4) + Character
83 .digit(hexString.charAt(i + 1), 16));
84 }
85 return array;
86 }
87
88 public static String hexToString(final String hexString) {
89 return new String(hexToBytes(hexString));
90 }
91
92 public static byte[] concatenateByteArrays(byte[] a, byte[] b) {
93 byte[] result = new byte[a.length + b.length];
94 System.arraycopy(a, 0, result, 0, a.length);
95 System.arraycopy(b, 0, result, a.length, b.length);
96 return result;
97 }
98
99 /**
100 * Escapes usernames or passwords for SASL.
101 */
102 public static String saslEscape(final String s) {
103 final StringBuilder sb = new StringBuilder((int) (s.length() * 1.1));
104 for (int i = 0; i < s.length(); i++) {
105 char c = s.charAt(i);
106 switch (c) {
107 case ',':
108 sb.append("=2C");
109 break;
110 case '=':
111 sb.append("=3D");
112 break;
113 default:
114 sb.append(c);
115 break;
116 }
117 }
118 return sb.toString();
119 }
120
121 public static String saslPrep(final String s) {
122 return Normalizer.normalize(s, Normalizer.Form.NFKC);
123 }
124
125 public static String random(int length, SecureRandom random) {
126 final byte[] bytes = new byte[length];
127 random.nextBytes(bytes);
128 return Base64.encodeToString(bytes, Base64.NO_PADDING | Base64.NO_WRAP | Base64.URL_SAFE);
129 }
130
131 public static String prettifyFingerprint(String fingerprint) {
132 if (fingerprint == null) {
133 return "";
134 } else if (fingerprint.length() < 40) {
135 return fingerprint;
136 }
137 StringBuilder builder = new StringBuilder(fingerprint);
138 for (int i = 8; i < builder.length(); i += 9) {
139 builder.insert(i, ' ');
140 }
141 return builder.toString();
142 }
143
144 public static String prettifyFingerprintCert(String fingerprint) {
145 StringBuilder builder = new StringBuilder(fingerprint);
146 for (int i = 2; i < builder.length(); i += 3) {
147 builder.insert(i, ':');
148 }
149 return builder.toString();
150 }
151
152 public static String[] getOrderedCipherSuites(final String[] platformSupportedCipherSuites) {
153 final Collection<String> cipherSuites = new LinkedHashSet<>(Arrays.asList(Config.ENABLED_CIPHERS));
154 final List<String> platformCiphers = Arrays.asList(platformSupportedCipherSuites);
155 cipherSuites.retainAll(platformCiphers);
156 cipherSuites.addAll(platformCiphers);
157 filterWeakCipherSuites(cipherSuites);
158 cipherSuites.remove("TLS_FALLBACK_SCSV");
159 return cipherSuites.toArray(new String[cipherSuites.size()]);
160 }
161
162 private static void filterWeakCipherSuites(final Collection<String> cipherSuites) {
163 final Iterator<String> it = cipherSuites.iterator();
164 while (it.hasNext()) {
165 String cipherName = it.next();
166 // remove all ciphers with no or very weak encryption or no authentication
167 for (String weakCipherPattern : Config.WEAK_CIPHER_PATTERNS) {
168 if (cipherName.contains(weakCipherPattern)) {
169 it.remove();
170 break;
171 }
172 }
173 }
174 }
175
176 public static Pair<Jid, String> extractJidAndName(X509Certificate certificate) throws CertificateEncodingException, IllegalArgumentException, CertificateParsingException {
177 Collection<List<?>> alternativeNames = certificate.getSubjectAlternativeNames();
178 List<String> emails = new ArrayList<>();
179 if (alternativeNames != null) {
180 for (List<?> san : alternativeNames) {
181 Integer type = (Integer) san.get(0);
182 if (type == 1) {
183 emails.add((String) san.get(1));
184 }
185 }
186 }
187 X500Name x500name = new JcaX509CertificateHolder(certificate).getSubject();
188 if (emails.size() == 0 && x500name.getRDNs(BCStyle.EmailAddress).length > 0) {
189 emails.add(IETFUtils.valueToString(x500name.getRDNs(BCStyle.EmailAddress)[0].getFirst().getValue()));
190 }
191 String name = x500name.getRDNs(BCStyle.CN).length > 0 ? IETFUtils.valueToString(x500name.getRDNs(BCStyle.CN)[0].getFirst().getValue()) : null;
192 if (emails.size() >= 1) {
193 return new Pair<>(Jid.of(emails.get(0)), name);
194 } else if (name != null) {
195 try {
196 Jid jid = Jid.of(name);
197 if (jid.isBareJid() && jid.getLocal() != null) {
198 return new Pair<>(jid, null);
199 }
200 } catch (IllegalArgumentException e) {
201 return null;
202 }
203 }
204 return null;
205 }
206
207 public static Bundle extractCertificateInformation(X509Certificate certificate) {
