use an internal CSPRNG for uuid generation internally in Azle

Author: lastmjs

dist/canister_templates/experimental.wasm

@@ -42,6 +42,7 @@ mod stable_b_tree_map_remove;
 mod stable_b_tree_map_values;
 mod time;
 mod trap;
+mod uuid;
 
 use wasmedge_quickjs::AsObject;
 
@@ -347,5 +348,10 @@ pub fn register(context: &mut wasmedge_quickjs::Context) {
         context.new_function::<trap::NativeFunction>("").into(),
     );
 
+    ic.set(
+        "uuid",
+        context.new_function::<uuid::NativeFunction>("").into(),
+    );
+
     context.get_global().set("_azleIcExperimental", ic.into());
 }

dist/canister_templates/stable.wasm

@@ -0,0 +1,21 @@
+use rand::RngCore;
+use wasmedge_quickjs::{Context, JsFn, JsValue};
+
+use crate::INTERNAL_CSPRNG;
+
+pub struct NativeFunction;
+impl JsFn for NativeFunction {
+    fn call(context: &mut Context, _this_val: JsValue, _argv: &[JsValue]) -> JsValue {
+        INTERNAL_CSPRNG.with(|csprng_refcell| {
+            let mut rng = csprng_refcell.borrow_mut();
+
+            let mut bytes = [0u8; 16];
+
+            rng.fill_bytes(&mut bytes);
+
+            let hex = format!("{:032x}", u128::from_be_bytes(bytes));
+
+            context.new_string(&hex).into()
+        })
+    }
+}

src/experimental/build/commands/build/wasm_binary/rust/experimental_canister_template/src/ic/mod.rs

@@ -10,11 +10,11 @@ use wasmedge_quickjs::AsObject;
 use crate::{
     MEMORY_MANAGER_REF_CELL, RUNTIME, WASM_DATA_REF_CELL, execute_method_js, ic,
     ic::{drain_microtasks, rand_seed::rand_seed},
+    seed_internal_csprng, upload_file,
     wasm_binary_manipulation::{WasmData, get_js_code, get_wasm_data},
+    web_assembly,
 };
 
-use crate::{upload_file, web_assembly};
-
 #[inline(never)]
 #[unsafe(no_mangle)]
 pub extern "C" fn init(function_index: i32) {
@@ -195,6 +195,13 @@ fn seed_from_raw_rand() {
                         .candid()?;
 
                 rand_seed(
+                    randomness
+                        .clone()
+                        .try_into()
+                        .map_err(|_| "seed must be exactly 32 bytes in length")?,
+                );
+
+                seed_internal_csprng(
                     randomness
                         .try_into()
                         .map_err(|_| "seed must be exactly 32 bytes in length")?,

src/experimental/build/commands/build/wasm_binary/rust/experimental_canister_template/src/ic/uuid.rs

@@ -16,11 +16,14 @@ mod guards;
 mod ic;
 mod init_and_post_upgrade;
 mod internal_canister_methods;
+mod seed_internal_csprng;
 mod stable_b_tree_map;
 mod upload_file;
 mod wasm_binary_manipulation;
 mod web_assembly;
 
+pub use seed_internal_csprng::seed_internal_csprng;
+
 #[global_allocator]
 static PEAK_ALLOC: PeakAlloc = PeakAlloc;
 
@@ -29,6 +32,8 @@ type Memory = VirtualMemory<DefaultMemoryImpl>;
 
 thread_local! {
     static CSPRNG: RefCell<StdRng> = RefCell::new(StdRng::from_seed([0;32]));
+    // Internal CSPRNG used exclusively for Azle internal UUID generation. It cannot be reseeded by user code.
+    static INTERNAL_CSPRNG: RefCell<StdRng> = RefCell::new(StdRng::from_seed([0;32]));
     static MEMORY_MANAGER_REF_CELL: RefCell<MemoryManager<DefaultMemoryImpl>> = RefCell::new(MemoryManager::init(DefaultMemoryImpl::default()));
     static RUNTIME: RefCell<Option<wasmedge_quickjs::Runtime>> = RefCell::new(None);
     static WASM_DATA_REF_CELL: RefCell<Option<wasm_binary_manipulation::WasmData>> = RefCell::new(None);

src/experimental/build/commands/build/wasm_binary/rust/experimental_canister_template/src/init_and_post_upgrade.rs

@@ -0,0 +1,11 @@
+use rand::{SeedableRng, rngs::StdRng};
+
+use crate::INTERNAL_CSPRNG;
+
+/// Seeds the internal Azle CSPRNG used for UUID generation. Not exposed to user code.
+pub fn seed_internal_csprng(seed: [u8; 32]) {
+    INTERNAL_CSPRNG.with(|csprng_refcell| {
+        let mut rng = csprng_refcell.borrow_mut();
+        *rng = StdRng::from_seed(seed);
+    });
+}

src/experimental/build/commands/build/wasm_binary/rust/experimental_canister_template/src/lib.rs

@@ -37,6 +37,7 @@ export type AzleIcExperimental = {
     msgRejectCode: () => number;
     msgReply: (bytes: ArrayBuffer) => void;
     randBytes: (byteLength: number) => ArrayBuffer;
+    uuid: () => string;
     randSeed: (seed: ArrayBuffer) => void;
     certifiedDataSet: (dataBytes: ArrayBuffer) => void;
     setTimer: (delayString: string) => string;

src/experimental/build/commands/build/wasm_binary/rust/experimental_canister_template/src/seed_internal_csprng.rs

@@ -49,6 +49,7 @@ mod stable_b_tree_map_remove;
 mod stable_b_tree_map_values;
 mod time;
 mod trap;
+mod uuid;
 
 #[allow(unused)]
 pub fn register(ctx: Ctx) -> Result<()> {
@@ -203,6 +204,8 @@ pub fn register(ctx: Ctx) -> Result<()> {
 
     ic.set("trap", trap::get_function(ctx.clone()))?;
 
+    ic.set("uuid", uuid::get_function(ctx.clone()))?;
+
     ctx.globals().set("_azleIc", ic)?;
 
     Ok(())

src/experimental/lib/ic/azle_ic_experimental.ts

@@ -0,0 +1,20 @@
+use rand::RngCore;
+use rquickjs::{Ctx, Function, Result};
+
+use crate::INTERNAL_CSPRNG;
+
+pub fn get_function(ctx: Ctx) -> Result<Function> {
+    Function::new(ctx.clone(), move || -> Result<String> {
+        INTERNAL_CSPRNG.with(|csprng_refcell| {
+            let mut rng = csprng_refcell.borrow_mut();
+
+            let mut bytes = [0u8; 16];
+
+            rng.fill_bytes(&mut bytes);
+
+            let hex = format!("{:032x}", u128::from_be_bytes(bytes));
+
+            Ok(hex)
+        })
+    })
+}