From c59897f6732e843ac38598171cb705e3417a5cfe01d1e3bcb405eb5150b79d13 Mon Sep 17 00:00:00 2001
From: Sergey Matveev <stargrave@stargrave.org>
Date: Tue, 15 Oct 2024 10:02:19 +0300
Subject: [PATCH] More sets usage

---
 gyac/yacpki/cmd/yacsdtool/main.go |  2 +-
 gyac/yacpki/signed-data.go        | 10 +++++-----
 spec/format/cer-load.cddl         |  3 ++-
 spec/format/cer.texi              |  9 +++------
 spec/format/signed-data.cddl      |  2 +-
 spec/schema.texi                  |  3 +++
 6 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/gyac/yacpki/cmd/yacsdtool/main.go b/gyac/yacpki/cmd/yacsdtool/main.go
index 7473cb4..6a62aee 100644
--- a/gyac/yacpki/cmd/yacsdtool/main.go
+++ b/gyac/yacpki/cmd/yacsdtool/main.go
@@ -87,7 +87,7 @@ func main() {
 	} else {
 		var sd yacpki.SignedData
 		sd.Load.T = *typ
-		sdHashes := []string{*hashAlgo}
+		sdHashes := map[string]*struct{}{*hashAlgo: nil}
 		sd.Hashes = &sdHashes
 		sigHashes := map[string][]byte{*hashAlgo: hasher.Sum(nil)}
 		when := time.Now().UTC().Truncate(1000 * time.Microsecond)
diff --git a/gyac/yacpki/signed-data.go b/gyac/yacpki/signed-data.go
index ce6f7f8..366340f 100644
--- a/gyac/yacpki/signed-data.go
+++ b/gyac/yacpki/signed-data.go
@@ -37,10 +37,10 @@ type SignedDataTBS struct {
 }
 
 type SignedData struct {
-	Hashes *[]string      `yac:"hash,omitempty"`
-	Cers   *[]*SignedData `yac:"certs,omitempty"`
-	Load   SignedDataLoad `yac:"load"`
-	Sigs   []*Sig         `yac:"sigs"`
+	Hashes *map[string]*struct{} `yac:"hash,omitempty"`
+	Cers   *[]*SignedData        `yac:"certs,omitempty"`
+	Load   SignedDataLoad        `yac:"load"`
+	Sigs   []*Sig                `yac:"sigs"`
 }
 
 func SignedDataParse(data []byte) (sd *SignedData, tail []byte, err error) {
@@ -108,7 +108,7 @@ func SignedDataParseItem(item *gyac.Item) (sd *SignedData, err error) {
 				return
 			}
 			var exists bool
-			for _, ai := range *sd.Hashes {
+			for ai := range *sd.Hashes {
 				if _, ok := (*sig.TBS.Hashes)[ai]; ok {
 					exists = true
 					break
diff --git a/spec/format/cer-load.cddl b/spec/format/cer-load.cddl
index 801f0e0..589cd0a 100644
--- a/spec/format/cer-load.cddl
+++ b/spec/format/cer-load.cddl
@@ -5,8 +5,9 @@ cer-load = {
     ? ku: {+ ku => nil},
     pub: [+ {av, id: uuid}],
     sub: {text => text}, ; subject
-    ? crit: [+ {t: text, * text => any}],
+    ? crit: {+ crit-text-type => any},
     * text => any
 }
 
 ku = "ca" / "sig" / "app-name" / text
+crit-ext-type = text
diff --git a/spec/format/cer.texi b/spec/format/cer.texi
index 843d388..c930697 100644
--- a/spec/format/cer.texi
+++ b/spec/format/cer.texi
@@ -43,12 +43,9 @@ It is a map with NIL values, to force deterministic encoding of the
 list. It @strong{must} be absent if empty.
 
 @item crit
-Optional list of critical (in terms of X.509) extensions. Non-critical
-ones may be placed outside that map, directly in @code{cer-load}. It
-@strong{must} be absent if empty.
-
-Each extension has required "t" field with specified extension type. All
-other values are extension-specific.
+Optional critical (in terms of X.509) extensions. Non-critical
+ones may be placed outside that map, directly in @code{cer-load}.
+It @strong{must} be absent if empty. Values are extension specific.
 
 @end table
 
diff --git a/spec/format/signed-data.cddl b/spec/format/signed-data.cddl
index 356f913..8797b68 100644
--- a/spec/format/signed-data.cddl
+++ b/spec/format/signed-data.cddl
@@ -2,7 +2,7 @@ ai = text ; algorithm identifier
 av = {a: ai, v: bytes}
 
 signed-data = {
-    ? hash: [+ ai], ; when using prehashing
+    ? hash: {+ ai => nil}, ; when using prehashing
     load: {
         t: text,
         ? v: bytes / text / blob / map / list,
diff --git a/spec/schema.texi b/spec/schema.texi
index afcb2ad..78415e5 100644
--- a/spec/schema.texi
+++ b/spec/schema.texi
@@ -30,6 +30,9 @@ identifiers. OIDs database can be considered as an external schema.
 Lacking it, or lacking its actual state, you probably won't be able even
 guessing the context of the data inside.
 
+Sets can be emulated by using MAPs with NIL values. That gives only
+1-byte overhead for each element, but reuses already existing code.
+
 If you really desire more compact encoding, even agree to use schema
 definitions, then think about replacing MAPs with LISTs. Non-present
 values can be indicated by NIL tag.
-- 
2.48.1