Add support for Sasl2 + Bind2

1 files changed, 96 insertions, 83 deletions

diff --git a/xmpp-vala/src/module/sasl.vala b/xmpp-vala/src/module/sasl.vala
index 3f3eca58..035cc723 100644
--- a/xmpp-vala/src/module/sasl.vala
+++ b/xmpp-vala/src/module/sasl.vala
@@ -44,52 +44,6 @@ namespace Xmpp.Sasl {
             stream.received_nonza.disconnect(this.received_nonza);
         }
 
-        private static size_t SHA1_SIZE = 20;
-
-        private static uint8[] sha1(uint8[] data) {
-            Checksum checksum = new Checksum(ChecksumType.SHA1);
-            checksum.update(data, data.length);
-            uint8[] res = new uint8[SHA1_SIZE];
-            checksum.get_digest(res, ref SHA1_SIZE);
-            return res;
-        }
-
-        private static uint8[] hmac_sha1(uint8[] key, uint8[] data) {
-            Hmac hmac = new Hmac(ChecksumType.SHA1, key);
-            hmac.update(data);
-            uint8[] res = new uint8[SHA1_SIZE];
-            hmac.get_digest(res, ref SHA1_SIZE);
-            return res;
-        }
-
-        private static uint8[] pbkdf2_sha1(string password, uint8[] salt, uint iterations) {
-            uint8[] res = new uint8[SHA1_SIZE];
-            uint8[] last = new uint8[salt.length + 4];
-            for(int i = 0; i < salt.length; i++) {
-                last[i] = salt[i];
-            }
-            last[salt.length + 3] = 1;
-            for(int i = 0; i < iterations; i++) {
-                last = hmac_sha1((uint8[]) password.to_utf8(), last);
-                xor_inplace(res, last);
-            }
-            return res;
-        }
-
-        private static void xor_inplace(uint8[] mix, uint8[] a2) {
-            for(int i = 0; i < mix.length; i++) {
-                mix[i] = mix[i] ^ a2[i];
-            }
-        }
-
-        private static uint8[] xor(uint8[] a1, uint8[] a2) {
-            uint8[] mix = new uint8[a1.length];
-            for(int i = 0; i < a1.length; i++) {
-                mix[i] = a1[i] ^ a2[i];
-            }
-            return mix;
-        }
-
         public void received_nonza(XmppStream stream, StanzaNode node) {
             if (node.ns_uri == NS_URI) {
                 if (node.name == "success") {
@@ -119,33 +73,10 @@ namespace Xmpp.Sasl {
                 } else if (node.name == "challenge" && stream.has_flag(Flag.IDENTITY)) {
                     Flag flag = stream.get_flag(Flag.IDENTITY);
                     if (flag.mechanism == Mechanism.SCRAM_SHA_1) {
-                        string challenge = (string) Base64.decode(node.get_string_content());
-                        string? server_nonce = null;
-                        uint8[] salt = null;
-                        uint iterations = 0;
-                        foreach(string c in challenge.split(",")) {
-                            string[] split = c.split("=", 2);
-                            if (split.length != 2) continue;
-                            switch(split[0]) {
-                                case "r": server_nonce = split[1]; break;
-                                case "s": salt = Base64.decode(split[1]); break;
-                                case "i": iterations = int.parse(split[1]); break;
-                            }
-                        }
-                        if (server_nonce == null || salt == null || iterations == 0) return;
-                        if (!server_nonce.has_prefix(flag.client_nonce)) return;
-                        string client_final_message_bare = @"c=biws,r=$server_nonce";
-                        uint8[] salted_password = pbkdf2_sha1(flag.password, salt, iterations);
-                        uint8[] client_key = hmac_sha1(salted_password, (uint8[]) "Client Key".to_utf8());
-                        uint8[] stored_key = sha1(client_key);
-                        string auth_message = @"n=$(flag.name),r=$(flag.client_nonce),$challenge,$client_final_message_bare";
-                        uint8[] client_signature = hmac_sha1(stored_key, (uint8[]) auth_message.to_utf8());
-                        uint8[] client_proof = xor(client_key, client_signature);
-                        uint8[] server_key = hmac_sha1(salted_password, (uint8[]) "Server Key".to_utf8());
-                        flag.server_signature = hmac_sha1(server_key, (uint8[]) auth_message.to_utf8());
-                        string client_final_message = @"$client_final_message_bare,p=$(Base64.encode(client_proof))";
+                        var challenge_response = compute_challenge_response(node.get_string_content(), flag.password, flag.client_nonce, flag.name);
+                        flag.server_signature = challenge_response.expected_server_signature;
                         stream.write(new StanzaNode.build("response", NS_URI).add_self_xmlns()
-                                .put_node(new StanzaNode.text(Base64.encode((uchar[]) (client_final_message).to_utf8()))));
+                                .put_node(new StanzaNode.text(Base64.encode((uchar[]) (challenge_response.response).to_utf8()))));
                     }
                 }
             }
@@ -206,17 +137,6 @@ namespace Xmpp.Sasl {
             }
         }
 
