Create a key pair for your Amazon EC2 instance - Amazon Elastic Compute Cloud
Create a key pair using Amazon EC2Create a key pair using AWS CloudFormationImport a public key to Amazon EC2

Create a key pair for your Amazon EC2 instance

You can use Amazon EC2 to create your key pairs, or you can use a third-party tool to create your key pairs, and then import them to Amazon EC2.

Amazon EC2 supports 2048-bit SSH-2 RSA keys for Linux and Windows instances. Amazon EC2 also supports ED25519 keys for Linux instances.

For instructions on how to connect to your instance after you have created a key pair, see Connect to your Linux instance using SSH and Connect to your Windows instance using RDP.

Create a key pair using Amazon EC2

When you create a key pair using Amazon EC2, the public key is stored in Amazon EC2, and you store the private key.

You can create up to 5,000 key pairs per Region. To request an increase, create a support case. For more information, see Creating a support case in the AWS Support User Guide.

Console
To create a key pair using Amazon EC2

  1. Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

  2. In the navigation pane, under Network & Security, choose Key Pairs.

  3. Choose Create key pair.

  4. For Name, enter a descriptive name for the key pair. Amazon EC2 associates the public key with the name that you specify as the key name. A key name can include up to 255 ASCII characters. It can’t include leading or trailing spaces.

  5. Select a key pair type appropriate for your operating system:

    (Linux instances) For Key pair type, choose either RSA or ED25519.

    (Windows instances) For Key pair type, choose RSA. ED25519 keys are not supported for Windows instances.

  6. For Private key file format, choose the format in which to save the private key. To save the private key in a format that can be used with OpenSSH, choose pem. To save the private key in a format that can be used with PuTTY, choose ppk.

  7. To add a tag to the public key, choose Add tag, and enter the key and value for the tag. Repeat for each tag.

  8. Choose Create key pair.

  9. The private key file is automatically downloaded by your browser. The base file name is the name that you specified as the name of your key pair, and the file name extension is determined by the file format that you chose. Save the private key file in a safe place.

    Important

    This is the only chance for you to save the private key file.

  10. If you plan to use an SSH client on a macOS or Linux computer to connect to your Linux instance, use the following command to set the permissions of your private key file so that only you can read it.

    chmod 400 key-pair-name.pem

    If you do not set these permissions, then you cannot connect to your instance using this key pair. For more information, see Error: Unprotected private key file.

AWS CLI
To create a key pair using Amazon EC2

  1. Use the create-key-pair command as follows to generate the key pair and to save the private key to a .pem file.

    For --key-name, specify a name for the public key. The name can be up to 255 ASCII characters.

    For --key-type, specify either rsa or ed25519. If you do not include the --key-type parameter, an rsa key is created by default. Note that ED25519 keys are not supported for Windows instances.

    For --key-format, specify either pem or ppk. If you do not include the --key-format parameter, a pem file is created by default.

    --query "KeyMaterial" prints the private key material to the output.

    --output text > my-key-pair.pem saves the private key material in a file with the specified extension. The extension can be either .pem or .ppk. The private key can have a name that's different from the public key name, but for ease of use, use the same name.

    aws ec2 create-key-pair \
    --key-name my-key-pair \
    --key-type rsa \
    --key-format pem \
    --query "KeyMaterial" \
    --output text > my-key-pair.pem

  2. If you plan to use an SSH client on a macOS or Linux computer to connect to your Linux instance, use the following command to set the permissions of your private key file so that only you can read it.

    chmod 400 key-pair-name.pem

    If you do not set these permissions, then you cannot connect to your instance using this key pair. For more information, see Error: Unprotected private key file.

PowerShell
To create a key pair using Amazon EC2

Use the New-EC2KeyPair AWS Tools for Windows PowerShell command as follows to generate the key and save it to a .pem or .ppk file.

For -KeyName, specify a name for the public key. The name can be up to 255 ASCII characters.

For -KeyType, specify either rsa or ed25519. If you do not include the -KeyType parameter, an rsa key is created by default. Note that ED25519 keys are not supported for Windows instances.

For -KeyFormat, specify either pem or ppk. If you do not include the -KeyFormat parameter, a pem file is created by default.

KeyMaterial prints the private key material to the output.

Out-File -Encoding ascii -FilePath C:\path\my-key-pair.pem saves the private key material in a file with the the specified extension. The extension can be .pem or .ppk. The private key can have a name that's different from the public key name, but for ease of use, use the same name.

PS C:\> (New-EC2KeyPair -KeyName "my-key-pair" -KeyType "rsa" -KeyFormat "pem").KeyMaterial | Out-File -Encoding ascii -FilePath C:\path\my-key-pair.pem

Create a key pair using AWS CloudFormation

When you create a new key pair using AWS CloudFormation, the private key is saved to AWS Systems Manager Parameter Store. The parameter name has the following format:

/ec2/keypair/key_pair_id

For more information, see AWS Systems Manager Parameter Store in the AWS Systems Manager User Guide.

