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Author: javascript-2020

blog/26-04-26/x509-certificates-in-js---encrypt-decrypt-data/ex/aes-encrypt-decrypt-browser.js

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+
+
+
+/*
+
+
+aes encrypt / decrypt
+
+
+30-04-26
+
+
+*/
+
+
+(async()=>{
+                                                                                console.clear();
+                                                                                
+                                                                                
+        var key         = await generateAesKey();
+        var encrypted   = await aesEncrypt(key,'hello world');
+        var txt         = await aesDecrypt(key,encrypted);
+        
+        console.log(txt);
+        
+        
+        
+        async function generateAesKey() {
+        
+              var key   = await crypto.subtle.generateKey({name:"AES-GCM",length: 256},true,["encrypt", "decrypt"]);
+              return key;
+              
+        }//generateAesKey
+        
+        
+        async function exportAesKey(key) {
+        
+              const raw = await crypto.subtle.exportKey("raw", key);
+              var b64   = btoa(String.fromCharCode(...new Uint8Array(raw)));
+              return b64;
+              
+        }//exportAesKey
+        
+        
+        async function importAesKey(base64) {
+        
+              const raw = Uint8Array.from(atob(base64), c => c.charCodeAt(0));
+              var key   = await  crypto.subtle.importKey("raw",raw,"AES-GCM",true,["encrypt", "decrypt"]);
+              return key;
+              
+        }//importAesKey
+        
+        
+        async function aesEncrypt(key, plaintext) {
+        
+              const iv = crypto.getRandomValues(new Uint8Array(12)); // 96-bit IV recommended
+              
+              const encoded = new TextEncoder().encode(plaintext);
+              
+              const ciphertext = await crypto.subtle.encrypt({name: "AES-GCM",iv},key,encoded);
+              
+              return {
+                iv: btoa(String.fromCharCode(...iv)),
+                data: btoa(String.fromCharCode(...new Uint8Array(ciphertext))),
+              };
+              
+        }//aesEncrypt
+        
+        
+        async function aesDecrypt(key, encrypted) {
+        
+              const iv = Uint8Array.from(atob(encrypted.iv), c => c.charCodeAt(0));
+              const data = Uint8Array.from(atob(encrypted.data), c => c.charCodeAt(0));
+              
+              const plaintext = await crypto.subtle.decrypt(
+                {
+                  name: "AES-GCM",
+                  iv,
+                },
+                key,
+                data
+              );
+              
+              return new TextDecoder().decode(plaintext);
+              
+        }//aesDecrypt
+        
+        
+        
+        
+})();
+
+
+