Network Encryption (TLS)
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.
The MinIO server searches the following directory for TLS keys and certificates:
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
%%USERPROFILE%%\.minio\certs private.key public.crt
%%USERPROFILE%% is the location of the User Profile folder of the user running the MinIO Server process.
You can use the MinIO certgen to mint self-signed certificates for enabling TLS 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"
You can place the generated
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.
Multiple Domain-Based TLS Certificates
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)
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.
%%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 (SAN), this would reveal the
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.
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) 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 icon: