From f0a662c348102931a09880c828b591da4f4799d3 Mon Sep 17 00:00:00 2001
From: Kenneth Pouncey <kjpou@pt.lu>
Date: Fri, 25 Sep 2020 11:59:32 +0200
Subject: [PATCH 01/15] [wasm][crypto] RandomNumberGenerator mapped to Web
 Crypto getRandomValues

- Uses Web Crypto API [`getRandomValues`](https://www.w3.org/TR/WebCryptoAPI/#Crypto-method-getRandomValues) if available.
- Falls back to `/dev/urandom` as default if the crypto library is missing.
---
 .../Native/Unix/System.Native/pal_random.c       | 16 ++++++++++++++++
 src/mono/wasm/runtime/driver.c                   | 12 ++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/src/libraries/Native/Unix/System.Native/pal_random.c b/src/libraries/Native/Unix/System.Native/pal_random.c
index 8f5e8927834a6..f3a4762ff9256 100644
--- a/src/libraries/Native/Unix/System.Native/pal_random.c
+++ b/src/libraries/Native/Unix/System.Native/pal_random.c
@@ -55,6 +55,10 @@ void SystemNative_GetNonCryptographicallySecureRandomBytes(uint8_t* buffer, int3
 #endif // HAVE_ARC4RANDOM_BUF
 }
 
+#ifdef __EMSCRIPTEN__
+int32_t mono_wasm_browser_crypto_getRandomValues(uint8_t* buffer, int32_t bufferLength);
+#endif
+
 /*
 
 Generate cryptographically strong random bytes.
@@ -68,6 +72,18 @@ int32_t SystemNative_GetCryptographicallySecureRandomBytes(uint8_t* buffer, int3
 
     assert(buffer != NULL);
 
+#ifdef __EMSCRIPTEN__
+    static bool sMissingBrowserCrypto;
+    if (!sMissingBrowserCrypto)
+    {
+        int32_t bff = mono_wasm_browser_crypto_getRandomValues(buffer, bufferLength);
+        if (bff == -1)
+            sMissingBrowserCrypto = true;
+        else
+            return 0;
+    }
+#endif
+
     if (!sMissingDevURandom)
     {
         if (rand_des == -1)
diff --git a/src/mono/wasm/runtime/driver.c b/src/mono/wasm/runtime/driver.c
index 3f17256b0431f..00fc09747ee43 100644
--- a/src/mono/wasm/runtime/driver.c
+++ b/src/mono/wasm/runtime/driver.c
@@ -940,3 +940,15 @@ mono_timezone_get_local_name (MonoString **result)
 	*result = mono_string_from_utf16 (tzd_local_name);
 	free (tzd_local_name);
 }
+
+EM_JS(int32_t, mono_wasm_browser_crypto_getRandomValues, (uint8_t* buffer, int32_t bufferLength),
+{
+	// check that we have crypto available
+	if (!(typeof crypto !== 'undefined' && crypto.subtle && typeof crypto.getRandomValues === 'function')) {
+		return -1;
+	}
+	// map the work array to the memory buffer passed with the length
+	var wrkArray = new Uint8Array(Module.HEAPU8.buffer, buffer, bufferLength);
+	crypto.getRandomValues(wrkArray);
+	return 0;
+});

From eb46e2fe649aa0684d97a88e07c8e8f0c42fe46a Mon Sep 17 00:00:00 2001
From: Kenneth Pouncey <kjpou@pt.lu>
Date: Mon, 28 Sep 2020 09:10:05 +0200
Subject: [PATCH 02/15] Remove the emscripten interface code from the driver.c.

---
 src/mono/wasm/runtime/driver.c        | 12 ------------
 src/mono/wasm/runtime/library_mono.js | 22 +++++++++++++++++-----
 2 files changed, 17 insertions(+), 17 deletions(-)

diff --git a/src/mono/wasm/runtime/driver.c b/src/mono/wasm/runtime/driver.c
index 00fc09747ee43..3f17256b0431f 100644
--- a/src/mono/wasm/runtime/driver.c
+++ b/src/mono/wasm/runtime/driver.c
@@ -940,15 +940,3 @@ mono_timezone_get_local_name (MonoString **result)
 	*result = mono_string_from_utf16 (tzd_local_name);
 	free (tzd_local_name);
 }
-
-EM_JS(int32_t, mono_wasm_browser_crypto_getRandomValues, (uint8_t* buffer, int32_t bufferLength),
-{
-	// check that we have crypto available
-	if (!(typeof crypto !== 'undefined' && crypto.subtle && typeof crypto.getRandomValues === 'function')) {
-		return -1;
-	}
-	// map the work array to the memory buffer passed with the length
-	var wrkArray = new Uint8Array(Module.HEAPU8.buffer, buffer, bufferLength);
-	crypto.getRandomValues(wrkArray);
-	return 0;
-});
diff --git a/src/mono/wasm/runtime/library_mono.js b/src/mono/wasm/runtime/library_mono.js
index 4ae04e16048d4..b3d29274515f8 100644
--- a/src/mono/wasm/runtime/library_mono.js
+++ b/src/mono/wasm/runtime/library_mono.js
@@ -85,6 +85,7 @@ var MonoSupportLib = {
 			module ["mono_wasm_new_root"] = MONO.mono_wasm_new_root;
 			module ["mono_wasm_new_roots"] = MONO.mono_wasm_new_roots;
 			module ["mono_wasm_release_roots"] = MONO.mono_wasm_release_roots;
+			//module ["mono_wasm_browser_crypto_getRandomValues"] = MONO.mono_wasm_browser_crypto_getRandomValues;
 		},
 
 		_base64Converter: {
@@ -211,7 +212,7 @@ var MonoSupportLib = {
 			},
 			/** @returns {ManagedPointer} */
 			get: function (index) {
-				this._check_in_range (index);				
+				this._check_in_range (index);
 				return Module.HEAP32[this.get_address_32 (index)];
 			},
 			set: function (index, value) {
@@ -317,7 +318,7 @@ var MonoSupportLib = {
 				throw new Error ("capacity >= 1");
 
 			capacity = capacity | 0;
-				
+
 			var capacityBytes = capacity * 4;
 			var offset = Module._malloc (capacityBytes);
 			if ((offset % 4) !== 0)
@@ -328,7 +329,7 @@ var MonoSupportLib = {
 			var result = Object.create (this._mono_wasm_root_buffer_prototype);
 			result.__offset = offset;
 			result.__offset32 = (offset / 4) | 0;
-			result.__count = capacity;	
+			result.__count = capacity;
 			result.length = capacity;
 			result.__handle = this.mono_wasm_register_root (offset, capacityBytes, msg || 0);
 
@@ -347,7 +348,7 @@ var MonoSupportLib = {
 		mono_wasm_new_root: function (value) {
 			var index = this._mono_wasm_claim_scratch_index ();
 			var buffer = this._scratch_root_buffer;
-				
+
 			var result = Object.create (this._mono_wasm_root_prototype);
 			result.__buffer = buffer;
 			result.__index = index;
@@ -395,7 +396,7 @@ var MonoSupportLib = {
 		 * Multiple objects may be passed on the argument list.
 		 * 'undefined' may be passed as an argument so it is safe to call this method from finally blocks
 		 *  even if you are not sure all of your roots have been created yet.
-		 * @param {... WasmRoot} roots 
+		 * @param {... WasmRoot} roots
 		 */
 		mono_wasm_release_roots: function () {
 			for (var i = 0; i < arguments.length; i++) {
@@ -2389,6 +2390,17 @@ var MonoSupportLib = {
 			pdb_b64
 		});
 	},
+
+	mono_wasm_browser_crypto_getRandomValues : function (buffer, bufferLength) {
+		// check that we have crypto available
+		if (!(typeof crypto !== 'undefined' && crypto.subtle && typeof crypto.getRandomValues === 'function')) {
+			return -1;
+		}
+		// map the work array to the memory buffer passed with the length
+		var wrkArray = new Uint8Array(Module.HEAPU8.buffer, buffer, bufferLength);
+		crypto.getRandomValues(wrkArray);
+		return 0;
+	},
 };
 
 autoAddDeps(MonoSupportLib, '$MONO')

From 878cfcf13b116de946984d0124745b2757f78e65 Mon Sep 17 00:00:00 2001
From: Kenneth Pouncey <kjpou@pt.lu>
Date: Mon, 28 Sep 2020 10:57:24 +0200
Subject: [PATCH 03/15] remove extraneous code comment

---
 src/mono/wasm/runtime/library_mono.js | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/mono/wasm/runtime/library_mono.js b/src/mono/wasm/runtime/library_mono.js
index b3d29274515f8..4547d68a0fa12 100644
--- a/src/mono/wasm/runtime/library_mono.js
+++ b/src/mono/wasm/runtime/library_mono.js
@@ -85,7 +85,6 @@ var MonoSupportLib = {
 			module ["mono_wasm_new_root"] = MONO.mono_wasm_new_root;
 			module ["mono_wasm_new_roots"] = MONO.mono_wasm_new_roots;
 			module ["mono_wasm_release_roots"] = MONO.mono_wasm_release_roots;
-			//module ["mono_wasm_browser_crypto_getRandomValues"] = MONO.mono_wasm_browser_crypto_getRandomValues;
 		},
 
 		_base64Converter: {

From 289efeff57beab92bd290bb12c53a9f67175ca41 Mon Sep 17 00:00:00 2001
From: Kenneth Pouncey <kjpou@pt.lu>
Date: Mon, 28 Sep 2020 10:59:42 +0200
Subject: [PATCH 04/15] Move emscripten definition around.

