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