Javascript bindings for group sessions

Makefile

@@ -15,7 +15,7 @@ JS_TARGET := javascript/olm.js
 
 JS_EXPORTED_FUNCTIONS := javascript/exported_functions.json
 
-PUBLIC_HEADERS := include/olm/olm.h
+PUBLIC_HEADERS := include/olm/olm.h include/olm/outbound_group_session.h include/olm/inbound_group_session.h
 
 SOURCES := $(wildcard src/*.cpp) $(wildcard src/*.c) \
     lib/crypto-algorithms/sha256.c \
@@ -34,7 +34,9 @@ FUZZER_DEBUG_BINARIES := $(patsubst $(BUILD_DIR)/fuzzers/fuzz_%,$(BUILD_DIR)/fuz
 TEST_BINARIES := $(patsubst tests/%,$(BUILD_DIR)/tests/%,$(basename $(TEST_SOURCES)))
 JS_OBJECTS := $(addprefix $(BUILD_DIR)/javascript/,$(OBJECTS))
 JS_PRE := $(wildcard javascript/*pre.js)
-JS_POST := $(wildcard javascript/*post.js)
+JS_POST := javascript/olm_outbound_group_session.js \
+    javascript/olm_inbound_group_session.js \
+    javascript/olm_post.js
 
 CPPFLAGS += -Iinclude -Ilib
 # we rely on <stdint.h>, which was introduced in C99
@@ -106,7 +108,8 @@ js: $(JS_TARGET)
 
 $(JS_TARGET): $(JS_OBJECTS) $(JS_PRE) $(JS_POST) $(JS_EXPORTED_FUNCTIONS)
 	$(EMCC_LINK) \
-               --pre-js $(JS_PRE) --post-js $(JS_POST) \
+               $(foreach f,$(JS_PRE),--pre-js $(f)) \
+               $(foreach f,$(JS_POST),--post-js $(f)) \
                -s "EXPORTED_FUNCTIONS=@$(JS_EXPORTED_FUNCTIONS)" \
                $(JS_OBJECTS) -o $@
 
@@ -122,7 +125,7 @@ fuzzers: $(FUZZER_BINARIES) $(FUZZER_DEBUG_BINARIES)
 .PHONY: fuzzers
 
 $(JS_EXPORTED_FUNCTIONS): $(PUBLIC_HEADERS)
-	perl -MJSON -ne '/(olm_[^( ]*)\(/ && push @f, "_$$1"; END { print encode_json \@f }' $^ > $@.tmp
+	perl -MJSON -ne '$$f{"_$$1"}=1 if /(olm_[^( ]*)\(/; END { @f=sort keys %f; print encode_json \@f }' $^ > $@.tmp
 	mv $@.tmp $@
 
 all: test js lib debug

javascript/README.md

@@ -23,3 +23,20 @@ Example:
     bob_session.create_inbound(bob, bob_message);
     var plaintext = bob_session.decrypt(message_1.type, bob_message);
     bob.remove_one_time_keys(bob_session);
+
+
+Group chat:
+
+    var outbound_session = new Olm.OutboundGroupSession();
+    outbound_session.create();
+
+    // exchange these over a secure channel
+    var session_id = group_session.session_id();
+    var session_key = group_session.session_key();
+    var message_index = group_session.message_index();
+
+    var inbound_session = new Olm.InboundGroupSession();
+    inbound_session.create(message_index, session_key);
+
+    var ciphertext = outbound_session.encrypt("Hello");
+    var plaintext = inbound_session.decrypt(ciphertext);

javascript/olm_inbound_group_session.js

@@ -0,0 +1,78 @@
+function InboundGroupSession() {
+    var size = Module['_olm_inbound_group_session_size']();
+    this.buf = malloc(size);
+    this.ptr = Module['_olm_inbound_group_session'](this.buf);
+}
+
+function inbound_group_session_method(wrapped) {
+    return function() {
+        var result = wrapped.apply(this, arguments);
+        if (result === OLM_ERROR) {
+            var message = Pointer_stringify(
+                Module['_olm_inbound_group_session_last_error'](arguments[0])
+            );
+            throw new Error("OLM." + message);
+        }
+        return result;
+    }
+}
+
+InboundGroupSession.prototype['free'] = function() {
+    Module['_olm_clear_inbound_group_session'](this.ptr);
+    free(this.ptr);
+}
+
+InboundGroupSession.prototype['pickle'] = restore_stack(function(key) {
+    var key_array = array_from_string(key);
+    var pickle_length = inbound_group_session_method(
+        Module['_olm_pickle_inbound_group_session_length']
+    )(this.ptr);
+    var key_buffer = stack(key_array);
+    var pickle_buffer = stack(pickle_length);
+    inbound_group_session_method(Module['_olm_pickle_inbound_group_session'])(
+        this.ptr, key_buffer, key_array.length, pickle_buffer, pickle_length
+    );
+    return Pointer_stringify(pickle_buffer, pickle_length);
+});
+
+InboundGroupSession.prototype['unpickle'] = restore_stack(function(key, pickle) {
+    var key_array = array_from_string(key);
+    var key_buffer = stack(key_array);
+    var pickle_array = array_from_string(pickle);
+    var pickle_buffer = stack(pickle_array);
+    inbound_group_session_method(Module['_olm_unpickle_inbound_group_session'])(
+        this.ptr, key_buffer, key_array.length, pickle_buffer,
+        pickle_array.length
+    );
+});
+
+InboundGroupSession.prototype['create'] = restore_stack(function(message_index, session_key) {
+    var key_array = array_from_string(session_key);
+    var key_buffer = stack(key_array);
+
+    inbound_group_session_method(Module['_olm_init_inbound_group_session'])(
+        this.ptr, message_index, key_buffer, key_array.length
+    );
+});
+
+InboundGroupSession.prototype['decrypt'] = restore_stack(function(
+    message
+) {
+    var message_array = array_from_string(message);
+    var message_buffer = stack(message_array);
+    var max_plaintext_length = session_method(
+        Module['_olm_group_decrypt_max_plaintext_length']
+    )(this.ptr, message_buffer, message_array.length);
+    // caculating the length destroys the input buffer.
+    // So we copy the array to a new buffer
+    var message_buffer = stack(message_array);
+    var plaintext_buffer = stack(max_plaintext_length);
+    var plaintext_length = session_method(Module["_olm_group_decrypt"])(
+        this.ptr,
+        message_buffer, message.length,
+        plaintext_buffer, max_plaintext_length
+    );
+    return Pointer_stringify(plaintext_buffer, plaintext_length);
+});
+
+olm_exports['InboundGroupSession'] = InboundGroupSession;

