encoding/base32: Replace assertions with error returns

Replace assertions with proper error handling in base32.decode() to allow
programs to handle invalid input gracefully rather than crashing.

The function now returns ([]byte, Error) instead of just []byte.

1 files changed, 31 insertions, 9 deletions

diff --git a/core/encoding/base32/base32.odin b/core/encoding/base32/base32.odin
index f3320428d..688b27544 100644
--- a/core/encoding/base32/base32.odin
+++ b/core/encoding/base32/base32.odin
@@ -7,6 +7,15 @@ package encoding_base32
 // Incase your specific version does not use padding, you may

 // truncate it from the encoded output.

 

+// Error represents errors that can occur during base32 decoding operations.

+// See RFC 4648 sections 3.2, 4 and 6.

+Error :: enum {

+	None,

+	Invalid_Character, // Input contains characters outside of base32 alphabet (A-Z, 2-7)

+	Invalid_Length,    // Input length is not valid for base32 (must be a multiple of 8 with proper padding)

+	Malformed_Input,   // Input has improper structure (wrong padding position or incomplete groups)

+}

+

 ENC_TABLE := [32]byte {

 	'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',

 	'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',

@@ -91,9 +100,9 @@ _encode :: proc(out, data: []byte, ENC_TBL := ENC_TABLE, allocator := context.al
 	}

 }

 

-decode :: proc(data: string, DEC_TBL := DEC_TABLE, allocator := context.allocator) -> []byte #no_bounds_check{

+decode :: proc(data: string, DEC_TBL := DEC_TABLE, allocator := context.allocator) -> ([]byte, Error) #no_bounds_check {

 	if len(data) == 0 {

-		return nil

+		return nil, .None

 	}

 

 	outi := 0

@@ -113,16 +122,29 @@ decode :: proc(data: string, DEC_TBL := DEC_TABLE, allocator := context.allocato
 			input := data[0]

 			data = data[1:]

 			if input == byte(PADDING) && j >= 2 && len(data) < 8 {

-				assert(!(len(data) + j < 8 - 1), "Corrupted input")

-				for k := 0; k < 8-1-j; k +=1 {

-					assert(len(data) < k || data[k] == byte(PADDING), "Corrupted input")

+				// assert(!(len(data) + j < 8 - 1), "Corrupted input")

+				if len(data) + j < 8 - 1 {

+					return nil, .Malformed_Input

+				}

+				// assert(len(data) < k || data[k] == byte(PADDING), "Corrupted input")

+				for k := 0; k < 8-1-j; k += 1 {

+					if len(data) < k || data[k] != byte(PADDING) {

+						return nil, .Malformed_Input

+					}

 				}

 				dlen, end = j, true

-				assert(dlen != 1 && dlen != 3 && dlen != 6, "Corrupted input")

+				// assert(dlen != 1 && dlen != 3 && dlen != 6, "Corrupted input")

+				if dlen == 1 || dlen == 3 || dlen == 6 {

+					return nil, .Invalid_Length

+				}

 				break

 			}

-			dbuf[j] = DEC_TABLE[input]

-			assert(dbuf[j] != 0xff, "Corrupted input")

+			decoded := DEC_TBL[input]

+			// assert(dbuf[j] != 0xff, "Corrupted input")

+			if decoded == 0 && input != byte(ENC_TABLE[0]) {

+				return nil, .Invalid_Character

+			}

+			dbuf[j] = decoded

 			j += 1

 		}

 

@@ -144,5 +166,5 @@ decode :: proc(data: string, DEC_TBL := DEC_TABLE, allocator := context.allocato
 		}

 		outi += 5

 	}

-	return out

+	return out, .None

 }