1package eu.siacs.conversations.utils;
2
3import static eu.siacs.conversations.utils.Random.SECURE_RANDOM;
4
5import android.os.Bundle;
6import android.util.Base64;
7import android.util.Pair;
8import androidx.annotation.StringRes;
9import eu.siacs.conversations.Config;
10import eu.siacs.conversations.R;
11import eu.siacs.conversations.entities.Account;
12import eu.siacs.conversations.entities.Message;
13import eu.siacs.conversations.xmpp.Jid;
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;
29import org.bouncycastle.asn1.x500.X500Name;
30import org.bouncycastle.asn1.x500.style.BCStyle;
31import org.bouncycastle.asn1.x500.style.IETFUtils;
32import org.bouncycastle.cert.jcajce.JcaX509CertificateHolder;
33
34public final class CryptoHelper {
35
36 public static final Pattern UUID_PATTERN =
37 Pattern.compile("[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}");
38 public static final byte[] ONE = new byte[] {0, 0, 0, 1};
39 private static final char[] CHARS =
40 "ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz123456789+-/#$!?".toCharArray();
41 private static final int PW_LENGTH = 12;
42 private static final char[] VOWELS = "aeiou".toCharArray();
43 private static final char[] CONSONANTS = "bcfghjklmnpqrstvwxyz".toCharArray();
44 private static final char[] hexArray = "0123456789abcdef".toCharArray();
45
46 public static String bytesToHex(byte[] bytes) {
47 char[] hexChars = new char[bytes.length * 2];
48 for (int j = 0; j < bytes.length; j++) {
49 int v = bytes[j] & 0xFF;
50 hexChars[j * 2] = hexArray[v >>> 4];
51 hexChars[j * 2 + 1] = hexArray[v & 0x0F];
52 }
53 return new String(hexChars);
54 }
55
56 public static String createPassword(SecureRandom random) {
57 StringBuilder builder = new StringBuilder(PW_LENGTH);
58 for (int i = 0; i < PW_LENGTH; ++i) {
59 builder.append(CHARS[random.nextInt(CHARS.length - 1)]);
60 }
61 return builder.toString();
62 }
63
64 public static String pronounceable() {
65 final int rand = SECURE_RANDOM.nextInt(4);
66 char[] output = new char[rand * 2 + (5 - rand)];
67 boolean vowel = SECURE_RANDOM.nextBoolean();
68 for (int i = 0; i < output.length; ++i) {
69 output[i] =
70 vowel
71 ? VOWELS[SECURE_RANDOM.nextInt(VOWELS.length)]
72 : CONSONANTS[SECURE_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] =
83 (byte)
84 ((Character.digit(hexString.charAt(i), 16) << 4)
85 + Character.digit(hexString.charAt(i + 1), 16));
86 }
87 return array;
88 }
89
90 public static String hexToString(final String hexString) {
91 return new String(hexToBytes(hexString));
92 }
93
94 public static byte[] concatenateByteArrays(byte[] a, byte[] b) {
95 byte[] result = new byte[a.length + b.length];
96 System.arraycopy(a, 0, result, 0, a.length);
97 System.arraycopy(b, 0, result, a.length, b.length);
98 return result;
99 }
100
101 /** Escapes usernames or passwords for SASL. */
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(final int length) {
126 final byte[] bytes = new byte[length];
127 SECURE_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 =
154 new LinkedHashSet<>(Arrays.asList(Config.ENABLED_CIPHERS));
155 final List<String> platformCiphers = Arrays.asList(platformSupportedCipherSuites);
156 cipherSuites.retainAll(platformCiphers);
157 cipherSuites.addAll(platformCiphers);
158 filterWeakCipherSuites(cipherSuites);
159 cipherSuites.remove("TLS_FALLBACK_SCSV");
160 return cipherSuites.toArray(new String[cipherSuites.size()]);
161 }
162
163 private static void filterWeakCipherSuites(final Collection<String> cipherSuites) {
164 final Iterator<String> it = cipherSuites.iterator();
165 while (it.hasNext()) {
166 String cipherName = it.next();
167 // remove all ciphers with no or very weak encryption or no authentication
168 for (String weakCipherPattern : Config.WEAK_CIPHER_PATTERNS) {
169 if (cipherName.contains(weakCipherPattern)) {
170 it.remove();
171 break;
172 }
173 }
174 }
175 }
176
177 public static Pair<Jid, String> extractJidAndName(X509Certificate certificate)
178 throws CertificateEncodingException,
