This commit creates a new index privilege named `maintenance`.
The privilege grants the following actions: `refresh`, `flush` (also synced-`flush`),
and `force-merge`. Previously the actions were only under the `manage` privilege
which in some situations was too permissive.
Co-authored-by: Amir H Movahed <arhd83@gmail.com>
The timeout.tcp_read AD/LDAP realm setting, despite the low-level
allusion, controls the time interval the realms wait for a response for
a query (search or bind). If the connection to the server is synchronous
(un-pooled) the response timeout is analogous to the tcp read timeout.
But the tcp read timeout is irrelevant in the common case of a pooled
connection (when a Bind DN is specified).
The timeout.tcp_read qualifier is hereby deprecated in favor of
timeout.response.
In addition, the default value for both timeout.tcp_read and
timeout.response is that of timeout.ldap_search, instead of the 5s (but
the default for timeout.ldap_search is still 5s). The
timeout.ldap_search defines the server-controlled timeout of a search
request. There is no practical use case to have a smaller tcp_read
timeout compared to ldap_search (in this case the request would time-out
on the client but continue to be processed on the server). The proposed
change aims to simplify configuration so that the more common
configuration change, adjusting timeout.ldap_search up, has the expected
result (no timeout during searches) without any additional
modifications.
Closes#46028
This commit deprecates the creation of dot-prefixed index names (e.g.
.watches) unless they are either 1) a hidden index, or 2) registered by
a plugin that extends SystemIndexPlugin. This is the first step
towards more thorough protections for system indices.
This commit also modifies several plugins which use dot-prefixed indices
to register indices they own as system indices, and adds a plugin to
register .tasks as a system index.
The docs tests have recently been running much slower than before (see #49753).
The gist here is that with ILM/SLM we do a lot of unnecessary setup / teardown work on each
test. Compounded with the slightly slower cluster state storage mechanism, this causes the
tests to run much slower.
In particular, on RAMDisk, docs:check is taking
ES 7.4: 6:55 minutes
ES master: 16:09 minutes
ES with this commit: 6:52 minutes
on SSD, docs:check is taking
ES 7.4: ??? minutes
ES master: 32:20 minutes
ES with this commit: 11:21 minutes
* Reload secure settings with password (#43197)
If a password is not set, we assume an empty string to be
compatible with previous behavior.
Only allow the reload to be broadcast to other nodes if TLS is
enabled for the transport layer.
* Add passphrase support to elasticsearch-keystore (#38498)
This change adds support for keystore passphrases to all subcommands
of the elasticsearch-keystore cli tool and adds a subcommand for
changing the passphrase of an existing keystore.
The work to read the passphrase in Elasticsearch when
loading, which will be addressed in a different PR.
Subcommands of elasticsearch-keystore can handle (open and create)
passphrase protected keystores
When reading a keystore, a user is only prompted for a passphrase
only if the keystore is passphrase protected.
When creating a keystore, a user is allowed (default behavior) to create one with an
empty passphrase
Passphrase can be set to be empty when changing/setting it for an
existing keystore
Relates to: #32691
Supersedes: #37472
* Restore behavior for force parameter (#44847)
Turns out that the behavior of `-f` for the add and add-file sub
commands where it would also forcibly create the keystore if it
didn't exist, was by design - although undocumented.
This change restores that behavior auto-creating a keystore that
is not password protected if the force flag is used. The force
OptionSpec is moved to the BaseKeyStoreCommand as we will presumably
want to maintain the same behavior in any other command that takes
a force option.
* Handle pwd protected keystores in all CLI tools (#45289)
This change ensures that `elasticsearch-setup-passwords` and
`elasticsearch-saml-metadata` can handle a password protected
elasticsearch.keystore.
For setup passwords the user would be prompted to add the
elasticsearch keystore password upon running the tool. There is no
option to pass the password as a parameter as we assume the user is
present in order to enter the desired passwords for the built-in
users.
For saml-metadata, we prompt for the keystore password at all times
even though we'd only need to read something from the keystore when
there is a signing or encryption configuration.
* Modify docs for setup passwords and saml metadata cli (#45797)
Adds a sentence in the documentation of `elasticsearch-setup-passwords`
and `elasticsearch-saml-metadata` to describe that users would be
prompted for the keystore's password when running these CLI tools,
when the keystore is password protected.
