diff --git a/.woodpecker/.publish.yml b/.woodpecker/.publish.yml
index 9e5f39a..6d3b34e 100644
--- a/.woodpecker/.publish.yml
+++ b/.woodpecker/.publish.yml
@@ -1,7 +1,19 @@
-branches: [main, dev]
+# branches: [main, dev]
 platform: linux/amd64
 
 pipeline:
+  dryrun:
+    image: woodpeckerci/plugin-docker-buildx
+    secrets: [ docker_username, docker_password ]
+    settings:
+      repo: chewingbever/vieter
+      tag: dev
+      platforms: [ linux/arm/v7, linux/arm64/v8, linux/amd64 ]
+      dry_run: true
+    when:
+      event: pull_request
+      branch: dev
+
   dev:
     image: woodpeckerci/plugin-docker-buildx
     secrets: [ docker_username, docker_password ]
diff --git a/src/pkg.v b/src/pkg.v
index 8d23b6a..8b1849c 100644
--- a/src/pkg.v
+++ b/src/pkg.v
@@ -2,6 +2,7 @@ module pkg
 
 import time
 import os
+import util
 
 #flag -larchive
 
@@ -120,8 +121,8 @@ fn parse_pkg_info_string(pkg_info_str &string) ?PkgInfo {
 			'arch' { pkg_info.arch = value }
 			'builddate' { pkg_info.build_date = value.int() }
 			'packager' { pkg_info.packager = value }
-			'md5sum' { pkg_info.md5sum = value }
-			'sha256sum' { pkg_info.sha256sum = value }
+			'md5sum' { continue }
+			'sha256sum' { continue }
 			'pgpsig' { pkg_info.pgpsig = value }
 			'pgpsigsize' { pkg_info.pgpsigsize = value.int() }
 			// Array values
@@ -192,7 +193,11 @@ pub fn read_pkg(pkg_path string) ?Pkg {
 	}
 
 	mut pkg_info := parse_pkg_info_string(unsafe { cstring_to_vstring(&char(buf)) }) ?
+
 	pkg_info.csize = i64(os.file_size(pkg_path))
+	pkg_info.md5sum, pkg_info.sha256sum = util.hash_file(pkg_path) or {
+		return error('Failed to hash package.')
+	}
 
 	return Pkg{
 		info: pkg_info
@@ -225,7 +230,6 @@ pub fn (p &PkgInfo) to_desc() string {
 	desc += format_entry('CSIZE', p.csize.str())
 	desc += format_entry('ISIZE', p.size.str())
 
-	// TODO calculate these
 	desc += format_entry('MD5SUM', p.md5sum)
 	desc += format_entry('SHA256SUM', p.sha256sum)
 
diff --git a/src/util.v b/src/util.v
new file mode 100644
index 0000000..cb17c3f
--- /dev/null
+++ b/src/util.v
@@ -0,0 +1,30 @@
+module util
+
+import os
+import crypto.md5
+import crypto.sha256
+
+// hash_file returns the md5 & sha256 hash of a given file
+pub fn hash_file(path &string) ?(string, string) {
+	file := os.open(path) or { return error('Failed to open file.') }
+
+	mut md5sum := md5.new()
+	mut sha256sum := sha256.new()
+
+	buf_size := i32(1_000_000)
+	mut buf := []byte{len: buf_size}
+	mut bytes_left := os.file_size(path)
+
+	for bytes_left > 0 {
+		// TODO check if just breaking here is safe
+		bytes_read := file.read(mut buf) or { break }
+		bytes_left -= u64(bytes_read)
+
+		if bytes_left > buf_size {
+			md5sum.write(buf)
+			sha256sum.write(buf)
+		}
+	}
+
+	return md5sum.sum(buf).hex(), sha256sum.sum(buf).hex()
+}