docs/daprdocs/content/en/developing-applications/building-blocks/cryptography/howto-cryptography.md

type	title	linkTitle	weight	description
docs	How to: Use the cryptography APIs	How to: Use cryptography	2000	Learn how to encrypt and decrypt files

Now that you've read about [Cryptography as a Dapr building block]({{< ref cryptography-overview.md >}}), let's walk through using the cryptography APIs with the SDKs.

{{% alert title="Note" color="primary" %}} Dapr cryptography is currently in alpha.

{{% /alert %}}

Encrypt

{{< tabs "JavaScript" "Go" ".NET" >}}

{{% codetab %}}

Using the Dapr SDK in your project, with the gRPC APIs, you can encrypt data in a buffer or a string:

// When passing data (a buffer or string), `encrypt` returns a Buffer with the encrypted message
const ciphertext = await client.crypto.encrypt(plaintext, {
    // Name of the Dapr component (required)
    componentName: "mycryptocomponent",
    // Name of the key stored in the component (required)
    keyName: "mykey",
    // Algorithm used for wrapping the key, which must be supported by the key named above.
    // Options include: "RSA", "AES"
    keyWrapAlgorithm: "RSA",
});

The APIs can also be used with streams, to encrypt data more efficiently when it comes from a stream. The example below encrypts a file, writing to another file, using streams:

// `encrypt` can be used as a Duplex stream
await pipeline(
    fs.createReadStream("plaintext.txt"),
    await client.crypto.encrypt({
        // Name of the Dapr component (required)
        componentName: "mycryptocomponent",
        // Name of the key stored in the component (required)
        keyName: "mykey",
        // Algorithm used for wrapping the key, which must be supported by the key named above.
        // Options include: "RSA", "AES"
        keyWrapAlgorithm: "RSA",
    }),
    fs.createWriteStream("ciphertext.out"),
);

{{% /codetab %}}

{{% codetab %}}

Using the Dapr SDK in your project, you can encrypt a stream of data, such as a file.

out, err := sdkClient.Encrypt(context.Background(), rf, dapr.EncryptOptions{
	// Name of the Dapr component (required)
	ComponentName: "mycryptocomponent",
	// Name of the key stored in the component (required)
	KeyName:       "mykey",
	// Algorithm used for wrapping the key, which must be supported by the key named above.
	// Options include: "RSA", "AES"
	Algorithm:     "RSA",
})

The following example puts the Encrypt API in context, with code that reads the file, encrypts it, then stores the result in another file.

// Input file, clear-text
rf, err := os.Open("input")
if err != nil {
	panic(err)
}
defer rf.Close()

// Output file, encrypted
wf, err := os.Create("output.enc")
if err != nil {
	panic(err)
}
defer wf.Close()

// Encrypt the data using Dapr
out, err := sdkClient.Encrypt(context.Background(), rf, dapr.EncryptOptions{
	// These are the 3 required parameters
	ComponentName: "mycryptocomponent",
	KeyName:       "mykey",
	Algorithm:     "RSA",
})
if err != nil {
	panic(err)
}

// Read the stream and copy it to the out file
n, err := io.Copy(wf, out)
if err != nil {
	panic(err)
}
fmt.Println("Written", n, "bytes")

The following example uses the Encrypt API to encrypt a string.

// Input string
rf := strings.NewReader("Amor, ch’a nullo amato amar perdona, mi prese del costui piacer sì forte, che, come vedi, ancor non m’abbandona")

// Encrypt the data using Dapr
enc, err := sdkClient.Encrypt(context.Background(), rf, dapr.EncryptOptions{
	ComponentName: "mycryptocomponent",
	KeyName:       "mykey",
	Algorithm:     "RSA",
})
if err != nil {
	panic(err)
}

// Read the encrypted data into a byte slice
enc, err := io.ReadAll(enc)
if err != nil {
	panic(err)
}

{{% /codetab %}}

{{% codetab %}}

Using the Dapr SDK in your project, with the gRPC APIs, you can encrypt data in a string or a byte array:

using var client = new DaprClientBuilder().Build();

const string componentName = "azurekeyvault"; //Change this to match your cryptography component
const string keyName = "myKey"; //Change this to match the name of the key in your cryptographic store

const string plainText = "This is the value we're going to encrypt today";

//Encode the string to a UTF-8 byte array and encrypt it
var plainTextBytes = Encoding.UTF8.GetBytes(plainText);
var encryptedBytesResult = await client.EncryptAsync(componentName, plaintextBytes, keyName, new EncryptionOptions(KeyWrapAlgorithm.Rsa));

{{% /codetab %}}

{{< /tabs >}}

Decrypt

{{< tabs "JavaScript" "Go" ".NET" >}}

{{% codetab %}}

Using the Dapr SDK, you can decrypt data in a buffer or using streams.

// When passing data as a buffer, `decrypt` returns a Buffer with the decrypted message
const plaintext = await client.crypto.decrypt(ciphertext, {
    // Only required option is the component name
    componentName: "mycryptocomponent",
});

// `decrypt` can also be used as a Duplex stream
await pipeline(
    fs.createReadStream("ciphertext.out"),
    await client.crypto.decrypt({
        // Only required option is the component name
        componentName: "mycryptocomponent",
    }),
    fs.createWriteStream("plaintext.out"),
);

{{% /codetab %}}

{{% codetab %}}

To decrypt a file, use the Decrypt gRPC API to your project.

In the following example, out is a stream that can be written to file or read in memory, as in the examples above.

out, err := sdkClient.Decrypt(context.Background(), rf, dapr.EncryptOptions{
	// Only required option is the component name
	ComponentName: "mycryptocomponent",
})

{{% /codetab %}}

{{% codetab %}}

To decrypt a string, use the 'DecryptAsync' gRPC API in your project.

In the following example, we'll take a byte array (such as from the example above) and decrypt it to a UTF-8 encoded string.

public async Task<string> DecryptBytesAsync(byte[] encryptedBytes)
{
  using var client = new DaprClientBuilder().Build();

  const string componentName = "azurekeyvault"; //Change this to match your cryptography component
  const string keyName = "myKey"; //Change this to match the name of the key in your cryptographic store

  var decryptedBytes = await client.DecryptAsync(componentName, encryptedBytes, keyName);
  var decryptedString = Encoding.UTF8.GetString(decryptedBytes.ToArray());
  return decryptedString;
}

{{% /codetab %}}

{{< /tabs >}}

Next steps

[Cryptography component specs]({{< ref supported-cryptography >}})