Add cached key encryptor/decryptor (#157)

Author: coltfred

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+## v8.1.0
+
+- Add `CachedKey`, which fetches then holds a cached DEK (Document Encryption Key) for repeated encrypt and decrypt operations without making additional TSP wrap/unwrap calls.
+  This is useful for many cryptographic operations using the same key in quick succession, such as inside a database transaction. Note that this key automatically expires after a short period of time.
+
 ## v8.0.1
 
 - We’ve removed the direct constructors for `TenantSecurityClient` and replaced them with a builder-based API. The static TenantSecurityClient.create method is still provided for convenience.

examples/cached-key-example/README.md

@@ -0,0 +1,63 @@
+# Cached Key Example
+
+In order to run this example, you need to be running a _Tenant Security Proxy_ (TSP) on your machine.
+Check the [README.md](../README.md) file in the parent directory to see how to start the TSP, if you haven't done so
+yet.
+
+Once the TSP is running, you can experiment with this example Java program. It demonstrates using
+`CachedEncryptor` and `CachedDecryptor` to encrypt and decrypt multiple records while minimizing
+calls to the TSP. The example code shows two scenarios:
+
+- encrypting three of a customer's records using a single cached key (one TSP wrap call)
+- decrypting all three records using a single cached key (one TSP unwrap call)
+
+## Why use a cached key?
+
+A normal `encrypt()` call wraps a new DEK through the TSP on every invocation. If you're encrypting
+several records in quick succession (like inside a database transaction), each call
+adds a network round trip.
+
+A `CachedEncryptor` wraps the DEK once, then all subsequent `encrypt()` calls are purely local
+CPU work. This means you can safely encrypt inside a database transaction without adding network
+latency or external failure modes to the transaction. The same applies to `CachedDecryptor` for
+reads.
+
+## Running the example
+
+To run the example, you will need to have a Java JRE 17+ and Maven installed on your computer.
+
+```bash
+export API_KEY='0WUaXesNgbTAuLwn'
+mvn package
+java -cp target/cached-key-example-0.1.0.jar com.ironcorelabs.cachedkey.CachedKeyExample
+```
+
+We've assigned an API key for you, but in production you will make your own and edit the TSP
+configuration with it. This should produce output like:
+
+```
+Using tenant tenant-gcp-l
+Encrypted 3 records with one TSP call
+Decrypted: Jim Bridger / 000-12-2345
+Decrypted: John Colter / 000-45-6789
+Decrypted: Sacagawea / 000-98-7654
+Decrypted 3 records with one TSP call
+```
+
+If you look at the TSP logs, you should see only two KMS operations: one wrap and one unwrap.
+Without cached keys, the same work would have required six KMS operations (three wraps + three
+unwraps).
+
+If you would like to experiment with a different tenant, just do:
+
+```bash
+export TENANT_ID=<selected-tenant-ID>
+java -cp target/cached-key-example-0.1.0.jar com.ironcorelabs.cachedkey.CachedKeyExample
+```
+
+The list of available tenants is listed in the [README.md](../README.md) in the parent directory.
+
+## Additional Resources
+
+If you would like some more in-depth information, our website features a section of technical
+documentation about the [SaaS Shield product](https://ironcorelabs.com/docs/saas-shield/).