---
 src/libraries/Native/Unix/System.Native/pal_random.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/libraries/Native/Unix/System.Native/pal_random.c b/src/libraries/Native/Unix/System.Native/pal_random.c
index f3a4762ff9256..4f75010ed6f70 100644
--- a/src/libraries/Native/Unix/System.Native/pal_random.c
+++ b/src/libraries/Native/Unix/System.Native/pal_random.c
@@ -55,10 +55,6 @@ void SystemNative_GetNonCryptographicallySecureRandomBytes(uint8_t* buffer, int3
 #endif // HAVE_ARC4RANDOM_BUF
 }
 
-#ifdef __EMSCRIPTEN__
-int32_t mono_wasm_browser_crypto_getRandomValues(uint8_t* buffer, int32_t bufferLength);
-#endif
-
 /*
 
 Generate cryptographically strong random bytes.
@@ -73,6 +69,10 @@ int32_t SystemNative_GetCryptographicallySecureRandomBytes(uint8_t* buffer, int3
     assert(buffer != NULL);
 
 #ifdef __EMSCRIPTEN__
+    #include <emscripten.h>
+    EMSCRIPTEN_KEEPALIVE int32_t
+    mono_wasm_browser_crypto_getRandomValues(uint8_t* buffer, int32_t bufferLength);
+
     static bool sMissingBrowserCrypto;
     if (!sMissingBrowserCrypto)
     {

From b5d372be59609461308b34e1fdda629b52fbac63 Mon Sep 17 00:00:00 2001
From: Kenneth Pouncey <kjpou@pt.lu>
Date: Mon, 28 Sep 2020 11:07:36 +0200
Subject: [PATCH 05/15] Address review comment

---
 src/libraries/Native/Unix/System.Native/pal_random.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/libraries/Native/Unix/System.Native/pal_random.c b/src/libraries/Native/Unix/System.Native/pal_random.c
index 4f75010ed6f70..b8a31ddcbdd94 100644
--- a/src/libraries/Native/Unix/System.Native/pal_random.c
+++ b/src/libraries/Native/Unix/System.Native/pal_random.c
@@ -63,9 +63,6 @@ Return 0 on success, -1 on failure.
 */
 int32_t SystemNative_GetCryptographicallySecureRandomBytes(uint8_t* buffer, int32_t bufferLength)
 {
-    static volatile int rand_des = -1;
-    static bool sMissingDevURandom;
-
     assert(buffer != NULL);
 
 #ifdef __EMSCRIPTEN__
@@ -82,7 +79,10 @@ int32_t SystemNative_GetCryptographicallySecureRandomBytes(uint8_t* buffer, int3
         else
             return 0;
     }
-#endif
+#else
+
+    static volatile int rand_des = -1;
+    static bool sMissingDevURandom;
 
     if (!sMissingDevURandom)
     {
@@ -137,6 +137,6 @@ int32_t SystemNative_GetCryptographicallySecureRandomBytes(uint8_t* buffer, int3
             return 0;
         }
     }
-
+#endif
     return -1;
 }

From cf74a12cb84b65fed75144a293c967bd0b5de35d Mon Sep 17 00:00:00 2001
From: Kenneth Pouncey <kjpou@pt.lu>
Date: Tue, 29 Sep 2020 09:37:48 +0200
Subject: [PATCH 06/15] Add javascript bridge implementation library to Native
 source tree.

- Javascript checks for crypto interface and uses `crypto.getRandomValues`
- Add api bridge call when building for emscripten browser.
- separate out into browser subdirectory
- If we couldn't find a proper implementation, as Math.random() is not suitable we will abort.

```

ABORT: no cryptographic support found getRandomValues. Consider polyfilling it if you want to use something insecure like Math.random(), e.g. put this in a --pre-js: var crypto = { getRandomValues: function(array) { for (var i = 0; i < array.length; i++) array[i] = (Math.random()*256)|0 } };