-        private static uchar[] get_plain_bytes(string name_s, string password_s) {
-            var name = name_s.to_utf8();
-            var password = password_s.to_utf8();
-            uchar[] res = new uchar[name.length + password.length + 2];
-            res[0] = 0;
-            res[name.length + 1] = 0;
-            for(int i = 0; i < name.length; i++) { res[i + 1] = (uchar) name[i]; }
-            for(int i = 0; i < password.length; i++) { res[i + name.length + 2] = (uchar) password[i]; }
-            return res;
-        }
-
         public override bool mandatory_outstanding(XmppStream stream) {
             return !stream.has_flag(Flag.IDENTITY) || !stream.get_flag(Flag.IDENTITY).finished;
         }
@@ -228,4 +148,97 @@ namespace Xmpp.Sasl {
         public override string get_ns() { return NS_URI; }
         public override string get_id() { return IDENTITY.id; }
     }
+
+    public static uchar[] get_plain_bytes(string name_s, string password_s) {
+        var name = name_s.to_utf8();
+        var password = password_s.to_utf8();
+        uchar[] res = new uchar[name.length + password.length + 2];
+        res[0] = 0;
+        res[name.length + 1] = 0;
+        for(int i = 0; i < name.length; i++) { res[i + 1] = (uchar) name[i]; }
+        for(int i = 0; i < password.length; i++) { res[i + name.length + 2] = (uchar) password[i]; }
+        return res;
+    }
+
+    public class ChallengeResponse {
+        public uint8[] expected_server_signature { get; set; }
+        public string response { get; set; }
+    }
+
+    public static ChallengeResponse compute_challenge_response(string challenge, string password, string client_nonce, string name) {
+        string challenge_base64 = (string) Base64.decode(challenge);
+        string? server_nonce = null;
+        uint8[] salt = null;
+        uint iterations = 0;
+        foreach(string c in challenge_base64.split(",")) {
+            string[] split = c.split("=", 2);
+            if (split.length != 2) continue;
+            switch(split[0]) {
+                case "r": server_nonce = split[1]; break;
+                case "s": salt = Base64.decode(split[1]); break;
+                case "i": iterations = int.parse(split[1]); break;
+            }
+        }
+        if (server_nonce == null || salt == null || iterations == 0) throw new Error(-1, 0, "SASL error");
+        if (!server_nonce.has_prefix(client_nonce)) throw new Error(-1, 0, "SASL error");
+        string client_final_message_bare = @"c=biws,r=$server_nonce";
+        uint8[] salted_password = pbkdf2_sha1(password, salt, iterations);
+        uint8[] client_key = hmac_sha1(salted_password, (uint8[]) "Client Key".to_utf8());
+        uint8[] stored_key = sha1(client_key);
+        string auth_message = @"n=$(name),r=$(client_nonce),$challenge_base64,$client_final_message_bare";
+        uint8[] client_signature = hmac_sha1(stored_key, (uint8[]) auth_message.to_utf8());
+        uint8[] client_proof = xor(client_key, client_signature);
+        uint8[] server_key = hmac_sha1(salted_password, (uint8[]) "Server Key".to_utf8());
+
+        return new ChallengeResponse() {
+            expected_server_signature = hmac_sha1(server_key, (uint8[]) auth_message.to_utf8()),
+            response = @"$client_final_message_bare,p=$(Base64.encode(client_proof))"
+        };
+    }
+
+    private static size_t SHA1_SIZE = 20;
+
+    private static uint8[] sha1(uint8[] data) {
+        Checksum checksum = new Checksum(ChecksumType.SHA1);
+        checksum.update(data, data.length);
+        uint8[] res = new uint8[SHA1_SIZE];
+        checksum.get_digest(res, ref SHA1_SIZE);
+        return res;
+    }
+
+    private static uint8[] hmac_sha1(uint8[] key, uint8[] data) {
+        Hmac hmac = new Hmac(ChecksumType.SHA1, key);
+        hmac.update(data);
+        uint8[] res = new uint8[SHA1_SIZE];
+        hmac.get_digest(res, ref SHA1_SIZE);
+        return res;
+    }
+
+    private static uint8[] pbkdf2_sha1(string password, uint8[] salt, uint iterations) {
+        uint8[] res = new uint8[SHA1_SIZE];
+        uint8[] last = new uint8[salt.length + 4];
+        for(int i = 0; i < salt.length; i++) {
+            last[i] = salt[i];
+        }
+        last[salt.length + 3] = 1;
+        for(int i = 0; i < iterations; i++) {
+            last = hmac_sha1((uint8[]) password.to_utf8(), last);
+            xor_inplace(res, last);
+        }
+        return res;
+    }
+
+    private static void xor_inplace(uint8[] mix, uint8[] a2) {
+        for(int i = 0; i < mix.length; i++) {
+            mix[i] = mix[i] ^ a2[i];
+        }
+    }
+
+    private static uint8[] xor(uint8[] a1, uint8[] a2) {
+        uint8[] mix = new uint8[a1.length];
+        for(int i = 0; i < a1.length; i++) {
+            mix[i] = a1[i] ^ a2[i];
+        }
+        return mix;
+    }
 }