encoding/base64: DecodeString accepts incorrectly padded input and may produce incorrect output.

[gopherbot]

by garrick@google.com:

What does 'go version' print?
go version go1.2 linux/amd64

What steps reproduce the problem?
http://play.golang.org/p/pt499XKHGk


What happened? Got 'abc' 

What should have happened instead? Want 'abcd' or an error.

Please provide any additional information below.

The following check in decode() assumes correctly padded input:

if in == '=' && j >= 2 && len(src) < 4 {

[ianlancetaylor]

Comment 1:

Labels changed: added repo-main, release-go1.3maybe.

[bradfitz]

Comment 2:

Well, you're ignoring the return values. If you looked at the return value, you'd see
the CorruptInputError at position 8.
But it's true that we're losing one byte of decoded output in that case.
CL on its wayl.

Owner changed to @bradfitz.

Status changed to Started.

[gopherbot]

Comment 3:

CL https://golang.org/cl/88330044 mentions this issue.

[bradfitz]

Comment 4:

This issue was closed by revision a6d3cc2.

Status changed to Fixed.