```
---
 .../browser/pal_entropy_bridge.js             | 23 +++++++++++++++++++
 .../browser/pal_random_browser.h              |  9 ++++++++
 .../Native/Unix/System.Native/pal_random.c    |  9 ++++----
 3 files changed, 36 insertions(+), 5 deletions(-)
 create mode 100644 src/libraries/Native/Unix/System.Native/browser/pal_entropy_bridge.js
 create mode 100644 src/libraries/Native/Unix/System.Native/browser/pal_random_browser.h

diff --git a/src/libraries/Native/Unix/System.Native/browser/pal_entropy_bridge.js b/src/libraries/Native/Unix/System.Native/browser/pal_entropy_bridge.js
new file mode 100644
index 0000000000000..fb536560ccf62
--- /dev/null
+++ b/src/libraries/Native/Unix/System.Native/browser/pal_entropy_bridge.js
@@ -0,0 +1,23 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+var DotNetEntropyLib = {
+    $DOTNETENTROPY: {
+    },
+    dotnet_browser_entropy : function (buffer, bufferLength) {
+        // check that we have crypto available
+        if (typeof crypto === 'object' && typeof crypto['getRandomValues'] === 'function') {
+            // for modern web browsers
+            // map the work array to the memory buffer passed with the length
+            var wrkArray = new Uint8Array(Module.HEAPU8.buffer, buffer, bufferLength);
+            crypto.getRandomValues(wrkArray);
+            return 0;
+        } else {
+            // we couldn't find a proper implementation, as Math.random() is not suitable
+            abort("no cryptographic support found for getRandomValues. Consider polyfilling it if you want to use something insecure like Math.random(), e.g. put this in a --pre-js: var crypto = { getRandomValues: function(array) { for (var i = 0; i < array.length; i++) array[i] = (Math.random()*256)|0 } };");
+        }
+    },
+};
+
+autoAddDeps(DotNetEntropyLib, '$DOTNETENTROPY')
+mergeInto(LibraryManager.library, DotNetEntropyLib)
diff --git a/src/libraries/Native/Unix/System.Native/browser/pal_random_browser.h b/src/libraries/Native/Unix/System.Native/browser/pal_random_browser.h
new file mode 100644
index 0000000000000..8226de64a2796
--- /dev/null
+++ b/src/libraries/Native/Unix/System.Native/browser/pal_random_browser.h
@@ -0,0 +1,9 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+#pragma once
+
+#include "pal_compiler.h"
+#include "pal_types.h"
+
+PALEXPORT int32_t dotnet_browser_entropy(uint8_t* buffer, int32_t bufferLength);
diff --git a/src/libraries/Native/Unix/System.Native/pal_random.c b/src/libraries/Native/Unix/System.Native/pal_random.c
index b8a31ddcbdd94..fb3d9b53d7eed 100644
--- a/src/libraries/Native/Unix/System.Native/pal_random.c
+++ b/src/libraries/Native/Unix/System.Native/pal_random.c
@@ -14,6 +14,9 @@
 #include "pal_config.h"
 #include "pal_random.h"
 
+#ifdef __EMSCRIPTEN__
+#include "browser/pal_random_browser.h"
+#endif
 /*
 
 Generate random bytes. The generated bytes are not cryptographically strong.
@@ -66,14 +69,10 @@ int32_t SystemNative_GetCryptographicallySecureRandomBytes(uint8_t* buffer, int3
     assert(buffer != NULL);
 
 #ifdef __EMSCRIPTEN__
-    #include <emscripten.h>
-    EMSCRIPTEN_KEEPALIVE int32_t
-    mono_wasm_browser_crypto_getRandomValues(uint8_t* buffer, int32_t bufferLength);
-
     static bool sMissingBrowserCrypto;
     if (!sMissingBrowserCrypto)
     {
-        int32_t bff = mono_wasm_browser_crypto_getRandomValues(buffer, bufferLength);
+        int32_t bff = dotnet_browser_entropy(buffer, bufferLength);
         if (bff == -1)
             sMissingBrowserCrypto = true;
         else

From 88fa846ac5644957a476a8a1093d145f703d947d Mon Sep 17 00:00:00 2001
From: Kenneth Pouncey <kjpou@pt.lu>
Date: Tue, 29 Sep 2020 09:39:15 +0200
Subject: [PATCH 07/15] Change tests to set random values of the buffer instead
 of return a single value.

---
 src/mono/wasm/runtime-test.js | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/src/mono/wasm/runtime-test.js b/src/mono/wasm/runtime-test.js
index b3fbf5dc3fbca..be3ed08bd4f9d 100644
--- a/src/mono/wasm/runtime-test.js
+++ b/src/mono/wasm/runtime-test.js
@@ -40,12 +40,13 @@ if (typeof console !== "undefined") {
 		console.error = console.log;
 }
 
-if (typeof crypto == 'undefined') {
+if (typeof crypto === 'undefined') {
 	// /dev/random doesn't work on js shells, so define our own
 	// See library_fs.js:createDefaultDevices ()
 	var crypto = {
 		getRandomValues: function (buffer) {
-			buffer[0] = (Math.random()*256)|0;
+			for (var i = 0; i < buffer.length; i++)
+				buffer[i] = (Math.random()*256)|0;
 		}
 	}
 }
@@ -120,7 +121,9 @@ runtime_args = [];
 enable_gc = true;
 enable_zoneinfo = false;
 working_dir='/';
+extra_scripts=[];
 while (args !== undefined && args.length > 0) {
+    console.log("processign arg: " + args [0]);
 	if (args [0].startsWith ("--profile=")) {
 		var arg = args [0].substring ("--profile=".length);
 
