remove suffix matching from host whitelist

Signatures are per-URL, so the whitelist should only support exact host
matches. Remove the suffix/wildcard matching that allowed patterns like
'.example.com' to bypass signature requirements for entire domain trees.

Leading dots in existing config entries are now stripped, so '.example.com'
becomes 'example.com' as an exact match (backwards-compatible normalisation).

Dockerfile

@@ -1,7 +1,29 @@
+# Lint stage
+# golangci/golangci-lint:v2.10.1-alpine, 2026-02-17
+FROM golangci/golangci-lint:v2.10.1-alpine@sha256:33bc6b6156d4c7da87175f187090019769903d04dd408833b83083ed214b0ddf AS lint
+
+RUN apk add --no-cache make build-base vips-dev libheif-dev pkgconfig
+
+WORKDIR /src
+
+# Copy go mod files first for better layer caching
+COPY go.mod go.sum ./
+RUN go mod download
+
+# Copy source code
+COPY . .
+
+# Run formatting check and linter
+RUN make fmt-check
+RUN make lint
+
 # Build stage
 # golang:1.25.4-alpine, 2026-02-25
 FROM golang:1.25.4-alpine@sha256:d3f0cf7723f3429e3f9ed846243970b20a2de7bae6a5b66fc5914e228d831bbb AS builder
 
+# Depend on lint stage passing
+COPY --from=lint /src/go.sum /dev/null
+
 ARG VERSION=dev
 
 # Install build dependencies for CGO image libraries
@@ -9,25 +31,7 @@ RUN apk add --no-cache \
     build-base \
     vips-dev \
     libheif-dev \
-    pkgconfig \
+    pkgconfig
-    curl
-
-# golangci-lint v2.10.1, 2026-02-25
-# SHA-256 checksums per architecture (amd64 / arm64)
-RUN set -e; \
-    ARCH="$(uname -m)"; \
-    if [ "$ARCH" = "aarch64" ] || [ "$ARCH" = "arm64" ]; then \
-      GOARCH="arm64"; \
-      HASH="6652b42ae02915eb2f9cb2a2e0cac99514c8eded8388d88ae3e06e1a52c00de8"; \
-    else \
-      GOARCH="amd64"; \
-      HASH="dfa775874cf0561b404a02a8f4481fc69b28091da95aa697259820d429b09c99"; \
-    fi; \
-    curl -sSfL "https://github.com/golangci/golangci-lint/releases/download/v2.10.1/golangci-lint-2.10.1-linux-${GOARCH}.tar.gz" -o /tmp/golangci-lint.tar.gz && \
-    echo "${HASH}  /tmp/golangci-lint.tar.gz" | sha256sum -c - && \
-    tar -xzf /tmp/golangci-lint.tar.gz -C /tmp && \
-    mv "/tmp/golangci-lint-2.10.1-linux-${GOARCH}/golangci-lint" /usr/local/bin/ && \
-    rm -rf /tmp/golangci-lint*
 
 WORKDIR /src
 
@@ -38,8 +42,8 @@ RUN GOTOOLCHAIN=auto go mod download
 # Copy source code
 COPY . .
 
-# Run all checks (fmt-check, lint, test)
+# Run tests
-RUN make check
+RUN make test
 
 # Build with CGO enabled
 RUN CGO_ENABLED=1 GOTOOLCHAIN=auto go build -ldflags "-X main.Version=${VERSION}" -o /pixad ./cmd/pixad

README.md

@@ -96,11 +96,10 @@ expiration 1704067200:
 4. URL:
    `/v1/image/cdn.example.com/photos/cat.jpg/800x600.webp?sig=<base64url>&exp=1704067200`
 
-**Whitelist patterns:**
+**Whitelist entries** are exact host matches only (e.g.
-
+`cdn.example.com`). Suffix/wildcard matching is not supported —
-- **Exact match**: `cdn.example.com` — matches only that host
+signatures are per-URL, so each allowed host must be listed
-- **Suffix match**: `.example.com` — matches `cdn.example.com`,
+explicitly.
-  `images.example.com`, and `example.com`
 
 ### Configuration
 

TODO.md

@@ -1,64 +1,65 @@
-# Status
+# Pixa 1.0 TODO
 
-pre-1.0. No git tags. Full policy file set is present, but make check
+Remaining tasks sorted by priority for a working 1.0 release.
-fails on main with 10 gosec lint findings, so main is not green.
 
