Update Emscripten to 2.0.9 upstream

.github/workflows/integration.yaml

@@ -75,16 +75,8 @@ jobs:
           cd $HOME
           git clone https://github.com/emscripten-core/emsdk.git
           cd $HOME/emsdk
-          # FIXME(ilammy, 2020-07-07): unpin emsdk version [T1698]
-          # Latest HEAD has a regression, we roll back to last good version.
-          git checkout 92d512faa832b3ff5d6b8bc991b6801e31d8e372
-          # FIXME(ilammy, 2020-06-07): migrate to "upstream" flavor
-          # LLVM flavor of Emscripten has some issues compiling our code,
-          # and latest versions of the fastcomp flavor started giving out
-          # compiler warnings (turned into errors by the build system).
-          # We need to migrate, but for the time being use the old version.
-          ./emsdk install  1.39.16-fastcomp
-          ./emsdk activate 1.39.16-fastcomp
+          ./emsdk install  2.0.9
+          ./emsdk activate 2.0.9
       - name: Install PHP from PPA
         run: |
           sudo apt install --yes software-properties-common

.github/workflows/test-wasm.yaml

@@ -58,16 +58,8 @@ jobs:
           cd $HOME
           git clone https://github.com/emscripten-core/emsdk.git
           cd $HOME/emsdk
-          # FIXME(ilammy, 2020-07-07): unpin emsdk version [T1698]
-          # Latest HEAD has a regression, we roll back to last good version.
-          git checkout 92d512faa832b3ff5d6b8bc991b6801e31d8e372
-          # FIXME(ilammy, 2020-06-07): migrate to "upstream" flavor
-          # LLVM flavor of Emscripten has some issues compiling our code,
-          # and latest versions of the fastcomp flavor started giving out
-          # compiler warnings (turned into errors by the build system).
-          # We need to migrate, but for the time being use the old version.
-          ./emsdk install  1.39.16-fastcomp
-          ./emsdk activate 1.39.16-fastcomp
+          ./emsdk install  2.0.9
+          ./emsdk activate 2.0.9
       - name: Check out code
         uses: actions/checkout@v2
         with:

CHANGELOG.md

@@ -50,6 +50,10 @@ _Code:_
   - `TSSession` initializer now returns an error (`nil`) when given incorrect key type ([#710](https://github.com/cossacklabs/themis/pull/710)).
   - Improved compatibility with Xcode 12 ([#742](https://github.com/cossacklabs/themis/pull/742)).
 
+- **WebAssembly**
+
+  - Updated Emscripten toolchain to the latest version ([#760](https://github.com/cossacklabs/themis/pull/760)).
+
 _Infrastructure:_
 
 - Improved package split making `libthemis` thinner ([#678](https://github.com/cossacklabs/themis/pull/678)).

Makefile

@@ -220,11 +220,17 @@ CFLAGS += -O2 -g
 # so they almost always use stack and need the frame pointer anyway.
 CFLAGS += -fno-omit-frame-pointer
 # Enable runtime stack canaries for functions to guard for buffer overflows.
+# FIXME(ilammy, 2020-10-29): enable stack canaries for WasmThemis too
+# Currently, stack protector is not supported by the "upstream" flavor
+# of Emscripten toolchain. Tracking issue is here:
+# https://github.com/emscripten-core/emscripten/issues/9780
+ifndef IS_EMSCRIPTEN
 ifeq (yes,$(call supported,-fstack-protector-strong))
 CFLAGS += -fstack-protector-strong
 else
 CFLAGS += -fstack-protector
 endif
+endif
 # Enable miscellaneous compile-time checks in standard library usage.
 CFLAGS += -D_FORTIFY_SOURCE=2
 # Prevent global offset table overwrite attacks.

