Add a cel function to X.509 templates - #1115
Open
maraino wants to merge 8 commits into
Open
Conversation
This commit adds a "cel" template function that compiles and evaluates a
CEL expression against the template data. It allows templates to do
filtering, mapping and conditional logic that is awkward to express with
Go's text/template.
The CEL environment exposes the usual template keys as typed variables:
Subject, SANs, Token, Webhooks, Insecure, AuthorizationCrt,
AuthorizationChain and CertificateRequest. The x509util and crypto/x509
structs are registered as native types, honoring a "cel" struct tag, and
the strings, encoders, lists, sets, network, regex and optional types
extensions are enabled.
Expressions are compiled with cel.CostLimit(1000) to bound the amount of
work a single expression can do.
For example:
```
{{cel "SANs.filter(s, s.Value.contains(\"foo\")).map(s, s.Value)"}}
```
Add a "cel" built-in that evaluates a CEL expression against the
template data:
{{ cel "Token.sub" }}
{{ cel "Subject.CommonName" | toJson }}
Each package builds a CEL environment declaring its template data
variables and native types, on top of shared options (optional types,
strings, encoders, lists, sets, network, regex, and two-variable
comprehensions) from internal/templates.
The environment is built lazily and compiled programs are cached in a
new fixed-capacity LRU cache (internal/lru), keeping compilation out of
the signing path. Evaluation is metered with a cost limit so a template
expression cannot make signing arbitrarily expensive.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
This commit adds a "cel" template function that compiles and evaluates a CEL expression against the template data. It allows templates to do filtering, mapping and conditional logic that is awkward to express with Go's text/template.
The CEL environment exposes the usual template keys as typed variables: Subject, SANs, Token, Webhooks, Insecure, AuthorizationCrt, AuthorizationChain and CertificateRequest. The x509util and crypto/x509 structs are registered as native types, honoring a "cel" struct tag, and the strings, encoders, lists, sets, network, regex and optional types extensions are enabled.
Expressions are compiled with cel.CostLimit(10000) to bound the amount of work a single expression can do.
For example: