Update README.md for OIDC changes (#764)

This commit is contained in:
Tom Keller
2023-07-07 16:49:10 -07:00
committed by GitHub
parent 3c981da079
commit 228a9916ee

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@@ -7,8 +7,24 @@ calls.
### Recent updates
**If you use OIDC, you may need to update your identity provider**
**GitHub OIDC Changes**
In #[357](https://github.com/aws-actions/configure-aws-credentials/issues/357), we
observed that GitHub recently started offering one of several intermediate OIDC
endpoint thumbprints. Because IAM requires statically configured endpoint
thumbprints, AWS customers that had only one thumbprint configured could see
intermittent authentication failures. **As of July 6, 2023, AWS has made a change to
IAM that will no longer require any particular certificate thumbprint for
tokens.actions.githubusercontent.com**, which is the GitHub OIDC endpoint. Instead,
AWS secures communication with GitHub OIDC using our library of trusted CAs rather
than using a certificate thumbprint to verify the server certificate. The IAM APIs
still require that a thumbprint is configured, but those thumbprints will be ignored
when authenticating tokens.actions.githubusercontent.com.
GitHub Enterprise Server customers use a different endpoint so they are not affected by
this change.
*Original message:*
There are now [two possible intermediary certificates](https://github.blog/changelog/2023-06-27-github-actions-update-on-oidc-integration-with-aws/) for the Actions SSL certificate. Previously, the certificate with the thumbprint `6938fd4d98bab03faadb97b34396831e3780aea1` was guaranteed to return. Now, the certificate with the thumbprint `1c58a3a8518e8759bf075b76b750d4f2df264fcd` can also be returned, so you will need to [update your identity provider](https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_providers_create_oidc.html) with this additional new thumbprint.
### Table of Contents
@@ -201,6 +217,11 @@ with the provider in as an IAM IdP. The GitHub OIDC provider only needs to be
created once per account (i.e. multiple IAM Roles that can be assumed by the
GitHub's OIDC can share a single OIDC Provider).
Note that the thumbprint has been set to all F's because the thumbprint is not
used when authenticating tokens.actions.githubusercontent.com. Instead, IAM
uses its library of trusted CAs to authenticate. However, this value is still
required by the API.
This CloudFormation template will configure the IdP for you.
```yaml
Parameters:
@@ -251,8 +272,7 @@ Resources:
ClientIdList:
- sts.amazonaws.com
ThumbprintList:
- 6938fd4d98bab03faadb97b34396831e3780aea1
- 1c58a3a8518e8759bf075b76b750d4f2df264fcd
- ffffffffffffffffffffffffffffffffffffffff
Outputs:
Role: