From ae79a323091350ca937c697816c79b38d6785114 Mon Sep 17 00:00:00 2001
From: Sasha Koshka <sashakoshka@tebibyte.media>
Date: Thu, 28 Aug 2025 12:51:55 -0400
Subject: [PATCH] generate: Respect limits when statically encoding

---
 generate/generate.go | 37 ++++++++++++++++++++++++++++++++-----
 1 file changed, 32 insertions(+), 5 deletions(-)

diff --git a/generate/generate.go b/generate/generate.go
index 0d70fce..9e0d132 100644
--- a/generate/generate.go
+++ b/generate/generate.go
@@ -343,7 +343,14 @@ func (this *Generator) generateEncodeValue(typ Type, valueSource, tagSource stri
 	case TypeBuffer:
 		// SBA: <data: U8>*
 		// LBA: <length: UN> <data: U8>*
-		nn, err := this.iprintf("if %s.Is(tape.LBA) {\n", tagSource)
+		nn, err := this.iprintf("if len(%s) > tape.MaxStructureLength {\n", valueSource)
+		n += nn; if err != nil { return n, err }
+		this.push()
+			nn, err = this.iprintf("return n, tape.ErrTooLong\n")
+		this.pop()
+		nn, err = this.iprintf("}\n")
+		n += nn; if err != nil { return n, err }
+		nn, err = this.iprintf("if %s.Is(tape.LBA) {\n", tagSource)
 		n += nn; if err != nil { return n, err }
 		this.push()
 			nn, err = this.iprintf(
@@ -355,14 +362,20 @@ func (this *Generator) generateEncodeValue(typ Type, valueSource, tagSource stri
 		this.pop()
 		nn, err = this.iprintf("}\n")
 		n += nn; if err != nil { return n, err }
-		
 		nn, err = this.iprintf("nn, err = encoder.Write([]byte(%s))\n", valueSource)
 		n += nn; if err != nil { return n, err }
 		nn, err = this.generateErrorCheck()
 		n += nn; if err != nil { return n, err }
 	case TypeArray:
 		// OTA: <length: UN> <elementTag: tape.Tag> <values>*
-		nn, err := this.iprintf(
+		nn, err := this.iprintf("if len(%s) > tape.MaxStructureLength {\n", valueSource)
+		n += nn; if err != nil { return n, err }
+		this.push()
+			nn, err = this.iprintf("return n, tape.ErrTooLong\n")
+		this.pop()
+		nn, err = this.iprintf("}\n")
+		n += nn; if err != nil { return n, err }
+		nn, err = this.iprintf(
 			"nn, err = encoder.WriteUintN(uint64(len(%s)), %s.CN())\n",
 			valueSource, tagSource)
 		n += nn; if err != nil { return n, err }
@@ -417,7 +430,14 @@ func (this *Generator) generateEncodeValue(typ Type, valueSource, tagSource stri
 		n += nn; if err != nil { return n, err }
 	case TypeTable:
 		// KTV: <length: UN> (<key: U16> <tag: Tag> <value>)*
-		nn, err := this.iprintf(
+		nn, err := this.iprintf("if len(%s) > tape.MaxStructureLength {\n", valueSource)
+		n += nn; if err != nil { return n, err }
+		this.push()
+			nn, err = this.iprintf("return n, tape.ErrTooLong\n")
+		this.pop()
+		nn, err = this.iprintf("}\n")
+		n += nn; if err != nil { return n, err }
+		nn, err = this.iprintf(
 			"nn, err = tape.EncodeAny(encoder, %s, %s)\n",
 			valueSource, tagSource)
 		n += nn; if err != nil { return n, err }
@@ -425,7 +445,14 @@ func (this *Generator) generateEncodeValue(typ Type, valueSource, tagSource stri
 		n += nn; if err != nil { return n, err }
 	case TypeTableDefined:
 		// KTV: <length: UN> (<key: U16> <tag: Tag> <value>)*
-		nn, err := this.iprintf(
+		nn, err := this.iprintf("if %d > tape.MaxStructureLength {\n", len(typ.Fields))
+		n += nn; if err != nil { return n, err }
+		this.push()
+			nn, err = this.iprintf("return n, tape.ErrTooLong\n")
+		this.pop()
+		nn, err = this.iprintf("}\n")
+		n += nn; if err != nil { return n, err }
+		nn, err = this.iprintf(
 			"nn, err = encoder.WriteUintN(%d, %s.CN())\n",
 			len(typ.Fields), tagSource)
 		n += nn; if err != nil { return n, err }