From 223c67106086266bc399b872fdedb4b7e06357a8 Mon Sep 17 00:00:00 2001
From: razzle <harry@razzle.cloud>
Date: Thu, 28 Dec 2023 21:31:28 -0500
Subject: [PATCH] repro tarballs for components + sboms

Signed-off-by: razzle <harry@razzle.cloud>
---
 src/pkg/layout/component.go |  2 +-
 src/pkg/layout/sbom.go      |  7 +---
 src/pkg/utils/io.go         | 70 +++++++++++++++++++++++++++++++++++++
 3 files changed, 72 insertions(+), 7 deletions(-)

diff --git a/src/pkg/layout/component.go b/src/pkg/layout/component.go
index 2309d8200c..8eef88efd8 100644
--- a/src/pkg/layout/component.go
+++ b/src/pkg/layout/component.go
@@ -65,7 +65,7 @@ func (c *Components) Archive(component types.ZarfComponent, cleanupTemp bool) (e
 	if size > 0 {
 		tb := fmt.Sprintf("%s.tar", base)
 		message.Debugf("Archiving %q", name)
-		if err := archiver.Archive([]string{base}, tb); err != nil {
+		if err := utils.CreateReproducibleTarballFromDir(base, tb); err != nil {
 			return err
 		}
 		if c.Tarballs == nil {
diff --git a/src/pkg/layout/sbom.go b/src/pkg/layout/sbom.go
index 8920331a52..782e38ed0f 100644
--- a/src/pkg/layout/sbom.go
+++ b/src/pkg/layout/sbom.go
@@ -60,14 +60,9 @@ func (s *SBOMs) Archive() (err error) {
 	dir := s.Path
 	tb := filepath.Join(filepath.Dir(dir), SBOMTar)
 
-	allSBOMFiles, err := filepath.Glob(filepath.Join(dir, "*"))
-	if err != nil {
+	if err := utils.CreateReproducibleTarballFromDir(dir, tb); err != nil {
 		return err
 	}
-
-	if err = archiver.Archive(allSBOMFiles, tb); err != nil {
-		return
-	}
 	s.Path = tb
 	return os.RemoveAll(dir)
 }
diff --git a/src/pkg/utils/io.go b/src/pkg/utils/io.go
index 436e8b0155..40d6bb7712 100755
--- a/src/pkg/utils/io.go
+++ b/src/pkg/utils/io.go
@@ -5,6 +5,7 @@
 package utils
 
 import (
+	"archive/tar"
 	"bufio"
 	"crypto/sha256"
 	"fmt"
@@ -16,6 +17,7 @@ import (
 	"path/filepath"
 	"regexp"
 	"strings"
+	"time"
 
 	"github.com/defenseunicorns/zarf/src/config"
 	"github.com/defenseunicorns/zarf/src/pkg/message"
@@ -422,3 +424,71 @@ func SHAsMatch(path, expected string) error {
 	}
 	return nil
 }
+
+// CreateReproducibleTarballFromDir creates a tarball from a directory with stripped headers
+func CreateReproducibleTarballFromDir(dirPath, tarballPath string) error {
+	// Create a new tarball for the output
+	outFile, err := os.Create(tarballPath)
+	if err != nil {
+		return fmt.Errorf("error creating tarball: %w", err)
+	}
+	defer outFile.Close()
+
+	tarWriter := tar.NewWriter(outFile)
+	defer tarWriter.Close()
+
+	// Walk through the directory and process each file
+	err = filepath.Walk(dirPath, func(filePath string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		// Create a new header
+		header, err := tar.FileInfoHeader(info, "")
+		if err != nil {
+			return fmt.Errorf("error creating tar header: %w", err)
+		}
+
+		// Strip non-deterministic header data
+		header.ModTime = time.Time{}
+		header.AccessTime = time.Time{}
+		header.ChangeTime = time.Time{}
+		header.Uid = 0
+		header.Gid = 0
+		header.Uname = ""
+		header.Gname = ""
+
+		// Ensure the header's name is correctly set relative to the base directory
+		relPath, err := filepath.Rel(dirPath, filePath)
+		if err != nil {
+			return fmt.Errorf("error getting relative path: %w", err)
+		}
+		header.Name = relPath
+
+		// Write the header to the tarball
+		if err := tarWriter.WriteHeader(header); err != nil {
+			return fmt.Errorf("error writing header: %w", err)
+		}
+
+		// If it's a file, write its content
+		if !info.IsDir() {
+			file, err := os.Open(filePath)
+			if err != nil {
+				return fmt.Errorf("error opening file: %w", err)
+			}
+			defer file.Close()
+
+			if _, err := io.Copy(tarWriter, file); err != nil {
+				return fmt.Errorf("error writing file to tarball: %w", err)
+			}
+		}
+
+		return nil
+	})
+
+	if err != nil {
+		return fmt.Errorf("error walking through directory: %w", err)
+	}
+
+	return nil
+}