Files
pixa/internal/allowlist/allowlist.go
T
clawbot 04b5db6fbf
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next -> main (1.0.0 milestone) (#105)
Accumulating milestone branch. One squashed commit per closed issue; `next` is kept green and mergeable to `main` at any time without notice.

Landed so far:

- `chore: update golangci-lint to v2.12.2 with canonical config` (#54) — canonical v2-schema `.golangci.yml`, pins bumped in `Dockerfile` and `script/bootstrap`, tree at `0 issues.`. Three behaviour deltas are recorded in that PR's body: `Cache.StoreVariant` takes a context, `MetadataStorage.Store` no longer leaks temp files on failure, and the `signing_key` too-short error text gained a `value too short:` prefix.

Sequencing for the milestone is tracked in #103.

Reviewed-on: #105
Co-authored-by: clawbot <clawbot@noreply.example.org>
2026-09-21 09:31:54 +02:00

85 lines
2.0 KiB
Go

// Package allowlist provides host-based URL allow-listing for the image proxy.
package allowlist
import (
"net/url"
"strings"
)
// HostAllowList checks whether source hosts are permitted.
type HostAllowList struct {
// exactHosts contains hosts that must match exactly (e.g., "cdn.example.com")
exactHosts map[string]struct{}
// suffixHosts contains domain suffixes to match
// (e.g., ".example.com" matches "cdn.example.com")
suffixHosts []string
}
// New creates a HostAllowList from a list of host patterns.
// Patterns starting with "." are treated as suffix matches.
// Examples:
// - "cdn.example.com" - exact match only
// - ".example.com" - matches cdn.example.com, images.example.com, etc.
func New(patterns []string) *HostAllowList {
w := &HostAllowList{
exactHosts: make(map[string]struct{}),
suffixHosts: make([]string, 0),
}
for _, pattern := range patterns {
pattern = strings.ToLower(strings.TrimSpace(pattern))
if pattern == "" {
continue
}
if strings.HasPrefix(pattern, ".") {
w.suffixHosts = append(w.suffixHosts, pattern)
} else {
w.exactHosts[pattern] = struct{}{}
}
}
return w
}
// IsAllowed checks if a URL's host is in the allow list.
func (w *HostAllowList) IsAllowed(u *url.URL) bool {
if u == nil {
return false
}
host := strings.ToLower(u.Hostname())
if host == "" {
return false
}
// Check exact match
if _, ok := w.exactHosts[host]; ok {
return true
}
// Check suffix match
for _, suffix := range w.suffixHosts {
if strings.HasSuffix(host, suffix) {
return true
}
// Also match if host equals the suffix without the leading dot
// e.g., pattern ".example.com" should match "example.com"
if host == strings.TrimPrefix(suffix, ".") {
return true
}
}
return false
}
// IsEmpty returns true if the allow list has no entries.
func (w *HostAllowList) IsEmpty() bool {
return len(w.exactHosts) == 0 && len(w.suffixHosts) == 0
}
// Count returns the total number of allow list entries.
func (w *HostAllowList) Count() int {
return len(w.exactHosts) + len(w.suffixHosts)
}