fix SDES encryption

aTalk/build.gradle

@@ -195,7 +195,6 @@ dependencies {
     implementation "com.google.android.material:material:${rootProject.supportLibraryVersion}"
 
     // libraries from maven repository
-    implementation 'ch.imvs:sdes4j:1.1.4'
     // for android better picker
     implementation 'com.code-troopers.betterpickers:library:3.1.0'
     implementation 'com.jakewharton:butterknife:10.1.0'

aTalk/src/main/java/ch/imvs/sdes4j/CryptoAttribute.java

@@ -0,0 +1,296 @@
+/*
+ * SDES4J
+ * Java implementation of SDES (Security Descriptions for Media Streams,
+ * RFC 4568).
+ * 
+ * Copyright (C) 2011 FHNW
+ *   University of Applied Sciences Northwestern Switzerland (FHNW)
+ *   School of Engineering
+ *   Institute of Mobile and Distributed Systems (IMVS)
+ *   http://sdes4j.imvs.ch
+ * 
+ * Distributable under LGPL license, see terms of license at gnu.org.
+ */
+package ch.imvs.sdes4j;
+
+import java.util.*;
+
+/**
+ * Primary class for a RFC4568 Crypto Attribute.
+ * 
+ * @author Ingo Bauersachs
+ */
+public class CryptoAttribute {
+    protected int tag;
+    protected CryptoSuite cryptoSuite;
+    protected KeyParam[] keyParams;
+    protected SessionParam[] sessionParams = null;
+
+    protected CryptoAttribute(){
+    }
+
+    /**
+     * Creates an instance of a CryptoAttribute from an SDes string in the
+     * format of
+     * <tt>tag 1*WSP crypto-suite 1*WSP key-params *(1*WSP session-param)</tt>
+     * 
+     * @param attribute the encoded SDes attribute
+     * @param f factory that creates the instances for each part of the
+     *            attribute
+     * @return a parsed crypto attribute
+     */
+    public static CryptoAttribute create(String attribute, SDesFactory f) {
+        CryptoAttribute result = f.createCryptoAttribute();
+        List<String> tokens = new LinkedList<String>();
+        for (String s : attribute.split("\\s")){
+            if(s.trim().length() > 0)
+                tokens.add(s);
+        }
+
+        result.setTag(tokens.remove(0));
+        result.setCryptoSuite(tokens.remove(0), f);
+
+        if (tokens.size() < 1)
+            throw new IllegalArgumentException("There must be at least one key parameter");
+        result.setKeyParams(tokens.remove(0), f);
+
+        result.setSessionParams(tokens, f);
+        return result;
+    }
+
+    /**
+     * Creates an instance of a CryptoAttribute from a SDes attributes (tag,
+     * crypto suite, key params and session params).
+     *
+     * @param tag unparsed tag as a string. 
+     * @param cryptoSuite the crypto suite as an unparsed string.
+     * @param keyParams An unparsed string representation of the key param list
+     * (each key must be separated by a ";").
+     * @param sessionParams An unparsed string representation of the session
+     * param list (each key must be separated by a " ").
+     * @param f factory that creates the instances for each part of the
+     *            attribute
+     *
+     * @return a parsed crypto attribute
+     */
+    public static CryptoAttribute create(String tag, String cryptoSuite, String keyParams, String sessionParams, SDesFactory f) {
+        CryptoAttribute result = f.createCryptoAttribute();
+
+        result.setTag(tag);
+        result.setCryptoSuite(cryptoSuite, f);
+        result.setKeyParams(keyParams, f);
+
+        List<String> tokens = new LinkedList<String>();
+        if(sessionParams != null) {
+            for (String s : sessionParams.split("\\s")) {
+                if(s.trim().length() > 0)
+                    tokens.add(s);
+            }
+        }
+
+        result.setSessionParams(tokens, f);
+
+        return result;
+    }
+
+    /**
+     * Creates a crypto attribute from already instantiated objects.
+     * 
+     * @param tag identifier for this particular crypto attribute
+     * @param cryptoSuite identifier that describes the encryption and
+     *            authentication algorithms
+     * @param keyParams one or more sets of keying material
+     * @param sessionParams the additional key parameters
+     */
+    public CryptoAttribute(int tag, CryptoSuite cryptoSuite, KeyParam[] keyParams, SessionParam[] sessionParams) {
+        if (tag > 99999999 || tag < 0)
+            throw new IllegalArgumentException("tag can have at most 10 digits and must be non-negative");
+
+        if (cryptoSuite == null)
+            throw new IllegalArgumentException("cryptoSuite cannot be null");
+
+        if (keyParams == null || keyParams.length == 0)
+            throw new IllegalArgumentException("keyParams cannot be null or empty");
+
+        this.tag = tag;
+        this.cryptoSuite = cryptoSuite;
+        this.keyParams = keyParams;
+
+        if (sessionParams == null)
+            this.sessionParams = new SessionParam[0];
+        else
+            this.sessionParams = sessionParams;
+    }
+
+    /**
+     * Gets the identifier for this particular crypto attribute.
+     * 
+     * @return the tag
+     */
+    public int getTag() {
+        return tag;
+    }
+
+    /**
+     * Sets the tag which is used as an identifier for this particular crypto
+     * attribute. The tag MUST be unique among all crypto attributes for a given
+     * media line.
+     * 