-# Next Step
+## P0: Critical for 1.0
 
-Fix the 10 gosec findings so make check passes on main. Fix each issue
+### Image Processing
-properly (no blanket nolint suppressions) and confirm lint, tests, and
+- [x] Add WebP encoding support (currently returns error)
-CI are green. This restores the main-always-green policy.
+- [x] Add AVIF encoding support (implemented via govips)
 
-# Completed Steps
+### Manual Testing (verify auth/encrypted URLs work)
+- [ ] Manual test: visit `/`, see login form
+- [ ] Manual test: enter wrong key, see error
+- [ ] Manual test: enter correct signing key, see generator form
+- [ ] Manual test: generate encrypted URL, verify it works
+- [ ] Manual test: wait for expiration or use short TTL, verify expired URL returns 410
+- [ ] Manual test: logout, verify redirected to login
 
-- 2026-02-25: Docker arm64 build fixed via architecture detection for
+### Cache Management
-  golangci-lint download (#16)
+- [ ] Implement cache size management/eviction (prevent disk from filling up)
-- 2026-02-25: full repo policy compliance pass (#14): LICENSE,
-  REPO_POLICIES.md, .editorconfig, Gitea Actions CI workflow, Docker
-  images pinned by hash, README restructured to policy sections, hooks
-  Makefile target, golangci-lint errors resolved
-- 2026-02-20: stale local dev config files removed (#12)
-- 2026-02-09: correctness fixes: negative cache checked in Service.Get()
-  before upstream fetch (#8); Stats() column scanning and HitRate
-  computation corrected (#9)
-- 2026-02-08: AllowHTTP propagated to SourceURL() scheme selection (#6)
-- WebP encoding support added (P0 item, checked off in TODO)
-- 2026-01-08: initial implementation with Makefile and TODO checklist
 
-# Future Steps
+### Configuration
+- [ ] Validate configuration on startup (fail fast on bad config)
 
-Compliance:
+## P1: Important for Production
 
-- After the gosec fix lands, verify CI runs make check green on main
+### Security
+- [ ] Implement blocked networks configuration (extend SSRF protection)
+- [ ] Add rate limiting global concurrent fetches (prevent resource exhaustion)
 
-P0, critical for 1.0 (from existing TODO.md):
+### Image Processing
+- [ ] Implement EXIF/metadata stripping (privacy)
 
-- Add AVIF encoding support (currently returns error)
+## P2: Nice to Have
-- Manual test pass for auth and encrypted URLs:
-    - visit /, see login form
-    - wrong key shows error; correct signing key shows generator form
-    - generated encrypted URL works
-    - expired URL (short TTL) returns 410
-    - logout redirects to login
-- Implement cache size management and eviction (prevent disk fill)
-- Validate configuration on startup (fail fast on bad config)
 
-P1, important for production:
+### Security
+- [ ] Implement referer blacklist
+- [ ] Add rate limiting per-IP
+- [ ] Add rate limiting per-origin
 
-- Blocked networks configuration (extend SSRF protection)
+### HTTP Response Handling
-- Rate limit global concurrent fetches (resource exhaustion)
+- [ ] Implement Last-Modified headers
-- EXIF/metadata stripping (privacy)
+- [ ] Implement Vary header for content negotiation
+- [ ] Implement X-Request-ID propagation
 
-P2, nice to have:
+### Additional Endpoints
+- [ ] Implement auto-format selection (format=auto based on Accept header)
 
-- Referer blacklist; per-IP and per-origin rate limiting
+### Configuration
-- Last-Modified headers; Vary header; X-Request-ID propagation
+- [ ] Add all configuration options from README
-- Auto-format selection (format=auto based on Accept header)
+- [ ] Implement environment variable overrides
-- All configuration options from README; env var overrides; YAML config
+- [ ] Implement YAML config file support
-  file support
+
-- Sentry error reporting (optional); comprehensive request logging;
+### Operational
-  Prometheus metrics
+- [ ] Implement Sentry error reporting (optional)
-- Integration tests for the image proxy flow; load tests for the
+- [ ] Add comprehensive request logging
-  1-5k req/s target
+- [ ] Add performance metrics (Prometheus)
-- Docs: configuration options, API endpoints, deployment guide, example
+- [ ] Write integration tests for image proxy flow
-  nginx/caddy reverse proxy config
+- [ ] Write load tests to verify 1-5k req/s target
+
+### Documentation
+- [ ] Document configuration options
+- [ ] Document API endpoints
+- [ ] Document deployment guide
+- [ ] Add example nginx/caddy reverse proxy config

config.example.yml

@@ -13,8 +13,7 @@ state_dir: ./data
 # Generate with: openssl rand -base64 32
 signing_key: "CHANGE_ME_generate_with_openssl_rand_base64_32"
 
-# Hosts that don't require signatures
+# Hosts that don't require signatures (exact match only)
-# Use "." prefix for wildcard subdomain matching (e.g., ".example.com" matches "cdn.example.com")
 whitelist_hosts:
   - s3.sneak.cloud
   - static.sneak.cloud

internal/imgcache/whitelist.go

@@ -5,23 +5,20 @@ import (
 	"strings"
 )
 