Co-Authored-By: Lisa Cawley <lcawley@elastic.co>
* Elasticsearch keystore passphrase for startup scripts (#44775)
This commit allows a user to provide a keystore password on Elasticsearch
startup, but only prompts when the keystore exists and is encrypted.
The entrypoint in Java code is standard input. When the Bootstrap class is
checking for secure keystore settings, it checks whether or not the keystore
is encrypted. If so, we read one line from standard input and use this as the
password. For simplicity's sake, we allow a maximum passphrase length of 128
characters. (This is an arbitrary limit and could be increased or eliminated.
It is also enforced in the keystore tools, so that a user can't create a
password that's too long to enter at startup.)
In order to provide a password on standard input, we have to account for four
different ways of starting Elasticsearch: the bash startup script, the Windows
batch startup script, systemd startup, and docker startup. We use wrapper
scripts to reduce systemd and docker to the bash case: in both cases, a
wrapper script can read a passphrase from the filesystem and pass it to the
bash script.
In order to simplify testing the need for a passphrase, I have added a
has-passwd command to the keystore tool. This command can run silently, and
exit with status 0 when the keystore has a password. It exits with status 1 if
the keystore doesn't exist or exists and is unencrypted.
A good deal of the code-change in this commit has to do with refactoring
packaging tests to cleanly use the same tests for both the "archive" and the
"package" cases. This required not only moving tests around, but also adding
some convenience methods for an abstraction layer over distribution-specific
commands.
* Adjust docs for password protected keystore (#45054)
This commit adds relevant parts in the elasticsearch-keystore
sub-commands reference docs and in the reload secure settings API
doc.
* Fix failing Keystore Passphrase test for feature branch (#50154)
One problem with the passphrase-from-file tests, as written, is that
they would leave a SystemD environment variable set when they failed,
and this setting would cause elasticsearch startup to fail for other
tests as well. By using a try-finally, I hope that these tests will fail
more gracefully.
It appears that our Fedora and Ubuntu environments may be configured to
store journald information under /var rather than under /run, so that it
will persist between boots. Our destructive tests that read from the
journal need to account for this in order to avoid trying to limit the
output we check in tests.
* Run keystore management tests on docker distros (#50610)
* Add Docker handling to PackagingTestCase
Keystore tests need to be able to run in the Docker case. We can do this
by using a DockerShell instead of a plain Shell when Docker is running.
* Improve ES startup check for docker
Previously we were checking truncated output for the packaged JDK as
an indication that Elasticsearch had started. With new preliminary
password checks, we might get a false positive from ES keystore
commands, so we have to check specifically that the Elasticsearch
class from the Bootstrap package is what's running.
* Test password-protected keystore with Docker (#50803)
This commit adds two tests for the case where we mount a
password-protected keystore into a Docker container and provide a
password via a Docker environment variable.
We also fix a logging bug where we were logging the identifier for an
array of strings rather than the contents of that array.
* Add documentation for keystore startup prompting (#50821)
When a keystore is password-protected, Elasticsearch will prompt at
startup. This commit adds documentation for this prompt for the archive,
systemd, and Docker cases.
Co-authored-by: Lisa Cawley <lcawley@elastic.co>
* Warn when unable to upgrade keystore on debian (#51011)
For Red Hat RPM upgrades, we warn if we can't upgrade the keystore. This
commit brings the same logic to the code for Debian packages. See the
posttrans file for gets executed for RPMs.
* Restore handling of string input
Adds tests that were mistakenly removed. One of these tests proved
we were not handling the the stdin (-x) option correctly when no
input was added. This commit restores the original approach of
reading stdin one char at a time until there is no more (-1, \r, \n)
instead of using readline() that might return null
* Apply spotless reformatting
* Use '--since' flag to get recent journal messages
When we get Elasticsearch logs from journald, we want to fetch only log
messages from the last run. There are two reasons for this. First, if
there are many logs, we might get a string that's too large for our
utility methods. Second, when we're looking for a specific message or
error, we almost certainly want to look only at messages from the last
execution.
Previously, we've been trying to do this by clearing out the physical
files under the journald process. But there seems to be some contention
over these directories: if journald writes a log file in between when
our deletion command deletes the file and when it deletes the log
directory, the deletion will fail.