@@ -144,6 +147,10 @@ while (args !== undefined && args.length > 0) {
 	} else if (args [0].startsWith ("--working-dir=")) {
 		var arg = args [0].substring ("--working-dir=".length);
 		working_dir = arg;
+        args = args.slice (1);
+	} else if (args [0].startsWith ("--extra-scripts=")) {
+		var extras = args [0].substring ("--extra-scripts=".length);
+		extra_scripts = extras.split(',');
 		args = args.slice (1);
 	} else {
 		break;
@@ -171,6 +178,19 @@ function loadScript (url)
 
 loadScript ("mono-config.js");
 
+// Load the extra script files which may contain poly fills to be loaded
+extra_scripts.forEach(scriptToLoad => {
+    try {
+        loadScript (scriptToLoad);
+    } catch (error) {
+        console.log(error + ": " + scriptToLoad);
+    }
+});
+
+// check if crypto polyfill is loaded
+if (typeof msrCrypto !== 'undefined')
+    var crypto = msrCrypto; /*polyfill*/
+
 var Module = {
 	mainScriptUrlOrBlob: "dotnet.js",
 

From 2b8987dbf44f026665418eac0991db97d6a75229 Mon Sep 17 00:00:00 2001
From: Kenneth Pouncey <kjpou@pt.lu>
Date: Tue, 29 Sep 2020 09:39:52 +0200
Subject: [PATCH 08/15] Remove old test code

---
 src/mono/wasm/runtime/library_mono.js | 11 -----------
 1 file changed, 11 deletions(-)

diff --git a/src/mono/wasm/runtime/library_mono.js b/src/mono/wasm/runtime/library_mono.js
index 4547d68a0fa12..dafc3e2068d8a 100644
--- a/src/mono/wasm/runtime/library_mono.js
+++ b/src/mono/wasm/runtime/library_mono.js
@@ -2389,17 +2389,6 @@ var MonoSupportLib = {
 			pdb_b64
 		});
 	},
-
-	mono_wasm_browser_crypto_getRandomValues : function (buffer, bufferLength) {
-		// check that we have crypto available
-		if (!(typeof crypto !== 'undefined' && crypto.subtle && typeof crypto.getRandomValues === 'function')) {
-			return -1;
-		}
-		// map the work array to the memory buffer passed with the length
-		var wrkArray = new Uint8Array(Module.HEAPU8.buffer, buffer, bufferLength);
-		crypto.getRandomValues(wrkArray);
-		return 0;
-	},
 };
 
 autoAddDeps(MonoSupportLib, '$MONO')

From 61f1c192703589ac2be99bee6448daa211814682 Mon Sep 17 00:00:00 2001
From: Kenneth Pouncey <kjpou@pt.lu>
Date: Tue, 29 Sep 2020 09:41:54 +0200
Subject: [PATCH 09/15] Remove testing code

---
 src/mono/wasm/runtime-test.js | 19 -------------------
 1 file changed, 19 deletions(-)

diff --git a/src/mono/wasm/runtime-test.js b/src/mono/wasm/runtime-test.js
index be3ed08bd4f9d..4b7e55769c03d 100644
--- a/src/mono/wasm/runtime-test.js
+++ b/src/mono/wasm/runtime-test.js
@@ -121,9 +121,7 @@ runtime_args = [];
 enable_gc = true;
 enable_zoneinfo = false;
 working_dir='/';
-extra_scripts=[];
 while (args !== undefined && args.length > 0) {
-    console.log("processign arg: " + args [0]);
 	if (args [0].startsWith ("--profile=")) {
 		var arg = args [0].substring ("--profile=".length);
 
@@ -148,10 +146,6 @@ while (args !== undefined && args.length > 0) {
 		var arg = args [0].substring ("--working-dir=".length);
 		working_dir = arg;
         args = args.slice (1);
-	} else if (args [0].startsWith ("--extra-scripts=")) {
-		var extras = args [0].substring ("--extra-scripts=".length);
-		extra_scripts = extras.split(',');
-		args = args.slice (1);
 	} else {
 		break;
 	}
@@ -178,19 +172,6 @@ function loadScript (url)
 
 loadScript ("mono-config.js");
 
-// Load the extra script files which may contain poly fills to be loaded
-extra_scripts.forEach(scriptToLoad => {
-    try {
-        loadScript (scriptToLoad);
-    } catch (error) {
-        console.log(error + ": " + scriptToLoad);
-    }
-});
-
-// check if crypto polyfill is loaded
-if (typeof msrCrypto !== 'undefined')
-    var crypto = msrCrypto; /*polyfill*/
-
 var Module = {
 	mainScriptUrlOrBlob: "dotnet.js",
 

