The address MinIO attributes a request to is read from X-Forwarded-For,
X-Real-IP or RFC 7239 Forwarded, and never from the connection unless all
three are absent. It becomes aws:SourceIp and the audit remotehost field,
so any client that can reach the API port chooses the value an IpAddress
condition is evaluated against and the address every logged action is
attributed to.
MINIO_API_TRUSTED_PROXIES now selects who may make that claim:
unset the historical behaviour, unchanged
none no forwarded header is believed; the TCP peer wins
<CIDRs> believed only from listed peers, chains read right-to-left
Reading right-to-left is what makes an appending proxy safe: each hop
appends the peer it actually saw, so an entry a client injected can only
sit to the left of one a proxy wrote. The stock nginx recipe
$proxy_add_x_forwarded_for appends, which leaves the client's entry
left-most - exactly where the untrusted path reads - so a deployment with
no direct route to the API port was forgeable too.
_MINIO_API_XFF_HEADER is deliberately untouched, in semantics and in read
timing. Widening it to mean "trust nothing" was implemented and reverted:
it is the only part of this change that could alter a deployed
configuration, and the new variable expresses the same guarantee at no
compatibility cost. Upstream's TestXFFDisabled is retained verbatim.
Notes on the allow-list mode, all covered by tests:
- it must name proxies, not the subnet they sit in; listed entries are
skipped while walking, so a range covering clients lets them forge
- a cluster must list its own nodes, because MinIO forwards between
them and a client can force a hop via the ListObjectsV2 token
- loopback is trusted as a peer, not as a chain entry, so FTP and SFTP
keep attributing their sessions
- the node-to-node forwarder drops X-Real-IP and Forwarded from a peer
not entitled to have set them
- the walk scans the header in place and stops after 100 hops, so a
long chain costs neither allocation nor unbounded work
No behaviour change for any deployment that does not set the new
variable: the untrusted path is a verbatim copy of the previous function
body, differentially verified against it over ~5.1M header combinations.
The LDAP STS allow-list now shares the list parser as pure code motion,
verified identical across every combination of 37 allow-list values and
21 peer addresses.
Co-authored-by: ChatGPT <noreply@openai.com>
Co-authored-by: Claude <noreply@anthropic.com>
Policy evaluation mixed server-derived identity and transport values with raw headers and query parameters. A client could therefore shadow internal condition keys, synthesize LDAP or JWT resource variables, substitute request tags for stored tags, or make a condition observe a value different from the one the handler actually used.
Partition condition sources, reserve internal names, adopt exact-name lookup from silo-pkg, and bind authorization to the effective request state. Preserve compatible query forms for storage class and upload tags with explicit header precedence, while restricting signature age and existing-object tags to authenticated or server-resolved values.
Tests sweep every supported key across header and query routes and exercise LDAP/OIDC variables, object-lock spelling, STS tags, metadata extraction, and end-to-end policy decisions.
Co-authored-by: ChatGPT <noreply@openai.com>
Co-authored-by: Claude <noreply@anthropic.com>
Following policies if present
```
"Condition": {
"IpAddress": {
"aws:SourceIp": [
"54.240.143.0/24",
"2001:DB8:1234:5678::/64"
]
}
}
```
And client is making a request to MinIO via IPv6 can
potentially crash the server.
Workarounds are turn-off IPv6 and use only IPv4
This is to ensure that there are no projects
that try to import `minio/minio/pkg` into
their own repo. Any such common packages should
go to `https://github.com/minio/pkg`
Feng Ruohang