src/wrappers/themis/wasm/src/secure_cell_context_imprint.js

@@ -73,7 +73,7 @@ module.exports = class SecureCellContextImprint {
 
         let status
         /// C API uses "size_t" for lengths, it's defined as "i32" in Emscripten
-        let result_length_ptr = libthemis.allocate(4, 'i32', libthemis.ALLOC_STACK)
+        let result_length_ptr = libthemis.allocate(new ArrayBuffer(4), libthemis.ALLOC_STACK)
         let master_key_ptr, message_ptr, context_ptr, result_ptr, result_length
         try {
             master_key_ptr = utils.heapAlloc(this.masterKey.length)
@@ -148,7 +148,7 @@ module.exports = class SecureCellContextImprint {
 
         let status
         /// C API uses "size_t" for lengths, it's defined as "i32" in Emscripten
-        let result_length_ptr = libthemis.allocate(4, 'i32', libthemis.ALLOC_STACK)
+        let result_length_ptr = libthemis.allocate(new ArrayBuffer(4), libthemis.ALLOC_STACK)
         let master_key_ptr, message_ptr, context_ptr, result_ptr, result_length
         try {
             master_key_ptr = utils.heapAlloc(this.masterKey.length)

src/wrappers/themis/wasm/src/secure_cell_seal.js

@@ -81,7 +81,7 @@ class SecureCellSeal {
 
         let status
         /// C API uses "size_t" for lengths, it's defined as "i32" in Emscripten
-        let result_length_ptr = libthemis.allocate(4, 'i32', libthemis.ALLOC_STACK)
+        let result_length_ptr = libthemis.allocate(new ArrayBuffer(4), libthemis.ALLOC_STACK)
         let master_key_ptr, message_ptr, context_ptr, result_ptr, result_length
         try {
             master_key_ptr = utils.heapAlloc(this.masterKey.length)
@@ -149,7 +149,7 @@ class SecureCellSeal {
 
         let status
         /// C API uses "size_t" for lengths, it's defined as "i32" in Emscripten
-        let result_length_ptr = libthemis.allocate(4, 'i32', libthemis.ALLOC_STACK)
+        let result_length_ptr = libthemis.allocate(new ArrayBuffer(4), libthemis.ALLOC_STACK)
         let master_key_ptr, message_ptr, context_ptr, result_ptr, result_length
         try {
             master_key_ptr = utils.heapAlloc(this.masterKey.length)
@@ -223,7 +223,7 @@ class SecureCellSealWithPassphrase extends SecureCellSeal {
 
         let status
         /// C API uses "size_t" for lengths, it's defined as "i32" in Emscripten
-        let result_length_ptr = libthemis.allocate(4, 'i32', libthemis.ALLOC_STACK)
+        let result_length_ptr = libthemis.allocate(new ArrayBuffer(4), libthemis.ALLOC_STACK)
         let master_key_ptr, message_ptr, context_ptr, result_ptr, result_length
         try {
             master_key_ptr = utils.heapAlloc(this.masterKey.length)
@@ -291,7 +291,7 @@ class SecureCellSealWithPassphrase extends SecureCellSeal {
 
         let status
         /// C API uses "size_t" for lengths, it's defined as "i32" in Emscripten
-        let result_length_ptr = libthemis.allocate(4, 'i32', libthemis.ALLOC_STACK)
+        let result_length_ptr = libthemis.allocate(new ArrayBuffer(4), libthemis.ALLOC_STACK)
         let master_key_ptr, message_ptr, context_ptr, result_ptr, result_length
         try {
             master_key_ptr = utils.heapAlloc(this.masterKey.length)

src/wrappers/themis/wasm/src/secure_cell_token_protect.js

@@ -66,8 +66,10 @@ module.exports = class SecureCellTokenProtect {
 
         let status
         /// C API uses "size_t" for lengths, it's defined as "i32" in Emscripten
-        let result_length_ptr = libthemis.allocate(4, 'i32', libthemis.ALLOC_STACK)
-        let token_length_ptr = libthemis.allocate(4, 'i32', libthemis.ALLOC_STACK)
+        /// allocate() with ALLOC_STACK cannot be called multiple times,
+        /// but we need two size_t values so allocate an array, of a sort.
+        let result_length_ptr = libthemis.allocate(new ArrayBuffer(2 * 4), libthemis.ALLOC_STACK)
+        let token_length_ptr = result_length_ptr + 4
         let master_key_ptr, message_ptr, context_ptr, result_ptr, result_length, token_ptr, token_length
         try {
             master_key_ptr = utils.heapAlloc(this.masterKey.length)
@@ -150,7 +152,7 @@ module.exports = class SecureCellTokenProtect {
 
         let status
         /// C API uses "size_t" for lengths, it's defined as "i32" in Emscripten
-        let result_length_ptr = libthemis.allocate(4, 'i32', libthemis.ALLOC_STACK)
+        let result_length_ptr = libthemis.allocate(new ArrayBuffer(4), libthemis.ALLOC_STACK)
         let master_key_ptr, message_ptr, context_ptr, token_ptr, result_ptr, result_length
         try {
             master_key_ptr = utils.heapAlloc(this.masterKey.length)

