From 5ce650382352c1503f40abf08129ada69402af55 Mon Sep 17 00:00:00 2001
From: bitflash-coin <bookofshamers@outlook.com>
Date: Tue, 4 Aug 2026 06:34:32 -0700
Subject: public commit

---
 src/test_btfchan.cpp | 83 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 83 insertions(+)
 create mode 100644 src/test_btfchan.cpp

(limited to 'src/test_btfchan.cpp')

diff --git a/src/test_btfchan.cpp b/src/test_btfchan.cpp
new file mode 100644
index 0000000..5a66560
--- /dev/null
+++ b/src/test_btfchan.cpp
@@ -0,0 +1,83 @@
+// Standalone tests for btfchan (ported from Itzal echan.rs behavior).
+// Build (UCRT64):
+//   g++ -std=gnu++14 test_btfchan.cpp btfchan.cpp -lsodium -o test_btfchan.exe
+
+#include "btfchan.h"
+#include <cstdio>
+#include <cstring>
+#include <string>
+#include <vector>
+
+using namespace btf;
+static int g_fail = 0;
+#define CHECK(cond, name) do { \
+    if (cond) { printf("  ok   %s\n", name); } \
+    else      { printf("  FAIL %s\n", name); g_fail++; } } while(0)
+
+int main()
+{
+    if (!ChanInit()) { printf("sodium init failed\n"); return 2; }
+
+    // Endpoint (service) has a static keypair; client only knows the static pub.
+    unsigned char ep_pk[32], ep_sk[32];
+    ChanKeypair(ep_pk, ep_sk);
+
+    printf("handshake_derives_same_key\n");
+    unsigned char eph_pub[32], k_client[32], k_endpoint[32];
+    CHECK(ChanClientHandshake(ep_pk, eph_pub, k_client), "client handshake ok");
+    CHECK(ChanEndpointHandshake(eph_pub, ep_sk, k_endpoint), "endpoint handshake ok");
+    CHECK(memcmp(k_client, k_endpoint, 32) == 0, "both sides derive the SAME shared key");
+
+    printf("encrypt_decrypt_roundtrip\n");
+    {
+        std::string msg = "one CPU one vote -- blinded over the wire";
+        std::vector<unsigned char> frame = ChanEncryptFrame(k_client,
+            (const unsigned char*)msg.data(), msg.size());
+        // frame = [len:4][nonce:24][ct||tag]
+        size_t bodylen = (frame[0]<<24)|(frame[1]<<16)|(frame[2]<<8)|frame[3];
+        CHECK(bodylen == frame.size() - 4, "length prefix correct");
+        std::vector<unsigned char> pt;
+        CHECK(ChanDecryptBody(k_endpoint, &frame[4], bodylen, pt), "endpoint decrypts");
+        CHECK(pt.size() == msg.size() && memcmp(pt.data(), msg.data(), msg.size()) == 0, "plaintext matches");
+    }
+
+    printf("tampered_ciphertext_fails\n");
+    {
+        std::string msg = "secret block";
+        std::vector<unsigned char> frame = ChanEncryptFrame(k_client,
+            (const unsigned char*)msg.data(), msg.size());
+        size_t bodylen = frame.size() - 4;
+        frame[frame.size()-1] ^= 0x01; // flip a bit in the tag/ciphertext
+        std::vector<unsigned char> pt;
+        CHECK(!ChanDecryptBody(k_endpoint, &frame[4], bodylen, pt), "tampered frame rejected");
+    }
+
+    printf("wrong_key_fails\n");
+    {
+        unsigned char other_pk[32], other_sk[32];
+        ChanKeypair(other_pk, other_sk);
+        unsigned char eph2[32], kbad[32];
+        ChanClientHandshake(other_pk, eph2, kbad); // box to a DIFFERENT endpoint
+        std::string msg = "for someone else";
+        std::vector<unsigned char> frame = ChanEncryptFrame(kbad,
+            (const unsigned char*)msg.data(), msg.size());
+        size_t bodylen = frame.size() - 4;
+        std::vector<unsigned char> pt;
+        CHECK(!ChanDecryptBody(k_endpoint, &frame[4], bodylen, pt), "our endpoint can't open someone else's box");
+    }
+
+    printf("empty_and_large_payloads\n");
+    {
+        std::vector<unsigned char> empty;
+        std::vector<unsigned char> f0 = ChanEncryptFrame(k_client, NULL, 0);
+        std::vector<unsigned char> o0;
+        CHECK(ChanDecryptBody(k_endpoint, &f0[4], f0.size()-4, o0) && o0.empty(), "empty payload roundtrips");
+        std::vector<unsigned char> big(200000, 0xAB);
+        std::vector<unsigned char> fb = ChanEncryptFrame(k_client, big.data(), big.size());
+        std::vector<unsigned char> ob;
+        CHECK(ChanDecryptBody(k_endpoint, &fb[4], fb.size()-4, ob) && ob == big, "200KB payload roundtrips");
+    }
+
+    printf("\n%s (%d failures)\n", g_fail == 0 ? "ALL TESTS PASSED" : "TESTS FAILED", g_fail);
+    return g_fail == 0 ? 0 : 1;
+}
-- 
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