208 Bundle information = new Bundle();
209 try {
210 JcaX509CertificateHolder holder = new JcaX509CertificateHolder(certificate);
211 X500Name subject = holder.getSubject();
212 try {
213 information.putString("subject_cn", subject.getRDNs(BCStyle.CN)[0].getFirst().getValue().toString());
214 } catch (Exception e) {
215 //ignored
216 }
217 try {
218 information.putString("subject_o", subject.getRDNs(BCStyle.O)[0].getFirst().getValue().toString());
219 } catch (Exception e) {
220 //ignored
221 }
222
223 X500Name issuer = holder.getIssuer();
224 try {
225 information.putString("issuer_cn", issuer.getRDNs(BCStyle.CN)[0].getFirst().getValue().toString());
226 } catch (Exception e) {
227 //ignored
228 }
229 try {
230 information.putString("issuer_o", issuer.getRDNs(BCStyle.O)[0].getFirst().getValue().toString());
231 } catch (Exception e) {
232 //ignored
233 }
234 try {
235 information.putString("sha1", getFingerprintCert(certificate.getEncoded()));
236 } catch (Exception e) {
237
238 }
239 return information;
240 } catch (CertificateEncodingException e) {
241 return information;
242 }
243 }
244
245 public static String getFingerprintCert(byte[] input) throws NoSuchAlgorithmException {
246 MessageDigest md = MessageDigest.getInstance("SHA-1");
247 byte[] fingerprint = md.digest(input);
248 return prettifyFingerprintCert(bytesToHex(fingerprint));
249 }
250
251 public static String getFingerprint(Jid jid, String androidId) {
252 return getFingerprint(jid.toEscapedString() + "\00" + androidId);
253 }
254
255 public static String getAccountFingerprint(Account account, String androidId) {
256 return getFingerprint(account.getJid().asBareJid(), androidId);
257 }
258
259 public static String getFingerprint(String value) {
260 try {
261 MessageDigest md = MessageDigest.getInstance("SHA-1");
262 return bytesToHex(md.digest(value.getBytes(StandardCharsets.UTF_8)));
263 } catch (Exception e) {
264 return "";
265 }
266 }
267
268 public static int encryptionTypeToText(int encryption) {
269 switch (encryption) {
270 case Message.ENCRYPTION_OTR:
271 return R.string.encryption_choice_otr;
272 case Message.ENCRYPTION_AXOLOTL:
273 case Message.ENCRYPTION_AXOLOTL_NOT_FOR_THIS_DEVICE:
274 case Message.ENCRYPTION_AXOLOTL_FAILED:
275 return R.string.encryption_choice_omemo;
276 case Message.ENCRYPTION_NONE:
277 return R.string.encryption_choice_unencrypted;
278 default:
279 return R.string.encryption_choice_pgp;
280 }
281 }
282
283 public static boolean isPgpEncryptedUrl(String url) {
284 if (url == null) {
285 return false;
286 }
287 final String u = url.toLowerCase();
288 return !u.contains(" ") && (u.startsWith("https://") || u.startsWith("http://") || u.startsWith("p1s3://")) && u.endsWith(".pgp");
289 }
290
291 public static String multihashAlgo(Multihash.Type type) throws NoSuchAlgorithmException {
292 switch(type) {
293 case sha1:
294 return "sha1";
295 case sha2_256:
296 return "sha-256";
297 case sha2_512:
298 return "sha-512";
299 default:
300 throw new NoSuchAlgorithmException("" + type);
301 }
302 }
303
304 public static Multihash.Type multihashType(String algo) throws NoSuchAlgorithmException {
305 if (algo.equals("SHA-1") || algo.equals("sha-1") || algo.equals("sha1")) {
306 return Multihash.Type.sha1;
307 } else if (algo.equals("SHA-256") || algo.equals("sha-256")) {
308 return Multihash.Type.sha2_256;
309 } else if (algo.equals("SHA-512") | algo.equals("sha-512")) {
310 return Multihash.Type.sha2_512;
311 } else {
312 throw new NoSuchAlgorithmException(algo);
313 }
314 }
315
316 public static Cid cid(byte[] digest, String algo) throws NoSuchAlgorithmException {
317 return Cid.buildCidV1(Cid.Codec.Raw, multihashType(algo), digest);
318 }
319
320 public static Cid[] cid(InputStream in, String[] algo) throws NoSuchAlgorithmException, IOException {
321 byte[] buf = new byte[4096];
322 int len;
323 MessageDigest[] md = new MessageDigest[algo.length];
324 for (int i = 0; i < md.length; i++) {
325 md[i] = MessageDigest.getInstance(algo[i]);
326 }
327 while ((len = in.read(buf)) != -1) {
328 for (int i = 0; i < md.length; i++) {
329 md[i].update(buf, 0, len);
330 }
331 }
332
333 Cid[] cid = new Cid[md.length];
334 for (int i = 0; i < cid.length; i++) {
335 cid[i] = cid(md[i].digest(), algo[i]);
336 }
337
338 return cid;
339 }
340}