179 IllegalArgumentException,
180 CertificateParsingException {
181 Collection<List<?>> alternativeNames = certificate.getSubjectAlternativeNames();
182 List<String> emails = new ArrayList<>();
183 if (alternativeNames != null) {
184 for (List<?> san : alternativeNames) {
185 Integer type = (Integer) san.get(0);
186 if (type == 1) {
187 emails.add((String) san.get(1));
188 }
189 }
190 }
191 X500Name x500name = new JcaX509CertificateHolder(certificate).getSubject();
192 if (emails.size() == 0 && x500name.getRDNs(BCStyle.EmailAddress).length > 0) {
193 emails.add(
194 IETFUtils.valueToString(
195 x500name.getRDNs(BCStyle.EmailAddress)[0].getFirst().getValue()));
196 }
197 String name =
198 x500name.getRDNs(BCStyle.CN).length > 0
199 ? IETFUtils.valueToString(
200 x500name.getRDNs(BCStyle.CN)[0].getFirst().getValue())
201 : null;
202 if (emails.size() >= 1) {
203 return new Pair<>(Jid.of(emails.get(0)), name);
204 } else if (name != null) {
205 try {
206 Jid jid = Jid.of(name);
207 if (jid.isBareJid() && jid.getLocal() != null) {
208 return new Pair<>(jid, null);
209 }
210 } catch (IllegalArgumentException e) {
211 return null;
212 }
213 }
214 return null;
215 }
216
217 public static Bundle extractCertificateInformation(X509Certificate certificate) {
218 Bundle information = new Bundle();
219 try {
220 JcaX509CertificateHolder holder = new JcaX509CertificateHolder(certificate);
221 X500Name subject = holder.getSubject();
222 try {
223 information.putString(
224 "subject_cn",
225 subject.getRDNs(BCStyle.CN)[0].getFirst().getValue().toString());
226 } catch (Exception e) {
227 // ignored
228 }
229 try {
230 information.putString(
231 "subject_o",
232 subject.getRDNs(BCStyle.O)[0].getFirst().getValue().toString());
233 } catch (Exception e) {
234 // ignored
235 }
236
237 X500Name issuer = holder.getIssuer();
238 try {
239 information.putString(
240 "issuer_cn",
241 issuer.getRDNs(BCStyle.CN)[0].getFirst().getValue().toString());
242 } catch (Exception e) {
243 // ignored
244 }
245 try {
246 information.putString(
247 "issuer_o", issuer.getRDNs(BCStyle.O)[0].getFirst().getValue().toString());
248 } catch (Exception e) {
249 // ignored
250 }
251 try {
252 information.putString("sha1", getFingerprintCert(certificate.getEncoded()));
253 } catch (Exception e) {
254
255 }
256 return information;
257 } catch (CertificateEncodingException e) {
258 return information;
259 }
260 }
261
262 public static String getFingerprintCert(byte[] input) throws NoSuchAlgorithmException {
263 MessageDigest md = MessageDigest.getInstance("SHA-1");
264 byte[] fingerprint = md.digest(input);
265 return prettifyFingerprintCert(bytesToHex(fingerprint));
266 }
267
268 public static String getFingerprint(Jid jid, String androidId) {
269 return getFingerprint(jid.toString() + "\00" + androidId);
270 }
271
272 public static String getAccountFingerprint(Account account, String androidId) {
273 return getFingerprint(account.getJid().asBareJid(), androidId);
274 }
275
276 public static String getFingerprint(String value) {
277 try {
278 MessageDigest md = MessageDigest.getInstance("SHA-1");
279 return bytesToHex(md.digest(value.getBytes(StandardCharsets.UTF_8)));
280 } catch (Exception e) {
281 return "";
282 }
283 }
284
285 public static @StringRes int encryptionTypeToText(final int encryption) {
286 return switch (encryption) {
287 case Message.ENCRYPTION_OTR -> R.string.encryption_choice_otr;
288 case Message.ENCRYPTION_AXOLOTL,
289 Message.ENCRYPTION_AXOLOTL_NOT_FOR_THIS_DEVICE,
290 Message.ENCRYPTION_AXOLOTL_FAILED ->
291 R.string.encryption_choice_omemo;
292 case Message.ENCRYPTION_PGP -> R.string.encryption_choice_pgp;
293 default -> R.string.encryption_choice_unencrypted;
294 };
295 }
296
297 public static boolean isPgpEncryptedUrl(String url) {
298 if (url == null) {
299 return false;
300 }
301 final String u = url.toLowerCase();
302 return !u.contains(" ")
303 && (u.startsWith("https://") || u.startsWith("http://") || u.startsWith("p1s3://"))
304 && u.endsWith(".pgp");
305 }
306}