From 38ae14cc4d23bf2d255bac0427ab4c2a0d827a21 Mon Sep 17 00:00:00 2001
From: Karl Burtram <karlb@microsoft.com>
Date: Mon, 3 Dec 2018 14:09:42 -0800
Subject: [PATCH] Use UTF8 for Azure token cache (#3391)

* Switch token cache encryption encoding to UTF8

* Try to parse as binary in fallback

* Code review feedback
---
 .../src/account-provider/tokenCache.ts        | 42 ++++++++++++-------
 1 file changed, 26 insertions(+), 16 deletions(-)

diff --git a/extensions/azurecore/src/account-provider/tokenCache.ts b/extensions/azurecore/src/account-provider/tokenCache.ts
index 8578504e3a..96e3bf4d4e 100644
--- a/extensions/azurecore/src/account-provider/tokenCache.ts
+++ b/extensions/azurecore/src/account-provider/tokenCache.ts
@@ -223,22 +223,16 @@ export default class TokenCache implements adal.TokenCache {
 		return this.getOrCreateEncryptionParams()
 			.then(encryptionParams => {
 				try {
-					let cacheCipher = fs.readFileSync(self._cacheSerializationPath, TokenCache.FsOptions);
-
-					let decipher = crypto.createDecipheriv(TokenCache.CipherAlgorithm, encryptionParams.key, encryptionParams.initializationVector);
-					let cacheJson = decipher.update(cacheCipher, 'hex', 'binary');
-					cacheJson += decipher.final('binary');
-
-					// Deserialize the JSON into the array of tokens
-					let cacheObj = <adal.TokenResponse[]>JSON.parse(cacheJson);
-					for (let objIndex in cacheObj) {
-						// Rehydrate Date objects since they will always serialize as a string
-						cacheObj[objIndex].expiresOn = new Date(<string>cacheObj[objIndex].expiresOn);
-					}
-
-					return cacheObj;
+					return self.decryptCache('utf8', encryptionParams);
 				} catch (e) {
-					throw e;
+					try {
+						// try to parse using 'binary' encoding and rewrite cache as UTF8
+						let response = self.decryptCache('binary', encryptionParams);
+						self.writeCache(response);
+						return response;
+					} catch (e) {
+						throw e;
+					}
 				}
 			})
 			.then(null, err => {
@@ -248,6 +242,22 @@ export default class TokenCache implements adal.TokenCache {
 			});
 	}
 
+	private decryptCache(encoding: crypto.Utf8AsciiBinaryEncoding, encryptionParams: EncryptionParams): adal.TokenResponse[] {
+		let cacheCipher = fs.readFileSync(this._cacheSerializationPath, TokenCache.FsOptions);
+		let decipher = crypto.createDecipheriv(TokenCache.CipherAlgorithm, encryptionParams.key, encryptionParams.initializationVector);
+		let cacheJson = decipher.update(cacheCipher, 'hex', encoding);
+		cacheJson += decipher.final(encoding);
+
+		// Deserialize the JSON into the array of tokens
+		let cacheObj = <adal.TokenResponse[]>JSON.parse(cacheJson);
+		for (let objIndex in cacheObj) {
+			// Rehydrate Date objects since they will always serialize as a string
+			cacheObj[objIndex].expiresOn = new Date(<string>cacheObj[objIndex].expiresOn);
+		}
+
+		return cacheObj;
+	}
+
 	private removeFromCache(cache: adal.TokenResponse[], entries: adal.TokenResponse[]): adal.TokenResponse[] {
 		entries.forEach((entry: adal.TokenResponse) => {
 			// Check to see if the entry exists
@@ -274,7 +284,7 @@ export default class TokenCache implements adal.TokenCache {
 					let cacheJson = JSON.stringify(cache);
 
 					let cipher = crypto.createCipheriv(TokenCache.CipherAlgorithm, encryptionParams.key, encryptionParams.initializationVector);
-					let cacheCipher = cipher.update(cacheJson, 'binary', 'hex');
+					let cacheCipher = cipher.update(cacheJson, 'utf8', 'hex');
 					cacheCipher += cipher.final('hex');
 
 					fs.writeFileSync(self._cacheSerializationPath, cacheCipher, TokenCache.FsOptions);