30 KiB
Network Encryption (TLS)
minio
Table of Contents
MinIO supports Transport Layer Security (TLS) 1.2+ encryption of incoming and outgoing traffic.
SSL is Deprecated
TLS is the successor to Secure Socket Layer (SSL) encryption. SSL is fully deprecated as of June 30th, 2018.
Enabling TLS
not k8s
The sections below describe how to enable TLS for MinIO. You may use TLS certificates from a well-known Certificate Authority, an internal or private CA, or self-signed certs.
Before beginning, note these important points:
- Configure TLS on each node.
- Ensure certs are readable by the user who runs the MinIO Server process.
- Update
MINIO_VOLUMES
and any needed services or apps to use anHTTPS
URL.
k8s
For Kubernetes clusters with a valid TLS Cluster Signing Certificate <minio-k8s-deploy-operator-tls>
,
the MinIO Kubernetes Operator can automatically generate TLS
certificates while deploying <minio-k8s-deploy-minio-tenant-security>
or modifying <minio-k8s-modify-minio-tenant-security>
a MinIO Tenant. The TLS certificate generation process is as
follows:
The Operator generates a Certificate Signing Request (CSR) associated to the Tenant. The
CSR (Certificate Signing Request)
includes the appropriate DNS Subject Alternate Names (SANs) for the Tenant services and pods.The Operator then waits for
CSR (Certificate Signing Request)
approvalThe
CSR (Certificate Signing Request)
waits pending approval. The Kubernetes TLS API can automatically approve theCSR (Certificate Signing Request)
if properly configured. Otherwise, a cluster administrator must manually approve theCSR (Certificate Signing Request)
before Kubernetes can generate the necessary certificates.The Operator applies the generated TLS Certificates to each MinIO Pod in the Tenant.
The Kubernetes TLS API uses the Kubernetes cluster Certificate
Authority (CA) signature algorithm when generating new TLS certificates.
See minio-TLS-supported-cipher-suites
for a complete list
of MinIO's supported TLS Cipher Suites and recommended signature
algorithms.
By default, Kubernetes places a certificate bundle on each pod at
/var/run/secrets/kubernetes.io/serviceaccount/ca.crt
. This
CA bundle should include the cluster or root CA used to sign the MinIO
Tenant TLS certificates. Other applications deployed within the
Kubernetes cluster can trust this cluster certificate to connect to a
MinIO Tenant using the MinIO service DNS name <concepts/services-networking/dns-pod-service/>
(e.g.
https://minio.minio-tenant-1.svc.cluster-domain.example:443
).
Subject Alternative Name Certificates
If you have a custom Subject Alternative Name (SAN) certificate that is not also a wildcard cert, the TLS certificate SAN must apply to the hostname for its parent node. Without a wildcard, the SAN must match exactly to be able to connect to the tenant.
Certificate Management with cert-manager
The MinIO Operator supports using cert-manager as a full replacement
for its built-in automatic certificate management or
user-driven manual certificate management. For instructions for
deploying the MinIO Operator and tenants using cert-manager, refer to
the cert-manager page <minio-certmanager>
.
linux
The MinIO Server searches for TLS keys and certificates for each node and uses those credentials for enabling TLS. The search location depends on your MinIO configuration:
Default Path
By default, the MinIO server looks for the TLS keys and certificates for each node in the following directory:
${HOME}/.minio/certs
Where ${HOME}
is the home directory of the user running
the MinIO Server process. You may need to create the
${HOME}/.minio/certs
directory if it does not exist.
For systemd
managed deployments this must correspond to
the USER
running the MinIO process. If that user has no
home directory, use the Custom Path
option instead.
Custom Path
You can specify a path for the MinIO server to search for
certificates using the minio server --certs-dir
or -S
parameter.
For example, the following command fragment directs the MinIO process
to use the /opt/minio/certs
directory for TLS
certificates.
minio server --certs-dir /opt/minio/certs ...
The user running the MinIO service must have read and write permissions to this directory.
Place the TLS certificates for the default domain (e.g.
minio.example.net
) in the /certs
directory,
with the private key as private.key
and public certificate
as public.crt
.
For example:
/path/to/certs
private.key
public.crt
You can use the MinIO certgen <certgen>
to mint self-signed
certificates for evaluating MinIO with TLS enabled. For example, the
following command generates a self-signed certificate with a set of IP
and DNS Subject Alternate Names (SANs) associated to the MinIO Server
hosts:
certgen -host "localhost,minio-*.example.net"
Place the generated public.crt
and
private.key
into the /path/to/certs
directory
to enable TLS for the MinIO deployment. Applications can use the
public.crt
as a trusted Certificate Authority to allow
connections to the MinIO deployment without disabling certificate
validation.
