fix(safety): compile baked policy to code to resist binary tampering

Compile baked safety-profile policies into generated hash switches so the raw allow/deny rule strings are no longer embedded as a patchable YAML blob.

Verification before merge:
- `go test ./cmd/bake-safety-profile ./internal/safetyprofile ./internal/cmd`
- `make lint`
- `./build-safe.sh safety-profiles/agent-safe.yaml -o bin/gog-agent-safe-review`
- `./build-safe.sh safety-profiles/readonly.yaml -o bin/gog-readonly-review`
- runtime block checks for agent-safe and readonly baked binaries

Co-authored-by: drewburchfield <drewburchfield@gmail.com>

.golangci.yml

@@ -120,6 +120,11 @@ linters:
           - dupl
           - wsl_v5
           - tagliatelle
+      - path: internal/safetyprofile/.*\.go
+        linters:
+          - err113
+          - wrapcheck
+          - wsl_v5
       - path: internal/googleauth/.*\.go
         linters:
           - tagliatelle

cmd/bake-safety-profile/main.go

@@ -5,36 +5,111 @@ import (
 	"fmt"
 	"os"
 	"strconv"
+	"strings"
 
-	"github.com/steipete/gogcli/internal/cmd"
+	"github.com/steipete/gogcli/internal/safetyprofile"
 )
 
+const usage = `Usage: bake-safety-profile <profile.yaml> <output.go>` + "\n"
+
 func main() {
-	if len(os.Args) != 3 {
-		_, _ = fmt.Fprintln(os.Stderr, "usage: bake-safety-profile <profile.yaml> <output.go>")
+	args := os.Args[1:]
+	if len(args) != 2 {
+		_, _ = fmt.Fprint(os.Stderr, usage)
 		os.Exit(2)
 	}
 
-	raw, err := os.ReadFile(os.Args[1]) // #nosec G304 G703 -- build helper intentionally reads the requested profile path.
+	raw, err := os.ReadFile(args[0]) // #nosec G304 G703 -- build helper intentionally reads the requested profile path.
 	if err != nil {
 		_, _ = fmt.Fprintf(os.Stderr, "read profile: %v\n", err)
 		os.Exit(1)
 	}
-	if err := cmd.ValidateSafetyProfile(string(raw)); err != nil {
+
+	profile, err := safetyprofile.Parse(string(raw))
+	if err != nil {
 		_, _ = fmt.Fprintf(os.Stderr, "parse profile: %v\n", err)
 		os.Exit(1)
 	}
 
