Prerequisites for signing container images

Before you begin signing, you need to set up an environment that bridges AWS Signer with Amazon ECR. Complete the following steps.

To prepare your signing environment

Prepare the AWS CLI

Install and configure the latest version of the AWS CLI. For more information, see Installing or updating the latest version of the AWS CLI in the AWS Command Line Interface User Guide.
Prepare Amazon ECR

Have an existing container image stored in an Amazon ECR private repository to sign. For more information, see Pushing an image in the Amazon Elastic Container Registry User Guide.

Download the container-signing tools

Two software packages need to be installed in your local environment for you to sign images:

The AWS Signer plugin for Notation
The open source supply chain security program Notation, developed by the Notary Project

AWS Signer provides an installer, which installs both the AWS Signer plugin for Notation and the Notation client. Separate installers are available for the AWS Signer plugin alone and the combined AWS Signer plugin with the Notation binary.

The installer includes the following.

Notation binary and third party license.
AWS Signer plugin binary and third party license.
Notation license.
Trust store and root certificate.
GovCloud trust store and root certificate, for use in the AWS GovCloud (US) Region.
A configurable trust policy. For information about configuring the trust policy, see Verify an image locally after signing.

The following table provides the installer and related files for each supported operating system and architecture. You can download our latest CHANGELOG to see the versions of the Notation CLI and plugin included in each installer release.

Notation binary and AWS Signer Plugin installer files
Platform	Architecture	Installer for Notation and AWS Signer plugin	AWS Signer plugin only	Signature file
RPM-based Linux (e.g., Amazon Linux)	x86_64	aws-signer-notation-cli_amd64.rpm	notation-aws-signer-plugin.zip	aws-signer-notation-cli_amd64.rpm.sig (installer) notation-aws-signer-plugin.sig (plugin)
RPM-based Linux (e.g., Amazon Linux)	arm64	aws-signer-notation-cli_arm64.rpm	notation-aws-signer-plugin.zip	aws-signer-notation-cli_arm64.rpm.sig (installer) notation-aws-signer-plugin.sig (plugin)
Debian-based Linux	x86_64	aws-signer-notation-cli_amd64.deb	notation-aws-signer-plugin.zip	aws-signer-notation-cli_amd64.deb.sig (installer) notation-aws-signer-plugin.sig (plugin)
Debian-based Linux	arm64	aws-signer-notation-cli_arm64.deb	notation-aws-signer-plugin.zip	aws-signer-notation-cli_arm64.deb.sig notation-aws-signer-plugin.sig (plugin)
macOS	x86_64	aws-signer-notation-cli_amd64.pkg	notation-aws-signer-plugin.zip	Included in the files.
macOS	arm64	aws-signer-notation-cli_arm64.pkg	notation-aws-signer-plugin.zip	Included in the files.
Microsoft Windows	x86_64	aws-signer-notation-cli.msi	notation-aws-signer-plugin.zip	Validate in Explorer

To download the required files to a Linux or MacOS environment, you can use wget:


$ wget download-link

On a Windows environment, you can use curl:


C:\> curl -UseBasicParsing download-link -o [filename].msi

(Optional) Verify signed packages.

For instructions to complete this step, select the tab for your platform.

Linux

Download the public key.


$ wget https://d2hvyiie56hcat.cloudfront.net/linux/public.key

Import the public key into your keyring. If you're using the unzip the AWS Signer plugin, first unzip downloaded file and then run command against the binary file within the zip file.
```
$  gpg --import public.key
gpg: key A3B52DA65461CF90: public key "AWS Signer Notation" imported
gpg: Total number processed: 1
gpg:               imported: 1
```
Make a note of the key value, as you need it in the next step. In the preceding example, the key value is A3B52DA65461CF90.
Verify the fingerprint by running the following command, replacing key-value with the value from the preceding step:
```
$  gpg --fingerprint key-value
pub   rsa3072 2023-04-24 [SC]
    E84A F8A2 A9B5 2F1F 4435  AE71 A3B5 2DA6 5461 CF90
uid           [ unknown] AWS Signer Notation
```
The fingerprint string should be E84A F8A2 A9B5 2F1F 4435 AE71 A3B5 2DA6 5461 CF90.

If the fingerprint string doesn't match, don't run the installer. Contact Amazon Web Services.

After you have verified the fingerprint, you can use it to verify the signature of the AWS Signer Notation package.
Download the package signature file using wget. To determine the correct signature file, see the preceding table.
```
$ wget signature-file-link
```
To verify the signature, run gpg --verify:
```
$  gpg --verify sig-filename downloaded-filename
gpg: Signature made Mon May 22 16:16:34 2023 PDT
gpg:                using RSA key A3B52DA65461CF90
gpg: Good signature from "AWS Signer Notation" [unknown]
gpg: WARNING: This key is not certified with a trusted signature!
gpg:          There is no indication that the signature belongs to the owner.
Primary key fingerprint: E84A F8A2 A9B5 2F1F 4435  AE71 A3B5 2DA6 5461 CF90
```
If the output includes the phrase BAD signature, check whether you performed the procedure correctly. If you continue to get this response, contact Amazon Web Services and avoid using the downloaded file.