-// HostWhitelist implements the Whitelist interface for checking allowed source hosts.
+// HostWhitelist checks whether a source host is allowed without a signature.
+// Only exact host matches are supported. Signatures are per-URL, so
+// wildcard/suffix matching is intentionally not provided.
 type HostWhitelist 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
 }
 
-// NewHostWhitelist creates a whitelist from a list of host patterns.
+// NewHostWhitelist creates a whitelist from a list of hostnames.
-// Patterns starting with "." are treated as suffix matches.
+// Each entry is treated as an exact host match. Leading dots are
-// Examples:
+// stripped so that legacy ".example.com" entries become "example.com".
-//   - "cdn.example.com" - exact match only
-//   - ".example.com" - matches cdn.example.com, images.example.com, etc.
 func NewHostWhitelist(patterns []string) *HostWhitelist {
 	w := &HostWhitelist{
-		exactHosts:  make(map[string]struct{}),
+		exactHosts: make(map[string]struct{}),
-		suffixHosts: make([]string, 0),
 	}
 
 	for _, pattern := range patterns {
@@ -30,9 +27,11 @@ func NewHostWhitelist(patterns []string) *HostWhitelist {
 			continue
 		}
 
-		if strings.HasPrefix(pattern, ".") {
+		// Strip leading dot — suffix matching is no longer supported;
-			w.suffixHosts = append(w.suffixHosts, pattern)
+		// ".example.com" is normalised to "example.com" as an exact entry.
-		} else {
+		pattern = strings.TrimPrefix(pattern, ".")
+
+		if pattern != "" {
 			w.exactHosts[pattern] = struct{}{}
 		}
 	}
@@ -40,7 +39,7 @@ func NewHostWhitelist(patterns []string) *HostWhitelist {
 	return w
 }
 
-// IsWhitelisted checks if a URL's host is in the whitelist.
+// IsWhitelisted checks if a URL's host is in the whitelist (exact match only).
 func (w *HostWhitelist) IsWhitelisted(u *url.URL) bool {
 	if u == nil {
 		return false
@@ -51,32 +50,17 @@ func (w *HostWhitelist) IsWhitelisted(u *url.URL) bool {
 		return false
 	}
 
-	// Check exact match
+	_, ok := w.exactHosts[host]
-	if _, ok := w.exactHosts[host]; ok {
-		return true
-	}
 
-	// Check suffix match
+	return ok
-	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 whitelist has no entries.
 func (w *HostWhitelist) IsEmpty() bool {
-	return len(w.exactHosts) == 0 && len(w.suffixHosts) == 0
+	return len(w.exactHosts) == 0
 }
 
 // Count returns the total number of whitelist entries.
 func (w *HostWhitelist) Count() int {
-	return len(w.exactHosts) + len(w.suffixHosts)
+	return len(w.exactHosts)
 }

internal/imgcache/whitelist_test.go

@@ -31,41 +31,41 @@ func TestHostWhitelist_IsWhitelisted(t *testing.T) {
 			want:     false,
 		},
 		{
-			name:     "suffix match",
+			name:     "no suffix matching for subdomains",
-			patterns: []string{".example.com"},
+			patterns: []string{"example.com"},
 			testURL:  "https://cdn.example.com/image.jpg",
-			want:     true,
+			want:     false,
 		},
 		{
-			name:     "suffix match deep subdomain",
+			name:     "leading dot stripped to exact match",
-			patterns: []string{".example.com"},
-			testURL:  "https://cdn.images.example.com/image.jpg",
-			want:     true,
-		},
-		{
-			name:     "suffix match apex domain",
 			patterns: []string{".example.com"},
 			testURL:  "https://example.com/image.jpg",
 			want:     true,
 		},
 		{
-			name:     "suffix match not found",
+			name:     "leading dot does not enable suffix matching",
 			patterns: []string{".example.com"},
-			testURL:  "https://notexample.com/image.jpg",
+			testURL:  "https://cdn.example.com/image.jpg",
 			want:     false,
 		},
 		{
-			name:     "suffix match partial not allowed",
+			name:     "leading dot does not match deep subdomain",
 			patterns: []string{".example.com"},
-			testURL:  "https://fakeexample.com/image.jpg",
+			testURL:  "https://cdn.images.example.com/image.jpg",
 			want:     false,
 		},
 		{
-			name:     "multiple patterns",
+			name:     "multiple patterns exact only",
-			patterns: []string{"cdn.example.com", ".images.org", "static.test.net"},
+			patterns: []string{"cdn.example.com", "photos.images.org", "static.test.net"},
 			testURL:  "https://photos.images.org/image.jpg",
 			want:     true,
 		},
+		{
+			name:     "multiple patterns no suffix leak",
+			patterns: []string{"cdn.example.com", "images.org"},
+			testURL:  "https://photos.images.org/image.jpg",
+			want:     false,
+		},
 		{
 			name:     "empty whitelist",
 			patterns: []string{},
@@ -86,7 +86,7 @@ func TestHostWhitelist_IsWhitelisted(t *testing.T) {
 		},
 		{
 			name:     "whitespace in patterns",
-			patterns: []string{"  cdn.example.com  ", "  .other.com  "},
+			patterns: []string{"  cdn.example.com  ", "  other.com  "},
 			testURL:  "https://cdn.example.com/image.jpg",
 			want:     true,
 		},
@@ -139,6 +139,11 @@ func TestHostWhitelist_IsEmpty(t *testing.T) {
 			patterns: []string{"example.com"},
 			want:     false,
 		},
+		{
+			name:     "leading dot normalised to entry",
+			patterns: []string{".example.com"},
+			want:     false,
+		},
 	}
 
