Describe public keys
You can describe the public keys that are stored in Amazon EC2. You can also retrieve the
public key material and identify the public key that was specified at launch.
Describe public keys
You can view the following information about your public keys that are stored in Amazon EC2:
public key name, ID, key type, fingerprint, public key material, the date and time (in the
UTC time zone) the key was created by Amazon EC2 (if the key was created by a third-party tool,
then it's the date and time the key was imported to Amazon EC2), and any tags that are associated
with the public key.
You can use the Amazon EC2 console or AWS CLI to view information about your public keys.
- Console
-
To view information about your public keys
Open the Amazon EC2 console at
https://console.aws.amazon.com/ec2/.
-
In the left navigator, choose Key Pairs.
-
You can view the information about each public key in the Key pairs table.
-
To view a public key's tags, select the check box next to the key, and then choose Actions, Manage tags.
- AWS CLI
-
To describe a public key
Use the describe-key-pairs command and specify the
--key-names
parameter.
aws ec2 describe-key-pairs --key-names key-pair-name
Example output
{
"KeyPairs": [
{
"KeyPairId": "key-0123456789example",
"KeyFingerprint": "1f:51:ae:28:bf:89:e9:d8:1f:25:5d:37:2d:7d:b8:ca:9f:f5:f1:6f",
"KeyName": "key-pair-name",
"KeyType": "rsa",
"Tags": [],
"CreateTime": "2022-04-28T11:37:26.000Z"
}
]
}
Alternatively, instead of --key-names
, you can specify the
--key-pair-ids
parameter to identify the public key.
aws ec2 describe-key-pairs --key-pair-ids key-0123456789example
To view the public key material in the output, you must specify the --include-public-key
parameter.
aws ec2 describe-key-pairs --key-names key-pair-name
--include-public-key
Example output – In the output, the PublicKey
field contains the public
key material.
{
"KeyPairs": [
{
"KeyPairId": "key-0123456789example",
"KeyFingerprint": "1f:51:ae:28:bf:89:e9:d8:1f:25:5d:37:2d:7d:b8:ca:9f:f5:f1:6f",
"KeyName": "key-pair-name",
"KeyType": "rsa",
"Tags": [],
"PublicKey": "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIIj7azlDjVHAsSxgcpCRZ3oWnTm0nAFM64y9jd22ioI/ my-key-pair",
"CreateTime": "2022-04-28T11:37:26.000Z"
}
]
}
Retrieve the public key material
You can use various methods to get access to the public key material. You can retrieve
the public key material from the matching private key on your local computer, or from the
instance metadata or the authorized_keys
file on
the instance that was launched with the public key, or by using the
describe-key-pairs
AWS CLI command.
Use one of the following methods to retrieve the public key material.
- From the private key
-
To retrieve the public key material from the private key
On your local Linux or macOS computer, you can use the
ssh-keygen command to retrieve the public key for your key
pair. Specify the path where you downloaded your private key (the
.pem
file).
ssh-keygen -y -f /path_to_key_pair
/my-key-pair.pem
The command returns the public key, as shown in the following
example.
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQClKsfkNkuSevGj3eYhCe53pcjqP3maAhDFcvBS7O6V
hz2ItxCih+PnDSUaw+WNQn/mZphTk/a/gU8jEzoOWbkM4yxyb/wB96xbiFveSFJuOp/d6RJhJOI0iBXr
lsLnBItntckiJ7FbtxJMXLvvwJryDUilBMTjYtwB+QhYXUMOzce5Pjz5/i8SeJtjnV3iAoG/cQk+0FzZ
qaeJAAHco+CY/5WrUBkrHmFJr6HcXkvJdWPkYQS3xqC0+FmUZofz221CBt5IMucxXPkX4rWi+z7wB3Rb
BQoQzd8v7yeb7OzlPnWOyN0qFU0XA246RA8QFYiCNYwI3f05p6KLxEXAMPLE
If the command fails, run the following command to ensure that you've
changed the permissions on your private key pair file so that only you can view
it.
chmod 400 key-pair-name
.pem
- From the instance metadata
-
You can use Instance Metadata Service Version 2 or Instance Metadata Service Version 1 to retrieve the public key from the
instance metadata.
If you change the key pair that you use to connect to the instance, Amazon EC2 does
not update the instance metadata to show the new public key. The instance metadata
continues to show the public key for the key pair that you specified when you
launched the instance.
To retrieve the public key material from the instance metadata
Use one of the following commands from your instance.
IMDSv2
[ec2-user ~]$
TOKEN=`curl -X PUT "http://169.254.169.254/latest/api/token" -H "X-aws-ec2-metadata-token-ttl-seconds: 21600"` \
&& curl -H "X-aws-ec2-metadata-token: $TOKEN" –v http://169.254.169.254/latest/meta-data/public-keys/0/openssh-key
IMDSv1
[ec2-user ~]$
curl http://169.254.169.254/latest/meta-data/public-keys/0/openssh-key
Example output
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQClKsfkNkuSevGj3eYhCe53pcjqP3maAhDFcvBS7O6V
hz2ItxCih+PnDSUaw+WNQn/mZphTk/a/gU8jEzoOWbkM4yxyb/wB96xbiFveSFJuOp/d6RJhJOI0iBXr
lsLnBItntckiJ7FbtxJMXLvvwJryDUilBMTjYtwB+QhYXUMOzce5Pjz5/i8SeJtjnV3iAoG/cQk+0FzZ
qaeJAAHco+CY/5WrUBkrHmFJr6HcXkvJdWPkYQS3xqC0+FmUZofz221CBt5IMucxXPkX4rWi+z7wB3Rb
BQoQzd8v7yeb7OzlPnWOyN0qFU0XA246RA8QFYiCNYwI3f05p6KLxEXAMPLE key-pair-name
For more information about instance metadata, see Retrieve instance metadata.
- From the instance
-
If you specify a key pair when launching a Linux instance, when the instance boots
for the first time, the content of the public key is placed on the instance in an
entry within ~/.ssh/authorized_keys
.
To retrieve the public key material from an instance
-
Connect to your instance.
-
In the terminal window, open the authorized_keys
file using your
favorite text editor (such as vim or nano).
[ec2-user ~]$
nano ~/.ssh/authorized_keys
The authorized_keys
file opens, displaying the public key followed by
the name of the key pair. The following is an example entry for the key pair named
key-pair-name
.
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQClKsfkNkuSevGj3eYhCe53pcjqP3maAhDFcvBS7O6V
hz2ItxCih+PnDSUaw+WNQn/mZphTk/a/gU8jEzoOWbkM4yxyb/wB96xbiFveSFJuOp/d6RJhJOI0iBXr
lsLnBItntckiJ7FbtxJMXLvvwJryDUilBMTjYtwB+QhYXUMOzce5Pjz5/i8SeJtjnV3iAoG/cQk+0FzZ
qaeJAAHco+CY/5WrUBkrHmFJr6HcXkvJdWPkYQS3xqC0+FmUZofz221CBt5IMucxXPkX4rWi+z7wB3Rb
BQoQzd8v7yeb7OzlPnWOyN0qFU0XA246RA8QFYiCNYwI3f05p6KLxEXAMPLE key-pair-name
- From describe-key-pairs
-
To retrieve the public key material from the describe-key-pairs
AWS CLI command
Use the describe-key-pairs command and specify the
--key-names
parameter to identify the public key. To include the
public key material in the output, specify the --include-public-key
parameter.
aws ec2 describe-key-pairs --key-names key-pair-name
--include-public-key
Example output – In the output, the PublicKey
field contains
the public key material.
{
"KeyPairs": [
{
"KeyPairId": "key-0123456789example",
"KeyFingerprint": "1f:51:ae:28:bf:89:e9:d8:1f:25:5d:37:2d:7d:b8:ca:9f:f5:f1:6f",
"KeyName": "key-pair-name",
"KeyType": "rsa",
"Tags": [],
"PublicKey": "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIIj7azlDjVHAsSxgcpCRZ3oWnTm0nAFM64y9jd22ioI/ my-key-pair",
"CreateTime": "2022-04-28T11:37:26.000Z"
}
]
}
Alternatively, instead of --key-names
, you can specify the
--key-pair-ids
parameter to identify the public key.
aws ec2 describe-key-pairs --key-pair-ids key-0123456789example
--include-public-key
Identify the public key specified at
launch
If you specify a public key when you launch an instance, the public key name is recorded
by the instance.
To identify the public key that was specified at launch
Open the Amazon EC2 console at
https://console.aws.amazon.com/ec2/.
-
In the navigation pane, choose Instances, and then select your
instance.
-
On the Details tab, under Instance
details, the Key pair assigned at launch field displays
the name of the public key that you specified when you launched the instance.
The value of the Key pair assigned at launch field does not
change even if you change the public key on the instance, or add public keys.