To create a key pair using AWS CloudFormation

  1. Specify the AWS::EC2::KeyPair resource in your template.

    Resources:
  NewKeyPair:
    Type: 'AWS::EC2::KeyPair'
    Properties: 
      KeyName: new-key-pair

  2. Use the describe-key-pairs command as follows to get the ID of the key pair.

    aws ec2 describe-key-pairs --filters Name=key-name,Values=new-key-pair --query KeyPairs[*].KeyPairId --output text

    The following is example output.

    key-05abb699beEXAMPLE

  3. Use the get-parameter command as follows to get the parameter for your key and save the key material in a .pem file.

    aws ssm get-parameter --name /ec2/keypair/key-05abb699beEXAMPLE --with-decryption --query Parameter.Value --output text > new-key-pair.pem
Required IAM permissions

To enable AWS CloudFormation to manage Parameter Store parameters on your behalf, the IAM role assumed by AWS CloudFormation or your user must have the following permissions:

  • ssm:PutParameter – Grants permission to create a parameter for the private key material.

  • ssm:DeleteParameter – Grants permission to delete the parameter that stored the private key material. This permission is required whether the key pair was imported or created by AWS CloudFormation.

When AWS CloudFormation deletes a key pair that was created or imported by a stack, it performs a permissions check to determine whether you have permission to delete parameters, even though AWS CloudFormation creates a parameter only when it creates a key pair, not when it imports a key pair. AWS CloudFormation tests for the required permission using a fabricated parameter name that does not match any parameter in your account. Therefore, you might see a fabricated parameter name in the AccessDeniedException error message.

Create a key pair using a third-party tool and import the public key to Amazon EC2

Instead of using Amazon EC2 to create a key pair, you can create an RSA or ED25519 key pair by using a third-party tool and then import the public key to Amazon EC2.

Requirements for key pairs

  • Supported types:

    • (Linux and Windows) RSA

    • (Linux only) ED25519

      Note

      ED25519 keys are not supported for Windows instances.

    • Amazon EC2 does not accept DSA keys.

  • Supported formats:

    • OpenSSH public key format (for Linux, the format in ~/.ssh/authorized_keys)

    • (Linux only) If you connect using SSH while using the EC2 Instance Connect API, the SSH2 format is also supported.

    • SSH private key file format must be PEM or PPK

    • (RSA only) Base64 encoded DER format

    • (RSA only) SSH public key file format as specified in RFC 4716

  • Supported lengths:

    • 1024, 2048, and 4096.

    • (Linux only) If you connect using SSH while using the EC2 Instance Connect API, the supported lengths are 2048 and 4096.

To create a key pair using a third-party tool

  1. Generate a key pair with a third-party tool of your choice. For example, you can use ssh-keygen (a tool provided with the standard OpenSSH installation). Alternatively, Java, Ruby, Python, and many other programming languages provide standard libraries that you can use to create a key pair.

    Important

    The private key must be in the PEM or PPK format. For example, use ssh-keygen -m PEM to generate the OpenSSH key in the PEM format.

  2. Save the public key to a local file. For example, ~/.ssh/my-key-pair.pub (Linux, macOS) or C:\keys\my-key-pair.pub (Windows). The file name extension for this file is not important.

  3. Save the private key to a local file that has the .pem or .ppk extension. For example, ~/.ssh/my-key-pair.pem or ~/.ssh/my-key-pair.ppk (Linux, macOS) or C:\keys\my-key-pair.pem or C:\keys\my-key-pair.ppk (Windows). The file extension is important because, depending on the tool you use to connect to your instance, you'll need a specific file format. OpenSSH requires a .pem file, while PuTTY requires a .ppk file.

    Important

    Save the private key file in a safe place. You'll need to provide the name of your public key when you launch an instance, and the corresponding private key each time you connect to the instance.

After you have created the key pair, use one of the following methods to import your public key to Amazon EC2.

Console
To import the public key to Amazon EC2

  1. Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

  2. In the navigation pane, choose Key Pairs.

  3. Choose Import key pair.

  4. For Name, enter a descriptive name for the public key. The name can include up to 255 ASCII characters. It can’t include leading or trailing spaces.

    Note

    When you connect to your instance from the EC2 console, the console suggests this name for the name of your private key file.

  5. Either choose Browse to navigate to and select your public key, or paste the contents of your public key into the Public key contents field.

  6. Choose Import key pair.

  7. Verify that the public key that you imported appears in the list of key pairs.

AWS CLI
To import the public key to Amazon EC2

Use the import-key-pair command.

To verify that the key pair was imported successfully

Use the describe-key-pairs command.

PowerShell
To import the public key to Amazon EC2

Use the Import-EC2KeyPair AWS Tools for Windows PowerShell command.

To verify that the key pair was imported successfully

Use the Get-EC2KeyPair AWS Tools for Windows PowerShell command.