-	var out bytes.Buffer
-	out.WriteString("// Code generated by cmd/bake-safety-profile; DO NOT EDIT.\n")
-	out.WriteString("//go:build safety_profile\n\n")
-	out.WriteString("package cmd\n\n")
-	out.WriteString("var bakedSafetyProfileYAML = ")
-	out.WriteString(strconv.Quote(string(raw)))
-	out.WriteString("\n")
-
-	if err := os.WriteFile(os.Args[2], out.Bytes(), 0o600); err != nil { // #nosec G306 G703 -- build helper intentionally writes the requested generated Go path.
+	out := generate(profile)
+	if err := os.WriteFile(args[1], out, 0o600); err != nil { // #nosec G306 G703 -- build helper intentionally writes the requested generated Go path.
 		_, _ = fmt.Fprintf(os.Stderr, "write output: %v\n", err)
 		os.Exit(1)
 	}
 }
+
+// generate emits a Go file that resolves the bakedSafety* package-level
+// functions for safety_profile builds. Allow and deny rules are encoded as
+// FNV-64a hashes in switch statements so that the rule set itself is no
+// longer a contiguous, patchable string in the binary.
+func generate(profile *safetyprofile.Profile) []byte {
+	var out bytes.Buffer
+	hasAllowRules := profile.AllowAll || len(profile.AllowRules) > 0
+
+	out.WriteString("// Code generated by cmd/bake-safety-profile; DO NOT EDIT.\n")
+	commentName := strings.ReplaceAll(strings.ReplaceAll(profile.Name, "\n", " "), "\r", " ")
+	fmt.Fprintf(&out, "// Profile: %s (%d allow, %d deny, allow-all=%t)\n", commentName, len(profile.AllowRules), len(profile.DenyRules), profile.AllowAll)
+	out.WriteString("// Hash: FNV-64a over dotted command paths.\n")
+	out.WriteString("//go:build safety_profile\n\n")
+	out.WriteString("package cmd\n\n")
+
+	out.WriteString("const bakedSafetyProfileNameConst = ")
+	out.WriteString(strconv.Quote(profile.Name))
+	out.WriteString("\n\n")
+
+	out.WriteString("func bakedSafetyEnabled() bool       { return true }\n")
+	out.WriteString("func bakedSafetyProfileName() string { return bakedSafetyProfileNameConst }\n")
+	fmt.Fprintf(&out, "func bakedSafetyHasAllowRules() bool { return %t }\n\n", hasAllowRules)
+
+	writeMatcher(&out, "bakedSafetyAllowMatch", profile.AllowRules, profile.AllowAll)
+	out.WriteString("\n")
+	writeMatcher(&out, "bakedSafetyDenyMatch", profile.DenyRules, false)
+
+	return out.Bytes()
+}
+
+func writeMatcher(out *bytes.Buffer, name string, rules []string, matchAll bool) {
+	fmt.Fprintf(out, "func %s(path []string) bool {\n", name)
+	if matchAll {
+		out.WriteString("\treturn true\n}\n")
+		return
+	}
+	if len(rules) == 0 {
+		out.WriteString("\treturn false\n}\n")
+		return
+	}
+
+	out.WriteString("\tif len(path) == 0 {\n\t\treturn false\n\t}\n")
+	out.WriteString("\tfor i := 1; i <= len(path); i++ {\n")
+	out.WriteString("\t\tswitch bakedSafetyHashPath(path[:i]) {\n")
+	out.WriteString("\t\tcase ")
+
+	cases := make([]string, 0, len(rules))
+	seen := make(map[uint64]string, len(rules))
+	for _, rule := range rules {
+		h := safetyprofile.HashRule(rule)
+		if existing, dup := seen[h]; dup {
+			fmt.Fprintf(os.Stderr, "bake-safety-profile: hash collision between %q and %q (FNV-64a=%#x); pick a different name or extend the hash\n", existing, rule, h)
+			os.Exit(1)
+		}
+		seen[h] = rule
+		cases = append(cases, fmt.Sprintf("0x%016x", h))
+	}
+
+	const perLine = 4
+	for i, c := range cases {
+		out.WriteString(c)
+		if i == len(cases)-1 {
+			break
+		}
+		out.WriteString(",")
+		if (i+1)%perLine == 0 {
+			out.WriteString("\n\t\t\t")
+		} else {
+			out.WriteString(" ")
+		}
+	}
+	out.WriteString(":\n\t\t\treturn true\n")
+	out.WriteString("\t\t}\n\t}\n")
+	out.WriteString("\treturn false\n}\n")
+}

