From 14cfb60952402a25cad6681552daed657cde8237 Mon Sep 17 00:00:00 2001 From: Sam Whited Date: Wed, 12 Nov 2014 10:15:38 -0500 Subject: [PATCH] Refactor authentication code --- .../conversations/crypto/sasl/DigestMd5.java | 72 +++++++++++++++++++ .../conversations/crypto/sasl/Plain.java | 25 +++++++ .../crypto/sasl/SaslMechanism.java | 27 +++++++ .../conversations/utils/CryptoHelper.java | 60 +--------------- .../conversations/xmpp/XmppConnection.java | 49 ++++++------- 5 files changed, 145 insertions(+), 88 deletions(-) create mode 100644 src/main/java/eu/siacs/conversations/crypto/sasl/DigestMd5.java create mode 100644 src/main/java/eu/siacs/conversations/crypto/sasl/Plain.java create mode 100644 src/main/java/eu/siacs/conversations/crypto/sasl/SaslMechanism.java diff --git a/src/main/java/eu/siacs/conversations/crypto/sasl/DigestMd5.java b/src/main/java/eu/siacs/conversations/crypto/sasl/DigestMd5.java new file mode 100644 index 00000000..f81bd0c5 --- /dev/null +++ b/src/main/java/eu/siacs/conversations/crypto/sasl/DigestMd5.java @@ -0,0 +1,72 @@ +package eu.siacs.conversations.crypto.sasl; + +import android.util.Base64; + +import java.math.BigInteger; +import java.nio.charset.Charset; +import java.security.MessageDigest; +import java.security.NoSuchAlgorithmException; +import java.security.SecureRandom; + +import eu.siacs.conversations.entities.Account; +import eu.siacs.conversations.utils.CryptoHelper; +import eu.siacs.conversations.xml.TagWriter; + +public class DigestMd5 extends SaslMechanism { + public DigestMd5(final TagWriter tagWriter, final Account account, final SecureRandom rng) { + super(tagWriter, account, rng); + } + + @Override + public String getMechanism() { + return "DIGEST-MD5"; + } + + @Override + public String getResponse(final String challenge) { + final String encodedResponse; + try { + final String[] challengeParts = new String(Base64.decode(challenge, + Base64.DEFAULT)).split(","); + String nonce = ""; + for (int i = 0; i < challengeParts.length; ++i) { + String[] parts = challengeParts[i].split("="); + if (parts[0].equals("nonce")) { + nonce = parts[1].replace("\"", ""); + } else if (parts[0].equals("rspauth")) { + return ""; + } + } + final String digestUri = "xmpp/" + account.getServer(); + final String nonceCount = "00000001"; + final String x = account.getUsername() + ":" + account.getServer() + ":" + + account.getPassword(); + final MessageDigest md = MessageDigest.getInstance("MD5"); + final byte[] y = md.digest(x.getBytes(Charset.defaultCharset())); + final String cNonce = new BigInteger(100, rng).toString(32); + final byte[] a1 = CryptoHelper.concatenateByteArrays(y, + (":" + nonce + ":" + cNonce).getBytes(Charset + .defaultCharset())); + final String a2 = "AUTHENTICATE:" + digestUri; + final String ha1 = CryptoHelper.bytesToHex(md.digest(a1)); + final String ha2 = CryptoHelper.bytesToHex(md.digest(a2.getBytes(Charset + .defaultCharset()))); + final String kd = ha1 + ":" + nonce + ":" + nonceCount + ":" + cNonce + + ":auth:" + ha2; + final String response = CryptoHelper.bytesToHex(md.digest(kd.getBytes(Charset + .defaultCharset()))); + final String saslString = "username=\"" + account.getUsername() + + "\",realm=\"" + account.getServer() + "\",nonce=\"" + + nonce + "\",cnonce=\"" + cNonce + "\",nc=" + nonceCount + + ",qop=auth,digest-uri=\"" + digestUri + "\",response=" + + response + ",charset=utf-8"; + encodedResponse = Base64.encodeToString( + saslString.getBytes(Charset.defaultCharset()), + Base64.NO_WRAP); + } catch (final NoSuchAlgorithmException e) { + return ""; + } + + return encodedResponse; + } +} diff --git a/src/main/java/eu/siacs/conversations/crypto/sasl/Plain.java b/src/main/java/eu/siacs/conversations/crypto/sasl/Plain.java new file mode 100644 index 00000000..e7760bbc --- /dev/null +++ b/src/main/java/eu/siacs/conversations/crypto/sasl/Plain.java @@ -0,0 +1,25 @@ +package eu.siacs.conversations.crypto.sasl; + +import android.util.Base64; + +import java.nio.charset.Charset; + +import eu.siacs.conversations.entities.Account; +import eu.siacs.conversations.xml.TagWriter; + +public class Plain extends SaslMechanism { + public Plain(final TagWriter tagWriter, final Account account) { + super(tagWriter, account, null); + } + + @Override + public String