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| author | Han-Wen Nienhuys <hanwen@google.com> | 2017-07-06 14:31:36 +0200 |
|---|---|---|
| committer | Han-Wen Nienhuys <hanwen@google.com> | 2017-07-06 15:27:25 +0000 |
| commit | a48ac81e47fd6f9ed1258f3b60ae9e75f93cb7ed (patch) | |
| tree | b7be75458c9a91301f24110eea1de9db3186d377 /ssh/cipher.go | |
| parent | d625dfd80595a76324dea1452ceb9cfbcaee8e3e (diff) | |
| download | go-x-crypto-a48ac81e47fd6f9ed1258f3b60ae9e75f93cb7ed.tar.xz | |
ssh: allow up to 255 bytes of padding in AES-GCM
The writing side would generate a maximum of 19 bytes of padding, so
the reading side erroneously checked this. However, RFC 5647 specifies
255 as the maximum amount of padding for AES-GCM.
Fixes golang/go#18953.
Change-Id: I416b0023c6e4cbd91a6a1b4214a03f1663b77248
Reviewed-on: https://go-review.googlesource.com/47590
Reviewed-by: Adam Langley <agl@golang.org>
Run-TryBot: Adam Langley <agl@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Diffstat (limited to 'ssh/cipher.go')
| -rw-r--r-- | ssh/cipher.go | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/ssh/cipher.go b/ssh/cipher.go index 13484ab..22bb30c 100644 --- a/ssh/cipher.go +++ b/ssh/cipher.go @@ -392,7 +392,9 @@ func (c *gcmCipher) readPacket(seqNum uint32, r io.Reader) ([]byte, error) { c.incIV() padding := plain[0] - if padding < 4 || padding >= 20 { + if padding < 4 { + // padding is a byte, so it automatically satisfies + // the maximum size, which is 255. return nil, fmt.Errorf("ssh: illegal padding %d", padding) } |