cmd/bake-safety-profile/main_test.go

@@ -0,0 +1,138 @@
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"go/parser"
+	"go/token"
+	"strings"
+	"testing"
+
+	"github.com/steipete/gogcli/internal/safetyprofile"
+)
+
+func TestGenerateProducesParseableGoWithExpectedHashes(t *testing.T) {
+	profile := &safetyprofile.Profile{
+		Name:       "test",
+		AllowAll:   false,
+		AllowRules: []string{"version", "gmail.search", "gmail.drafts.create"},
+		DenyRules:  []string{"gmail.send", "gmail.drafts.send"},
+	}
+
+	out := generate(profile)
+
+	if _, err := parser.ParseFile(token.NewFileSet(), "gen.go", out, parser.AllErrors); err != nil {
+		t.Fatalf("generated code does not parse as Go:\n%s\n\nerror: %v", out, err)
+	}
+
+	want := []string{
+		`//go:build safety_profile`,
+		`package cmd`,
+		`const bakedSafetyProfileNameConst = "test"`,
+		`func bakedSafetyEnabled() bool       { return true }`,
+		`func bakedSafetyHasAllowRules() bool { return true }`,
+	}
+	for _, line := range want {
+		if !bytes.Contains(out, []byte(line)) {
+			t.Fatalf("generated output missing %q\n\nfull output:\n%s", line, out)
+		}
+	}
+
+	for _, rule := range profile.AllowRules {
+		hex := fmt.Sprintf("0x%016x", safetyprofile.HashRule(rule))
+		if !bytes.Contains(out, []byte(hex)) {
+			t.Fatalf("expected allow hash %s for rule %q in output", hex, rule)
+		}
+	}
+	for _, rule := range profile.DenyRules {
+		hex := fmt.Sprintf("0x%016x", safetyprofile.HashRule(rule))
+		if !bytes.Contains(out, []byte(hex)) {
+			t.Fatalf("expected deny hash %s for rule %q in output", hex, rule)
+		}
+	}
+
+	for _, rule := range profile.AllowRules {
+		if bytes.Contains(out, []byte(fmt.Sprintf("%q", rule))) {
+			t.Fatalf("rule string %q must not appear in generated output", rule)
+		}
+	}
+	for _, rule := range profile.DenyRules {
+		if bytes.Contains(out, []byte(fmt.Sprintf("%q", rule))) {
+			t.Fatalf("rule string %q must not appear in generated output", rule)
+		}
+	}
+}
+
+func TestGenerateSanitizesProfileNameInComment(t *testing.T) {
+	profile := &safetyprofile.Profile{
+		Name:      "bad\nname\rwith-controls",
+		AllowAll:  true,
+		DenyRules: []string{},
+	}
+	out := generate(profile)
+
+	if _, err := parser.ParseFile(token.NewFileSet(), "gen.go", out, parser.AllErrors); err != nil {
+		t.Fatalf("generated code with control chars in name does not parse:\n%s\n\nerror: %v", out, err)
+	}
+	if bytes.Contains(out, []byte("\nname\r")) || bytes.Contains(out, []byte("\nname\n")) {
+		t.Fatalf("comment header leaked control chars from profile name:\n%s", out)
+	}
+}
+
+func TestGenerateAllowAllEmitsConstantTrue(t *testing.T) {
+	profile := &safetyprofile.Profile{
+		Name:      "full",
+		AllowAll:  true,
+		DenyRules: []string{},
+	}
+	out := string(generate(profile))
+
+	allowFn := extractFunc(t, out, "bakedSafetyAllowMatch")
+	if !strings.Contains(allowFn, "return true") || strings.Contains(allowFn, "switch ") {
+		t.Fatalf("AllowAll allow matcher should be `return true` only, got:\n%s", allowFn)
+	}
+
+	denyFn := extractFunc(t, out, "bakedSafetyDenyMatch")
+	if !strings.Contains(denyFn, "return false") {
+		t.Fatalf("empty deny matcher should `return false`, got:\n%s", denyFn)
+	}
+}
+
+func TestGenerateEmptyAllowEmitsConstantFalse(t *testing.T) {
+	profile := &safetyprofile.Profile{
+		Name:      "deny-only",
+		AllowAll:  false,
+		DenyRules: []string{"gmail.send"},
+	}
+	out := string(generate(profile))
+
+	if !strings.Contains(out, "func bakedSafetyHasAllowRules() bool { return false }") {
+		t.Fatalf("expected hasAllowRules=false for deny-only profile, got:\n%s", out)
+	}
+	allowFn := extractFunc(t, out, "bakedSafetyAllowMatch")
+	if !strings.Contains(allowFn, "return false") || strings.Contains(allowFn, "switch ") {
+		t.Fatalf("empty allow matcher should be `return false` only, got:\n%s", allowFn)
+	}
+}
+
+func extractFunc(t *testing.T, src, name string) string {
+	t.Helper()
+	start := strings.Index(src, "func "+name+"(")
+	if start < 0 {
+		t.Fatalf("function %s not found in:\n%s", name, src)
+	}
+	depth := 0
+	for i := start; i < len(src); i++ {
+		switch src[i] {
+		case '{':
+			depth++
+		case '}':
+			depth--
+			if depth == 0 {
+				return src[start : i+1]
+			}
+		}
+	}
+	t.Fatalf("function %s has unbalanced braces", name)
+	return ""
+}

docs/safety-profiles.md

@@ -67,6 +67,21 @@ bin/gog-readonly --enable-commands gmail.send gmail send \
 The command still fails because the baked policy is checked before runtime
 allowlists.
 
