Add LDAP based users-groups system
This change adds support to integrate an LDAP server for user
authentication. This works via a custom STS API for LDAP. Each user
accessing the MinIO who can be authenticated via LDAP receives
temporary credentials to access the MinIO server.
LDAP is enabled only over TLS.
User groups are also supported via LDAP. The administrator may
configure an LDAP search query to find the group attribute of a user -
this may correspond to any attribute in the LDAP tree (that the user
has access to view). One or more groups may be returned by such a
query.
A group is mapped to an IAM policy in the usual way, and the server
enforces a policy corresponding to all the groups and the user's own
mapped policy.
When LDAP is configured, the internal MinIO users system is disabled.
This is a behavior change from AWS S3, but it is done with
better judgment on our end to allow the listing of buckets only
which user has access to.
The advantage is this declutters the UI for users and only
lists bucket which they have access to.
Precursor for this feature to be applicable is a policy
must have the following actions
```
s3:ListAllMyBuckets
```
and
```
s3:ListBucket
```
enabled in the policy.
This allows for canonicalization of the strings
throughout our code and provides a common space
for all these constants to reside.
This list is rather non-exhaustive but captures
all the headers used in AWS S3 API operations
This PR adds support for adding session policies
for further restrictions on STS credentials, useful
in situations when applications want to generate
creds for multiple interested parties with different
set of policy restrictions.
This session policy is not mandatory, but optional.
Fixes#7732
Different gateway implementations due to different backend
API errors, might return different unsupported errors at
our handler layer. Current code posed a problem for us because
this information was lost and we would convert it to InternalError
in this situation all S3 clients end up retrying the request.
To avoid this unexpected situation implement a way to support
this cleanly such that the underlying information is not lost
which is returned by gateway.
This PR supports iam and bucket policies to have
policy variable replacements in resource and
condition key values.
For example
- ${aws:username}
- ${aws:userid}
In many situations, while testing we encounter
ErrInternalError, to reduce logging we have
removed logging from quite a few places which
is acceptable but when ErrInternalError occurs
we should have a facility to log the corresponding
error, this helps to debug Minio server.
This PR introduces two new features
- AWS STS compatible STS API named AssumeRoleWithClientGrants
```
POST /?Action=AssumeRoleWithClientGrants&Token=<jwt>
```
This API endpoint returns temporary access credentials, access
tokens signature types supported by this API
- RSA keys
- ECDSA keys
Fetches the required public key from the JWKS endpoints, provides
them as rsa or ecdsa public keys.
- External policy engine support, in this case OPA policy engine
- Credentials are stored on disks
This commit adds a check to the server's admin-API such that it only
accepts Admin-API requests with authenticated bodies. Further this
commit updates the `madmin` package to always add the
`X-Amz-Content-Sha256` header.
This change improves the Admin-API security since the server does not
accept unauthenticated request bodies anymore.
After this commit `mc` must be updated to the new `madmin` api because
requests over TLS connections will fail.
This commit fixes a DoS vulnerability for certain APIs using
signature V4 by verifying the content-md5 and/or content-sha56 of
the request body in a streaming mode.
The issue was caused by reading the entire body of the request into
memory to verify the content-md5 or content-sha56 checksum if present.
The vulnerability could be exploited by either replaying a V4 request
(in the 15 min time frame) or sending a V4 presigned request with a
large body.
This commit fixes a DoS vulnerability in the
request authentication. The root cause is an 'unlimited'
read-into-RAM from the request body.
Since this read happens before the request authentication
is verified the vulnerability can be exploit without any
access privileges.
This commit limits the size of the request body to 3 MB.
This is about the same size as AWS. The limit seems to be
between 1.6 and 3.2 MB - depending on the AWS machine which
is handling the request.
- remove old bucket policy handling
- add new policy handling
- add new policy handling unit tests
This patch brings support to bucket policy to have more control not
limiting to anonymous. Bucket owner controls to allow/deny any rest
API.
For example server side encryption can be controlled by allowing
PUT/GET objects with encryptions including bucket owner.
This change fixes an authentication bypass attack against the
minio Admin-API. Therefore the Admin-API rejects now all types of
requests except valid signature V2 and signature V4 requests - this
includes signature V2/V4 pre-signed requests.
Fixes#5411
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
The following commit f44f2e341c
fix was incomplete and we still had presigned URLs printing
in query strings in wrong fashion.
This PR fixes this properly. Avoid double encoding
percent encoded strings such as
`s3%!!(MISSING)A(MISSING)`
Print properly as json encoded.
`s3%3AObjectCreated%3A%2A`
We can't use Content-Encoding to verify if `aws-chunked` is set
or not. Just use 'streaming' signature header instead.
While this is considered mandatory, on the contrary aws-sdk-java
doesn't set this value
http://docs.aws.amazon.com/AmazonS3/latest/API/sigv4-streaming.html
```
Set the value to aws-chunked.
```
We will relax it and behave appropriately. Also this PR supports
saving custom encoding after trimming off the `aws-chunked`
parameter.
Fixes#3983
Content-Encoding is set to "aws-chunked" which is an S3 specific
API value which is no meaning for an object. This is how S3
behaves as well for a streaming signature uploaded object.
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.
Golang HTTP client automatically detects content-type but
for S3 clients this content-type might be incorrect or
might misbehave.
For example:
```
Content-Type: text/xml; charset=utf-8
```
Should be
```
Content-Type: application/xml
```
Allow this to be set properly.
Aditya Manthramurthy