add option for extra HTTP headers containing checksums

config/config.go

@@ -86,6 +86,7 @@ type Configuration struct {
 	CheckInterval           int        `yaml:"CheckInterval"`
 	RepositoryScanInterval  int        `yaml:"RepositoryScanInterval"`
 	MaxLinkHeaders          int        `yaml:"MaxLinkHeaders"`
+	CheckSumHeaders         bool       `yaml:"CheckSumHeaders"`
 	FixTimezoneOffsets      bool       `yaml:"FixTimezoneOffsets"`
 	Hashes                  hashing    `yaml:"Hashes"`
 	DisallowRedirects       bool       `yaml:"DisallowRedirects"`

http/pagerenderer.go

@@ -5,6 +5,8 @@ package http
 
 import (
 	"bytes"
+	"encoding/base64"
+	"encoding/hex"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -91,6 +93,22 @@ func (w *RedirectRenderer) Write(ctx *Context, results *mirrors.Results) (status
 			}
 		}
 
+		// Generate checksum headers
+		if GetConfig().CheckSumHeaders {
+			if len(results.FileInfo.Md5) > 0 {
+				md5, _ := hex.DecodeString(results.FileInfo.Md5)
+				ctx.ResponseWriter().Header().Add("Content-MD5", fmt.Sprintf("%s", base64.StdEncoding.EncodeToString(md5)))
+			}
+			if len(results.FileInfo.Sha1) > 0 {
+				sha1, _ := hex.DecodeString(results.FileInfo.Sha1)
+				ctx.ResponseWriter().Header().Add("Content-SHA1", fmt.Sprintf("%s", base64.StdEncoding.EncodeToString(sha1)))
+			}
+			if len(results.FileInfo.Sha256) > 0 {
+				sha256, _ := hex.DecodeString(results.FileInfo.Sha256)
+				ctx.ResponseWriter().Header().Add("Content-SHA256", fmt.Sprintf("%s", base64.StdEncoding.EncodeToString(sha256)))
+			}
+		}
+
 		// Finally issue the redirect
 		http.Redirect(ctx.ResponseWriter(), ctx.Request(), results.MirrorList[0].AbsoluteURL+path, http.StatusFound)
 		return http.StatusFound, nil

mirrorbits.conf

@@ -137,6 +137,10 @@
 ## Affected mirrors will need to be rescanned after enabling this feature.
 # FixTimezoneOffsets: false
 
+## Send Content-(MD5|SHA1|SHA256) headers
+## requires the hashing algorithm to be enabled
+# CheckSumHeaders: true
+
 ## List of mirrors to use as fallback which will be used in case mirrorbits
 ## is unable to answer a request because the database is unreachable.
 ## Note: Mirrorbits will redirect to one of these mirrors based on the user