diff options
| author | Gustav Westling <zegl@westling.xyz> | 2017-07-06 20:30:26 +0200 |
|---|---|---|
| committer | Brad Fitzpatrick <bradfitz@golang.org> | 2017-07-06 21:16:45 +0000 |
| commit | d1340ee2e91a873d689cf11b74022f60476cd729 (patch) | |
| tree | bae70dfe4e9dea0cc3daa5f0682ee481435c8603 /src/encoding/base32 | |
| parent | 23ae7a70f9f28fe34547d2857e5efa789625052a (diff) | |
| download | go-d1340ee2e91a873d689cf11b74022f60476cd729.tar.xz | |
encoding/base32: make NoPadding Encoding's DecodedLen return exact size
CL 47341 added support for decoding non-padded messages. But DecodedLen
still returned a multiple of 5 for messages without a padding, even
though it is possible to calculate the len exactly when using NoPadding.
This change makes DecodedLen return the exact number of bytes that
will be written. A change to the decoding logic is also made so that it
can handle this case.
DecodedLen now has the same behaviour as DecodedLen in encoding/base64.
Fixes #20854
Change-Id: I729e0b1c0946c866fb675c854f835f366dd4b5a4
Reviewed-on: https://go-review.googlesource.com/47710
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Diffstat (limited to 'src/encoding/base32')
| -rw-r--r-- | src/encoding/base32/base32.go | 9 | ||||
| -rw-r--r-- | src/encoding/base32/base32_test.go | 10 |
2 files changed, 11 insertions, 8 deletions
diff --git a/src/encoding/base32/base32.go b/src/encoding/base32/base32.go index 0270e8f4d4..bf341b54f3 100644 --- a/src/encoding/base32/base32.go +++ b/src/encoding/base32/base32.go @@ -341,7 +341,11 @@ func (enc *Encoding) decode(dst, src []byte) (n int, end bool, err error) { case 2: dst[0] = dbuf[0]<<3 | dbuf[1]>>2 } - dst = dst[5:] + + if !end { + dst = dst[5:] + } + switch dlen { case 2: n += 1 @@ -495,8 +499,7 @@ func NewDecoder(enc *Encoding, r io.Reader) io.Reader { // corresponding to n bytes of base32-encoded data. func (enc *Encoding) DecodedLen(n int) int { if enc.padChar == NoPadding { - // +6 represents the missing padding - return (n + 6) / 8 * 5 + return n * 5 / 8 } return n / 8 * 5 diff --git a/src/encoding/base32/base32_test.go b/src/encoding/base32/base32_test.go index 6fe292b476..56b229d15a 100644 --- a/src/encoding/base32/base32_test.go +++ b/src/encoding/base32/base32_test.go @@ -551,13 +551,13 @@ func TestEncodedDecodedLen(t *testing.T) { }}, {"NoPadding", StdEncoding.WithPadding(NoPadding), []test{ {0, 0, 0}, - {1, 2, 5}, - {2, 4, 5}, + {1, 2, 1}, + {2, 4, 2}, {5, 8, 5}, - {6, 10, 10}, - {7, 12, 10}, + {6, 10, 6}, + {7, 12, 7}, {10, 16, 10}, - {11, 18, 15}, + {11, 18, 11}, }}, } { t.Run(test.name, func(t *testing.T) { |