From ce13ad1ff03c0740875fd69caf515606e5dc073b Mon Sep 17 00:00:00 2001
From: Kenneth Pouncey <kjpou@pt.lu>
Date: Tue, 29 Sep 2020 10:36:43 +0200
Subject: [PATCH 10/15] Incorporate the PAL bridge layer into the
 `--js-library` build process

---
 src/mono/wasm/Makefile | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/mono/wasm/Makefile b/src/mono/wasm/Makefile
index 4fc42d4f7ad0d..6354eb5260afd 100644
--- a/src/mono/wasm/Makefile
+++ b/src/mono/wasm/Makefile
@@ -15,6 +15,7 @@ PINVOKE_TABLE?=$(TOP)/artifacts/obj/wasm/pinvoke-table.h
 MONO_BIN_DIR?=$(BINDIR)/mono/Browser.wasm.$(CONFIG)
 NATIVE_BIN_DIR?=$(BINDIR)/native/net5.0-Browser-$(CONFIG)-wasm
 ICU_LIBDIR?=
+SYSTEM_NATIVE_LIBDIR?=$(TOP)/src/libraries/Native/Unix/System.Native/browser
 ENABLE_ES6?=false
 
 all: build-native icu-data
@@ -81,8 +82,8 @@ $(NATIVE_BIN_DIR):
 $(BUILDS_OBJ_DIR):
 	mkdir -p $$@
 
-$(NATIVE_BIN_DIR)/dotnet.js: $(BUILDS_OBJ_DIR)/driver.o $(BUILDS_OBJ_DIR)/pinvoke.o $(BUILDS_OBJ_DIR)/corebindings.o runtime/library_mono.js runtime/binding_support.js runtime/dotnet_support.js $(2) | $(NATIVE_BIN_DIR)
-	$(EMCC) $(EMCC_FLAGS) $(1) --js-library runtime/library_mono.js --js-library runtime/binding_support.js --js-library runtime/dotnet_support.js $(BUILDS_OBJ_DIR)/driver.o $(BUILDS_OBJ_DIR)/pinvoke.o $(BUILDS_OBJ_DIR)/corebindings.o $(2) -o $(NATIVE_BIN_DIR)/dotnet.js
+$(NATIVE_BIN_DIR)/dotnet.js: $(BUILDS_OBJ_DIR)/driver.o $(BUILDS_OBJ_DIR)/pinvoke.o $(BUILDS_OBJ_DIR)/corebindings.o runtime/library_mono.js runtime/binding_support.js runtime/dotnet_support.js $(SYSTEM_NATIVE_LIBDIR)/pal_entropy_bridge.js $(2) | $(NATIVE_BIN_DIR)
+	$(EMCC) $(EMCC_FLAGS) $(1) --js-library runtime/library_mono.js --js-library runtime/binding_support.js --js-library runtime/dotnet_support.js --js-library $(SYSTEM_NATIVE_LIBDIR)/pal_entropy_bridge.js $(BUILDS_OBJ_DIR)/driver.o $(BUILDS_OBJ_DIR)/pinvoke.o $(BUILDS_OBJ_DIR)/corebindings.o $(2) -o $(NATIVE_BIN_DIR)/dotnet.js
 
 $(BUILDS_OBJ_DIR)/pinvoke-table.h: $(PINVOKE_TABLE) | $(BUILDS_OBJ_DIR)
 	if cmp -s $(PINVOKE_TABLE) $$@ ; then : ; else cp $(PINVOKE_TABLE) $$@ ; fi

From 5e593bb525e1f7c1b57bfaa0f32be4c6a27be2b0 Mon Sep 17 00:00:00 2001
From: Kenneth Pouncey <kjpou@pt.lu>
Date: Wed, 30 Sep 2020 08:46:21 +0200
Subject: [PATCH 11/15] Address review comments about directory structure and
 naming

---
 .../Unix/System.Native/browser/pal_random_browser.h      | 9 ---------
 src/libraries/Native/Unix/System.Native/pal_random.c     | 4 +---
 .../{browser/pal_entropy_bridge.js => pal_random.js}     | 0
 src/mono/wasm/Makefile                                   | 6 +++---
 4 files changed, 4 insertions(+), 15 deletions(-)
 delete mode 100644 src/libraries/Native/Unix/System.Native/browser/pal_random_browser.h
 rename src/libraries/Native/Unix/System.Native/{browser/pal_entropy_bridge.js => pal_random.js} (100%)

