From aa799d4d9b1186be0e48367715e34c665ee7404c Mon Sep 17 00:00:00 2001
From: Chris Duncan <chris@zoso.dev>
Date: Sat, 9 Aug 2025 00:11:11 -0700
Subject: [PATCH] Throw on invalid base32 characters during conversion.

---
 src/lib/convert.ts | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/lib/convert.ts b/src/lib/convert.ts
index 5b20a05..23624a0 100644
--- a/src/lib/convert.ts
+++ b/src/lib/convert.ts
@@ -17,10 +17,15 @@ export class base32 {
 			: 8 - leftover
 		let bits = 0
 		let value = 0
+		let letter = -1
 		let index = 0
 		let output = new Uint8Array(Math.ceil((base32.length * 5) / 8))
 		for (let i = 0; i < base32.length; i++) {
-			value = (value << 5) | ALPHABET.indexOf(base32[i])
+			letter = ALPHABET.indexOf(base32[i])
+			if (letter < 0) {
+				throw new RangeError('Invalid base32 character', { cause: base32[i] })
+			}
+			value = (value << 5) | letter
 			bits += 5
 			if (bits >= 8) {
 				output[index++] = (value >>> (bits + offset - 8)) & 255
-- 
2.47.3