minio/internal/etag
Andreas Auernhammer 062f3ea43a
etag: fix incorrect multipart detection (#14631)
This commit fixes a subtle bug in the ETag
`IsEncrypted` implementation.

An encrypted ETag may contain random bytes,
i.e. some randomness used for encryption.
This random value can contain a '-' byte
simple due to being randomly generated.

Before, the `IsEncrypted` implementation
incorrectly assumed that an encrypted ETag
cannot contain a '-' since it would be a
multipart ETag. Multipart ETags have a
16 byte value followed by a '-' and the part number.
For example:
```
059ba80b807c3c776fb3bcf3f33e11ae-2
```

However, the following encrypted ETag
```
20000f00db2d90a7b40782d4cff2b41a7799fc1e7ead25972db65150118dfbe2ba76a3c002da28f85c840cd2001a28a9
```
also contains a '-' byte but is not a multipart ETag.

This commit fixes the `IsEncrypted` implementation
simply by checking whether the ETag is at least 32
bytes long. A valid multipart ETag is never 32 bytes
long since a part number must be <= 10000.

However, an encrypted ETag must be at least 32 bytes
long. It contains the encrypted ETag bytes (16 bytes)
and the authentication tag added by the AEAD cipher (again
16 bytes).

Signed-off-by: Andreas Auernhammer <hi@aead.dev>
2022-03-25 18:21:01 -07:00
..
etag_test.go etag: fix incorrect multipart detection (#14631) 2022-03-25 18:21:01 -07:00
etag.go etag: fix incorrect multipart detection (#14631) 2022-03-25 18:21:01 -07:00
reader.go rename all remaining packages to internal/ (#12418) 2021-06-01 14:59:40 -07:00