diff --git a/src/libraries/Native/Unix/System.Native/browser/pal_random_browser.h b/src/libraries/Native/Unix/System.Native/browser/pal_random_browser.h
deleted file mode 100644
index 8226de64a2796..0000000000000
--- a/src/libraries/Native/Unix/System.Native/browser/pal_random_browser.h
+++ /dev/null
@@ -1,9 +0,0 @@
-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-
-#pragma once
-
-#include "pal_compiler.h"
-#include "pal_types.h"
-
-PALEXPORT int32_t dotnet_browser_entropy(uint8_t* buffer, int32_t bufferLength);
diff --git a/src/libraries/Native/Unix/System.Native/pal_random.c b/src/libraries/Native/Unix/System.Native/pal_random.c
index fb3d9b53d7eed..b824b2968f95c 100644
--- a/src/libraries/Native/Unix/System.Native/pal_random.c
+++ b/src/libraries/Native/Unix/System.Native/pal_random.c
@@ -14,9 +14,6 @@
 #include "pal_config.h"
 #include "pal_random.h"
 
-#ifdef __EMSCRIPTEN__
-#include "browser/pal_random_browser.h"
-#endif
 /*
 
 Generate random bytes. The generated bytes are not cryptographically strong.
@@ -69,6 +66,7 @@ int32_t SystemNative_GetCryptographicallySecureRandomBytes(uint8_t* buffer, int3
     assert(buffer != NULL);
 
 #ifdef __EMSCRIPTEN__
+    extern int32_t dotnet_browser_entropy(uint8_t* buffer, int32_t bufferLength);
     static bool sMissingBrowserCrypto;
     if (!sMissingBrowserCrypto)
     {
diff --git a/src/libraries/Native/Unix/System.Native/browser/pal_entropy_bridge.js b/src/libraries/Native/Unix/System.Native/pal_random.js
similarity index 100%
rename from src/libraries/Native/Unix/System.Native/browser/pal_entropy_bridge.js
rename to src/libraries/Native/Unix/System.Native/pal_random.js
diff --git a/src/mono/wasm/Makefile b/src/mono/wasm/Makefile
index 6354eb5260afd..12f1962920fd9 100644
--- a/src/mono/wasm/Makefile
+++ b/src/mono/wasm/Makefile
@@ -15,7 +15,7 @@ PINVOKE_TABLE?=$(TOP)/artifacts/obj/wasm/pinvoke-table.h
 MONO_BIN_DIR?=$(BINDIR)/mono/Browser.wasm.$(CONFIG)
 NATIVE_BIN_DIR?=$(BINDIR)/native/net5.0-Browser-$(CONFIG)-wasm
 ICU_LIBDIR?=
-SYSTEM_NATIVE_LIBDIR?=$(TOP)/src/libraries/Native/Unix/System.Native/browser
+SYSTEM_NATIVE_LIBDIR?=$(TOP)/src/libraries/Native/Unix/System.Native
 ENABLE_ES6?=false
 
 all: build-native icu-data
@@ -82,8 +82,8 @@ $(NATIVE_BIN_DIR):
 $(BUILDS_OBJ_DIR):
 	mkdir -p $$@
 
-$(NATIVE_BIN_DIR)/dotnet.js: $(BUILDS_OBJ_DIR)/driver.o $(BUILDS_OBJ_DIR)/pinvoke.o $(BUILDS_OBJ_DIR)/corebindings.o runtime/library_mono.js runtime/binding_support.js runtime/dotnet_support.js $(SYSTEM_NATIVE_LIBDIR)/pal_entropy_bridge.js $(2) | $(NATIVE_BIN_DIR)
-	$(EMCC) $(EMCC_FLAGS) $(1) --js-library runtime/library_mono.js --js-library runtime/binding_support.js --js-library runtime/dotnet_support.js --js-library $(SYSTEM_NATIVE_LIBDIR)/pal_entropy_bridge.js $(BUILDS_OBJ_DIR)/driver.o $(BUILDS_OBJ_DIR)/pinvoke.o $(BUILDS_OBJ_DIR)/corebindings.o $(2) -o $(NATIVE_BIN_DIR)/dotnet.js
+$(NATIVE_BIN_DIR)/dotnet.js: $(BUILDS_OBJ_DIR)/driver.o $(BUILDS_OBJ_DIR)/pinvoke.o $(BUILDS_OBJ_DIR)/corebindings.o runtime/library_mono.js runtime/binding_support.js runtime/dotnet_support.js $(SYSTEM_NATIVE_LIBDIR)/pal_random.js $(2) | $(NATIVE_BIN_DIR)
+	$(EMCC) $(EMCC_FLAGS) $(1) --js-library runtime/library_mono.js --js-library runtime/binding_support.js --js-library runtime/dotnet_support.js --js-library $(SYSTEM_NATIVE_LIBDIR)/pal_random.js $(BUILDS_OBJ_DIR)/driver.o $(BUILDS_OBJ_DIR)/pinvoke.o $(BUILDS_OBJ_DIR)/corebindings.o $(2) -o $(NATIVE_BIN_DIR)/dotnet.js
 
