feed, receiver, wrapper: replace MD5 \w SHA-256

also refactored weepinbell.utils.digest. business logic no longer depend
on a concrete algorithm like SHA-256 or MD5, it's just a `digest`
function whose defaults can be replaced anytime.

4 files changed, 22 insertions, 10 deletions

diff --git a/src/weepinbell/feed.clj b/src/weepinbell/feed.clj
index 7f1963d..aa118c5 100644
--- a/src/weepinbell/feed.clj
+++ b/src/weepinbell/feed.clj
@@ -1,14 +1,14 @@
 (ns weepinbell.feed
   (:require [clj-rss.core :as rss]
             [weepinbell.utils.url :refer [get-domain]]
-            [weepinbell.utils.digest :refer [md5-hash]])
+            [weepinbell.utils.digest :refer [digest]])
   (:import [java.time Instant]))
 
 (defn make-feed-items [wms config]
   (->> wms
        (map #(let [wm (:webmention %)
                    id (if-let [id (:id wm)] id
-                              (md5-hash (str (:source wm) (:target wm))))
+                              (digest (str (:source wm) (:target wm))))
                    permalink (str (:base-url config) "/api/mention/" id)
                    modified (:modified wm)
                    pub-date (when modified
diff --git a/src/weepinbell/receiver.clj b/src/weepinbell/receiver.clj
index bf4bce7..b805e43 100644
--- a/src/weepinbell/receiver.clj
+++ b/src/weepinbell/receiver.clj
@@ -3,7 +3,7 @@
   (:require [clojure.string :as string]
             [clojure.core.async :refer [put!]]
             [weepinbell.utils.url :refer [get-domain valid-http-url?]]
-            [weepinbell.utils.digest :refer [md5-hash]]))
+            [weepinbell.utils.digest :refer [digest]]))
 
 ;; utilities
 (defn- remove-anchor 
@@ -68,7 +68,7 @@
          (put! wmc new-wm)
          ;; respond with 201 when Webmention passed checks and
          ;; was sent into queue, include a Location header
-         (let [wm-id (md5-hash (str source target))
+         (let [wm-id (digest (str source target))
                wm-url (str (:base-url config) "/api/mention/" wm-id)
                response {:status 201
                          :message "Webmention is accepted and pending for verification."
diff --git a/src/weepinbell/utils/digest.clj b/src/weepinbell/utils/digest.clj
index 979c547..4e50709 100644
--- a/src/weepinbell/utils/digest.clj
+++ b/src/weepinbell/utils/digest.clj
@@ -1,7 +1,19 @@
 (ns weepinbell.utils.digest 

-  (:import java.security.MessageDigest))

+  (:import java.security.MessageDigest)

+  (:require [clojure.string :refer [upper-case]]))

 

-(defn md5-hash [^String s] 

-  (let [algorithm (MessageDigest/getInstance "MD5") 

+(defn- java-digest [^String s algo] 

+  (let [algorithm (MessageDigest/getInstance algo) 

         raw-bytes (.digest algorithm (.getBytes s "UTF-8"))] 

     (apply str (map #(format "%02x" %) raw-bytes))))

+

+(defn digest 

+  ([s]

+   (digest s :sha-256 32))

+  ([s algo]

+   (digest s algo 32))

+  ([s algo length]

+   (->> (java-digest s (upper-case (name algo)))

+        (take length)

+        (apply str))))

+

diff --git a/src/weepinbell/wrapper.clj b/src/weepinbell/wrapper.clj
index a3659e7..e013f6d 100644
--- a/src/weepinbell/wrapper.clj
+++ b/src/weepinbell/wrapper.clj
@@ -4,7 +4,7 @@
                                       download-file]]
             [weepinbell.microformats-parser :as mf-parser]
             [taoensso.timbre :as timbre]
-            [weepinbell.utils.digest :refer [md5-hash]]))
+            [weepinbell.utils.digest :refer [digest]]))
 
 (defn- find-mf-photo [mf]
   (or (-> mf
@@ -18,7 +18,7 @@
   (if raw-photo
     (let [photo-url (str raw-photo)
           file-ext (or (re-find #"\.(?:jpg|jpeg|png|gif|webp)" photo-url) ".jpg")
-          filename  (str (md5-hash photo-url) file-ext)
+          filename  (str (digest photo-url) file-ext)
           local-path (str "data/avatars/" filename)
           public-path (str "/avatars/" filename)]
                  ;; download photo if not exists
@@ -38,7 +38,7 @@
                javamap->map)
         wm {:source source
             :target target
-            :id (md5-hash (str source target))
+            :id (digest (str source target))
             :modified (System/currentTimeMillis)}
         proxied-photo (-> mf 
                           find-mf-photo