It seems to me that we might be able to use journald's "--since" flag to
retrieve only log messages from the last run, and that this might be
less likely to fail due to race conditions in file deletion.
Unfortunately, it looks as if the "--since" flag has a granularity of
one-second. I've added a two-second sleep to make sure that there's a
sufficient gap between the test that will read from journald and the
test before it.
* Use new journald wrapper pattern
* Update version added in secure settings request
Co-authored-by: Lisa Cawley <lcawley@elastic.co>
Co-authored-by: Ioannis Kakavas <ikakavas@protonmail.com>
This commit sets `xpack.security.ssl.diagnose.trust` to false in all
of our tests when running in FIPS 140 mode and when settings objects
are used to create an instance of the SSLService. This is needed
in 7.x because setting xpack.security.ssl.diagnose.trust to true
wraps SunJSSE TrustManager with our own DiagnosticTrustManager and
this is not allowed when SunJSSE is in FIPS mode.
An alternative would be to set xpack.security.fips.enabled to
true which would also implicitly disable
xpack.security.ssl.diagnose.trust but would have additional effects
(would require that we set PBKDF2 for password hashing algorithm in
all test clusters, would prohibit using JKS keystores in nodes even
if relevant tests have been muted in FIPS mode etc.)
Relates: #49900Resolves: #51268
* Don't overwrite target field with SetSecurityUserProcessor
This change fix problem with `SetSecurityUserProcessor` which was overwriting
whole target field and not only fields really filled by the processor.
Closes#51428
* Unused imports removed
This change changes the way to run our test suites in
JVMs configured in FIPS 140 approved mode. It does so by:
- Configuring any given runtime Java in FIPS mode with the bundled
policy and security properties files, setting the system
properties java.security.properties and java.security.policy
with the == operator that overrides the default JVM properties
and policy.
- When runtime java is 11 and higher, using BouncyCastle FIPS
Cryptographic provider and BCJSSE in FIPS mode. These are
used as testRuntime dependencies for unit
tests and internal clusters, and copied (relevant jars)
explicitly to the lib directory for testclusters used in REST tests
- When runtime java is 8, using BouncyCastle FIPS
Cryptographic provider and SunJSSE in FIPS mode.
Running the tests in FIPS 140 approved mode doesn't require an
additional configuration either in CI workers or locally and is
controlled by specifying -Dtests.fips.enabled=true
The ApiKeyService would aggressively "close" ApiKeyCredentials objects
during processing. However, under rare circumstances, the verfication
of the secret key would be performed asychronously and may need access
to the SecureString after it had been closed by the caller.
The trigger for this would be if the cache already held a Future for
that ApiKey, but the future was not yet complete. In this case the
verification of the secret key would take place asynchronously on the
generic thread pool.
This commit moves the "close" of the credentials to the body of the
listener so that it only occurs after key verification is complete.
Backport of: #51244
API Key expiration value has millisecond precision as we use
{@link Instant#toEpoqueMilli()} when creating the API key
document.
It could often happen that `Instant.now()` Instant in the testCreateApiKey
was close enough to the ApiKeyService's `clock.instant()` Instant,
when the nanos were removed from the latter ( due to the call
to `toEpoqueMilli()` ) the result of comparing these two Instants
was a few nanos short of a 7 days.
Resolves: #47958
When not truncated, a long SAML response XML document can fill max
line length and mask the actual exception message that the trace
statement is meant to inform about.
The same XML Document is also printed in full on trace level in
SamlRequestHandler#parseSamlMessage() so there is no loss of
information
This change introduces a new feature for indices so that they can be
hidden from wildcard expansion. The feature is referred to as hidden
indices. An index can be marked hidden through the use of an index
setting, `index.hidden`, at creation time. One primary use case for
this feature is to have a construct that fits indices that are created
by the stack that contain data used for display to the user and/or
intended for querying by the user. The desire to keep them hidden is
to avoid confusing users when searching all of the data they have
indexed and getting results returned from indices created by the
system.
Hidden indices have the following properties:
* API calls for all indices (empty indices array, _all, or *) will not
return hidden indices by default.
* Wildcard expansion will not return hidden indices by default unless
the wildcard pattern begins with a `.`. This behavior is similar to
shell expansion of wildcards.
* REST API calls can enable the expansion of wildcards to hidden
indices with the `expand_wildcards` parameter. To expand wildcards
to hidden indices, use the value `hidden` in conjunction with `open`
and/or `closed`.