If you are reconfiguring an existing deployment that did not
previously have TLS enabled, update MINIO_VOLUMES
to specify https
instead
of http
. You may also need to update URLs used by
applications or clients.
container
Start the MinIO container with the minio/minio:latest server --certs-dir <minio server --certs-dir>
parameter and specify the path to a directory in which MinIO searches
for certificates. You must mount a local host volume to that path when
starting the container to ensure the MinIO Server can access the
necessary certificates.
Place the TLS certificates for the default domain (e.g.
minio.example.net
) in the specified directory, with the
private key as private.key
and public certificate as
public.crt
. For example:
/opts/certs
private.key
public.crt
You can use the MinIO certgen <certgen>
to mint self-signed
certificates for evaluating MinIO with TLS enabled. For example, the
following command generates a self-signed certificate with a set of IP
and DNS SANs associated to the MinIO Server hosts:
certgen -host "localhost,minio-*.example.net"
You may need to start the container and set a --hostname
that matches the TLS certificate DNS SAN.
Move the certificates to the local host machine path that the
container mounts to its --certs-dir
path. When the MinIO
container starts, the server searches the specified location for
certificates and uses them to enable TLS. Applications can use the
public.crt
as a trusted Certificate Authority to allow
connections to the MinIO deployment without disabling certificate
validation.
If you are reconfiguring an existing deployment that did not
previously have TLS enabled, update MINIO_VOLUMES
to specify https
instead
of http
. You may also need to update URLs used by
applications or clients.
macos
The MinIO server searches the following directory for TLS keys and certificates:
${HOME}/.minio/certs
For deployments started with a custom TLS directory minio server --certs-dir
,
use that directory instead of the defaults.
Place the TLS certificates for the default domain (e.g.
minio.example.net
) in the /certs
directory,
with the private key as private.key
and public certificate
as public.crt
.
For example:
${HOME}/.minio/certs
private.key
public.crt
Where ${HOME}
is the home directory of the user running
the MinIO Server process. You may need to create the
${HOME}/.minio/certs
directory if it does not exist.
You can use the MinIO certgen <certgen>
to mint self-signed
certificates for evaluating MinIO with TLS enabled. For example, the
following command generates a self-signed certificate with a set of IP
and DNS SANs associated to the MinIO Server hosts:
certgen -host "localhost,minio-*.example.net"
Place the generated public.crt
and
private.key
into the /.minio/certs
directory
to enable TLS for the MinIO deployment. Applications can use the
public.crt
as a trusted Certificate Authority to allow
connections to the MinIO deployment without disabling certificate
validation.
If you are reconfiguring an existing deployment that did not
previously have TLS enabled, update MINIO_VOLUMES
to specify https
instead
of http
. You may also need to update URLs used by
applications or clients.
windows
The MinIO server searches the following directory for TLS keys and certificates:
%%USERPROFILE%%\.minio\certs
For deployments started with a custom TLS directory minio server --certs-dir
,
use that directory instead of the defaults.
Place the TLS certificates for the default domain (e.g.
minio.example.net
) in the /certs
directory,
with the private key as private.key
and public certificate
as public.crt
.
For example:
%%USERPROFILE%%\.minio\certs
private.key
public.crt
Where %%USERPROFILE%%
is the location of the User
Profile folder of the user running the MinIO Server process.
You can use the MinIO certgen <certgen>
to mint self-signed
certificates for evaluating MinIO with TLS enabled. For example, the
following command generates a self-signed certificate with a set of IP
and DNS SANs associated to the MinIO Server hosts:
certgen.exe -host "localhost,minio-*.example.net"
Place the generated public.crt
and
private.key
into the \.minio\certs
directory
to enable TLS for the MinIO deployment. Applications can use the
public.crt
as a trusted Certificate Authority to allow
connections to the MinIO deployment without disabling certificate
validation.
If you are reconfiguring an existing deployment that did not
previously have TLS enabled, update MINIO_VOLUMES
to specify https
instead
of http
. You may also need to update URLs used by
applications or clients.
k8s
Supported Secret Types
MinIO supports three types of secrets in Kubernetes <concepts/configuration/secret/#secret-types>
.
opaque
Using
private.key
andpublic.crt
files.tls
Using
tls.key
andtls.crt
files.cert-manager 1.7.x or later
Running on Kubernetes 1.21 or later.
