How to: Use the cryptography APIs

Learn how to encrypt and decrypt files

Now that you’ve read about Cryptography as a Dapr building block, let’s walk through using the cryptography APIs with the SDKs.

Note

Dapr cryptography is currently in alpha.

Encrypt

• Python
• JavaScript
• .NET
• Go

Using the Dapr SDK in your project, with the gRPC APIs, you can encrypt a stream of data, such as a file or a string:

# When passing data (a buffer or string), `encrypt` returns a Buffer with the encrypted message
def encrypt_decrypt_string(dapr: DaprClient):
    message = 'The secret is "passw0rd"'
    # Encrypt the message
    resp = dapr.encrypt(
        data=message.encode(),
        options=EncryptOptions(
            # Name of the cryptography component (required)
            component_name=CRYPTO_COMPONENT_NAME,
            # Key stored in the cryptography component (required)
            key_name=RSA_KEY_NAME,
            # Algorithm used for wrapping the key, which must be supported by the key named above.
            # Options include: "RSA", "AES"
            key_wrap_algorithm='RSA',
        ),
    )
    # The method returns a readable stream, which we read in full in memory
    encrypt_bytes = resp.read()
    print(f'Encrypted the message, got {len(encrypt_bytes)} bytes')

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"),
);

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));

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)
}

Decrypt

• Python
• JavaScript
• .NET
• Go

To decrypt a stream of data, use decrypt.

def encrypt_decrypt_string(dapr: DaprClient):
    message = 'The secret is "passw0rd"'
    # ...
    # Decrypt the encrypted data
    resp = dapr.decrypt(
        data=encrypt_bytes,
        options=DecryptOptions(
            # Name of the cryptography component (required)
            component_name=CRYPTO_COMPONENT_NAME,
            # Key stored in the cryptography component (required)
            key_name=RSA_KEY_NAME,
        ),
    )
    # The method returns a readable stream, which we read in full in memory
    decrypt_bytes = resp.read()
    print(f'Decrypted the message, got {len(decrypt_bytes)} bytes')
    print(decrypt_bytes.decode())
    assert message == decrypt_bytes.decode()

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"),
);

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;
}

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",
})

Next steps

Cryptography component specs

Last modified October 11, 2024: Fixed typo (#4389) (fe17926)