From b9c9df9825e6d917882c26004edfef7b57d0a11c9b45a44f27c5580d06f2e2f9 Mon Sep 17 00:00:00 2001
From: Sergey Matveev <stargrave@stargrave.org>
Date: Thu, 21 Nov 2024 12:03:28 +0300
Subject: [PATCH] Fixed TAI64N[A] *seconds validation

---
 cyac/lib/dec.c | 16 +++++++++-------
 cyac/lib/err.c |  2 ++
 cyac/lib/err.h |  1 +
 gyac/dec.go    | 20 +++++++++++++++-----
 pyac/pyac.py   |  4 ++--
 5 files changed, 29 insertions(+), 14 deletions(-)

diff --git a/cyac/lib/dec.c b/cyac/lib/dec.c
index ad1c776..2bdc739 100644
--- a/cyac/lib/dec.c
+++ b/cyac/lib/dec.c
@@ -241,21 +241,23 @@ YACAtomDecode( // NOLINT(misc-no-recursion)
         if (v > ((uint64_t)1 << (uint8_t)63)) {
             return YACErrTAI64TooBig;
         }
-        switch (l) {
-        case 12:
+        if (l > 8) {
             v = yacFromBE(buf + 1 + 8, 4);
+            if ((l == 8) && (v == 0)) {
+                return YACErrTAI64NonMinimal;
+            }
             if (v > 999999999) {
                 return YACErrTAI64BadNsec;
             }
-            break;
-        case 16:
+        }
+        if (l > 12) {
             v = yacFromBE(buf + 1 + 8 + 4, 4);
+            if (v == 0) {
+                return YACErrTAI64NonMinimal;
+            }
             if (v > 999999999) {
                 return YACErrTAI64BadAsec;
             }
-            break;
-        default:
-            break;
         }
         break;
     }
diff --git a/cyac/lib/err.c b/cyac/lib/err.c
index c951942..2eb870b 100644
--- a/cyac/lib/err.c
+++ b/cyac/lib/err.c
@@ -34,6 +34,8 @@ YACErr2Str(const enum YACErr err)
         return "TAI64InPast";
     case YACErrTAI64IsLeap:
         return "TAI64IsLeap";
+    case YACErrTAI64NonMinimal:
+        return "TAI64NonMinimal";
     case YACErrMapBadKey:
         return "MapBadKey";
     case YACErrMapNoVal:
diff --git a/cyac/lib/err.h b/cyac/lib/err.h
index 00726a6..55898d7 100644
--- a/cyac/lib/err.h
+++ b/cyac/lib/err.h
@@ -57,6 +57,7 @@ enum YACErr {
     YACErrTAI64BadAsec,
     YACErrTAI64InPast,
     YACErrTAI64IsLeap,
+    YACErrTAI64NonMinimal,
     YACErrMapBadKey,
     YACErrMapNoVal,
     YACErrMapUnordered,
diff --git a/gyac/dec.go b/gyac/dec.go
index 17ba262..7c4d825 100644
--- a/gyac/dec.go
+++ b/gyac/dec.go
@@ -281,14 +281,24 @@ func AtomDecode(buf []byte) (item *Item, off int, err error) {
 			err = errors.New("reserved TAI64 values in use")
 			return
 		}
-		switch l {
-		case 12:
-			if FromBE(buf[1+8:1+8+4]) > 999999999 {
+		if l > 8 {
+			nsecs := FromBE(buf[1+8 : 1+8+4])
+			if l == 8 && nsecs == 0 {
+				err = errors.New("non-minimal TAI64N")
+				return
+			}
+			if nsecs > 999999999 {
 				err = errors.New("too many nanoseconds")
 				return
 			}
-		case 16:
-			if FromBE(buf[1+8+4:1+8+4+4]) > 999999999 {
+		}
+		if l > 12 {
+			asecs := FromBE(buf[1+8+4 : 1+8+4+4])
+			if asecs == 0 {
+				err = errors.New("non-minimal TAI64NA")
+				return
+			}
+			if asecs > 999999999 {
 				err = errors.New("too many attoseconds")
 				return
 			}
diff --git a/pyac/pyac.py b/pyac/pyac.py
index dbdcc69..bac693c 100755
--- a/pyac/pyac.py
+++ b/pyac/pyac.py
@@ -299,14 +299,14 @@ def loads(v, sets=False, leapsecUTCAllow=False):
         if l > 8:
             nsecs = int.from_bytes(v[1+8:1+8+4], "big")
             if (l == 8) and (nsecs == 0):
-                raise DecodeError("non-minimal encoding")
+                raise DecodeError("non-minimal TAI64N")
             if nsecs > 999999999:
                 raise DecodeError("too many nanoseconds")
         asecs = 0
         if l > 12:
             asecs = int.from_bytes(v[1+8+4:1+8+4+4], "big")
             if asecs == 0:
-                raise DecodeError("non-minimal encoding")
+                raise DecodeError("non-minimal TAI64NA")
             if asecs > 999999999:
                 raise DecodeError("too many attoseconds")
         secs = tai2utc(secs - TAI64Base, leapsecUTCAllow)
-- 
2.50.0