Warn about not reusing IVs

Will Bamberg · Will Bamberg · commit 1f0a368d554b · 2019-01-08T16:04:24.000-08:00
diff --git a/web-crypto/encrypt-decrypt/aes-cbc.js b/web-crypto/encrypt-decrypt/aes-cbc.js
@@ -23,6 +23,7 @@
   */
   async function encryptMessage(key) {
     let encoded = getMessageEncoding();
+    // The iv must never be reused with a given key.
     iv = window.crypto.getRandomValues(new Uint8Array(16));
     ciphertext = await window.crypto.subtle.encrypt(
       {
diff --git a/web-crypto/encrypt-decrypt/aes-ctr.js b/web-crypto/encrypt-decrypt/aes-ctr.js
@@ -23,6 +23,7 @@
   */
   async function encryptMessage(key) {
     let encoded = getMessageEncoding();
+    // The counter block value must never be reused with a given key.
     counter = window.crypto.getRandomValues(new Uint8Array(16)),
     ciphertext = await window.crypto.subtle.encrypt(
       {
diff --git a/web-crypto/encrypt-decrypt/aes-gcm.js b/web-crypto/encrypt-decrypt/aes-gcm.js
@@ -23,6 +23,7 @@
   */
   async function encryptMessage(key) {
     let encoded = getMessageEncoding();
+    // The iv must never be reused with a given key.
     iv = window.crypto.getRandomValues(new Uint8Array(12));
     ciphertext = await window.crypto.subtle.encrypt(
       {

Original file line number	Diff line number	Diff line change
`@@ -23,6 +23,7 @@`
`23`	`23`	`*/`
`24`	`24`	`async function encryptMessage(key) {`
`25`	`25`	`let encoded = getMessageEncoding();`
	`26`	`+ // The iv must never be reused with a given key.`
`26`	`27`	`iv = window.crypto.getRandomValues(new Uint8Array(16));`
`27`	`28`	`ciphertext = await window.crypto.subtle.encrypt(`
`28`	`29`	`{`