 $(BUILDS_OBJ_DIR)/pinvoke-table.h: $(PINVOKE_TABLE) | $(BUILDS_OBJ_DIR)
 	if cmp -s $(PINVOKE_TABLE) $$@ ; then : ; else cp $(PINVOKE_TABLE) $$@ ; fi

From 76de399c75193a5571f54cdf3593230ee60e7da4 Mon Sep 17 00:00:00 2001
From: Kenneth Pouncey <kjpou@pt.lu>
Date: Thu, 1 Oct 2020 05:48:00 +0200
Subject: [PATCH 12/15] Update src/mono/wasm/runtime-test.js

Co-authored-by: Ryan Lucia <ryan@luciaonline.net>
---
 src/mono/wasm/runtime-test.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/mono/wasm/runtime-test.js b/src/mono/wasm/runtime-test.js
index 4964c73e6ac1b..ca080a26f60ee 100644
--- a/src/mono/wasm/runtime-test.js
+++ b/src/mono/wasm/runtime-test.js
@@ -68,7 +68,7 @@ if (typeof crypto === 'undefined') {
 	var crypto = {
 		getRandomValues: function (buffer) {
 			for (var i = 0; i < buffer.length; i++)
-				buffer[i] = (Math.random()*256)|0;
+				buffer [i] = (Math.random () * 256) | 0;
 		}
 	}
 }

From 8077f7cf801618831d10f2fc1de0c2bbdfa26134 Mon Sep 17 00:00:00 2001
From: Kenneth Pouncey <kjpou@pt.lu>
Date: Thu, 1 Oct 2020 06:21:18 +0200
Subject: [PATCH 13/15] Add note about insecure code for testing purposes

---
 src/mono/wasm/runtime-test.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/mono/wasm/runtime-test.js b/src/mono/wasm/runtime-test.js
index ca080a26f60ee..992236692eedd 100644
--- a/src/mono/wasm/runtime-test.js
+++ b/src/mono/wasm/runtime-test.js
@@ -63,6 +63,7 @@ if (typeof console !== "undefined") {
 }
 
 if (typeof crypto === 'undefined') {
+	// **NOTE** this is a simple insecure polyfill for testing purposes only
 	// /dev/random doesn't work on js shells, so define our own
 	// See library_fs.js:createDefaultDevices ()
 	var crypto = {

From ec16f1a182470a4787e13ab3f89487eb8054edcd Mon Sep 17 00:00:00 2001
From: Kenneth Pouncey <kjpou@pt.lu>
Date: Thu, 1 Oct 2020 06:23:17 +0200
Subject: [PATCH 14/15] Formatting

---
 src/mono/wasm/runtime-test.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/mono/wasm/runtime-test.js b/src/mono/wasm/runtime-test.js
index 992236692eedd..1d217aae5dade 100644
--- a/src/mono/wasm/runtime-test.js
+++ b/src/mono/wasm/runtime-test.js
@@ -168,7 +168,7 @@ while (args !== undefined && args.length > 0) {
 	} else if (args [0].startsWith ("--working-dir=")) {
 		var arg = args [0].substring ("--working-dir=".length);
 		working_dir = arg;
-        args = args.slice (1);
+		args = args.slice (1);
 	} else {
 		break;
 	}

From 7b7e9d28132f177641bf66e18a118622a122744e Mon Sep 17 00:00:00 2001
From: Kenneth Pouncey <kjpou@pt.lu>
Date: Thu, 1 Oct 2020 06:58:30 +0200
Subject: [PATCH 15/15] Return -1 if crypto does not exist instead of aborting
 from js.  This allows the managed code exception flow to continue as normal.

---
 src/libraries/Native/Unix/System.Native/pal_random.js | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/libraries/Native/Unix/System.Native/pal_random.js b/src/libraries/Native/Unix/System.Native/pal_random.js
index fb536560ccf62..231eda0b8ca86 100644
--- a/src/libraries/Native/Unix/System.Native/pal_random.js
+++ b/src/libraries/Native/Unix/System.Native/pal_random.js
@@ -14,7 +14,8 @@ var DotNetEntropyLib = {
             return 0;
         } else {
             // we couldn't find a proper implementation, as Math.random() is not suitable
-            abort("no cryptographic support found for getRandomValues. Consider polyfilling it if you want to use something insecure like Math.random(), e.g. put this in a --pre-js: var crypto = { getRandomValues: function(array) { for (var i = 0; i < array.length; i++) array[i] = (Math.random()*256)|0 } };");
+            // instead of aborting here we will return and let managed code handle the message
+            return -1;
         }
     },
 };