A presigned or signed PUT authorized for a single object could be turned
into a server-side copy of any object the signing key can read by adding
an unsigned x-amz-copy-source header, executed as the signer. SigV4
verification only walked the signed-headers list, never the headers that
actually arrived; the meta-header check matched only X-Amz-Meta- and ran
only on the presigned path, so an unsigned x-amz-* header outside the
list was never seen while the router still dispatched the PUT to
CopyObjectHandler.
Reject any x-amz-* request header not covered by the signed headers, on
both the presigned (doesPresignedSignatureMatch) and Authorization-header
(doesSignatureMatch) paths, matching AWS S3. The check tests membership
in the signed set rather than value equality, so a header whose first
value is empty (e.g. {"", "/src/secret"}) cannot slip through.
X-Amz-Content-Sha256 is exempt (payload hash: read from the query for
presigned requests and bound into the string-to-sign for signed ones, so
it is self-protected) and X-Amz-Signature-Age is exempt (an internal
scratch header written after verification, so repeated verification of
the same request stays idempotent). The synthesized X-Amz-Tagging header
in PutObjectTagging is now injected after signature verification.
Tests that previously added x-amz-copy-source and friends after signing
(relying on the vulnerable behavior) now re-sign, mirroring real S3
clients. Adds checkUnsignedHeaders unit cases and TestPresignedVerifyIdempotent.
Reported by Oren Yomtov. Inherited unchanged from upstream minio/minio.
Tracked as SN-2026-011.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Signed-off-by: Feng Ruohang <rh@vonng.com>
x-amz-signed-headers is meant for HTTP headers only
not for query params, using that to verify things
further can lead to failure.
The generated presigned URL with custom metadata
is already kosher (tamper proof).
fixes#18281
A huge number of goroutines would build up from various monitors
When creating test filesystems provide a context so they can shut down when no longer needed.
The AddUser() API endpoint was accepting a policy field.
This API is used to update a user's secret key and account
status, and allows a regular user to update their own secret key.
The policy update is also applied though does not appear to
be used by any existing client-side functionality.
This fix changes the accepted request body type and removes
the ability to apply policy changes as that is possible via the
policy set API.
NOTE: Changing passwords can be disabled as a workaround
for this issue by adding an explicit "Deny" rule to disable the API
for users.
As we use etcd's watch interface, we do not need the
network notifications as they are no-ops anyway.
Bonus: Remove globalEtcdClient global usage in IAM
Looks like policy restriction was not working properly
for normal users when they are not svc or STS accounts.
- svc accounts are now properly fixed to get
right permissions when its inherited, so
we do not have to set 'owner = true'
- sts accounts have always been using right
permissions, do not need an explicit lookup
- regular users always have proper policy mapping
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`
This commit refactors the code in `cmd/crypto`
and separates SSE-S3, SSE-C and SSE-KMS.
This commit should not cause any behavior change
except for:
- `IsRequested(http.Header)`
which now returns the requested type {SSE-C, SSE-S3,
SSE-KMS} and does not consider SSE-C copy headers.
However, SSE-C copy headers alone are anyway not valid.
x-amz-content-sha256 can be optional for any AWS signature v4
requests, make sure to skip sha256 calculation when payload
checksum is not set.
Here is the overall expected behavior
** Signed request **
- X-Amz-Content-Sha256 is set to 'empty' or some 'value' or its
not 'UNSIGNED-PAYLOAD'- use it to validate the incoming payload.
- X-Amz-Content-Sha256 is set to 'UNSIGNED-PAYLOAD' - skip checksum verification
- X-Amz-Content-Sha256 is not set we use emptySHA256
** Presigned request **
- X-Amz-Content-Sha256 is set to 'empty' or some 'value' or its
not 'UNSIGNED-PAYLOAD'- use it to validate the incoming payload
- X-Amz-Content-Sha256 is set to 'UNSIGNED-PAYLOAD' - skip checksum verification
- X-Amz-Content-Sha256 is not set we use 'UNSIGNED-PAYLOAD'
Fixes#5339
This is a consolidation effort, avoiding usage
of naked strings in codebase. Whenever possible
use constants which can be repurposed elsewhere.
This also fixes `goconst ./...` reported issues.
Feng Ruohang