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