From 0edd117cd2853dd33f97b15ac0e23da603432535 Mon Sep 17 00:00:00 2001
From: Red <bradley.t.sheehan@gmail.com>
Date: Tue, 17 Sep 2024 16:37:38 -0600
Subject: [PATCH] implement hash160 (#26)

* fix hash + fix test cases

Co-authored-by: Nikita Orlov <stringnickq@gmail.com>
Co-authored-by: Thomas Coratger <60488569+tcoratger@users.noreply.github.com>
---
 src/hashes/hash160.zig | 50 ++++++++++++++++++++++++++++++++++++++++++
 src/hashes/lib.zig     |  1 +
 2 files changed, 51 insertions(+)
 create mode 100644 src/hashes/hash160.zig

diff --git a/src/hashes/hash160.zig b/src/hashes/hash160.zig
new file mode 100644
index 0000000..a5a5e25
--- /dev/null
+++ b/src/hashes/hash160.zig
@@ -0,0 +1,50 @@
+const std = @import("std");
+const testing = std.testing;
+const Sha256 = std.crypto.hash.sha2.Sha256;
+const Ripemd160 = @import("ripemd160.zig").Ripemd160;
+
+pub const Hash160 = struct {
+    const Self = @This();
+    pub const digest_length = 20;
+    pub const Options = struct {};
+
+    pub fn init(_: Options) Self {
+        return .{};
+    }
+
+    pub inline fn hash(b: []const u8, out: *[digest_length]u8, _: Options) void {
+        var sha_out: [Sha256.digest_length]u8 = undefined;
+
+        // Step 1: Compute SHA256 hash
+        Sha256.hash(b, &sha_out, .{});
+
+        // Step 2: Compute RIPEMD160 of the SHA256 result
+        Ripemd160.hash(&sha_out, out, .{});
+    }
+};
+
+// Testing Hash160 against known vectors
+test "hash160 vectors" {
+    const test_cases = [_]struct {
+        input: []const u8,
+        expected: []const u8,
+    }{
+        .{ .input = "hello", .expected = "b6a9c8c230722b7c748331a8b450f05566dc7d0f" },
+        .{ .input = "blockchain", .expected = "755f6f4af6e11c5cf642f0ed6ecda89d8619cee7" },
+        .{ .input = "abc", .expected = "bb1be98c142444d7a56aa3981c3942a978e4dc33" },
+        .{ .input = "bitcoin", .expected = "6b2904910f9b40b2244eed93a7b8d992b22f8d32" },
+    };
+
+    for (test_cases) |case| {
+        errdefer {
+            std.log.err("test case failed, case = {s}", .{std.json.fmt(case, .{})});
+        }
+        var expected_output: [Hash160.digest_length]u8 = undefined;
+        _ = try std.fmt.hexToBytes(&expected_output, case.expected);
+
+        var actual_output: [Hash160.digest_length]u8 = undefined;
+
+        Hash160.hash(case.input, &actual_output, .{});
+        try testing.expectEqualSlices(u8, &expected_output, &actual_output);
+    }
+}
diff --git a/src/hashes/lib.zig b/src/hashes/lib.zig
index 20f5bc4..c640ffb 100644
--- a/src/hashes/lib.zig
+++ b/src/hashes/lib.zig
@@ -1 +1,2 @@
 pub const Ripemd160 = @import("ripemd160.zig").Ripemd160;
+pub const Hash160 = @import("hash160.zig").Hash160;