Merge pull request #56 from hax0kartik/main

Add target for generating header_and_shortids from block

rust_bitcoin_lib/src/lib.rs

@@ -130,6 +130,34 @@ pub unsafe extern "C" fn rust_bitcoin_addrv2(data: *const u8, len: usize, actual
     }
 }
 
+#[no_mangle]
+pub unsafe extern "C" fn rust_bitcoin_headerandshortids(data: *const u8, len: usize) -> i32 {
+    // Safety: Ensure that the data pointer is valid for the given length
+    let data_slice = slice::from_raw_parts(data, len);
+
+    let res = deserialize_partial::<Block>(data_slice);
+
+    match res {
+        Ok(block) => {
+            // 101 is a random nonce value and 2 specifies that we want to use segwit
+            let compact = HeaderAndShortIds::from_block(&block.0, 101, 2, &[]);
+
+            match compact {
+                Ok(c) => return (c.prefilled_txs.len() + c.short_ids.len()).try_into().unwrap(),
+                Err(_) => return -1,
+            }
+
+        },
+        Err(err) => {
+            if err.to_string().starts_with("unsupported segwit version") {
+                return -2;
+            }
+
+            return -1;
+        }
+    }
+}
+
 #[no_mangle]
 pub unsafe extern "C" fn rust_bitcoin_cmpctblocks(data: *const u8, len: usize) -> i32 {
     // Safety: Ensure that the data pointer is valid for the given length

targets/headerandshortids.cpp

@@ -0,0 +1,38 @@
+#include <fuzzer/FuzzedDataProvider.h>
+#include <string>
+#include <iostream>
+
+#include "bitcoin/src/test/fuzz/fuzz.h"
+#include "bitcoin/src/blockencodings.h"
+#include "bitcoin/src/streams.h"
+
+extern "C" int rust_bitcoin_headerandshortids(const uint8_t *data, size_t len);
+
+int HeaderAndShortIdsCore(Span<const uint8_t> buffer) 
+{
+    DataStream ds{buffer};
+    CBlock block;
+    int res = 0;
+    try {
+        ds >> TX_WITH_WITNESS(block);
+        if (block.vtx.size() < 1) return res;
+        CBlockHeaderAndShortTxIDs block_header_and_short_txids {block}; // use the value of 101 as nonce
+        res = block_header_and_short_txids.BlockTxCount();
+    } catch (const std::ios_base::failure& e) {
+        if (std::string(e.what()).find("Superfluous witness record") != std::string::npos)
+            return -2;
+        return -1;
+    }
+    return res;
+}
+
+FUZZ_TARGET(header_and_shortids)
+{
+    int core{HeaderAndShortIdsCore(buffer)};
+    int rust_bitcoin{rust_bitcoin_headerandshortids(buffer.data(), buffer.size())};
+
+    if (core == -2 || rust_bitcoin == -2)
+        return;
+
+    assert(core == rust_bitcoin);
+}