javascript/olm_outbound_group_session.js

@@ -0,0 +1,104 @@
+
+function OutboundGroupSession() {
+    var size = Module['_olm_outbound_group_session_size']();
+    this.buf = malloc(size);
+    this.ptr = Module['_olm_outbound_group_session'](this.buf);
+}
+
+function outbound_group_session_method(wrapped) {
+    return function() {
+        var result = wrapped.apply(this, arguments);
+        if (result === OLM_ERROR) {
+            var message = Pointer_stringify(
+                Module['_olm_outbound_group_session_last_error'](arguments[0])
+            );
+            throw new Error("OLM." + message);
+        }
+        return result;
+    }
+}
+
+OutboundGroupSession.prototype['free'] = function() {
+    Module['_olm_clear_outbound_group_session'](this.ptr);
+    free(this.ptr);
+}
+
+OutboundGroupSession.prototype['pickle'] = restore_stack(function(key) {
+    var key_array = array_from_string(key);
+    var pickle_length = outbound_group_session_method(
+        Module['_olm_pickle_outbound_group_session_length']
+    )(this.ptr);
+    var key_buffer = stack(key_array);
+    var pickle_buffer = stack(pickle_length);
+    outbound_group_session_method(Module['_olm_pickle_outbound_group_session'])(
+        this.ptr, key_buffer, key_array.length, pickle_buffer, pickle_length
+    );
+    return Pointer_stringify(pickle_buffer, pickle_length);
+});
+
+OutboundGroupSession.prototype['unpickle'] = restore_stack(function(key, pickle) {
+    var key_array = array_from_string(key);
+    var key_buffer = stack(key_array);
+    var pickle_array = array_from_string(pickle);
+    var pickle_buffer = stack(pickle_array);
+    outbound_group_session_method(Module['_olm_unpickle_outbound_group_session'])(
+        this.ptr, key_buffer, key_array.length, pickle_buffer,
+        pickle_array.length
+    );
+});
+
+OutboundGroupSession.prototype['create'] = restore_stack(function(key) {
+    var random_length = session_method(
+        Module['_olm_init_outbound_group_session_random_length']
+    )(this.ptr);
+    var random = random_stack(random_length);
+    outbound_group_session_method(Module['_olm_init_outbound_group_session'])(
+        this.ptr, random, random_length
+    );
+});
+
+OutboundGroupSession.prototype['encrypt'] = restore_stack(function(plaintext) {
+    var plaintext_array = array_from_string(plaintext);
+    var message_length = outbound_group_session_method(
+        Module['_olm_group_encrypt_message_length']
+    )(this.ptr, plaintext_array.length);
+    var plaintext_buffer = stack(plaintext_array);
+    var message_buffer = stack(message_length);
+    outbound_group_session_method(Module['_olm_group_encrypt'])(
+        this.ptr,
+        plaintext_buffer, plaintext_array.length,
+        message_buffer, message_length
+    );
+    return Pointer_stringify(message_buffer, message_length);
+});
+
+OutboundGroupSession.prototype['session_id'] = restore_stack(function(key) {
+    var length = outbound_group_session_method(
+        Module['_olm_outbound_group_session_id_length']
+    )(this.ptr);
+    var session_id = stack(length);
+    outbound_group_session_method(Module['_olm_outbound_group_session_id'])(
+        this.ptr, session_id, length
+    );
+    return Pointer_stringify(session_id, length);
+});
+
+OutboundGroupSession.prototype['session_key'] = restore_stack(function(key) {
+    var key_length = outbound_group_session_method(
+        Module['_olm_outbound_group_session_key_length']
+    )(this.ptr);
+    var key = stack(key_length);
+    outbound_group_session_method(Module['_olm_outbound_group_session_key'])(
+        this.ptr, key, key_length
+    );
+    return Pointer_stringify(key, key_length);
+});
+
+OutboundGroupSession.prototype['message_index'] = function() {
+    var idx = outbound_group_session_method(
+        Module['_olm_outbound_group_session_message_index']
+    )(this.ptr);
+    return idx;
+};
+
+olm_exports['OutboundGroupSession'] = OutboundGroupSession;