Note the warning about trust. A key is trusted only if you or someone who you trust has signed it. This doesn't mean that the signature is invalid, only that you have not verified the public key.

Windows

To verify the signature of the MSI installer or the plugin EXE file, using Windows PowerShell run the following command:


C:\> Get-AuthenticodeSignature filename

You can also verify the signature by right-clicking on the file in an Explorer window, choosing Properties, and then choosing Digital Signatures.

You should see a result similar to the following:


SignerCertificate                         Status             Path
-----------------                         ------             ----
[40-character hexamecimal number]         Valid              downloaded-file

MacOS

To verify the signature of the PKG installer, run the following command. This example uses the amd64 package, but the signature of the arm64 package can be verified similarly.


$ pkgutil --check-signature aws-signer-notation-cli_amd64.pkg

You should see a result similar to the following:


Package "aws-signer-notation-cli_amd64.pkg":
    Status: signed by a developer certificate issued by Apple for distribution
    Notarization: trusted by the Apple notary service
    Signed with a trusted timestamp on: 2023-05-19 15:17:15 +0000
    Certificate Chain:
     1. Developer ID Installer: AMZN Mobile LLC (94KV3E626L)
         Expires: 2027-06-28 22:57:06 +0000
         SHA256 Fingerprint:
              49 68 39 4A BA 83 3B F0 CC 5E 98 3B E7 C1 72 AC 85 97 65 18 B9 4C  
              BA 34 62 BF E9 23 76 98 C5 DA
         ------------------------------------------------------------------------
     2. Developer ID Certification Authority
         Expires: 2031-09-17 00:00:00 +0000
         SHA256 Fingerprint:
              F1 6C D3 C5 4C 7F 83 CE A4 BF 1A 3E 6A 08 19 C8 AA A8 E4 A1 52 8F
              D1 44 71 5F 35 06 43 D2 DF 3A
         ------------------------------------------------------------------------
     3. Apple Root CA
         Expires: 2035-02-09 21:40:36 +0000
         SHA256 Fingerprint:
              B0 B1 73 0E CB C7 FF 45 05 14 2C 49 F1 29 5E 6E DA 6B CA ED 7E 2C
              68 C5 BE 91 B5 A1 10 01 F0 24

To verify the signature of the AWS Signer Notation plugin executable, run the following command.


$ codesign -dv --verbose=4 ./notation-com.amazonaws.signer.notation.plugin

You should see a result similar to the following.


Executable=/path/to/notation-com.amazonaws.signer.notation.plugin
Identifier=notation-com.amazonaws.signer.notation.plugin_darwin_arm64
Format=Mach-O thin (arm64)
CodeDirectory v=20500 size=74278 flags=0x10000(runtime) hashes=2314+2 location=embedded
VersionPlatform=1
VersionMin=720896
VersionSDK=720896
Hash type=sha256 size=32
CandidateCDHash sha256=e4000dbdf4e6243be9d290b1520d95bf9027a5e4
CandidateCDHashFull sha256=e4000dbdf4e6243be9d290b1520d95bf9027a5e42b699a354fc39ac0f498477f
Hash choices=sha256
CMSDigest=e4000dbdf4e6243be9d290b1520d95bf9027a5e42b699a354fc39ac0f498477f
CMSDigestType=2
Executable Segment base=0
Executable Segment limit=3571712
Executable Segment flags=0x1
Page size=4096Launch Constraints:None
CDHash=e4000dbdf4e6243be9d290b1520d95bf9027a5e4
Signature size=9070
Authority=Developer ID Application: AMZN Mobile LLC (94KV3E626L)
Authority=Developer ID Certification Authority
Authority=Apple Root CATimestamp=May 19, 2023 at 7:51:07 AM
Info.plist=not bound
TeamIdentifier=94KV3E626L
Runtime Version=11.0.0
Sealed Resources=none
Internal requirements count=1 size=220

Install the packages

For instructions to complete this step, select the tab for your platform.
Linux (RPM)
If you downloaded an RPM package on a Linux server, change to the directory containing the package and enter the following:
```
$ sudo rpm -U filename
```
Linux (DEB)
If you downloaded a DEB package on a Linux server, change to the directory containing the package and enter the following:
```
$ sudo dpkg -i -E filename
```
Windows
Install the package with the following command.
```
C:\> msiexec /i filename
```
This command also works from within PowerShell. For more information, see Microsoft Standard Installer command-line options in the Microsoft Windows documentation.
MacOS
If you downloaded a PKG package on a macOS server, change to the directory containing the package and enter the following:
```
$ sudo installer -pkg filename -target /
```
Verify the package installation

After downloading and installing the package, to verify the installation was successful, do the following.
1. Verify that the Notation directory structure for your operating system was created.
2. Use the following command to display the Notation client version.
```
notation version
```
3. Use the following command to list the installed plugins for the Notation client and verify that you see the com.amazonaws.signer.notation.plugin plugin.
```
notation plugin ls
```

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Document Conventions

Signing container images

Signing procedure