 	for _, tt := range tests {
@@ -168,14 +173,14 @@ func TestHostWhitelist_Count(t *testing.T) {
 			want:     3,
 		},
 		{
-			name:     "suffix hosts only",
+			name:     "leading dots normalised to exact",
 			patterns: []string{".a.com", ".b.com"},
 			want:     2,
 		},
 		{
-			name:     "mixed",
+			name:     "mixed deduplication",
-			patterns: []string{"exact.com", ".suffix.com"},
+			patterns: []string{"example.com", ".example.com"},
-			want:     2,
+			want:     1,
 		},
 	}
 

scripts/manual-test.sh

@@ -48,7 +48,7 @@ fi
 
 # Test 3: Wrong password shows error
 echo "--- Test 3: Login with wrong password ---"
-WRONG_LOGIN=$(curl -sf -X POST "$BASE_URL/" -d "password=wrong-key" -c "$COOKIE_JAR")
+WRONG_LOGIN=$(curl -sf -X POST "$BASE_URL/" -d "key=wrong-key" -c "$COOKIE_JAR")
 if echo "$WRONG_LOGIN" | grep -qi "invalid\|error\|incorrect\|wrong"; then
     pass "Wrong password shows error message"
 else
@@ -57,7 +57,7 @@ fi
 
 # Test 4: Correct password redirects to generator
 echo "--- Test 4: Login with correct signing key ---"
-curl -sf -X POST "$BASE_URL/" -d "password=$SIGNING_KEY" -c "$COOKIE_JAR" -b "$COOKIE_JAR" -L -o /dev/null
+curl -sf -X POST "$BASE_URL/" -d "key=$SIGNING_KEY" -c "$COOKIE_JAR" -b "$COOKIE_JAR" -L -o /dev/null
 GENERATOR_PAGE=$(curl -sf "$BASE_URL/" -b "$COOKIE_JAR")
 if echo "$GENERATOR_PAGE" | grep -qi "generate\|url\|source\|logout"; then
     pass "Correct password shows generator page"
@@ -68,12 +68,12 @@ fi
 # Test 5: Generate encrypted URL
 echo "--- Test 5: Generate encrypted URL ---"
 GEN_RESULT=$(curl -sf -X POST "$BASE_URL/generate" -b "$COOKIE_JAR" \
-    -d "source_url=$TEST_IMAGE_URL" \
+    -d "url=$TEST_IMAGE_URL" \
     -d "width=800" \
     -d "height=600" \
     -d "format=jpeg" \
     -d "quality=85" \
-    -d "fit_mode=cover" \
+    -d "fit=cover" \
     -d "ttl=3600")
 if echo "$GEN_RESULT" | grep -q "/v1/e/"; then
     pass "Encrypted URL generated"
@@ -121,10 +121,10 @@ fi
 # Test 9: Generate short-TTL URL and verify expiration
 echo "--- Test 9: Expired URL returns 410 ---"
 # Login again
-curl -sf -X POST "$BASE_URL/" -d "password=$SIGNING_KEY" -c "$COOKIE_JAR" -b "$COOKIE_JAR" -L -o /dev/null
+curl -sf -X POST "$BASE_URL/" -d "key=$SIGNING_KEY" -c "$COOKIE_JAR" -b "$COOKIE_JAR" -L -o /dev/null
 # Generate URL with 1 second TTL
 GEN_RESULT=$(curl -sf -X POST "$BASE_URL/generate" -b "$COOKIE_JAR" \
-    -d "source_url=$TEST_IMAGE_URL" \
+    -d "url=$TEST_IMAGE_URL" \
     -d "width=100" \
     -d "height=100" \
     -d "format=jpeg" \