Merge pull request #42 from artenator/master

added box detached api
lvh · Jun 15, 2018 · 26f85ef · 26f85ef
2 parents 017cf73 + 1948f55
commit 26f85ef
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diff --git a/src/caesium/binding.clj b/src/caesium/binding.clj
@@ -111,6 +111,23 @@
       ^bytes ^{Pinned {}} pk
       ^bytes ^{Pinned {}} sk]]
 
+    [^int crypto_box_detached
+     [^bytes ^{Pinned {}} c
+      ^bytes ^{Pinned {}} mac
+      ^bytes ^{Pinned {}} m
+      ^long ^{LongLong {}} mlen
+      ^bytes ^{Pinned {}} n
+      ^bytes ^{Pinned {}} pk
+      ^bytes ^{Pinned {}} sk]]
+    [^int crypto_box_open_detached
+     [^bytes ^{Pinned {}} m
+      ^bytes ^{Pinned {}} c
+      ^bytes ^{Pinned {}} mac
+      ^long ^{LongLong {}} clen
+      ^bytes ^{Pinned {}} n
+      ^bytes ^{Pinned {}} pk
+      ^bytes ^{Pinned {}} sk]]
+
     [^long ^{size_t {}} crypto_sign_bytes []]
     [^long ^{size_t {}} crypto_sign_seedbytes []]
     [^long ^{size_t {}} crypto_sign_publickeybytes []]

diff --git a/src/caesium/crypto/box.clj b/src/caesium/crypto/box.clj
@@ -253,3 +253,38 @@
   libsodium function."
   [pk sk ctext]
   (box-seal-open ctext pk sk))
+
+(defn box-detached-to-bufs! [c mac m mlen n pk sk]
+  (b/call! detached c mac m mlen n pk sk))
+
+(defn box-detached [ptext nonce pk sk]
+  (let [c (bb/alloc (bb/buflen ptext))
+        mac (bb/alloc macbytes)]
+    (box-detached-to-bufs!
+     c
+     mac
+     (bb/->indirect-byte-buf ptext)
+     (bb/buflen ptext)
+     (bb/->indirect-byte-buf nonce)
+     (bb/->indirect-byte-buf pk)
+     (bb/->indirect-byte-buf sk))
+    {:c (bb/->bytes c)
+     :mac (bb/->bytes mac)}))
+
+(defn box-open-detached-to-bufs! [m c mac clen n pk sk]
+  (let [res (b/call! open_detached m c mac clen n pk sk)]
+    (if (zero? res)
+      m
+      (throw (RuntimeException. "Ciphertext verification failed")))))
+
+(defn box-open-detached [ctext mac nonce pk sk]
+  (let [m (bb/alloc (bb/buflen ctext))]
+    (box-open-detached-to-bufs!
+     m
+     (bb/->indirect-byte-buf ctext)
+     (bb/->indirect-byte-buf mac)
+     (bb/buflen ctext)
+     (bb/->indirect-byte-buf nonce)
+     (bb/->indirect-byte-buf pk)
+     (bb/->indirect-byte-buf sk))
+    (bb/->bytes m)))
diff --git a/test/caesium/crypto/box_test.clj b/test/caesium/crypto/box_test.clj
@@ -62,3 +62,22 @@
       (is (thrown-with-msg?
            RuntimeException #"Ciphertext verification failed"
            (b/anonymous-decrypt bob-pk bob-sk forgery))))))
+
+(deftest detached-test
+  (let [nonce (box-vector "nonce")
+        ptext (box-vector "plaintext")
+        c-kat (box-vector "ciphertext")
+        bob-pk (box-vector "bob-public-key")
+        bob-sk (box-vector "bob-secret-key")
+        alice-pk (box-vector "alice-public-key")
+        alice-sk (box-vector "alice-secret-key")
+        {:keys [c mac]} (b/box-detached ptext nonce alice-pk bob-sk)
+        open-detached (b/box-open-detached c mac nonce bob-pk alice-sk)]
+    (is (bb/bytes= (byte-array (drop b/macbytes c-kat)) c))
+    (is (bb/bytes= (byte-array (take b/macbytes c-kat)) mac))
+    (is (bb/bytes= ptext open-detached))
+    (let [forged-c (r/randombytes (- (alength ^bytes c-kat) b/macbytes))
+          forged-mac (r/randombytes b/macbytes)]
+      (is (thrown-with-msg?
+           RuntimeException #"Ciphertext verification failed"
+           (b/box-open-detached forged-c forged-mac nonce bob-pk alice-sk))))))