From 72baa6099ce1920c103dcb3a32cf77d8f1a73d08 Mon Sep 17 00:00:00 2001
From: Dillon Lees <dlees@specterops.io>
Date: Mon, 23 Jan 2023 13:47:56 -0500
Subject: [PATCH] Generate sha256 message digest for built binaries

---
 BUILD   | 31 +++++++++++++++++++++++++++++++
 def.bzl | 27 +++++++++++++++++++++++++++
 2 files changed, 58 insertions(+)
 create mode 100644 def.bzl

diff --git a/BUILD b/BUILD
index 9d98259d..72064f6d 100644
--- a/BUILD
+++ b/BUILD
@@ -1,6 +1,7 @@
 load("@io_bazel_rules_go//go:def.bzl", "go_binary", "go_library", "go_test")
 load("@bazel_gazelle//:def.bzl", "gazelle")
 load("@build_bazel_rules_nodejs//:index.bzl", "pkg_npm")
+load("//:def.bzl", "sha256sum")
 
 # gazelle:prefix github.com/bazelbuild/bazelisk
 gazelle(name = "gazelle")
@@ -85,6 +86,11 @@ go_binary(
     visibility = ["//visibility:public"],
 )
 
+sha256sum(
+   name = "bazelisk-darwin-amd64-sha",
+   src = ":bazelisk-darwin-amd64",
+)
+
 go_binary(
     name = "bazelisk-darwin-arm64",
     out = "bazelisk-darwin_arm64",
@@ -99,6 +105,11 @@ go_binary(
     visibility = ["//visibility:public"],
 )
 
+sha256sum(
+   name = "bazelisk-darwin-arm64-sha",
+   src = ":bazelisk-darwin-arm64",
+)
+
 genrule(
     name = "bazelisk-darwin-universal",
     srcs = [
@@ -113,6 +124,11 @@ genrule(
     ],
 )
 
+sha256sum(
+   name = "bazelisk-darwin-universal-sha",
+   src = ":bazelisk-darwin-universal",
+)
+
 go_binary(
     name = "bazelisk-linux-amd64",
     out = "bazelisk-linux_amd64",
@@ -127,6 +143,11 @@ go_binary(
     visibility = ["//visibility:public"],
 )
 
+sha256sum(
+   name = "bazelisk-linux-amd64-sha",
+   src = ":bazelisk-linux-amd64",
+)
+
 go_binary(
     name = "bazelisk-linux-arm64",
     out = "bazelisk-linux_arm64",
@@ -141,6 +162,11 @@ go_binary(
     visibility = ["//visibility:public"],
 )
 
+sha256sum(
+   name = "bazelisk-linux-arm64-sha",
+   src = ":bazelisk-linux-arm64",
+)
+
 go_binary(
     name = "bazelisk-windows-amd64",
     out = "bazelisk-windows_amd64.exe",
@@ -151,6 +177,11 @@ go_binary(
     visibility = ["//visibility:public"],
 )
 
+sha256sum(
+   name = "bazelisk-windows-amd64-sha",
+   src = ":bazelisk-windows-amd64",
+)
+
 pkg_npm(
     name = "npm_package",
     package_name = "@bazel/bazelisk",
diff --git a/def.bzl b/def.bzl
new file mode 100644
index 00000000..8bcf3afb
--- /dev/null
+++ b/def.bzl
@@ -0,0 +1,27 @@
+def _sha256sum_impl(ctx):
+  ctx.actions.run_shell(
+    outputs = [ctx.outputs.sha256],
+    inputs = [ctx.file.src],
+    command = "CWD=$PWD && cd `dirname {0}` && sha256sum `basename {0}` > $CWD/{1}".format(ctx.file.src.path, ctx.outputs.sha256.path),
+  )
+
+  return DefaultInfo(files = depset([ctx.outputs.sha256]))
+
+_sha256sum = rule(
+  implementation = _sha256sum_impl,
+  attrs = {
+    "src": attr.label(mandatory = True, allow_single_file = True),
+    "sha256": attr.output(),
+  }
+)
+
+def sha256sum(name, src, **kwargs):
+  """
+  Macro to create a sha256 message digest file
+  """
+  _sha256sum(
+    name = name,
+    src = src,
+    sha256 = "%s.sha256" % src,
+    **kwargs,
+  )