refactor(node): skip concat on counter mode de/encrypt

panva · Nov 3, 2021 · c373148 · c373148
1 parent 0c6d3f3
commit c373148
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Showing 2 changed files with 10 additions and 7 deletions.
diff --git a/src/runtime/node/decrypt.ts b/src/runtime/node/decrypt.ts
@@ -51,8 +51,8 @@ async function cbcDecrypt(
 
   let plaintext!: Uint8Array
   try {
-    const cipher = createDecipheriv(algorithm, encKey, iv)
-    plaintext = concat(cipher.update(ciphertext), cipher.final())
+    const decipher = createDecipheriv(algorithm, encKey, iv)
+    plaintext = concat(decipher.update(ciphertext), decipher.final())
   } catch {
     //
   }
@@ -77,13 +77,15 @@ async function gcmDecrypt(
     throw new JOSENotSupported(`alg ${enc} is not supported by your javascript runtime`)
   }
   try {
-    const cipher = createDecipheriv(algorithm, cek, iv, { authTagLength: 16 })
-    cipher.setAuthTag(tag)
+    const decipher = createDecipheriv(algorithm, cek, iv, { authTagLength: 16 })
+    decipher.setAuthTag(tag)
     if (aad.byteLength) {
-      cipher.setAAD(aad, { plaintextLength: ciphertext.length })
+      decipher.setAAD(aad, { plaintextLength: ciphertext.length })
     }
 
-    return concat(cipher.update(ciphertext), cipher.final())
+    const plaintext = decipher.update(ciphertext)
+    decipher.final()
+    return plaintext
   } catch {
     throw new JWEDecryptionFailed()
   }

diff --git a/src/runtime/node/encrypt.ts b/src/runtime/node/encrypt.ts
@@ -61,7 +61,8 @@ async function gcmEncrypt(
     cipher.setAAD(aad, { plaintextLength: plaintext.length })
   }
 
-  const ciphertext = concat(cipher.update(plaintext), cipher.final())
+  const ciphertext = cipher.update(plaintext)
+  cipher.final()
   const tag = cipher.getAuthTag()
 
   return { ciphertext, tag }