There are more AWS SDK examples available in the [AWS Doc SDK Examples](https://github.com/awsdocs/aws-doc-sdk-examples) GitHub repo.

# Use `GenerateRandom` with an AWS SDK or CLI
<a name="kms_example_kms_GenerateRandom_section"></a>

The following code examples show how to use `GenerateRandom`.

------
#### [ CLI ]

**AWS CLI**  
**Example 1: To generate a 256-bit random byte string (Linux or macOs)**  
The following `generate-random` example generates a 256-bit (32-byte), base64-encoded random byte string. The example decodes the byte string and saves it in the random file.  
When you run this command, you must use the `number-of-bytes` parameter to specify the length of the random value in bytes.  
You don't specify a KMS key when you run this command. The random byte string is unrelated to any KMS key.  
By default, AWS KMS generates the random number. However, if you specify a [custom key store](https://docs.aws.amazon.com/kms/latest/developerguide/custom-key-store-overview.html), the random byte string is generated in the AWS CloudHSM cluster associated with the custom key store.  
This example uses the following parameters and values:  
It uses the required `--number-of-bytes` parameter with a value of `32` to request a 32-byte (256-bit) string.It uses the `--output` parameter with a value of `text` to direct the AWS CLI to return the output as text, instead of JSON.It uses the `--query parameter` to extract the value of the `Plaintext` property from the response.It pipes ( \$1 ) the output of the command to the `base64` utility, which decodes the extracted output.It uses the redirection operator ( > ) to save decoded byte string to the `ExampleRandom` file.It uses the redirection operator ( > ) to save the binary ciphertext to a file.  

```
aws kms generate-random \
    --number-of-bytes 32 \
    --output text \
    --query Plaintext | base64 --decode > ExampleRandom
```
This command produces no output.  
For more information, see [GenerateRandom](https://docs.aws.amazon.com/kms/latest/APIReference/API_GenerateRandom.html) in the *AWS Key Management Service API Reference*.  
**Example 2: To generate a 256-bit random number (Windows Command Prompt)**  
The following example uses the `generate-random` command to generate a 256-bit (32-byte), base64-encoded random byte string. The example decodes the byte string and saves it in the random file. This example is the same as the previous example, except that it uses the `certutil` utility in Windows to base64-decode the random byte string before saving it in a file.  
First, generate a base64-encoded random byte string and saves it in a temporary file, `ExampleRandom.base64`.  

```
aws kms generate-random \
    --number-of-bytes 32 \
    --output text \
    --query Plaintext > ExampleRandom.base64
```
Because the output of the `generate-random` command is saved in a file, this example produces no output.  
Now use the `certutil -decode` command to decode the base64-encoded byte string in the `ExampleRandom.base64` file. Then, it saves the decoded byte string in the `ExampleRandom` file.  

```
certutil -decode ExampleRandom.base64 ExampleRandom
```
Output:  

```
Input Length = 18
Output Length = 12
CertUtil: -decode command completed successfully.
```
For more information, see [GenerateRandom](https://docs.aws.amazon.com/kms/latest/APIReference/API_GenerateRandom.html) in the *AWS Key Management Service API Reference*.  
+  For API details, see [GenerateRandom](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/kms/generate-random.html) in *AWS CLI Command Reference*. 

------
#### [ Rust ]

**SDK for Rust**  
 There's more on GitHub. Find the complete example and learn how to set up and run in the [AWS Code Examples Repository](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/rustv1/examples/kms#code-examples). 

```
async fn make_string(client: &Client, length: i32) -> Result<(), Error> {
    let resp = client
        .generate_random()
        .number_of_bytes(length)
        .send()
        .await?;

    // Did we get an encrypted blob?
    let blob = resp.plaintext.expect("Could not get encrypted text");
    let bytes = blob.as_ref();

    let s = base64::encode(bytes);

    println!();
    println!("Data key:");
    println!("{}", s);

    Ok(())
}
```
+  For API details, see [GenerateRandom](https://docs.rs/aws-sdk-kms/latest/aws_sdk_kms/client/struct.Client.html#method.generate_random) in *AWS SDK for Rust API reference*. 

------