* Creation of a hidden index will ignore global index templates. A
global index template is one with a match-all pattern.
* Index templates can make an index hidden, with the exception of a
global index template.
* Accessing a hidden index directly requires no additional parameters.
Backport of #50452
This commit changes our behavior so that when we receive a
request with an invalid/expired/wrong access token or API Key
we do not fallback to authenticating as the anonymous user even if
anonymous access is enabled for Elasticsearch.
When we receive a request with an Authorization header that contains
a Bearer token that is not generated by us or that is malformed in
some way, attempting to decode it as one of our own might cause a
number of exceptions that are not IOExceptions. This commit ensures
that we catch and log these too and call onResponse with `null, so
that we can return 401 instead of 500.
Resolves: #50497
Replace DES with AES to align with modern encryption standards
Backport also fixs Files.readString API that is not available in Java 8
Resolves: #50843
This change adds a new `kibana_admin` role, and deprecates
the old `kibana_user` and`kibana_dashboard_only_user`roles.
The deprecation is implemented via a new reserved metadata
attribute, which can be consumed from the API and also triggers
deprecation logging when used (by a user authenticating to
Elasticsearch).
Some docs have been updated to avoid references to these
deprecated roles.
Backport of: #46456
Co-authored-by: Larry Gregory <lgregorydev@gmail.com>
This adds a new "http" sub-command to the certutil CLI tool.
The http command generates certificates/CSRs for use on the http
interface of an elasticsearch node/cluster.
It is designed to be a guided tool that provides explanations and
sugestions for each of the configuration options. The generated zip
file output includes extensive "readme" documentation and sample
configuration files for core Elastic products.
Backport of: #49827
Previously custom realms were limited in what services and components
they had easy access to. It was possible to work around this because a
security extension is packaged within a Plugin, so there were ways to
store this components in static/SetOnce variables and access them from
the realm, but those techniques were fragile, undocumented and
difficult to discover.
This change includes key services as an argument to most of the methods
on SecurityExtension so that custom realm / role provider authors can
have easy access to them.
Backport of: #50534
The Document Level Security BitSet cache stores a secondary "lookup
map" so that it can determine which cache entries to invalidate when
a Lucene index is closed (merged, etc).
There was a memory leak because this secondary map was not cleared
when entries were naturally evicted from the cache (due to size/ttl
limits).
This has been solved by adding a cache removal listener and processing
those removal events asyncronously.
Backport of: #50635
When creating a role, we do not check if the exceptions for
the field permissions are a subset of granted fields. If such
a role is assigned to a user then that user's authentication fails
for this reason.
We added a check to validate role query in #46275 and on the same lines,
this commit adds check if the exceptions for the field
permissions is a subset of granted fields when parsing the
index privileges from the role descriptor.
Backport of: #50212
Co-authored-by: Yogesh Gaikwad <bizybot@users.noreply.github.com>
This commit changes the default behavior for
xpack.security.ssl.diagnose.trust when running in a FIPS 140 JVM.
More specifically, when xpack.security.fips_mode.enabled is true:
- If xpack.security.ssl.diagnose.trust is not explicitly set, the
default value of it becomes false and a log message is printed
on info level, notifying of the fact that the TLS/SSL diagnostic
messages are not enabled when in a FIPS 140 JVM.
- If xpack.security.ssl.diagnose.trust is explicitly set, the value of
it is honored, even in FIPS mode.
This is relevant only for 7.x where we support Java 8 in which
SunJSSE can still be used as a FIPS 140 provider for TLS. SunJSSE
in FIPS mode, disallows the use of other TrustManager implementations
than the one shipped with SunJSSE.
Hide the `.async-search-*` in Security by making it a restricted index namespace.
The namespace is hard-coded.
To grant privileges on restricted indices, one must explicitly toggle the
`allow_restricted_indices` flag in the indices permission in the role definition.
As is the case with any other index, if a certain user lacks all permissions for an
index, that index is effectively nonexistent for that user.
The OpenIdConnectRealm had a bug which would cause it not to populate
User metadata for collections contained in the user JWT claims.
This commit fixes that bug.