Note
For the best support of tls or cert-manager secrets, upgrade to Operator version 5.0.10 or later.
Multiple Domain-Based TLS Certificates
k8s
The MinIO Operator supports attaching user-specified TLS certificates
when deploying <minio-k8s-deploy-minio-tenant-security>
or modifying <minio-k8s-modify-minio-tenant-security>
the MinIO Tenant.
These custom certificates support Server Name
Indication (SNI), where the MinIO server identifies which
certificate to use based on the hostname specified by the connecting
client. For example, you can generate certificates signed by your
organization's preferred Certificate Authority (CA) and attach those to
the MinIO Tenant. Applications which trust that CA (Certificate Authority)
can connect to the MinIO Tenant and fully validate the Tenant TLS
certificates.
linux
The MinIO server supports multiple TLS certificates, where the server
uses Server Name
Indication (SNI) to identify which certificate to use when
responding to a client request. When a client connects using a specific
hostname, MinIO uses SNI (Server Name Indication)
to select the
appropriate TLS certificate for that hostname.
For example, consider a MinIO deployment reachable through the following hostnames:
https://minio.example.net
(default TLS certificates)https://s3.example.net
https://minio.internal-example.net
Place the certificates in the /certs
folder, creating a
subfolder in /certs
for each additional domain for which
MinIO should present TLS certificates. While MinIO has no requirements
for folder names, consider creating subfolders whose name matches the
domain to improve human readability. Place the TLS private and public
key for that domain in the subfolder.
The root path for this folder depends on whether you use the default
certificate path or a custom certificate path (minio server --certs-dir
or -S
).
Default Certificate Path
${HOME}/.minio/certs
private.key
public.crt
s3-example.net/
private.key
public.crt
internal-example.net/
private.key
public.crt
Custom Certificate Path
The following example assumes the MinIO Server was started with
--certs dir | -S /opt/minio/certs
:
/opt/minio/certs
private.key
public.crt
s3-example.net/
private.key
public.crt
internal-example.net/
private.key
public.crt
While you can have a single TLS certificate that covers all hostnames
with multiple Subject Alternative Names (SANs), this would reveal the
internal-example.net
and s3-example.net
hostnames to any client which inspects the server certificate. Using a
TLS certificate per hostname better protects each individual hostname
from discovery. The individual TLS certificate SANs
must apply to the hostname for their respective parent
node.
If the client-specified hostname or IP address does not match any of the configured TLS certificates, the connection typically fails with a certificate validation error.
container
The MinIO server supports multiple TLS certificates, where the server
uses Server Name
Indication (SNI) to identify which certificate to use when
responding to a client request. When a client connects using a specific
hostname, MinIO uses SNI (Server Name Indication)
to select the
appropriate TLS certificate for that hostname.
For example, consider a MinIO deployment reachable through the following hostnames:
https://minio.example.net
(default TLS certificates)https://s3.example.net
https://minio.internal-example.net
Start the MinIO container with the minio/minio:latest server --certs-dir <minio server --certs-dir>
parameter and specify the path to a directory in which MinIO searches
for certificates. You must mount a local host volume to that path when
starting the container to ensure the MinIO Server can access the
necessary certificates.
Place the TLS certificates for the default domain (e.g.
minio.example.net
) in the specified directory, with the
private key as private.key
and public certificate as
public.crt
. For other hostnames, create a subfolder whose
name matches the domain to improve human readability. Place the TLS
private and public key for that domain in the subfolder.
For example:
/opts/certs
private.key
public.crt
s3-example.net/
private.key
public.crt
internal-example.net/
private.key
public.crt
When the MinIO container starts, the server searches the mounted
location /opts/certs
for certificates and uses them enable
TLS. MinIO serves clients connecting to the container using a supported
hostname with the associated certificates. Applications can use the
public.crt
as a trusted Certificate Authority to allow
connections to the MinIO deployment without disabling certificate
validation.
While you can have a single TLS certificate that covers all hostnames
with multiple Subject Alternative Names (SANs), this would reveal the
internal-example.net
and s3-example.net
hostnames to any client which inspects the server certificate. Using one
TLS certificate per hostname better protects each individual hostname
from discovery. The individual TLS certificate SANs
must apply to the hostname for their respective parent
node.