+## Tamper Resistance
+
+The generator emits the allow and deny rule sets as `switch` statements on the
+FNV-64a hash of each dotted command path, not as raw YAML. The compiled rule
+table never contains the rule strings themselves, so to re-enable a blocked
+command an attacker has to patch compiled machine code rather than flip ASCII
+bytes in a YAML blob; the cost goes from a one-line `sed` invocation to
+disassembly-level work.
+
+Note that command names may still appear in the binary from unrelated metadata
+(API URLs, error message format strings, Kong help text). What this hardening
+guarantees is that the rule set itself is no longer a contiguous, patchable
+string. The profile name (e.g. `agent-safe`) is also embedded as a constant so
+error messages can reference it.
+
 ## Preset Profiles
 
 `safety-profiles/agent-safe.yaml`

internal/cmd/safety_profile.go

@@ -1,18 +1,27 @@
 package cmd
 
 import (
-	"fmt"
+	"hash/fnv"
 	"strings"
 
 	"github.com/alecthomas/kong"
-	"gopkg.in/yaml.v3"
 )
 
 type bakedSafetyProfile struct {
 	enabled bool
 	name    string
-	allow   map[string]bool
-	deny    map[string]bool
+}
+
+// bakedSafetyHashPath returns the FNV-64a hash of the dotted command path.
+// The generated allow/deny matchers switch on these hashes so that rule
+// strings never appear in the binary's data section. The build-time
+// generator hashes via internal/safetyprofile.HashRule; both call hash/fnv
+// over the same input, and TestSafetyProfileHashAgreement asserts they
+// produce identical values.
+func bakedSafetyHashPath(parts []string) uint64 {
+	h := fnv.New64a()
+	_, _ = h.Write([]byte(strings.Join(parts, ".")))
+	return h.Sum64()
 }
 
 func enforceBakedSafetyProfile(kctx *kong.Context) error {
@@ -42,38 +51,36 @@ func bakedSafetyProfileError(path []string, profileName string, included bool) e
 	return usagef("command %q is not included in baked safety profile %q", command, profileName)
 }
 
+// loadBakedSafetyProfile constructs a profile handle from the package-level
+// hooks supplied by either the generated safety_profile_baked_gen.go (for
+// safety_profile builds) or safety_profile_default.go (for stock and test
+// builds). The error result is retained for compatibility with the upstream
+// caller signatures; the profile is validated by cmd/bake-safety-profile at
+// build time, so the runtime path cannot fail.
+//
+//nolint:unparam // error preserved to keep upstream caller signatures unchanged.
 func loadBakedSafetyProfile() (bakedSafetyProfile, error) {
-	raw := strings.TrimSpace(bakedSafetyProfileYAML)
-	if raw == "" {
-		return bakedSafetyProfile{}, nil
-	}
-	profile, err := parseSafetyProfile(raw)
-	if err != nil {
-		return bakedSafetyProfile{}, err
-	}
-	return *profile, nil
-}
-
-func ValidateSafetyProfile(raw string) error {
-	_, err := parseSafetyProfile(raw)
-	return err
+	return bakedSafetyProfile{
+		enabled: bakedSafetyEnabled(),
+		name:    bakedSafetyProfileName(),
+	}, nil
 }
 
 func (p bakedSafetyProfile) allowsCommandPath(path []string) bool {
 	if !p.enabled || len(path) == 0 {
 		return true
 	}
-	if commandPathMatches(p.deny, path) {
+	if bakedSafetyDenyMatch(path) {
 		return false
 	}
-	if len(p.allow) == 0 {
+	if !bakedSafetyHasAllowRules() {
 		return true
 	}
-	return commandPathMatches(p.allow, path)
+	return bakedSafetyAllowMatch(path)
 }
 
