Count an own secret's prompt by character and refuse {member} on a single secret (issue 789)

internal/catalogue/manifest.go

@@ -14,6 +14,7 @@ import (
 	"sort"
 	"strconv"
 	"strings"
+	"unicode/utf8"
 )
 
 // Scopes a claim can have.
@@ -2190,7 +2191,7 @@ func ParseManifest(raw []byte) (Manifest, error) {
 					"may make it (novox/hq ADR 0228)",
 				m.Module, name, own.IssuedBy, IssuedOutside))
 		}
-		problems = append(problems, ownSecretPromptProblems(m, name, own.Prompt)...)
+		problems = append(problems, ownSecretPromptProblems(m, name, own.Prompt, IsFamily(name))...)
 	}
 	localOf := map[string]string{}
 	for _, to := range m.SecretRequirements() {
@@ -2785,8 +2786,10 @@ var promptPlaceholder = regexp.MustCompile(`\{[^{}]*\}`)
 
 // ownSecretPromptProblems is what is wrong with an own secret's declared prompt, in the module check's words:
 // empty is fine (no prompt is declared, and the desk asks by name alone as it does today); otherwise one line,
-// at most PromptMax characters, holding only the `{member}` placeholder.
+// at most PromptMax characters — counting what a person reads, not its bytes — holding only the `{member}`
-func ownSecretPromptProblems(m Manifest, name, prompt string) []string {
+// placeholder, and only where the secret is a family: a single secret's prompt has no member to fill, so
+// `{member}` there would stay in the prompt literally (novox/hq issue 789).
+func ownSecretPromptProblems(m Manifest, name, prompt string, family bool) []string {
 	if prompt == "" {
 		return nil
 	}
@@ -2796,10 +2799,10 @@ func ownSecretPromptProblems(m Manifest, name, prompt string) []string {
 			"%s names its secret %q with a prompt that holds more than one line; a prompt is one line (novox/hq issue 789)",
 			m.Module, name))
 	}
-	if len(prompt) > PromptMax {
+	if n := utf8.RuneCountInString(prompt); n > PromptMax {
 		problems = append(problems, fmt.Sprintf(
 			"%s names its secret %q with a prompt %d characters long; a prompt is at most %d characters",
-			m.Module, name, len(prompt), PromptMax))
+			m.Module, name, n, PromptMax))
 	}
 	for _, ph := range promptPlaceholder.FindAllString(prompt, -1) {
 		if ph != "{member}" {
@@ -2807,6 +2810,11 @@ func ownSecretPromptProblems(m Manifest, name, prompt string) []string {
 				"%s names its secret %q with a prompt that holds %s; a prompt holds only the {member} placeholder, "+
 					"filled with a family's member suffix (novox/hq issue 789)",
 				m.Module, name, ph))
+		} else if !family {
+			problems = append(problems, fmt.Sprintf(
+				"%s names its secret %q with a prompt that holds {member}; {member} is replaced only for a "+
+					"family's member (novox/hq issue 789)",
+				m.Module, name))
 		}
 	}
 	return problems

internal/catalogue/own_secret_prompt_test.go

@@ -58,6 +58,31 @@ func TestAnOwnSecretWithNoPromptIsFine(t *testing.T) {
 	}
 }
 
+// PromptMax counts characters, not bytes: a prompt of 100 multi-byte characters is well within it even
+// though it holds well over 120 bytes (novox/hq issue 789).
+func TestAPromptOfMultiByteCharactersIsCountedByCharacter(t *testing.T) {
+	prompt := strings.Repeat("é", 100)
+	if n := len(prompt); n <= 120 {
+		t.Fatalf("the test prompt is %d bytes, not over 120 as intended", n)
+	}
+	_, err := ParseManifest([]byte(`{"module":"mesh-mail","version":"1","own-secrets":{
+		"smtp-relay-key":{"path":"/var/lib/mesh-mail/smtp-relay-key","taken":"at-start",
+			"prompt":` + jsonString(prompt) + `}}}`))
+	if err != nil {
+		t.Fatalf("a 100-character prompt was refused: %v", err)
+	}
+}
+
+// {member} is replaced only for a family's member: a single secret's prompt may not hold it (novox/hq issue 789).
+func TestAPromptHoldingMemberOnASingleSecretIsRefused(t *testing.T) {
+	_, err := ParseManifest([]byte(`{"module":"mesh-mail","version":"1","own-secrets":{
+		"smtp-relay-key":{"path":"/var/lib/mesh-mail/smtp-relay-key","taken":"at-start",
+			"prompt":"For {member}"}}}`))
+	if err == nil || !strings.Contains(err.Error(), "{member} is replaced only for a family's member") {
+		t.Fatalf("a single secret's prompt holding {member}: %v; want a refusal saying so", err)
+	}
+}
+
 // A prompt that is not one short line naming only {member} is refused by the module check (novox/hq issue 789).
 func TestAMalformedPromptIsRefused(t *testing.T) {
 	for name, c := range map[string]struct{ prompt, says string }{