Add sha1 precompile

Cargo.toml

@@ -9,6 +9,7 @@ members = [
     "identity",
     "keccak256",
     "ripemd160",
+    "sha1",
     "sha256",
 ]
 

Makefile

@@ -1,4 +1,4 @@
-TARGETS=bls12pairing ecadd ecmul ecpairing ed25519 identity keccak256 ripemd160 sha256
+TARGETS=bls12pairing ecadd ecmul ecpairing ed25519 identity keccak256 ripemd160 sha1 sha256
 
 all:
 	@cargo build --release --target wasm32-unknown-unknown

sha1/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "ewasm-precompile-sha1"
+version = "0.1.0"
+authors = ["Alex Beregszaszi <alex@rtfs.hu>"]
+license = "Apache-2.0"
+repository = "https://github.com/ewasm/ewasm-precompiles"
+description = "Ethereum SHA1 precompile in Rust"
+publish = false
+
+[dependencies]
+sha1 = "0.6"
+ewasm_api = "0.5"
+
+[lib]
+crate-type = ["cdylib"]

sha1/README.md

@@ -0,0 +1,3 @@
+# sha1
+
+This is the precompile for enabling SHA-1 hashing according to [EIP-180](https://github.com/ethereum/EIPs/issues/180)

sha1/src/lib.rs

@@ -0,0 +1,21 @@
+extern crate ewasm_api;
+extern crate sha1;
+
+#[cfg(not(test))]
+#[no_mangle]
+pub extern "C" fn main() {
+    let length = ewasm_api::calldata_size();
+
+    // charge a base fee plus a word fee for every 256-bit word
+    let base_fee = 62;
+    let word_fee = 8;
+    let total_cost = base_fee + ((length + 31) / 32) * word_fee;
+
+    ewasm_api::consume_gas(total_cost as u64);
+
+    let data = ewasm_api::unsafe_calldata_copy(0, length);
+
+    let hash = sha1::Sha1::from(data).digest().bytes();
+
+    ewasm_api::finish_data(&hash)
+}