Backport of: #50521
In security we currently monitor a set of files for changes:
- config/role_mapping.yml (or alternative configured path)
- config/roles.yml
- config/users
- config/users_roles
This commit prevents unnecessary reloading when the file change actually doesn't change the internal structure.
Backport of: #50207
Co-authored-by: Anton Shuvaev <anton.shuvaev91@gmail.com>
This drops all remaining references to `BaseRestHandler.logger` which
has been deprecated for something like a year now. I replaced all of the
references with locally declared loggers which is so much less spooky
action at a distance to me.
This adds a new cluster privilege `monitor_snapshot` which is a restricted
version of `create_snapshot`, granting the same privileges to view
snapshot and repository info and status but not granting the actual
privilege to create a snapshot.
Co-authored-by: j-bean <anton.shuvaev91@gmail.com>
XPackPlugin created an SSLService within the plugin contructor.
This has 2 negative consequences:
1. The service may be constructed based on a partial view of settings.
Other plugins are free to add setting values via the
additionalSettings() method, but this (necessarily) happens after
plugins have been constructed.
2. Any exceptions thrown during the plugin construction are handled
differently than exceptions thrown during "createComponents".
Since SSL configurations exceptions are relatively common, it is
far preferable for them to be thrown and handled as part of the
createComponents flow.
This commit moves the creation of the SSLService to
XPackPlugin.createComponents, and alters the sequence of some other
steps to accommodate this change.
Backport of: #49667
Our REST infrastructure will reject requests that have a body where the
body of the request is never consumed. This ensures that we reject
requests on endpoints that do not support having a body. This requires
cooperation from the REST handlers though, to actually consume the body,
otherwise the REST infrastructure will proceed with rejecting the
request. This commit addresses an issue in the has privileges API where
we would prematurely try to reject a request for not having a username,
before consuming the body. Since the body was not consumed, the REST
infrastructure would instead reject the request as a bad request.
* Remove BlobContainer Tests against Mocks
Removing all these weird mocks as asked for by #30424.
All these tests are now part of real repository ITs and otherwise left unchanged if they had
independent tests that didn't call the `createBlobStore` method previously.
The HDFS tests also get added coverage as a side-effect because they did not have an implementation
of the abstract repository ITs.
Closes#30424
This test was fixed as part of #49736 so that it used a
TokenService mock instance that was enabled, so that token
verification fails because the token is invalid and not because
the token service is not enabled.
When the randomly generated token we send, decodes to being of
version > 7.2 , we need to have mocked a GetResponse for the call
that TokenService#getUserTokenFromId will make, otherwise this
hangs and times out.
Return a 401 in all cases when a request is submitted with an
access token that we can't consume. Before this change, we would
throw a 500 when a request came in with an access token that we
had generated but was then invalidated/expired and deleted from
the tokens index.
Resolves: #38866
Backport of #49736
* Copying the request is not necessary here. We can simply release it once the response has been generated and a lot of `Unpooled` allocations that way
* Relates #32228
* I think the issue that preventet that PR that PR from being merged was solved by #39634 that moved the bulk index marker search to ByteBuf bulk access so the composite buffer shouldn't require many additional bounds checks (I'd argue the bounds checks we add, we save when copying the composite buffer)
* I couldn't neccessarily reproduce much of a speedup from this change, but I could reproduce a very measureable reduction in GC time with e.g. Rally's PMC (4g heap node and bulk requests of size 5k saw a reduction in young GC time by ~10% for me)
- Improves HTTP client hostname verification failure messages
- Adds "DiagnosticTrustManager" which logs certificate information
when trust cannot be established (hostname failure, CA path failure,
etc)
These diagnostic messages are designed so that many common TLS
problems can be diagnosed based solely (or primarily) on the
elasticsearch logs.
These diagnostics can be disabled by setting
xpack.security.ssl.diagnose.trust: false
Backport of: #48911
Add a mirror of the maven repository of the shibboleth project
and upgrade opensaml and related dependencies to the latest
version available version
Resolves: #44947
This change adds a dynamic cluster setting named `indices.id_field_data.enabled`.
When set to `false` any attempt to load the fielddata for the `_id` field will fail
with an exception. The default value in this change is set to `false` in order to prevent
fielddata usage on this field for future versions but it will be set to `true` when backporting
to 7x. When the setting is set to true (manually or by default in 7x) the loading will also issue
a deprecation warning since we want to disallow fielddata entirely when https://github.com/elastic/elasticsearch/issues/26472
is implemented.