If the client-specified hostname or IP address does not match any of the configured TLS certificates, the connection typically fails with a certificate validation error.
macos
The MinIO server supports multiple TLS certificates, where the server uses Server Name Indication (SNI) to identify which certificate to use when responding to a client request. When a client connects using a specific hostname, MinIO uses SNI to select the appropriate TLS certificate for that hostname.
For example, consider a MinIO deployment reachable through the following hostnames:
https://minio.example.net
(default TLS certificates)https://s3.example.net
https://minio.internal-example.net
Create a subfolder in /certs
for each additional domain
for which MinIO should present TLS certificates. While MinIO has no
requirements for folder names, consider creating subfolders whose name
matches the domain to improve human readability. Place the TLS private
and public key for that domain in the subfolder.
For example:
${HOME}/.minio/certs
private.key
public.crt
s3-example.net/
private.key
public.crt
internal-example.net/
private.key
public.crt
While you can have a single TLS certificate that covers all hostnames
with multiple Subject Alternative Names (SANs), this would reveal the
internal-example.net
and s3-example.net
hostnames to any client which inspects the server certificate. Using a
TLS certificate per hostname better protects each individual hostname
from discovery. The individual TLS certificate SANs
must apply to the hostname for their respective parent
node.
If the client-specified hostname or IP address does not match any of the configured TLS certificates, the connection typically fails with a certificate validation error.
windows
The MinIO server supports multiple TLS certificates, where the server uses Server Name Indication (SNI) to identify which certificate to use when responding to a client request. When a client connects using a specific hostname, MinIO uses SNI to select the appropriate TLS certificate for that hostname.
For example, consider a MinIO deployment reachable through the following hostnames:
https://minio.example.net
(default TLS certificates)https://s3.example.net
https://minio.internal-example.net
Create a subfolder in /certs
for each additional domain
for which MinIO should present TLS certificates. While MinIO has no
requirements for folder names, consider creating subfolders whose name
matches the domain to improve human readability. Place the TLS private
and public key for that domain in the subfolder.
For example:
%%USERPROFILE%%\.minio\certs
private.key
public.crt
s3-example.net\
private.key
public.crt
internal-example.net\
private.key
public.crt
While you can have a single TLS certificate that covers all hostnames
with multiple Subject Alternative Names (SANs), this would reveal the
internal-example.net
and s3-example.net
hostnames to any client which inspects the server certificate. Using a
TLS certificate per hostname better protects each individual hostname
from discovery. The individual TLS certificate SANs
must apply to the hostname for their respective parent
node.
If the client-specified hostname or IP address does not match any of the configured TLS certificates, the connection typically fails with a certificate validation error.
Supported TLS Cipher Suites
MinIO recommends generating ECDSA (e.g. NIST
P-256 curve) or EdDSA (e.g. Curve25519 <7748>
) TLS private keys/certificates
due to their lower computation requirements compared to RSA.
MinIO supports the following TLS 1.2 and 1.3 cipher suites as
supported by Go.
The lists mark recommended algorithms with a star-fill
icon:
TLS 1.3
TLS_CHACHA20_POLY1305_SHA256
star-fill
TLS_AES_128_GCM_SHA256
TLS_AES_256_GCM_SHA384
TLS 1.2
TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305
star-fill
TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
star-fill
TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
star-fill
TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305
TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
Third-Party Certificate Authorities
k8s
The MinIO Kubernetes Operator can automatically attach third-party
Certificate Authorities when deploying <minio-k8s-deploy-minio-tenant-security>
or modifying <minio-k8s-modify-minio-tenant-security>
a MinIO Tenant.
You can add, update, or remove CAs from the tenant at any time. You must restart the MinIO Tenant for the changes to the configured CAs to apply.
The Operator places the specified CAs on each MinIO Server pod such that all pods have a consistent set of trusted CAs.
If the MinIO Server cannot match an incoming client's TLS certificate issuer against any of the available CAs, the server rejects the connection as invalid.
linux
The MinIO Server validates the TLS certificate presented by each connecting client against the host system's trusted root certificate store.
Place the CA certificates in the /certs/CAs
folder. The
root path for this folder depends on whether you use the default
certificate path or a custom certificate path (minio server --certs-dir
or -S
)
Default Certificate Path
mv myCA.crt ${HOME}/certs/CAs
Custom Certificate Path
The following example assumes the MinIO Server was started with
--certs dir /opt/minio/certs
:
mv myCA.crt /opt/minio/certs/CAs/
Place the certificate file for each CA into the /CAs
subdirectory. Ensure all hosts in the MinIO deployment have a consistent
set of trusted CAs in that directory. If the MinIO Server cannot match
an incoming client's TLS certificate issuer against any of the available
CAs, the server rejects the connection as invalid.
container
Start the MinIO container with the minio/minio:latest server --certs-dir <minio server --certs-dir>
parameter and specify the path to a directory in which MinIO searches
for certificates. You must mount a local host volume to that path when
starting the container to ensure the MinIO Server can access the
necessary certificates.
