1package eu.siacs.conversations.utils;
2
3import android.os.Bundle;
4import android.util.Pair;
5
6import org.bouncycastle.asn1.x500.X500Name;
7import org.bouncycastle.asn1.x500.style.BCStyle;
8import org.bouncycastle.asn1.x500.style.IETFUtils;
9import org.bouncycastle.cert.jcajce.JcaX509CertificateHolder;
10
11import java.security.MessageDigest;
12import java.security.NoSuchAlgorithmException;
13import java.security.cert.CertificateEncodingException;
14import java.security.cert.CertificateParsingException;
15import java.security.cert.X509Certificate;
16import java.text.Normalizer;
17import java.util.ArrayList;
18import java.util.Arrays;
19import java.util.Collection;
20import java.util.Iterator;
21import java.util.LinkedHashSet;
22import java.util.List;
23import java.util.Locale;
24import java.util.regex.Pattern;
25
26import eu.siacs.conversations.Config;
27import eu.siacs.conversations.R;
28import eu.siacs.conversations.entities.Message;
29import eu.siacs.conversations.xmpp.jid.InvalidJidException;
30import eu.siacs.conversations.xmpp.jid.Jid;
31
32public final class CryptoHelper {
33 public static final String FILETRANSFER = "?FILETRANSFERv1:";
34 private final static char[] hexArray = "0123456789abcdef".toCharArray();
35
36 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}");
37 final public static byte[] ONE = new byte[] { 0, 0, 0, 1 };
38
39 public static String bytesToHex(byte[] bytes) {
40 char[] hexChars = new char[bytes.length * 2];
41 for (int j = 0; j < bytes.length; j++) {
42 int v = bytes[j] & 0xFF;
43 hexChars[j * 2] = hexArray[v >>> 4];
44 hexChars[j * 2 + 1] = hexArray[v & 0x0F];
45 }
46 return new String(hexChars);
47 }
48
49 public static byte[] hexToBytes(String hexString) {
50 int len = hexString.length();
51 byte[] array = new byte[len / 2];
52 for (int i = 0; i < len; i += 2) {
53 array[i / 2] = (byte) ((Character.digit(hexString.charAt(i), 16) << 4) + Character
54 .digit(hexString.charAt(i + 1), 16));
55 }
56 return array;
57 }
58
59 public static String hexToString(final String hexString) {
60 return new String(hexToBytes(hexString));
61 }
62
63 public static byte[] concatenateByteArrays(byte[] a, byte[] b) {
64 byte[] result = new byte[a.length + b.length];
65 System.arraycopy(a, 0, result, 0, a.length);
66 System.arraycopy(b, 0, result, a.length, b.length);
67 return result;
68 }
69
70 /**
71 * Escapes usernames or passwords for SASL.
72 */
73 public static String saslEscape(final String s) {
74 final StringBuilder sb = new StringBuilder((int) (s.length() * 1.1));
75 for (int i = 0; i < s.length(); i++) {
76 char c = s.charAt(i);
77 switch (c) {
78 case ',':
79 sb.append("=2C");
80 break;
81 case '=':
82 sb.append("=3D");
83 break;
84 default:
85 sb.append(c);
86 break;
87 }
88 }
89 return sb.toString();
90 }
91
92 public static String saslPrep(final String s) {
93 return Normalizer.normalize(s, Normalizer.Form.NFKC);
94 }
95
96 public static String prettifyFingerprint(String fingerprint) {
97 if (fingerprint==null) {
98 return "";
99 } else if (fingerprint.length() < 40) {
100 return fingerprint;
101 }
102 StringBuilder builder = new StringBuilder(fingerprint.toLowerCase(Locale.US).replaceAll("\\s", ""));
103 for(int i=8;i<builder.length();i+=9) {
104 builder.insert(i, ' ');
105 }
106 return builder.toString();
107 }
108
109 public static String prettifyFingerprintCert(String fingerprint) {
110 StringBuilder builder = new StringBuilder(fingerprint);
111 for(int i=2;i < builder.length(); i+=3) {
112 builder.insert(i,':');
113 }
114 return builder.toString();
115 }
116
117 public static String[] getOrderedCipherSuites(final String[] platformSupportedCipherSuites) {