Closes#43599
Authentication has grown more complex with the addition of new realm
types and authentication methods. When user authentication does not
behave as expected it can be difficult to determine where and why it
failed.
This commit adds DEBUG and TRACE logging at key points in the
authentication flow so that it is possible to gain addition insight
into the operation of the system.
Backport of: #49575
The AuthenticationService has a feature to "smart order" the realm
chain so that whicherver realm was the last one to successfully
authenticate a given user will be tried first when that user tries to
authenticate again.
There was a bug where the building of this realm order would
incorrectly drop the first realm from the default chain unless that
realm was the "last successful" realm.
In most cases this didn't cause problems because the first realm is
the reserved realm and so it is unusual for a user that authenticated
against a different realm to later need to authenticate against the
resevered realm.
This commit fixes that bug and adds relevant asserts and tests.
Backport of: #49473
All the implementations of `EsBlobStoreTestCase` use the exact same
bootstrap code that is also used by their implementation of
`EsBlobStoreContainerTestCase`.
This means all tests might as well live under `EsBlobStoreContainerTestCase`
saving a lot of code duplication. Also, there was no HDFS implementation for
`EsBlobStoreTestCase` which is now automatically resolved by moving the tests over
since there is a HDFS implementation for the container tests.
This commit adds a deprecation warning when starting
a node where either of the server contexts
(xpack.security.transport.ssl and xpack.security.http.ssl)
meet either of these conditions:
1. The server lacks a certificate/key pair (i.e. neither
ssl.keystore.path not ssl.certificate are configured)
2. The server has some ssl configuration, but ssl.enabled is not
specified. This new validation does not care whether ssl.enabled is
true or false (though other validation might), it simply makes it
an error to configure server SSL without being explicit about
whether to enable that configuration.
Backport of: #45892
This commit changes the ThreadContext to just use a regular ThreadLocal
over the lucene CloseableThreadLocal. The CloseableThreadLocal solves
issues with ThreadLocals that are no longer needed during runtime but
in the case of the ThreadContext, we need it for the runtime of the
node and it is typically not closed until the node closes, so we miss
out on the benefits that this class provides.
Additionally by removing the close logic, we simplify code in other
places that deal with exceptions and tracking to see if it happens when
the node is closing.
Closes#42577
Ensures that methods that are called from different threads ( i.e.
from the callbacks of org.apache.http.concurrent.FutureCallback )
catch `Exception` instead of only the expected checked exceptions.
This resolves a bug where OpenIdConnectAuthenticator#mergeObjects
would throw an IllegalStateException that was never caught causing
the thread to hang and the listener to never be called. This would
in turn cause Kibana requests to authenticate with OpenID Connect
to timeout and fail without even logging anything relevant.
This also guards against unexpected Exceptions that might be thrown
by invoked library methods while performing the necessary operations
in these callbacks.
Backport of #48849. Update `.editorconfig` to make the Java settings the
default for all files, and then apply a 2-space indent to all `*.gradle`
files. Then reformat all the files.
This commit introduces a consistent, and type-safe manner for handling
global build parameters through out our build logic. Primarily this
replaces the existing usages of extra properties with static accessors.
It also introduces and explicit API for initialization and mutation of
any such parameters, as well as better error handling for uninitialized
or eager access of parameter values.
Closes#42042
Previous behavior while copying HTTP headers to the ThreadContext,
would allow multiple HTTP headers with the same name, handling only
the first occurrence and disregarding the rest of the values. This
can be confusing when dealing with multiple Headers as it is not
obvious which value is read and which ones are silently dropped.
According to RFC-7230, a client must not send multiple header fields
with the same field name in a HTTP message, unless the entire field
value for this header is defined as a comma separated list or this
specific header is a well-known exception.
This commits changes the behavior in order to be more compliant to
the aforementioned RFC by requiring the classes that implement
ActionPlugin to declare if a header can be multi-valued or not when
registering this header to be copied over to the ThreadContext in
ActionPlugin#getRestHeaders.
If the header is allowed to be multivalued, then all such headers
are read from the HTTP request and their values get concatenated in
a comma-separated string.
If the header is not allowed to be multivalued, and the HTTP
request contains multiple such Headers with different values, the
request is rejected with a 400 status.