+     * @param stringTag unparsed tag as a string. 
+     */
+    private void setTag(String stringTag) {
+        int tag = Integer.valueOf(stringTag);
+        if (tag > 99999999 || tag < 0)
+            throw new IllegalArgumentException("tag can have at most 10 digits and must be non-negative");
+        this.tag = tag;
+    }
+
+    /**
+     * Gets the identifier that describes the encryption and authentication
+     * algorithms (e.g., AES_CM_128_HMAC_SHA1_80) for the transport in question.
+     * 
+     * @return the cryptoSuite
+     */
+    public CryptoSuite getCryptoSuite() {
+        return cryptoSuite;
+    }
+
+    /**
+     * Sets the identifier that describes the encryption and authentication
+     * algorithms (e.g., AES_CM_128_HMAC_SHA1_80) for the transport in question.
+     * 
+     * @param stringCryptoSuite the crypto suite as an unparsed string.
+     * @param f factory that creates the crypto suite instance
+     */
+    private void setCryptoSuite(String stringCryptoSuite, SDesFactory f) {
+        this.cryptoSuite = f.createCryptoSuite(stringCryptoSuite);
+    }
+
+    /**
+     * Gets one or more sets of keying material for the crypto-suite in
+     * question.
+     * 
+     * @return the keyParams
+     */
+    public KeyParam[] getKeyParams() {
+        return keyParams;
+    }
+
+    /**
+     * Sets one or more sets of keying material for the crypto-suite in
+     * question.
+     * 
+     * @param stringKeyParams An unparsed string representation of the key param
+     * list (each key must be separated by a ";").
+     * @param f factory that creates the key params instances
+     */
+    private void setKeyParams(String stringKeyParams, SDesFactory f) {
+        String[] params = stringKeyParams.split(";");
+        List<KeyParam> keyParams = new LinkedList<KeyParam>();
+        for (String p : params) {
+            keyParams.add(f.createKeyParam(p));
+        }
+        this.keyParams = keyParams.toArray(f.createKeyParamArray(0));
+    }
+
+    /**
+     * Gets the additional key parameters for this particular crypto attribute.
+     * 
+     * @return the sessionParams
+     */
+    public SessionParam[] getSessionParams() {
+        return sessionParams;
+    }
+
+    /**
+     * Sets additional key parameters for this particular crypto attribute.
+     * 
+     * @param tokens List of String-Tokens where the matching items are consumed
+     *            and removed from the list
+     * @param f factory that creates the session params instances
+     */
+    private void setSessionParams(List<String> tokens, SDesFactory f) {
+        List<SessionParam> sessionParams = new LinkedList<SessionParam>();
+        while (tokens.size() > 0) {
+            sessionParams.add(f.createSessionParam(tokens.remove(0)));
+        }
+        this.sessionParams = sessionParams.toArray(f.createSessionParamArray(0));
+    }
+
+    /**
+     * Encodes this crypto attribute as a string according to the ABNF rule
+     * <tt>tag 1*WSP crypto-suite 1*WSP key-params *(1*WSP session-param)</tt>
+     * 
+     * @return Complete crypto attribute for use in the SDP.
+     */
+    public String encode() {
+        StringBuilder sb = new StringBuilder();
+        sb.append(tag);
+        sb.append(' ');
+        sb.append(cryptoSuite.encode());
+        sb.append(' ');
+        sb.append(getKeyParamsString());
+        if (sessionParams != null && sessionParams.length > 0) {
+            sb.append(' ');
+            sb.append(getSessionParamsString());
+        }
+
+        return sb.toString();
+    }
+
+    /**
+     * Returns a string representation the key parameters according to the ABNF
+     * rule key-params.
+     * 
+     * @return String representation of the list of key params separated by ";".
+     */
+    public String getKeyParamsString() {
+        StringBuilder sb = new StringBuilder();
+
+        for (int i = 0; i < keyParams.length; i++) {
+            sb.append(keyParams[i].encode());
+            if (i < keyParams.length - 1)
+                sb.append(';');
+        }
+
+        return sb.toString();
+    }
+
+    /**
+     * Returns a string representation of the session parameters according to
+     * the ABNF rule session-param.
+     *
+     * @return Returns a string representation of the list of session params
+     * separated by " ", or null if there are no session params.
+     */
+    public String getSessionParamsString() {
+        if (sessionParams != null && sessionParams.length > 0) {
+            StringBuilder sb = new StringBuilder();
+            for (int i = 0; i < sessionParams.length; i++) {
+                sb.append(sessionParams[i].encode());
+                if (i < sessionParams.length - 1)
+                    sb.append(' ');
+            }
+            return sb.toString();
+        }
+        else{
+            return null;
+        }
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj != null && obj instanceof CryptoAttribute)
+        {
+            CryptoAttribute other = (CryptoAttribute)obj;
+            return encode().equals(other.encode());
+        }
+
+        return false;
+    }
+
+    @Override
+    public int hashCode() {
+        return encode().hashCode();
+    }
+}

