With --auth-proxy set and --auth-key unset, serve s3 registered every client
supplied access key ID with an empty secret and verified the SigV4 signature
against that, so anyone could sign a request for an arbitrary access key ID with
an empty secret and be let in. The proxy program was only ever given the access
key ID (as both user and pass) so it had nothing with which to authenticate the
client either.
An S3 client never sends its secret, only a signature made with it, so the
server has to know the secret to check the request. The auth proxy protocol as
been changed to handle this. For serve s3 the proxy program is given just the
access key ID as the user (no pass or public_key) and must return the matching
secret as _secret_access_key in its output. rclone verifies the request's
signature against that secret, refusing the request if the proxy rejects the
access key ID, doesn't return a secret or returns an empty one, or the signature
doesn't match. The secret is only used for this server's own verification and is
never registered with gofakes3, so other serve s3 instances in the same process
don't honour it.
The proxy's answers are cached. If a signature fails against a cached secret the
proxy is consulted again so a rotated secret takes effect immediately - but only
for a signature mismatch, and at most once every 10 seconds per access key ID
and client IP, so a stream of bad signatures can't make the proxy program run
for every request. A rotation never shuts down the cached backend under requests
still using it. A cached answer is checked with the proxy again once it is 5
minutes old even if in constant use, so revoking an access key ID takes effect
within 5 minutes.
This means --auth-key is no longer needed with --auth-proxy: it is ignored and a
warning is given at startup if both are set. The proxy is the source of truth
for both the credentials and the backend they map to. Presigned URLs (credential
in the query string) are now recognised by the proxy middleware too. The auth
proxy docs are added to serve s3.
Note that the serve s3 auth proxy protocol has changed. The proxy program is now
given the access key ID as "user" (it was previously given an MD5 hash of it,
with the access key ID as "pass") and must return the matching secret as
"_secret_access_key".
This needs gofakes3 v0.0.9 for signature.V4SignVerifyWithSecret.
gofakes3 kept the keys given with --auth-key in a store global to the process,
so when more than one serve s3 was running in one rclone (eg started via the rc)
each accepted the others' credentials and a client with the key for one server
could read and write the backend of another.
This updates gofakes3 to v0.0.9 which keeps auth keys per instance and adds a
test that two servers only accept their own keys.
From v1.70.0 until the serve Provider refactor (f425f8d46), an S3 server started
through the rc serve/start API with a per-server proxyOpt.AuthProxy
decided whether to enable proxy authentication by checking the
process-global proxy.Opt.AuthProxy instead of the supplied
proxyOpt.AuthProxy. In the normal rc case the global is empty, so the
auth proxy was silently ignored and the server served the fixed
filesystem supplied to serve/start rather than routing each access key
to the backend chosen by the proxy, bypassing the operator's intended
per-key authorization.
The Provider refactor fixed this incidentally by building the provider
from the proxyOpt passed to the constructor. This adds a regression test
so the per-server option cannot silently stop working again, and only
logs "allowing anonymous access" when neither an auth key nor an auth
proxy is configured so the log reflects the effective mode.
TestS3Minio brings up a minio container via the fstest/testserver
framework, which exec's bash init.d scripts that shell out to docker.
This is not available on all platforms - Windows has no POSIX shell to
run the scripts, and macOS CI runners have no docker daemon - which
caused the build to fail there.
Add testy.SkipUnlessDocker to detect whether the framework can run and
skip the test when it cannot.
Previously serve s3 buffered every part of a multipart upload in memory
(in the gofakes3 S3 library) and concatenated them when the upload
completed, so memory use grew with the size of the upload.
serve s3 now streams the parts, in part-number order, into a single
PutStream upload to the underlying remote, which performs its own upload
with bounded memory. The whole file is never held in memory - memory use
is bounded by the parts in flight. This works for any remote that
supports PutStream (nearly all, including crypt) and for any part size,
so clients that don't produce uniform-sized parts (for example
PostgreSQL backup tools such as pgBarman and pgBackRest) work too.
Parts must arrive in ascending, contiguous part-number order; parts
uploaded out of order are buffered until their turn, and there is no
per-part retry (a failure aborts the whole upload). These trade-offs are
documented.
Passing --disable-multipart-streaming, or using a remote without
PutStream, reverts to buffering the parts in memory (the previous
behaviour); a one-off NOTICE is logged the first time this happens.
Fixes#7453
This commit modernizes Go usage. This was done with:
go run golang.org/x/tools/gopls/internal/analysis/modernize/cmd/modernize@latest -fix -test ./...
Then files needed to be `go fmt`ed and a few comments needed to be
restored.
The modernizations include replacing
- if/else conditional assignment by a call to the built-in min or max functions added in go1.21
- sort.Slice(x, func(i, j int) bool) { return s[i] < s[j] } by a call to slices.Sort(s), added in go1.21
- interface{} by the 'any' type added in go1.18
- append([]T(nil), s...) by slices.Clone(s) or slices.Concat(s), added in go1.21
- loop around an m[k]=v map update by a call to one of the Collect, Copy, Clone, or Insert functions from the maps package, added in go1.21
- []byte(fmt.Sprintf...) by fmt.Appendf(nil, ...), added in go1.19
- append(s[:i], s[i+1]...) by slices.Delete(s, i, i+1), added in go1.21
- a 3-clause for i := 0; i < n; i++ {} loop by for i := range n {}, added in go1.22
This implements --auth-proxy for serve s3. In addition it:
* add listbuckets tests with and without authProxy
* use auth proxy test framework
* servetest: implement workaround for #7454
* update github.com/rclone/gofakes3 to fix race condition
- Changes
- Rename `--s3-authkey` to `--auth-key` to get it out of the s3 backend namespace
- Enable `Content-MD5` integrity checks
- Remove locking after code audit
- Documentation
- Factor out documentation into seperate file
- Add Quickstart to docs
- Add Bugs section to docs
- Add experimental tag to docs
- Add rclone provider to s3 backend docs
- Fixes
- Correct quirks in s3 backend
- Change fmt.Printlns into fs.Logs
- Make metadata storage per backend not global
- Log on startup if anonymous access is enabled
- Coding style fixes
- rename fs to vfs to save confusion with the rest of rclone code
- rename db to b for *s3Backend
Fixes#7062
- add context to log and fallthrough to error log level
- test: use rclone random lib to generate random strings
- calculate hash from vfs cache if file is uploading
- add server started log with server url
- remove md5 hasher
Nick Craig-Wood
Sawjan Gurung
Artur Neumann
Mikubill