examples/cached-key-example/pom.xml

@@ -0,0 +1,85 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <groupId>com.ironcorelabs</groupId>
+  <artifactId>cached-key-example</artifactId>
+  <packaging>jar</packaging>
+  <version>0.1.0</version>
+
+  <name>cached-key-example</name>
+  <url>https://www.docs.ironcorelabs.com</url>
+  <licenses>
+    <license>
+      <name>Apache-2</name>
+      <url>https://opensource.org/licenses/Apache-2.0</url>
+      <distribution>repo</distribution>
+    </license>
+  </licenses>
+
+  <properties>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    <maven.compiler.source>1.8</maven.compiler.source>
+    <maven.compiler.target>1.8</maven.compiler.target>
+  </properties>
+
+  <dependencies>
+    <dependency>
+      <groupId>com.ironcorelabs</groupId>
+      <artifactId>tenant-security-java</artifactId>
+      <version>8.1.0</version>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-gpg-plugin</artifactId>
+        <version>1.6</version>
+        <executions>
+          <execution>
+            <id>sign-artifacts</id>
+            <phase>verify</phase>
+            <goals>
+              <goal>sign</goal>
+            </goals>
+          </execution>
+        </executions>
+      </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <version>3.3</version>
+        <configuration>
+          <source>1.8</source>
+          <target>1.8</target>
+          <testSource>1.8</testSource>
+          <testTarget>1.8</testTarget>
+          <compilerArgument>-Xlint:unchecked</compilerArgument>
+        </configuration>
+      </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-source-plugin</artifactId>
+        <version>3.0.1</version>
+      </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-shade-plugin</artifactId>
+        <version>3.2.1</version>
+        <executions>
+          <execution>
+            <phase>package</phase>
+            <goals>
+              <goal>shade</goal>
+            </goals>
+          </execution>
+        </executions>
+      </plugin>
+    </plugins>
+  </build>
+</project>

examples/cached-key-example/src/main/java/com/ironcorelabs/cachedkey/CachedKeyExample.java

@@ -0,0 +1,93 @@
+package com.ironcorelabs.cachedkey;
+
+import com.ironcorelabs.tenantsecurity.kms.v1.*;
+import com.ironcorelabs.tenantsecurity.kms.v1.exception.TenantSecurityException;
+import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ExecutionException;
+
+/**
+ * Demonstrates using CachedEncryptor and CachedDecryptor to encrypt/decrypt multiple records with a
+ * single TSP call.
+ */
+public class CachedKeyExample {
+
+  private static final String TSP_ADDR = "http://localhost:32804";
+
+  public static void main(String[] args) throws Exception {
+
+    String API_KEY = System.getenv("API_KEY");
+    if (API_KEY == null) {
+      System.out.println("Must set the API_KEY environment variable.");
+      System.exit(1);
+    }
+
+    String tenantId = System.getenv("TENANT_ID");
+    if (tenantId == null) {
+      tenantId = "tenant-gcp-l";
+    }
+    System.out.println("Using tenant " + tenantId);
+
+    TenantSecurityClient client =
+        new TenantSecurityClient.Builder(TSP_ADDR, API_KEY).allowInsecureHttp(true).build();
+
+    DocumentMetadata metadata = new DocumentMetadata(tenantId, "serviceOrUserId", "PII");
+
+    // Simulate a database table: each row has an encrypted record and its EDEK
+    List<Map<String, byte[]>> encryptedRows = new ArrayList<>();
+    String sharedEdek;
+
+    // Encrypt: one TSP call, then N local encrypts
+    //
+    // In a real application this block would be inside a database transaction. The
+    // createCachedEncryptor call is the only network round trip — every encrypt() after
+    // that is purely local CPU work, so it won't add latency or failure modes to the
+    // transaction.
+    try (CachedEncryptor encryptor = client.createCachedEncryptor(metadata).get()) {
+      String[][] customers =
+          {{"000-12-2345", "2825-519 Stone Creek Rd, Bozeman, MT 59715", "Jim Bridger"},
+              {"000-45-6789", "100 Main St, Helena, MT 59601", "John Colter"},
+              {"000-98-7654", "742 Evergreen Terrace, Missoula, MT 59801", "Sacagawea"},};
+
+      for (String[] customer : customers) {
+        Map<String, byte[]> record = new HashMap<>();
+        record.put("ssn", customer[0].getBytes(StandardCharsets.UTF_8));
+        record.put("address", customer[1].getBytes(StandardCharsets.UTF_8));
+        record.put("name", customer[2].getBytes(StandardCharsets.UTF_8));
+
+        // This encrypt is local — no TSP call
+        EncryptedDocument encrypted = encryptor.encrypt(record, metadata).get();
+        encryptedRows.add(encrypted.getEncryptedFields());
+      }
+
+      // All rows share this EDEK; store it alongside the rows (or once per batch)
+      sharedEdek = encryptor.getEdek();
+
+      System.out
+          .println("Encrypted " + encryptor.getOperationCount() + " records with one TSP call");
+    }
+    // leaving the `try` block zeroes the DEK and reports usage to the TSP
+
+    // Decrypt: one TSP call, then N local decrypts
+    try (CachedDecryptor decryptor = client.createCachedDecryptor(sharedEdek, metadata).get()) {
+      for (Map<String, byte[]> row : encryptedRows) {
+        EncryptedDocument doc = new EncryptedDocument(row, sharedEdek);
+
+        // This decrypt is local — no TSP call
+        PlaintextDocument plaintext = decryptor.decrypt(doc, metadata).get();
+        Map<String, byte[]> fields = plaintext.getDecryptedFields();
+
+        System.out.println("Decrypted: " + new String(fields.get("name"), StandardCharsets.UTF_8)
+            + " / " + new String(fields.get("ssn"), StandardCharsets.UTF_8));
+      }
+
+      System.out
+          .println("Decrypted " + decryptor.getOperationCount() + " records with one TSP call");
+    }
+
+    System.exit(0);
+  }
+}

