From: Ian Lance Taylor <iant@golang.org>
Date: Thu, 22 Aug 2024 20:47:13 +0000 (-0700)
Subject: encoding/base32, encoding/base64: document Decode to short buffer
X-Git-Tag: go1.24rc1~1078
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=7b0fdd13230038aabf249f0335097a2cdc233f5c;p=gostls13.git

encoding/base32, encoding/base64: document Decode to short buffer

Document that if one of the Decode methods in these packages is given
a short buffer, it panics.

Fixes #69024

Change-Id: I1c0e4c74274965c1cfa0422cc8f86af4fefb1d00
Reviewed-on: https://go-review.googlesource.com/c/go/+/607499
Auto-Submit: Ian Lance Taylor <iant@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
---

diff --git a/src/encoding/base32/base32.go b/src/encoding/base32/base32.go
index 9e988ef39b..66f24e98a6 100644
--- a/src/encoding/base32/base32.go
+++ b/src/encoding/base32/base32.go
@@ -387,7 +387,8 @@ func (enc *Encoding) decode(dst, src []byte) (n int, end bool, err error) {
 
 // Decode decodes src using the encoding enc. It writes at most
 // [Encoding.DecodedLen](len(src)) bytes to dst and returns the number of bytes
-// written. If src contains invalid base32 data, it will return the
+// written. The caller must ensure that dst is large enough to hold all
+// the decoded data. If src contains invalid base32 data, it will return the
 // number of bytes successfully written and [CorruptInputError].
 // Newline characters (\r and \n) are ignored.
 func (enc *Encoding) Decode(dst, src []byte) (n int, err error) {
diff --git a/src/encoding/base64/base64.go b/src/encoding/base64/base64.go
index 87f45863bd..7f0fa2de78 100644
--- a/src/encoding/base64/base64.go
+++ b/src/encoding/base64/base64.go
@@ -508,7 +508,8 @@ func (d *decoder) Read(p []byte) (n int, err error) {
 
 // Decode decodes src using the encoding enc. It writes at most
 // [Encoding.DecodedLen](len(src)) bytes to dst and returns the number of bytes
-// written. If src contains invalid base64 data, it will return the
+// written. The caller must ensure that dst is large enough to hold all
+// the decoded data. If src contains invalid base64 data, it will return the
 // number of bytes successfully written and [CorruptInputError].
 // New line characters (\r and \n) are ignored.
 func (enc *Encoding) Decode(dst, src []byte) (n int, err error) {