 func (p bakedSafetyProfile) commandPathError(path []string) error {
-	if commandPathMatches(p.deny, path) {
+	if bakedSafetyDenyMatch(path) {
 		return bakedSafetyProfileError(path, p.name, true)
 	}
 	return bakedSafetyProfileError(path, p.name, false)
@@ -162,100 +169,3 @@ func applySafetyProfileVisibility(root *kong.Node, profile bakedSafetyProfile) f
 		}
 	}
 }
-
-func parseSafetyProfile(raw string) (*bakedSafetyProfile, error) {
-	var root map[string]any
-	if err := yaml.Unmarshal([]byte(raw), &root); err != nil {
-		return nil, err
-	}
-
-	profile := &bakedSafetyProfile{
-		enabled: true,
-		name:    "unnamed",
-		allow:   map[string]bool{},
-		deny:    map[string]bool{},
-	}
-
-	if name, ok := root["name"].(string); ok && strings.TrimSpace(name) != "" {
-		profile.name = strings.TrimSpace(name)
-	}
-	if err := addSafetyProfileList(profile.allow, root["allow"]); err != nil {
-		return nil, fmt.Errorf("allow: %w", err)
-	}
-	if err := addSafetyProfileList(profile.deny, root["deny"]); err != nil {
-		return nil, fmt.Errorf("deny: %w", err)
-	}
-
-	for key, value := range root {
-		switch key {
-		case "name", "description", "allow", "deny":
-			continue
-		}
-		prefix := []string{key}
-		if key == "aliases" {
-			prefix = nil
-		}
-		if err := flattenSafetyProfileNode(profile, prefix, value); err != nil {
-			return nil, err
-		}
-	}
-
-	if len(profile.allow) == 0 && len(profile.deny) == 0 {
-		return nil, fmt.Errorf("profile has no allow or deny entries")
-	}
-	return profile, nil
-}
-
-func addSafetyProfileList(out map[string]bool, value any) error {
-	if value == nil {
-		return nil
-	}
-	items, ok := value.([]any)
-	if !ok {
-		return fmt.Errorf("expected list")
-	}
-	for _, item := range items {
-		s, ok := item.(string)
-		if !ok {
-			return fmt.Errorf("expected string item")
-		}
-		rule := normalizeSafetyProfileRule(s)
-		if rule != "" {
-			out[rule] = true
-		}
-	}
-	return nil
-}
-
-func flattenSafetyProfileNode(profile *bakedSafetyProfile, prefix []string, value any) error {
-	switch typed := value.(type) {
-	case bool:
-		rule := normalizeSafetyProfileRule(strings.Join(prefix, "."))
-		if rule == "" {
-			return fmt.Errorf("empty safety profile command path")
-		}
-		if typed {
-			profile.allow[rule] = true
-		} else {
-			profile.deny[rule] = true
-		}
-		return nil
-	case map[string]any:
-		for key, child := range typed {
-			next := append(append([]string{}, prefix...), key)
-			if err := flattenSafetyProfileNode(profile, next, child); err != nil {
-				return err
-			}
-		}
-		return nil
-	default:
-		return fmt.Errorf("unsupported safety profile value at %q", strings.Join(prefix, "."))
-	}
-}
-
-func normalizeSafetyProfileRule(rule string) string {
-	rule = strings.TrimSpace(strings.ToLower(rule))
-	rule = strings.ReplaceAll(rule, " ", ".")
-	rule = strings.Trim(rule, ".")
-	return rule
-}

internal/cmd/safety_profile_default.go

@@ -2,4 +2,33 @@
 
 package cmd
 
-var bakedSafetyProfileYAML = ""
+// bakedSafetyTestProfile is the test-only override that backs the
+// bakedSafety* package-level functions in non-safety builds. Production
+// safety_profile builds compile safety_profile_baked_gen.go instead, which
+// resolves these functions to a generated hash switch and never reads this
+// variable. Tests in this package mutate the struct via withBakedSafetyProfile
+// to set up scenarios; stock binaries leave it zeroed and the profile reports
+// disabled.
+var bakedSafetyTestProfile struct {
+	enabled       bool
+	name          string
+	hasAllowRules bool
+	allowAll      bool
+	allow         map[string]bool
+	deny          map[string]bool
+}
+
+func bakedSafetyEnabled() bool       { return bakedSafetyTestProfile.enabled }
+func bakedSafetyProfileName() string { return bakedSafetyTestProfile.name }
+func bakedSafetyHasAllowRules() bool { return bakedSafetyTestProfile.hasAllowRules }
+
+func bakedSafetyAllowMatch(path []string) bool {
+	if bakedSafetyTestProfile.allowAll {
+		return true
+	}
+	return commandPathMatches(bakedSafetyTestProfile.allow, path)
+}
+
+func bakedSafetyDenyMatch(path []string) bool {
+	return commandPathMatches(bakedSafetyTestProfile.deny, path)
+}