examples/large-documents/README.md

@@ -11,8 +11,7 @@ fields that share a DEK. The example code shows two scenarios:
 - encrypting a large document as many subdocs, using the disk for persistence
 - retrieving and decrypting subdocs individually
 
-To run the example, you will need to have Java and Maven installed on your computer. Try a `java -version` to see
-what version you are using. We tested the example code using 1.8.
+To run the example, you will need to have Java JRE 17+ and Maven installed on your computer.
 
 If java is ready to go, execute these commands:
 

examples/logging-example/README.md

@@ -10,8 +10,7 @@ to use the Tenant Security Client (TSC) SDK to log security events. The example
 - logging a user create security event with minimal metadata
 - logging a login security event with additional metadata
 
-To run the example, you will need to have Java and Maven installed on your computer. Try a `java -version` to see
-what version you are using. We tested the example code using 1.8.
+To run the example, you will need to have Java JRE 17+ and Maven installed on your computer.
 
 If java is ready to go, execute these commands:
 

examples/rekey-example/README.md

@@ -15,7 +15,7 @@ to use the Tenant Security Client (TSC) SDK to rekey data. The example code cont
 - Rekeying the encrypted record to a new tenant
 - Decrypting the encrypted record with the new tenant
 
-To run the example, you will need to have a Java JRE 8+ and Maven installed on your computer.
+To run the example, you will need to have a Java JRE 17+ and Maven installed on your computer.
 
 ```bash
 export API_KEY='0WUaXesNgbTAuLwn'

examples/simple-roundtrip/README.md

@@ -10,7 +10,7 @@ to use the Tenant Security Client (TSC) SDK to encrypt and decrypt data. The exa
 - encryption and decryption of a record that you might store in a key-value store or a database
 - encryption and decryption of a file, using the file-system for storage
 
-To run the example, you will need to have a Java JRE 8+ and Maven installed on your computer.
+To run the example, you will need to have a Java JRE 17+ and Maven installed on your computer.
 
 ```bash
 export API_KEY='0WUaXesNgbTAuLwn'

flake.lock

@@ -13,6 +13,10 @@
             maven
             openjdk17
           ];
+          # Nix sets SOURCE_DATE_EPOCH to 1980-01-01T00:00:00Z (315532800) for
+          # reproducible builds, but maven-javadoc-plugin requires at least
+          # 1980-01-01T00:00:02Z. Bump by 2 seconds to satisfy the validation.
+          SOURCE_DATE_EPOCH = 315532802;
         };
       }
     );