aTalk/src/main/java/ch/imvs/sdes4j/CryptoSuite.java

@@ -0,0 +1,31 @@
+/*
+ * SDES4J
+ * Java implementation of SDES (Security Descriptions for Media Streams,
+ * RFC 4568).
+ * 
+ * Copyright (C) 2011 FHNW
+ *   University of Applied Sciences Northwestern Switzerland (FHNW)
+ *   School of Engineering
+ *   Institute of Mobile and Distributed Systems (IMVS)
+ *   http://sdes4j.imvs.ch
+ * 
+ * Distributable under LGPL license, see terms of license at gnu.org.
+ */
+package ch.imvs.sdes4j;
+
+/**
+ * Interface for grammar implementations of an identifier that describes the
+ * encryption and authentication algorithms (e.g., AES_CM_128_HMAC_SHA1_80) for
+ * the transport in question
+ * 
+ * @author Ingo Bauersachs
+ */
+public interface CryptoSuite {
+    /**
+     * Encodes the information contained in this object for use in the complete
+     * crypto attribute.
+     * 
+     * @return The name of the crypto suite.
+     */
+    String encode();
+}

aTalk/src/main/java/ch/imvs/sdes4j/KeyParam.java

@@ -0,0 +1,39 @@
+/*
+ * SDES4J
+ * Java implementation of SDES (Security Descriptions for Media Streams,
+ * RFC 4568).
+ * 
+ * Copyright (C) 2011 FHNW
+ *   University of Applied Sciences Northwestern Switzerland (FHNW)
+ *   School of Engineering
+ *   Institute of Mobile and Distributed Systems (IMVS)
+ *   http://sdes4j.imvs.ch
+ * 
+ * Distributable under LGPL license, see terms of license at gnu.org.
+ */
+package ch.imvs.sdes4j;
+
+/**
+ * The key-param provides keying material for the crypto-suite in question. It
+ * consists of a method and the actual keying information
+ * 
+ * @author Ingo Bauersachs
+ */
+public interface KeyParam {
+    /**
+     * Gets the method name that defines the type of the key information. Only
+     * one method is defined, namely, "inline", which indicates that the actual
+     * keying material is provided in the key-info field itself.
+     * 
+     * @return <code>inline</code>
+     */
+    String getKeyMethod();
+
+    /**
+     * Encodes the information contained in this object for use in the complete
+     * crypto attribute.
+     * 
+     * @return Textual representation of the key parameter.
+     */
+    String encode();
+}