internal/cmd/safety_profile_test.go

@@ -1,3 +1,5 @@
+//go:build !safety_profile
+
 package cmd
 
 import (
@@ -5,39 +7,51 @@ import (
 	"path/filepath"
 	"strings"
 	"testing"
+
+	"github.com/steipete/gogcli/internal/safetyprofile"
 )
 
 func withBakedSafetyProfile(t *testing.T, raw string) {
 	t.Helper()
-	prev := bakedSafetyProfileYAML
-	bakedSafetyProfileYAML = raw
-	t.Cleanup(func() { bakedSafetyProfileYAML = prev })
+	profile, err := safetyprofile.Parse(raw)
+	if err != nil {
+		t.Fatalf("safetyprofile.Parse: %v", err)
+	}
+	allow := make(map[string]bool, len(profile.AllowRules))
+	for _, r := range profile.AllowRules {
+		allow[r] = true
+	}
+	deny := make(map[string]bool, len(profile.DenyRules))
+	for _, r := range profile.DenyRules {
+		deny[r] = true
+	}
+	prev := bakedSafetyTestProfile
+	bakedSafetyTestProfile.enabled = true
+	bakedSafetyTestProfile.name = profile.Name
+	bakedSafetyTestProfile.allowAll = profile.AllowAll
+	bakedSafetyTestProfile.hasAllowRules = profile.AllowAll || len(profile.AllowRules) > 0
+	bakedSafetyTestProfile.allow = allow
+	bakedSafetyTestProfile.deny = deny
+	t.Cleanup(func() { bakedSafetyTestProfile = prev })
 }
 
-func TestParseSafetyProfileNestedAndAliases(t *testing.T) {
-	profile, err := parseSafetyProfile(`
-name: test
-gmail:
-  search: true
-  send: false
-aliases:
-  send: false
-allow:
-  - version
-deny:
-  - auth.remove
-`)
-	if err != nil {
-		t.Fatalf("parseSafetyProfile: %v", err)
+func TestSafetyProfileHashAgreement(t *testing.T) {
+	cases := []struct {
+		path []string
+		rule string
+	}{
+		{[]string{"version"}, "version"},
+		{[]string{"gmail", "send"}, "gmail.send"},
+		{[]string{"gmail", "drafts", "send"}, "gmail.drafts.send"},
+		{[]string{"gmail", "drafts", "create"}, "gmail.drafts.create"},
+		{[]string{"calendar", "alias", "set"}, "calendar.alias.set"},
+		{[]string{"a"}, "a"},
 	}
-	for _, rule := range []string{"gmail.search", "version"} {
-		if !profile.allow[rule] {
-			t.Fatalf("expected allow rule %q in %#v", rule, profile.allow)
-		}
-	}
-	for _, rule := range []string{"gmail.send", "send", "auth.remove"} {
-		if !profile.deny[rule] {
-			t.Fatalf("expected deny rule %q in %#v", rule, profile.deny)
+	for _, c := range cases {
+		runtime := bakedSafetyHashPath(c.path)
+		codegen := safetyprofile.HashRule(c.rule)
+		if runtime != codegen {
+			t.Fatalf("hash mismatch for %v / %q: runtime=%#x codegen=%#x", c.path, c.rule, runtime, codegen)
 		}
 	}
 }

internal/safetyprofile/hash.go

@@ -0,0 +1,13 @@
+package safetyprofile
+
+import "hash/fnv"
+
+// HashRule returns the FNV-64a hash of a dotted-path safety rule
+// (e.g. "gmail.send"). The build-time generator and the runtime matcher both
+// hash with this algorithm so that rule strings never appear in the binary's
+// data section.
+func HashRule(rule string) uint64 {
+	h := fnv.New64a()
+	_, _ = h.Write([]byte(rule))
+	return h.Sum64()
+}

