How to create a SFTP/SSH Key On MacOS

Learn about SFTP and SSH authentication RSA keys and how to create then on MacOS

Introduction

RSA keys provide a secure method of authenticating with an SSH or SFTP server without requiring a password. They are based on asymmetric encryption, which uses a matching pair of keys: one public and one private. The public key is shared with the server or service provider, while the private key remains securely on your machine and is used to establish the connection.

The keys are stored locally as text files, typically in the .ssh directory or saved in the client you are using to connect.

For additional protection, the private key can be encrypted with a passphrase, ensuring that even if the file is accessed, it cannot be used without the added layer of security. This combination of encryption and key management makes RSA keys both convenient and highly secure for remote authentication.

Key things to remember:

• The private key is used on the client

• The public key is used on the server - and can be shared

• Where possible - the private key should be password encrypted

If you are connecting using SFTP or SSH - you should never share your private key. Only share the public key.

How to Create an RSA SSH Key on macOS

MacOS comes with everything you need to create a RSA key. You will need to be familiar with using a terminal (command prompt) - but thats an easy hurdle to get past.

1. Open Terminal

• Press Command + Space and type Terminal, then hit Enter.

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2. Generate the SSH Key

Run the following command in your Terminal:

ssh-keygen -t rsa -b 4096 -C "[email protected]"

• -t rsa → specifies RSA as the key type.

• -b 4096 → sets the key length to 4096 bits (more secure than the default 2048).

• -C → adds a label (usually your email) for identification.

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3. Save the Key

You’ll be asked where to save the key:

Enter file in which to save the key (/Users/yourname/.ssh/id_rsa):

• Press Enter to accept the default path (~/.ssh/id_rsa), or type a custom filename if you want multiple keys.

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4. Set a Passphrase (Optional)

You can add a passphrase for extra security, or press Enter to leave it empty.

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5. Copy the Public Key

Copy your public key to the clipboard:

pbcopy < ~/.ssh/id_rsa.pub

Now you can paste it into GitHub, GitLab, or any server you want to connect to.