118 final Collection<String> cipherSuites = new LinkedHashSet<>(Arrays.asList(Config.ENABLED_CIPHERS));
119 final List<String> platformCiphers = Arrays.asList(platformSupportedCipherSuites);
120 cipherSuites.retainAll(platformCiphers);
121 cipherSuites.addAll(platformCiphers);
122 filterWeakCipherSuites(cipherSuites);
123 return cipherSuites.toArray(new String[cipherSuites.size()]);
124 }
125
126 private static void filterWeakCipherSuites(final Collection<String> cipherSuites) {
127 final Iterator<String> it = cipherSuites.iterator();
128 while (it.hasNext()) {
129 String cipherName = it.next();
130 // remove all ciphers with no or very weak encryption or no authentication
131 for (String weakCipherPattern : Config.WEAK_CIPHER_PATTERNS) {
132 if (cipherName.contains(weakCipherPattern)) {
133 it.remove();
134 break;
135 }
136 }
137 }
138 }
139
140 public static Pair<Jid,String> extractJidAndName(X509Certificate certificate) throws CertificateEncodingException, InvalidJidException, CertificateParsingException {
141 Collection<List<?>> alternativeNames = certificate.getSubjectAlternativeNames();
142 List<String> emails = new ArrayList<>();
143 if (alternativeNames != null) {
144 for(List<?> san : alternativeNames) {
145 Integer type = (Integer) san.get(0);
146 if (type == 1) {
147 emails.add((String) san.get(1));
148 }
149 }
150 }
151 X500Name x500name = new JcaX509CertificateHolder(certificate).getSubject();
152 if (emails.size() == 0) {
153 emails.add(IETFUtils.valueToString(x500name.getRDNs(BCStyle.EmailAddress)[0].getFirst().getValue()));
154 }
155 String name = IETFUtils.valueToString(x500name.getRDNs(BCStyle.CN)[0].getFirst().getValue());
156 if (emails.size() >= 1) {
157 return new Pair<>(Jid.fromString(emails.get(0)), name);
158 } else {
159 return null;
160 }
161 }
162
163 public static Bundle extractCertificateInformation(X509Certificate certificate) {
164 Bundle information = new Bundle();
165 try {
166 JcaX509CertificateHolder holder = new JcaX509CertificateHolder(certificate);
167 X500Name subject = holder.getSubject();
168 try {
169 information.putString("subject_cn", subject.getRDNs(BCStyle.CN)[0].getFirst().getValue().toString());
170 } catch (Exception e) {
171 //ignored
172 }
173 try {
174 information.putString("subject_o",subject.getRDNs(BCStyle.O)[0].getFirst().getValue().toString());
175 } catch (Exception e) {
176 //ignored
177 }
178
179 X500Name issuer = holder.getIssuer();
180 try {
181 information.putString("issuer_cn", issuer.getRDNs(BCStyle.CN)[0].getFirst().getValue().toString());
182 } catch (Exception e) {
183 //ignored
184 }
185 try {
186 information.putString("issuer_o", issuer.getRDNs(BCStyle.O)[0].getFirst().getValue().toString());
187 } catch (Exception e) {
188 //ignored
189 }
190 try {
191 information.putString("sha1", getFingerprintCert(certificate.getEncoded()));
192 } catch (Exception e) {
193
194 }
195 return information;
196 } catch (CertificateEncodingException e) {
197 return information;
198 }
199 }
200
201 public static String getFingerprintCert(byte[] input) throws NoSuchAlgorithmException {
202 MessageDigest md = MessageDigest.getInstance("SHA-1");
203 byte[] fingerprint = md.digest(input);
204 return prettifyFingerprintCert(bytesToHex(fingerprint));
205 }
206
207 public static int encryptionTypeToText(int encryption) {
208 switch (encryption) {
209 case Message.ENCRYPTION_OTR:
210 return R.string.encryption_choice_otr;
211 case Message.ENCRYPTION_AXOLOTL:
212 return R.string.encryption_choice_omemo;
213 case Message.ENCRYPTION_NONE:
214 return R.string.encryption_choice_unencrypted;
215 default:
216 return R.string.encryption_choice_pgp;
217 }
218 }
219}