--- type: docs title: "Quickstart: Cryptography" linkTitle: Cryptography weight: 79 description: Get started with the Dapr Cryptography building block --- {{% alert title="Alpha" color="warning" %}} The cryptography building block is currently in **alpha**. {{% /alert %}} Let's take a look at the Dapr [cryptography building block]({{< ref cryptography >}}). In this Quickstart, you'll create an application that encrypts and decrypts data using the Dapr cryptography APIs. You'll: - Encrypt and then decrypt a short string (using an RSA key), reading the result in-memory, in a Go byte slice. - Encrypt and then decrypt a large file (using an AES key), storing the encrypted and decrypted data to files using streams. {{% alert title="Note" color="primary" %}} This example uses the Dapr SDK, which leverages gRPC and is **strongly** recommended when using cryptographic APIs to encrypt and decrypt messages. {{% /alert %}} Currently, you can experience the cryptography API using the Go SDK. {{< tabs "Go" >}} {{% codetab %}} > This quickstart includes a Go application called `crypto-quickstart`. ### Pre-requisites For this example, you will need: - [Dapr CLI and initialized environment](https://docs.dapr.io/getting-started). - [Latest version of Go](https://go.dev/dl/). - [Docker Desktop](https://www.docker.com/products/docker-desktop) - [OpenSSL](https://www.openssl.org/source/) available on your system ### Step 1: Set up the environment Clone the [sample provided in the Quickstarts repo](https://github.com/dapr/quickstarts/tree/master/cryptography) ```bash git clone https://github.com/dapr/quickstarts.git ``` In the terminal, from the root directory, navigate to the cryptography sample. ```bash cd cryptography/go/sdk ``` ### Step 2: Run the application with Dapr Navigate into the folder with the source code: ```bash cd ./crypto-quickstart ``` The application code defines two required keys: - Private RSA key - A 256-bit symmetric (AES) key Generate two keys, an RSA key and and AES key using OpenSSL and write these to two files: ```bash mkdir -p keys # Generate a private RSA key, 4096-bit keys openssl genpkey -algorithm RSA -pkeyopt rsa_keygen_bits:4096 -out keys/rsa-private-key.pem # Generate a 256-bit key for AES openssl rand -out keys/symmetric-key-256 32 ``` Run the Go service app with Dapr: ```bash dapr run --app-id crypto-quickstart --resources-path ../../../components/ -- go run . ``` **Expected output** ``` == APP == dapr client initializing for: 127.0.0.1:52407 == APP == Encrypted the message, got 856 bytes == APP == Decrypted the message, got 24 bytes == APP == The secret is "passw0rd" == APP == Wrote decrypted data to encrypted.out == APP == Wrote decrypted data to decrypted.out.jpg ``` ### What happened? #### `local-storage.yaml` Earlier, you created a directory inside `crypto-quickstarts` called `keys`. In [the `local-storage` component YAML](https://github.com/dapr/quickstarts/tree/master/cryptography/components/local-storage.yaml), the `path` metadata maps to the newly created `keys` directory. ```yml apiVersion: dapr.io/v1alpha1 kind: Component metadata: name: localstorage spec: type: crypto.dapr.localstorage version: v1 metadata: - name: path # Path is relative to the folder where the example is located value: ./keys ``` #### `app.go` [The application file](https://github.com/dapr/quickstarts/tree/master/cryptography/go/sdk/crypto-quickstart/app.go) encrypts and decrypts messages and files using the RSA and AES keys that you generated. The application creates a new Dapr SDK client: ```go func main() { // Create a new Dapr SDK client client, err := dapr.NewClient() //... // Step 1: encrypt a string using the RSA key, then decrypt it and show the output in the terminal encryptDecryptString(client) // Step 2: encrypt a large file and then decrypt it, using the AES key encryptDecryptFile(client) } ``` ##### Encrypting and decrypting a string using the RSA key Once the client is created, the application encrypts a message: ```go func encryptDecryptString(client dapr.Client) { // ... // Encrypt the message encStream, err := client.Encrypt(context.Background(), strings.NewReader(message), dapr.EncryptOptions{ ComponentName: CryptoComponentName, // Name of the key to use // Since this is a RSA key, we specify that as key wrapping algorithm KeyName: RSAKeyName, KeyWrapAlgorithm: "RSA", }, ) // ... // The method returns a readable stream, which we read in full in memory encBytes, err := io.ReadAll(encStream) // ... fmt.Printf("Encrypted the message, got %d bytes\n", len(encBytes)) ``` The application then decrypts the message: ```go // Now, decrypt the encrypted data decStream, err := client.Decrypt(context.Background(), bytes.NewReader(encBytes), dapr.DecryptOptions{ // We just need to pass the name of the component ComponentName: CryptoComponentName, // Passing the name of the key is optional KeyName: RSAKeyName, }, ) // ... // The method returns a readable stream, which we read in full in memory decBytes, err := io.ReadAll(decStream) // ... // Print the message on the console fmt.Printf("Decrypted the message, got %d bytes\n", len(decBytes)) fmt.Println(string(decBytes)) } ``` ##### Encrypt and decrpyt a large file using the AES key Next, the application encrypts a large image file: ```go func encryptDecryptFile(client dapr.Client) { const fileName = "liuguangxi-66ouBTTs_x0-unsplash.jpg" // Get a readable stream to the input file plaintextF, err := os.Open(fileName) // ... defer plaintextF.Close() // Encrypt the file encStream, err := client.Encrypt(context.Background(), plaintextF, dapr.EncryptOptions{ ComponentName: CryptoComponentName, // Name of the key to use // Since this is a symmetric key, we specify AES as key wrapping algorithm KeyName: SymmetricKeyName, KeyWrapAlgorithm: "AES", }, ) // ... // Write the encrypted data to a file "encrypted.out" encryptedF, err := os.Create("encrypted.out") // ... encryptedF.Close() fmt.Println("Wrote decrypted data to encrypted.out") ``` The application then decrypts the large image file: ```go // Now, decrypt the encrypted data // First, open the file "encrypted.out" again, this time for reading encryptedF, err = os.Open("encrypted.out") // ... defer encryptedF.Close() // Now, decrypt the encrypted data decStream, err := client.Decrypt(context.Background(), encryptedF, dapr.DecryptOptions{ // We just need to pass the name of the component ComponentName: CryptoComponentName, // Passing the name of the key is optional KeyName: SymmetricKeyName, }, ) // ... // Write the decrypted data to a file "decrypted.out.jpg" decryptedF, err := os.Create("decrypted.out.jpg") // ... decryptedF.Close() fmt.Println("Wrote decrypted data to decrypted.out.jpg") } ``` {{% /codetab %}} {{< /tabs >}} ## Watch the demo Watch this [demo video of the cryptography API from the Dapr Community Call #83](https://youtu.be/PRWYX4lb2Sg?t=1148): ## Tell us what you think! We're continuously working to improve our Quickstart examples and value your feedback. Did you find this Quickstart helpful? Do you have suggestions for improvement? Join the discussion in our [discord channel](https://discord.com/channels/778680217417809931/953427615916638238). ## Next steps - Walk through [more examples of encrypting and decrypting using the cryptography API]({{< ref howto-cryptography.md >}}) - Learn more about [cryptography as a Dapr building block]({{< ref cryptography-overview.md >}}) {{< button text="Explore Dapr tutorials >>" page="getting-started/tutorials/_index.md" >}}