src/wrappers/themis/wasm/src/secure_comparator.js

@@ -106,7 +106,7 @@ class SecureComparator {
 
         let status
         /// C API uses "size_t" for lengths, it's defined as "i32" in Emscripten
-        let message_length_ptr = libthemis.allocate(4, 'i32', libthemis.ALLOC_STACK)
+        let message_length_ptr = libthemis.allocate(new ArrayBuffer(4), libthemis.ALLOC_STACK)
         let message_ptr, message_length
         try {
             status = libthemis._secure_comparator_begin_compare(this.comparatorPtr,
@@ -143,7 +143,7 @@ class SecureComparator {
 
         let status
         /// C API uses "size_t" for lengths, it's defined as "i32" in Emscripten
-        let reply_length_ptr = libthemis.allocate(4, 'i32', libthemis.ALLOC_STACK)
+        let reply_length_ptr = libthemis.allocate(new ArrayBuffer(4), libthemis.ALLOC_STACK)
         let request_ptr, reply_ptr, reply_length
         try {
             request_ptr = utils.heapAlloc(request.length)

src/wrappers/themis/wasm/src/secure_keygen.js

@@ -122,8 +122,10 @@ function generateECKeyPair() {
     var err
 
     // C API uses "size_t" for lengths, it's defined as "i32" on Emscripten
-    let private_len_ptr = libthemis.allocate(4, 'i32', libthemis.ALLOC_STACK)
-    let public_len_ptr = libthemis.allocate(4, 'i32', libthemis.ALLOC_STACK)
+    /// allocate() with ALLOC_STACK cannot be called multiple times,
+    /// but we need two size_t values so allocate an array, of a sort.
+    let private_len_ptr = libthemis.allocate(new ArrayBuffer(2 * 4), libthemis.ALLOC_STACK)
+    let public_len_ptr = private_len_ptr + 4
 
     err = libthemis._themis_gen_ec_key_pair(null, private_len_ptr, null, public_len_ptr)
     if (err != ThemisErrorCode.BUFFER_TOO_SMALL) {
@@ -179,7 +181,7 @@ function generateSymmetricKey() {
     var err
 
     // C API uses "size_t" for lengths, it's defined as "i32" on Emscripten
-    let key_len_ptr = libthemis.allocate(4, 'i32', libthemis.ALLOC_STACK)
+    let key_len_ptr = libthemis.allocate(new ArrayBuffer(4), libthemis.ALLOC_STACK)
 
     err = libthemis._themis_gen_sym_key(null, key_len_ptr)
     if (err != ThemisErrorCode.BUFFER_TOO_SMALL) {

src/wrappers/themis/wasm/src/secure_message.js

@@ -73,7 +73,7 @@ class SecureMessage {
 
         let status
         /// C API uses "size_t" for lengths, it's defined as "i32" in Emscripten
-        let result_length_ptr = libthemis.allocate(4, 'i32', libthemis.ALLOC_STACK)
+        let result_length_ptr = libthemis.allocate(new ArrayBuffer(4), libthemis.ALLOC_STACK)
         let private_key_ptr, public_key_ptr, message_ptr, result_ptr, result_length
         try {
             private_key_ptr = utils.heapAlloc(this.privateKey.length)
@@ -134,7 +134,7 @@ class SecureMessage {
 
         let status
         /// C API uses "size_t" for lengths, it's defined as "i32" in Emscripten
-        let result_length_ptr = libthemis.allocate(4, 'i32', libthemis.ALLOC_STACK)
+        let result_length_ptr = libthemis.allocate(new ArrayBuffer(4), libthemis.ALLOC_STACK)
         let private_key_ptr, public_key_ptr, message_ptr, result_ptr, result_length
         try {
             private_key_ptr = utils.heapAlloc(this.privateKey.length)
@@ -205,7 +205,7 @@ class SecureMessageSign {
 