For deployments started with a custom TLS directory minio server --certs-dir
,
the server searches in the /CAs
path at that specified
directory. For example:
/opts/certs
private.key
public.crt
/CAs
my-ca.crt
Place the certificate file for each CA into the /CAs
subdirectory. Ensure all hosts in the MinIO deployment have a consistent
set of trusted CAs in that directory. If the MinIO Server cannot match
an incoming client's TLS certificate issuer against any of the available
CAs, the server rejects the connection as invalid.
macos
The MinIO Server validates the TLS certificate presented by each connecting client against the host system's trusted root certificate store.
You can place additional trusted Certificate Authority files in the following directory:
${HOME}/.minio/certs/CAs
Where ${HOME}
is the home directory of the user running
the MinIO Server process. You may need to create the
${HOME}/.minio/certs
directory if it does not exist.
For deployments started with a custom TLS directory minio server --certs-dir
,
the server searches in the /certs/CAs
path at that
specified directory.
Place the certificate file for each CA into the /CAs
subdirectory. Ensure all hosts in the MinIO deployment have a consistent
set of trusted CAs in that directory. If the MinIO Server cannot match
an incoming client's TLS certificate issuer against any of the available
CAs, the server rejects the connection as invalid.
windows
The MinIO Server validates the TLS certificate presented by each connecting client against the host system's trusted root certificate store.
You can place additional trusted Certificate Authority files in the following directory:
%%USERPROFILE%%\.minio\certs\CAs
Where %%USERPROFILE%%
is the location of the User
Profile folder of the user running the MinIO Server process.
For deployments started with a custom TLS directory minio server --certs-dir
,
the server searches in the \CAs
path at that specified
directory.
Place the certificate file for each CA into the /CAs
subdirectory. Ensure all hosts in the MinIO deployment have a consistent
set of trusted CAs in that directory. If the MinIO Server cannot match
an incoming client's TLS certificate issuer against any of the available
CAs, the server rejects the connection as invalid.
Self-signed, Internal, Private Certificates, and Public CAs with Intermediate Certificates
not k8s
If using Certificates signed by a non-global or non-public Certificate Authority, or if using a global CA that requires the use of intermediate certificates, you must provide those CAs to the MinIO Server. If the MinIO server does not have the necessary CAs, it may return warnings or errors related to TLS validation when connecting to other services.
Place the CA certificates in the /certs/CAs
folder. The
root path for this folder depends on whether you use the default
certificate path or a custom certificate path (minio server --certs-dir
or -S
)
Default Certificate Path
mv myCA.crt ${HOME}/.minio/certs/CAs
Custom Certificate Path
The following example assumes the MinIO Server was started with
--certs dir /opt/minio/certs
:
mv myCA.crt /opt/minio/certs/CAs/
For a self-signed certificate, the Certificate Authority is typically the private key used to sign the cert.
For certificates signed by an internal, private, or other non-global Certificate Authority, use the same CA that signed the cert. A non-global CA must include the full chain of trust from the intermediate certificate to the root.
If the provided file is not an X.509 certificate, MinIO ignores it and may return errors for validating certificates signed by that CA.
k8s
If deploying MinIO Tenants with certificates minted by a non-global or non-public Certificate Authority, or if using a global CA that requires the use of intermediate certificates, you must provide those CAs to the Operator to ensure it can trust those certificates.
The Operator may log warnings related to TLS cert validation for Tenants deployed with untrusted certificates.
The following procedure attaches a secret containing the
public.crt
of the Certificate Authority to the MinIO
Operator. You can specify multiple CAs in a single certificate, as long
as you maintain the BEGIN
and END
delimiters
as-is.
Create the
operator-ca-tls
secretThe following creates a Kubernetes secret in the MinIO Operator namespace (
minio-operator
).kubectl create secret generic operator-ca-tls \ --from-file=public.crt -n minio-operator
The
public.crt
file must correspond to a valid TLS certificate containing one or more CA definitions.Restart the Operator
Once created, you must restart the Operator to load the new CAs:
kubectl rollout restart deployments.apps/minio-operator -n minio-operator