From e6b350a1d48ca0490b7a3447bb8d0a4235514b76 Mon Sep 17 00:00:00 2001
From: Doan Luu Duc Tai <doan@luuduct.ai>
Date: Fri, 30 Oct 2026 21:39:57 -0500
Subject: Implement experimental file-based encrypted private chat

Add fixed-suite Rust/WASI identity files, signed challenge authentication, ciphertext-only SQLite storage, a minimal LibreJS-compatible interface, and consistent backup snapshots. Keep production unchanged and document the local workflow, limits, source distribution, and browser recovery tests.
---
 crates/chat-crypto/browser/wasi.mjs | 50 +++++++++++++++++++++++++++++++------
 1 file changed, 43 insertions(+), 7 deletions(-)

(limited to 'crates/chat-crypto/browser/wasi.mjs')

diff --git a/crates/chat-crypto/browser/wasi.mjs b/crates/chat-crypto/browser/wasi.mjs
index d27fe4b..80d1299 100644
--- a/crates/chat-crypto/browser/wasi.mjs
+++ b/crates/chat-crypto/browser/wasi.mjs
@@ -15,10 +15,14 @@
 
 // @license magnet:?xt=urn:btih:0b31508aeb0634b347b8270c7bee4d411b5d4109&dn=agpl-3.0.txt AGPL-3.0
 
-export async function runProbe(bytes) {
+async function execute(bytes, input) {
     let memory;
     let output = '';
     let errors = '';
+    const stdoutDecoder = new TextDecoder('utf-8', { fatal: true });
+    const stderrDecoder = new TextDecoder('utf-8', { fatal: true });
+    const stdin = new TextEncoder().encode(input);
+    let position = 0;
     let randomCalls = 0;
     let randomBytes = 0;
     const data = () => new DataView(memory.buffer);
@@ -54,15 +58,28 @@ export async function runProbe(bytes) {
             for (let index = 0; index < count; index += 1) {
                 const address = data().getUint32(vectors + index * 8, true);
                 const length = data().getUint32(vectors + index * 8 + 4, true);
-                const text = new TextDecoder().decode(new Uint8Array(memory.buffer, address, length));
+                const text = (fd === 1 ? stdoutDecoder : stderrDecoder).decode(new Uint8Array(memory.buffer, address, length), { stream: true });
                 if (fd === 1) output += text; else errors += text;
                 total += length;
-                if (output.length + errors.length > 65536) throw new Error('Probe output exceeded its limit');
+                if (output.length + errors.length > 1048576) throw new Error('Probe output exceeded its limit');
             }
             put32(written, total);
             return 0;
         },
-        fd_read(fd, vectors, count, read) { if (fd !== 0) return 8; put32(read, 0); return 0; },
+        fd_read(fd, vectors, count, read) {
+            if (fd !== 0) return 8;
+            let total = 0;
+            for (let index = 0; index < count && position < stdin.length; index += 1) {
+                const address = data().getUint32(vectors + index * 8, true);
+                const capacity = data().getUint32(vectors + index * 8 + 4, true);
+                const length = Math.min(capacity, stdin.length - position);
+                new Uint8Array(memory.buffer, address, length).set(stdin.subarray(position, position + length));
+                position += length;
+                total += length;
+            }
+            put32(read, total);
+            return 0;
+        },
         fd_fdstat_get(fd, address) {
             if (fd > 2) return 8;
             new Uint8Array(memory.buffer, address, 24).fill(0);
@@ -97,10 +114,29 @@ export async function runProbe(bytes) {
     memory = instance.exports.memory;
     try { instance.exports._start(); }
     catch (error) { if (!(error instanceof Exit) || error.code !== 0) throw new Error(`${error.message}: ${errors}`); }
-    if (!output.startsWith('PASS: backend=OpenSSL ') || randomCalls === 0) {
-        throw new Error(`OpenSSL probe did not pass: ${errors || output}`);
-    }
+    output += stdoutDecoder.decode();
+    errors += stderrDecoder.decode();
+    stdin.fill(0);
     return { output, randomCalls, randomBytes };
 }
 
+async function runProbe(bytes) {
+    const result = await execute(bytes, '');
+    if (!result.output.startsWith('PASS: backend=OpenSSL ') || result.randomCalls === 0) {
+        throw new Error('OpenSSL probe did not pass');
+    }
+    return result;
+}
+
+async function runCommand(bytes, request) {
+    const input = JSON.stringify(request);
+    if (input.length > 8388608) throw new Error('Crypto request exceeds its limit');
+    const result = await execute(bytes, input);
+    const response = JSON.parse(result.output);
+    if (response.error) throw new Error(response.error);
+    return response;
+}
+
+globalThis.stackChatWasi = Object.freeze({ runCommand, runProbe });
+
 // @license-end
-- 
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