Table Of Contents


User Guide

First time using the AWS CLI? See the User Guide for help getting started.

[ aws . kms ]



Encrypts plaintext into ciphertext by using a customer master key (CMK). The Encrypt operation has two primary use cases:

  • You can encrypt up to 4 kilobytes (4096 bytes) of arbitrary data such as an RSA key, a database password, or other sensitive information.
  • You can use the Encrypt operation to move encrypted data from one AWS region to another. In the first region, generate a data key and use the plaintext key to encrypt the data. Then, in the new region, call the Encrypt method on same plaintext data key. Now, you can safely move the encrypted data and encrypted data key to the new region, and decrypt in the new region when necessary.

You don't need use this operation to encrypt a data key within a region. The GenerateDataKey and GenerateDataKeyWithoutPlaintext operations return an encrypted data key.

Also, you don't need to use this operation to encrypt data in your application. You can use the plaintext and encrypted data keys that the GenerateDataKey operation returns.

The result of this operation varies with the key state of the CMK. For details, see How Key State Affects Use of a Customer Master Key in the AWS Key Management Service Developer Guide .

To perform this operation on a CMK in a different AWS account, specify the key ARN or alias ARN in the value of the KeyId parameter.

See also: AWS API Documentation

See 'aws help' for descriptions of global parameters.


--key-id <value>
--plaintext <value>
[--encryption-context <value>]
[--grant-tokens <value>]
[--cli-input-json <value>]
[--generate-cli-skeleton <value>]


--key-id (string)

A unique identifier for the customer master key (CMK).

To specify a CMK, use its key ID, Amazon Resource Name (ARN), alias name, or alias ARN. When using an alias name, prefix it with "alias/" . To specify a CMK in a different AWS account, you must use the key ARN or alias ARN.

For example:

  • Key ID: 1234abcd-12ab-34cd-56ef-1234567890ab
  • Key ARN: arn:aws:kms:us-east-2:111122223333:key/1234abcd-12ab-34cd-56ef-1234567890ab
  • Alias name: alias/ExampleAlias
  • Alias ARN: arn:aws:kms:us-east-2:111122223333:alias/ExampleAlias

To get the key ID and key ARN for a CMK, use ListKeys or DescribeKey . To get the alias name and alias ARN, use ListAliases .

--plaintext (blob)

Data to be encrypted.

--encryption-context (map)

Name-value pair that specifies the encryption context to be used for authenticated encryption. If used here, the same value must be supplied to the Decrypt API or decryption will fail. For more information, see Encryption Context .

Shorthand Syntax:


JSON Syntax:

{"string": "string"

--grant-tokens (list)

A list of grant tokens.

For more information, see Grant Tokens in the AWS Key Management Service Developer Guide .


"string" "string" ...

--cli-input-json (string) Performs service operation based on the JSON string provided. The JSON string follows the format provided by --generate-cli-skeleton. If other arguments are provided on the command line, the CLI values will override the JSON-provided values. It is not possible to pass arbitrary binary values using a JSON-provided value as the string will be taken literally.

--generate-cli-skeleton (string) Prints a JSON skeleton to standard output without sending an API request. If provided with no value or the value input, prints a sample input JSON that can be used as an argument for --cli-input-json. If provided with the value output, it validates the command inputs and returns a sample output JSON for that command.

See 'aws help' for descriptions of global parameters.


Example 1: To encrypt the contents of a file on Linux or MacOS

The following encrypt command demonstrates the recommended way to encrypt data with the AWS CLI.

aws kms encrypt \
    --key-id 1234abcd-12ab-34cd-56ef-1234567890ab \
    --plaintext fileb://ExamplePlaintextFile \
    --output text \
    --query CiphertextBlob | base64 \
    --decode > ExampleEncryptedFile

The command does several things:

  1. Uses the fileb:// prefix to specify the --plaintext parameter.

    The fileb:// prefix instructs the CLI to read the data to encrypt, called the plaintext, from a file and pass the file's contents to the command's --plaintext parameter. If the file is not in the current directory, type the full path to file. For example: fileb:///var/tmp/ExamplePlaintextFile or fileb://C:\Temp\ExamplePlaintextFile.

    For more information about reading AWS CLI parameter values from a file, see Loading Parameters from a File in the AWS Command Line Interface User Guide and Best Practices for Local File Parameters on the AWS Command Line Tool Blog

  2. Uses the --output and --query parameters to control the command's output.

    These parameters extract the encrypted data, called the ciphertext, from the command's output.

    For more information about controlling output, see Controlling Command Output in the AWS Command Line Interface User Guide.

  3. Uses the base64 utility to decode the extracted output.

    This utility decodes the extracted ciphertext to binary data. The ciphertext that is returned by a successful encrypt command is base64-encoded text. You must decode this text before you can use the AWS CLI to decrypt it.

  4. Saves the binary ciphertext to a file.

    The final part of the command (> ExampleEncryptedFile) saves the binary ciphertext to a file to make decryption easier. For an example command that uses the AWS CLI to decrypt data, see the decrypt examples.

Example 2: Using the AWS CLI to encrypt data on Windows

The preceding example assumes the base64 utility is available, which is commonly the case on Linux and MacOS. For the Windows command prompt, use certutil instead of base64. This requires two commands, as shown in the following examples.

aws kms encrypt \
    --key-id 1234abcd-12ab-34cd-56ef-1234567890ab \
    --plaintext fileb://ExamplePlaintextFile \
    --output text \
    --query CiphertextBlob > C:\Temp\ExampleEncryptedFile.base64

certutil -decode C:\Temp\ExampleEncryptedFile.base64 C:\Temp\ExampleEncryptedFile


CiphertextBlob -> (blob)

The encrypted plaintext. When you use the HTTP API or the AWS CLI, the value is Base64-encoded. Otherwise, it is not encoded.

KeyId -> (string)

The ID of the key used during encryption.