internal/safetyprofile/parse.go

@@ -0,0 +1,156 @@
+package safetyprofile
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+
+	"gopkg.in/yaml.v3"
+)
+
+const literalAll = "all"
+
+// Parse validates the YAML form of a safety profile and returns the Profile
+// the generator emits as code. Allow and deny lists are sorted and
+// deduplicated; "all" / "*" entries on the allow side collapse into the
+// AllowAll flag. Wildcards on the deny side or as a parent of a nested rule
+// are rejected because they would be silent no-ops in the hashed runtime
+// switch.
+func Parse(raw string) (*Profile, error) {
+	parsed, err := parseRaw(raw)
+	if err != nil {
+		return nil, err
+	}
+	out := &Profile{
+		Name:     parsed.name,
+		AllowAll: parsed.allow[literalAll] || parsed.allow["*"],
+	}
+	for k := range parsed.allow {
+		if k == literalAll || k == "*" {
+			continue
+		}
+		out.AllowRules = append(out.AllowRules, k)
+	}
+	for k := range parsed.deny {
+		out.DenyRules = append(out.DenyRules, k)
+	}
+	sort.Strings(out.AllowRules)
+	sort.Strings(out.DenyRules)
+	return out, nil
+}
+
+type rawProfile struct {
+	name  string
+	allow map[string]bool
+	deny  map[string]bool
+}
+
+func parseRaw(raw string) (*rawProfile, error) {
+	var root map[string]any
+	if err := yaml.Unmarshal([]byte(raw), &root); err != nil {
+		return nil, err
+	}
+
+	profile := &rawProfile{
+		name:  "unnamed",
+		allow: map[string]bool{},
+		deny:  map[string]bool{},
+	}
+
+	if rawName, present := root["name"]; present {
+		name, ok := rawName.(string)
+		if !ok || strings.TrimSpace(name) == "" {
+			return nil, fmt.Errorf("name: expected non-empty string, got %T", rawName)
+		}
+		profile.name = strings.TrimSpace(name)
+	}
+	if err := addList(profile.allow, root["allow"]); err != nil {
+		return nil, fmt.Errorf("allow: %w", err)
+	}
+	if err := addList(profile.deny, root["deny"]); err != nil {
+		return nil, fmt.Errorf("deny: %w", err)
+	}
+
+	for key, value := range root {
+		switch key {
+		case "name", "description", "allow", "deny":
+			continue
+		}
+		prefix := []string{key}
+		if key == "aliases" {
+			prefix = nil
+		}
+		if err := flatten(profile, prefix, value); err != nil {
+			return nil, err
+		}
+	}
+
+	if profile.deny[literalAll] || profile.deny["*"] {
+		return nil, fmt.Errorf("deny: wildcards %q and %q are not allowed; list specific commands or remove the entry", literalAll, "*")
+	}
+
+	if len(profile.allow) == 0 && len(profile.deny) == 0 {
+		return nil, fmt.Errorf("profile has no allow or deny entries")
+	}
+	return profile, nil
+}
+
+func addList(out map[string]bool, value any) error {
+	if value == nil {
+		return nil
+	}
+	items, ok := value.([]any)
+	if !ok {
+		return fmt.Errorf("expected list")
+	}
+	for _, item := range items {
+		s, ok := item.(string)
+		if !ok {
+			return fmt.Errorf("expected string item")
+		}
+		rule := normalize(s)
+		if rule != "" {
+			out[rule] = true
+		}
+	}
+	return nil
+}
+
+func flatten(profile *rawProfile, prefix []string, value any) error {
+	switch typed := value.(type) {
+	case bool:
+		rule := normalize(strings.Join(prefix, "."))
+		if rule == "" {
+			return fmt.Errorf("empty safety profile command path")
+		}
+		if typed {
+			profile.allow[rule] = true
+		} else {
+			profile.deny[rule] = true
+		}
+		return nil
+	case map[string]any:
+		if len(prefix) > 0 {
+			root := normalize(prefix[0])
+			if root == literalAll || root == "*" {
+				return fmt.Errorf("safety profile rules cannot be nested under wildcard %q at %q; list specific commands", prefix[0], strings.Join(prefix, "."))
+			}
+		}
+		for key, child := range typed {
+			next := append(append([]string{}, prefix...), key)
+			if err := flatten(profile, next, child); err != nil {
+				return err
+			}
+		}
+		return nil
+	default:
+		return fmt.Errorf("unsupported safety profile value at %q", strings.Join(prefix, "."))
+	}
+}
+
+func normalize(rule string) string {
+	rule = strings.TrimSpace(strings.ToLower(rule))
+	rule = strings.ReplaceAll(rule, " ", ".")
+	rule = strings.Trim(rule, ".")
+	return rule
+}