         let status
         /// C API uses "size_t" for lengths, it's defined as "i32" in Emscripten
-        let result_length_ptr = libthemis.allocate(4, 'i32', libthemis.ALLOC_STACK)
+        let result_length_ptr = libthemis.allocate(new ArrayBuffer(4), libthemis.ALLOC_STACK)
         let private_key_ptr, message_ptr, result_ptr, result_length
         try {
             private_key_ptr = utils.heapAlloc(this.privateKey.length)
@@ -271,7 +271,7 @@ class SecureMessageVerify {
 
         let status
         /// C API uses "size_t" for lengths, it's defined as "i32" in Emscripten
-        let result_length_ptr = libthemis.allocate(4, 'i32', libthemis.ALLOC_STACK)
+        let result_length_ptr = libthemis.allocate(new ArrayBuffer(4), libthemis.ALLOC_STACK)
         let public_key_ptr, message_ptr, result_ptr, result_length
         try {
             public_key_ptr = utils.heapAlloc(this.publicKey.length)

src/wrappers/themis/wasm/src/secure_session.js

@@ -216,7 +216,7 @@ class SecureSession {
     connectionRequest() {
         let status
         /// C API uses "size_t" for lengths, it's defined as "i32" in Emscripten
-        let request_length_ptr = libthemis.allocate(4, 'i32', libthemis.ALLOC_STACK)
+        let request_length_ptr = libthemis.allocate(new ArrayBuffer(4), libthemis.ALLOC_STACK)
         let request_ptr, request_length
         try {
             status = libthemis._secure_session_generate_connect_request(
@@ -259,7 +259,7 @@ class SecureSession {
 
         let status
         /// C API uses "size_t" for lengths, it's defined as "i32" in Emscripten
-        let reply_length_ptr = libthemis.allocate(4, 'i32', libthemis.ALLOC_STACK)
+        let reply_length_ptr = libthemis.allocate(new ArrayBuffer(4), libthemis.ALLOC_STACK)
         let message_ptr, reply_ptr, reply_length
         try {
             message_ptr = utils.heapAlloc(message.length)
@@ -315,7 +315,7 @@ class SecureSession {
 
         let status
         /// C API uses "size_t" for lengths, it's defined as "i32" in Emscripten
-        let wrapped_length_ptr = libthemis.allocate(4, 'i32', libthemis.ALLOC_STACK)
+        let wrapped_length_ptr = libthemis.allocate(new ArrayBuffer(4), libthemis.ALLOC_STACK)
         let message_ptr, wrapped_ptr, wrapped_length
         try {
             message_ptr = utils.heapAlloc(message.length)
@@ -368,7 +368,7 @@ class SecureSession {
 
         let status
         /// C API uses "size_t" for lengths, it's defined as "i32" in Emscripten
-        let unwrapped_length_ptr = libthemis.allocate(4, 'i32', libthemis.ALLOC_STACK)
+        let unwrapped_length_ptr = libthemis.allocate(new ArrayBuffer(4), libthemis.ALLOC_STACK)
         let message_ptr, unwrapped_ptr, unwrapped_length
         try {
             message_ptr = utils.heapAlloc(message.length)

src/wrappers/themis/wasm/wasmthemis.mk

@@ -25,7 +25,12 @@ WASM_PRE_JS  = $(abspath $(WASM_PATH)/emscripten/pre.js)
 WASM_PACKAGE = $(BIN_PATH)/wasm-themis.tgz
 
 $(BIN_PATH)/libthemis.js: LDFLAGS += -s EXTRA_EXPORTED_RUNTIME_METHODS=@$(WASM_RUNTIME)
-$(BIN_PATH)/libthemis.js: LDFLAGS += -s RESERVED_FUNCTION_POINTERS=1
+$(BIN_PATH)/libthemis.js: LDFLAGS += -s ALLOW_TABLE_GROWTH
+# FIXME(ilammy, 2020-11-29): rely in EMSCRIPTEN_KEEPALIVE instead of LINKABLE
+# For some reason existing EMSCRIPTEN_KEEPALIVE macros do not work and without
+# LINKABLE flag wasm-ld ends up stripping *all* Themis functions from "*.wasm"
+# output, as if removed by dead code elimination.
+$(BIN_PATH)/libthemis.js: LDFLAGS += -s LINKABLE=1
 $(BIN_PATH)/libthemis.js: LDFLAGS += --pre-js $(WASM_PRE_JS)
 
 $(BIN_PATH)/libthemis.js: CMD = $(CC) -o $@ $(filter %.o %a, $^) $(LDFLAGS)