getMechanism() { + return "PLAIN"; + } + + @Override + public String getStartAuth() { + final String sasl = '\u0000' + account.getUsername() + '\u0000' + account.getPassword(); + return Base64.encodeToString(sasl.getBytes(Charset.defaultCharset()), Base64.NO_WRAP); + } +} diff --git a/src/main/java/eu/siacs/conversations/crypto/sasl/SaslMechanism.java b/src/main/java/eu/siacs/conversations/crypto/sasl/SaslMechanism.java new file mode 100644 index 00000000..5eddd5c2 --- /dev/null +++ b/src/main/java/eu/siacs/conversations/crypto/sasl/SaslMechanism.java @@ -0,0 +1,27 @@ +package eu.siacs.conversations.crypto.sasl; + +import java.security.SecureRandom; + +import eu.siacs.conversations.entities.Account; +import eu.siacs.conversations.xml.TagWriter; + +public abstract class SaslMechanism { + + final protected TagWriter tagWriter; + final protected Account account; + final protected SecureRandom rng; + + public SaslMechanism(final TagWriter tagWriter, final Account account, final SecureRandom rng) { + this.tagWriter = tagWriter; + this.account = account; + this.rng = rng; + } + + public abstract String getMechanism(); + public String getStartAuth() { + return ""; + } + public String getResponse(final String challenge) { + return ""; + } +} diff --git a/src/main/java/eu/siacs/conversations/utils/CryptoHelper.java b/src/main/java/eu/siacs/conversations/utils/CryptoHelper.java index 47595c6e..11042d07 100644 --- a/src/main/java/eu/siacs/conversations/utils/CryptoHelper.java +++ b/src/main/java/eu/siacs/conversations/utils/CryptoHelper.java @@ -1,14 +1,7 @@ package eu.siacs.conversations.utils; -import java.math.BigInteger; -import java.nio.charset.Charset; -import java.security.MessageDigest; -import java.security.NoSuchAlgorithmException; import java.security.SecureRandom; -import eu.siacs.conversations.entities.Account; -import android.util.Base64; - public class CryptoHelper { public static final String FILETRANSFER = "?FILETRANSFERv1:"; final protected static char[] hexArray = "0123456789abcdef".toCharArray(); @@ -36,64 +29,13 @@ public class CryptoHelper { return array; } - public static String saslPlain(String username, String password) { - String sasl = '\u0000' + username + '\u0000' + password; - return Base64.encodeToString(sasl.getBytes(Charset.defaultCharset()), - Base64.NO_WRAP); - } - - private static byte[] concatenateByteArrays(byte[] a, byte[] b) { + public static byte[] concatenateByteArrays(byte[] a, byte[] b) { byte[] result = new byte[a.length + b.length]; System.arraycopy(a, 0, result, 0, a.length); System.arraycopy(b, 0, result, a.length, b.length); return result; } - public static String saslDigestMd5(Account account, String challenge, - SecureRandom random) { - try { - String[] challengeParts = new String(Base64.decode(challenge, - Base64.DEFAULT)).split(","); - String nonce = ""; - for (int i = 0; i < challengeParts.length; ++i) { - String[] parts = challengeParts[i].split("="); - if (parts[0].equals("nonce")) { - nonce = parts[1].replace("\"", ""); - } else if (parts[0].equals("rspauth")) { - return null; - } - } - String digestUri = "xmpp/" + account.getServer(); - String nonceCount = "00000001"; - String x = account.getUsername() + ":" + account.getServer() + ":" - + account.getPassword(); - MessageDigest md = MessageDigest.getInstance("MD5"); - byte[] y = md.digest(x.getBytes(Charset.defaultCharset())); - String cNonce = new BigInteger(100, random).toString(32); - byte[] a1 = concatenateByteArrays(y, - (":" + nonce + ":" + cNonce).getBytes(Charset - .defaultCharset())); - String a2 = "AUTHENTICATE:" + digestUri; - String ha1 = bytesToHex(md.digest(a1)); - String ha2 = bytesToHex(md.digest(a2.getBytes(Charset - .defaultCharset()))); - String kd = ha1 + ":" + nonce + ":" + nonceCount + ":" + cNonce - + ":auth:" + ha2; - String response = bytesToHex(md.digest(kd.getBytes(Charset - .defaultCharset()))); - String saslString = "username=\"" + account.getUsername() - + "\",realm=\"" + account.getServer() + "\",nonce=\"" - + nonce + "\",cnonce=\"" + cNonce + "\",nc=" + nonceCount - + ",qop=auth,digest-uri=\"" + digestUri + "\",response=" - + response + ",charset=utf-8"; - return Base64.encodeToString( - saslString.getBytes(Charset.defaultCharset()), - Base64.NO_WRAP); - } catch (NoSuchAlgorithmException e) { - return null; - } - } - public static String randomMucName(SecureRandom random) { return randomWord(3, random) + "." + randomWord(7, random); } diff --git a/src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java b/src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java index 4bd3668a..26854aa3 100644 --- a/src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java +++ b/src/main/java/eu/siacs/conversations/xmpp/XmppConnection.java @@ -39,9 +39,11 @@ import javax.net.ssl.SSLSocketFactory; import javax.net.ssl.X509TrustManager; import eu.siacs.conversations.Config; +import eu.siacs.conversations.crypto.sasl.DigestMd5; +import eu.siacs.conversations.crypto.sasl.Plain; +import eu.siacs.conversations.crypto.sasl.SaslMechanism; import eu.siacs.conversations.entities.Account; import eu.siacs.conversations.services.XmppConnectionService; -import eu.siacs.conversations.utils.CryptoHelper; import eu.siacs.conversations.utils.DNSHelper; import eu.siacs.conversations.utils.zlib.ZLibInputStream; import eu.siacs.conversations.utils.zlib.ZLibOutputStream; @@ -104,6 +106,8 @@ public class XmppConnection implements Runnable { private OnMessageAcknowledged acknowledgedListener = null; private XmppConnectionService mXmppConnectionService = null; + private SaslMechanism saslMechanism; + public XmppConnection(Account account, XmppConnectionService service) { this.account = account; this.wakeLock = service.getPowerManager().newWakeLock( @@ -287,12 +291,11 @@ public class XmppConnection implements Runnable { tagReader.readElement(nextTag); changeStatus(Account.STATUS_UNAUTHORIZED); } else if (nextTag.isStart("challenge")) { - String challange = tagReader.readElement(nextTag).getContent(); - Element response = new Element("response"); + final String challenge = tagReader.readElement(nextTag).getContent(); + final Element response = new Element("response"); response.setAttribute("xmlns", "urn:ietf:params:xml:ns:xmpp-sasl"); - response.setContent(CryptoHelper.saslDigestMd5(account, - challange, mXmppConnectionService.getRNG())); + response.setContent(saslMechanism.getResponse(challenge)); tagWriter.writeElement(response); } else if (nextTag.isStart("enabled")) { Element enabled = tagReader.readElement(nextTag); @@ -592,23 +595,6 @@ public class XmppConnection implements Runnable { } } - private void sendSaslAuthPlain() throws IOException { - String saslString = CryptoHelper.saslPlain(account.getUsername(), - account.getPassword()); - Element auth = new Element("auth"); - auth.setAttribute("xmlns", "urn:ietf:params:xml:ns:xmpp-sasl"); - auth.setAttribute("mechanism", "PLAIN"); - auth.setContent(saslString); - tagWriter.writeElement(auth); - } - - private void sendSaslAuthDigestMd5() throws IOException { - Element auth = new Element("auth"); - auth.setAttribute("xmlns", "urn:ietf:params:xml:ns:xmpp-sasl"); - auth.setAttribute("mechanism", "DIGEST-MD5"); - tagWriter.writeElement(auth); - } - private void processStreamFeatures(Tag currentTag) throws XmlPullParserException, IOException { this.streamFeatures = tagReader.readElement(currentTag); @@ -626,14 +612,19 @@ public class XmppConnection implements Runnable { disconnect(true); } else if (this.streamFeatures.hasChild("mechanisms") && shouldAuthenticate && usingEncryption) { - List mechanisms = extractMechanisms(streamFeatures + final List mechanisms = extractMechanisms(streamFeatures .findChild("mechanisms")); - if (mechanisms.contains("PLAIN")) { - sendSaslAuthPlain(); - } else if (mechanisms.contains("DIGEST-MD5")) { - sendSaslAuthDigestMd5(); - } - } else if (this.streamFeatures.hasChild("sm", "urn:xmpp:sm:" + final Element auth = new Element("auth"); + auth.setAttribute("xmlns", "urn:ietf:params:xml:ns:xmpp-sasl"); + if (mechanisms.contains("DIGEST-MD5")) { + saslMechanism = new DigestMd5(tagWriter, account, mXmppConnectionService.getRNG()); + } else if (mechanisms.contains("PLAIN")) { + saslMechanism = new Plain(tagWriter, account); + auth.setContent(((Plain)saslMechanism).getStartAuth()); + } + auth.setAttribute("mechanism", saslMechanism.getMechanism()); + tagWriter.writeElement(auth); + } else if (this.streamFeatures.hasChild("sm", "urn:xmpp:sm:" + smVersion) && streamId != null) { ResumePacket resume = new ResumePacket(this.streamId,