internal/safetyprofile/parse_test.go

@@ -0,0 +1,74 @@
+package safetyprofile
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestParseRejectsDenyWildcards(t *testing.T) {
+	for _, raw := range []string{
+		"name: x\nallow:\n  - version\ndeny:\n  - all\n",
+		"name: x\nallow:\n  - version\ndeny:\n  - \"*\"\n",
+		"name: x\nallow:\n  - version\nall: false\n",
+		"name: x\nallow:\n  - version\n\"*\": false\n",
+		"name: x\nallow:\n  - version\naliases:\n  all: false\n",
+	} {
+		_, err := Parse(raw)
+		if err == nil {
+			t.Fatalf("expected error parsing deny wildcard, got nil for: %s", raw)
+		}
+		if !strings.Contains(err.Error(), "wildcards") {
+			t.Fatalf("unexpected error: %v", err)
+		}
+	}
+}
+
+func TestParseRejectsWildcardPrefix(t *testing.T) {
+	for _, raw := range []string{
+		"name: x\nallow:\n  - version\nall:\n  gmail: false\n",
+		"name: x\nallow:\n  - version\n\"*\":\n  gmail: false\n",
+	} {
+		_, err := Parse(raw)
+		if err == nil {
+			t.Fatalf("expected error parsing wildcard prefix, got nil for: %s", raw)
+		}
+		if !strings.Contains(err.Error(), "wildcard") {
+			t.Fatalf("unexpected error: %v", err)
+		}
+	}
+}
+
+func TestParseRejectsNonStringName(t *testing.T) {
+	for _, raw := range []string{
+		"name: 42\nallow:\n  - version\n",
+		"name: true\nallow:\n  - version\n",
+		"name: \"\"\nallow:\n  - version\n",
+	} {
+		_, err := Parse(raw)
+		if err == nil {
+			t.Fatalf("expected error for invalid name, got nil for: %s", raw)
+		}
+		if !strings.Contains(err.Error(), "name:") {
+			t.Fatalf("unexpected error: %v", err)
+		}
+	}
+}
+
+func TestHashRuleKnownValues(t *testing.T) {
+	cases := []struct {
+		rule string
+		want uint64
+	}{
+		{"version", HashRule("version")},
+		{"gmail.send", HashRule("gmail.send")},
+	}
+	for _, c := range cases {
+		got := HashRule(c.rule)
+		if got != c.want {
+			t.Fatalf("HashRule(%q) = %#x, want %#x", c.rule, got, c.want)
+		}
+	}
+	if HashRule("a") == HashRule("b") {
+		t.Fatalf("expected distinct hashes for distinct rules")
+	}
+}

internal/safetyprofile/profile.go

@@ -0,0 +1,17 @@
+// Package safetyprofile parses and hashes baked safety profile YAML for the
+// build-time generator (cmd/bake-safety-profile). It is intentionally outside
+// internal/cmd so the runtime CLI binary does not pull in the parser or its
+// dependencies.
+package safetyprofile
+
+// Profile is the build-time intermediate representation that the generator
+// consumes to emit the hash-based allow and deny switches. Rules are sorted
+// and deduplicated; AllowAll captures the "all" / "*" wildcard so the
+// generator can emit a constant-true matcher instead of enumerating every
+// command.
+type Profile struct {
+	Name       string
+	AllowAll   bool
+	AllowRules []string
+	DenyRules  []string
+}