11.2.2 backport 1948 1968 Added locks to encrypt/decrypt in truststore password obfuscation and fixed race condition

build.gradle

@@ -85,7 +85,7 @@ if(hasProperty('buildProfile') && buildProfile == "jre8") {
 	}
 }
 
-jar.archiveFileName = "${archivesBaseName}-${version}.${jreVersion}-preview.jar"
+jar.archiveFileName = "${archivesBaseName}-${version}.${jreVersion}.jar"
 jar {
 	manifest {
         attributes 'Title': "Microsoft JDBC Driver ${archiveVersion} for SQL Server",
@@ -130,7 +130,7 @@ dependencies {
     implementation 'org.osgi:org.osgi.core:6.0.0',
 			'org.osgi:org.osgi.compendium:5.0.0'
 	compileOnly 'com.azure:azure-security-keyvault-keys:4.2.8',
-			'com.azure:azure-identity:1.3.3',
+			'com.azure:azure-identity:1.7.0-beta.2',
 			'org.antlr:antlr4-runtime:4.9.2',
 			'com.google.code.gson:gson:2.8.7',
 			'org.bouncycastle:bcprov-jdk15on:1.69',
@@ -152,7 +152,7 @@ dependencies {
 			'com.google.code.gson:gson:2.8.7',
 			'org.bouncycastle:bcprov-jdk15on:1.69',
 			'com.azure:azure-security-keyvault-keys:4.2.8',
-			'com.azure:azure-identity:1.3.3',
+			'com.azure:azure-identity:1.7.0-beta.2',
 			'com.microsoft.azure:adal4j:1.6.7',
 			'com.h2database:h2:1.4.200'
 }

src/main/java/com/microsoft/sqlserver/jdbc/SecureStringUtil.java

@@ -3,6 +3,8 @@
 import java.security.SecureRandom;
 import java.text.MessageFormat;
 import java.util.Arrays;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReentrantLock;
 
 import javax.crypto.Cipher;
 import javax.crypto.KeyGenerator;
@@ -41,7 +43,11 @@ final class SecureStringUtil {
     private Cipher decryptCipher;
 
     /* singleton instance */
-    private static SecureStringUtil instance;
+    private static volatile SecureStringUtil instance;
+
+    private static final Lock INSTANCE_LOCK = new ReentrantLock();
+    private static final Lock ENCRYPT_LOCK = new ReentrantLock();
+    private static final Lock DECRYPT_LOCK = new ReentrantLock();
 
     /**
      * Get reference to SecureStringUtil instance
@@ -53,7 +59,14 @@ final class SecureStringUtil {
      */
     static SecureStringUtil getInstance() throws SQLServerException {
         if (instance == null) {
-            instance = new SecureStringUtil();
+            INSTANCE_LOCK.lock();
+            try {
+                if (instance == null) {
+                    instance = new SecureStringUtil();
+                }
+            } finally {
+                INSTANCE_LOCK.unlock();
+            }
         }
         return instance;
     }
@@ -90,18 +103,19 @@ private SecureStringUtil() throws SQLServerException {
      * @return encrypted string
      * 
      * @throws SQLServerException
-     *         if error
+     *         Throws an exception if the method fails to encrypt the character array
      */
     byte[] getEncryptedBytes(char[] chars) throws SQLServerException {
-        if (chars == null)
-            return null;
-
-        byte[] iv = new byte[IV_LENGTH];
-        SecureRandom random = new SecureRandom();
-        random.nextBytes(iv);
-        GCMParameterSpec ivParamSpec = new GCMParameterSpec(TAG_LENGTH * 8, iv);
-
+        ENCRYPT_LOCK.lock();
         try {
+            if (chars == null) {
+                return null;
+            }
+
+            byte[] iv = new byte[IV_LENGTH];
+            SecureRandom random = new SecureRandom();
+            random.nextBytes(iv);
+            GCMParameterSpec ivParamSpec = new GCMParameterSpec(TAG_LENGTH * 8, iv);
             encryptCipher.init(Cipher.ENCRYPT_MODE, secretKey, ivParamSpec);
 
             byte[] cipherText = encryptCipher.doFinal(Util.charsToBytes(chars));
@@ -113,29 +127,34 @@ byte[] getEncryptedBytes(char[] chars) throws SQLServerException {
             MessageFormat form = new MessageFormat(SQLServerException.getErrString("R_EncryptionFailed"));
             Object[] msgArgs = {e.getMessage()};
             throw new SQLServerException(this, form.format(msgArgs), null, 0, false);
+        } finally {
+            ENCRYPT_LOCK.unlock();
         }
     }
 
     /**
      * Get decrypted value of an encrypted string
      * 
      * @param bytes
+     *        The byte array to decrypt into a character array
      * 
      * @return decrypted string
      * 
      * @throws SQLServerException
+     *         Throws an exception if the method fails to decrypt the byte array
      */
     char[] getDecryptedChars(byte[] bytes) throws SQLServerException {
-        if (bytes == null)
-            return null;
-
-        byte[] iv = new byte[IV_LENGTH];
-        System.arraycopy(bytes, 0, iv, 0, IV_LENGTH);
-
-        GCMParameterSpec ivParamSpec = new GCMParameterSpec(TAG_LENGTH * 8, iv);
-
+        DECRYPT_LOCK.lock();
         byte[] plainText = null;
         try {
+            if (bytes == null) {
+                return null;
+            }
+
+            byte[] iv = new byte[IV_LENGTH];
+            System.arraycopy(bytes, 0, iv, 0, IV_LENGTH);
+
+            GCMParameterSpec ivParamSpec = new GCMParameterSpec(TAG_LENGTH * 8, iv);
             decryptCipher.init(Cipher.DECRYPT_MODE, secretKey, ivParamSpec);
 
             plainText = decryptCipher.doFinal(bytes, IV_LENGTH, bytes.length - IV_LENGTH);
@@ -148,6 +167,7 @@ char[] getDecryptedChars(byte[] bytes) throws SQLServerException {
             if (plainText != null) {
                 Arrays.fill(plainText, (byte) 0);
             }
+            DECRYPT_LOCK.unlock();
         }
     }
 }