Cryptography

Summary

Pomerium uses cryptography to secure data in transit, at rest, and to provide guarantees around confidentiality, authenticity, and integrity between its services and upstream servers it manages access for.

Encryption at rest

Confidential data stored at rest is encrypted using the authenticated encryption with associated data construction XChaCha20-Poly1305 with 196-bit nonces. Nonces are randomly generated for every encrypted object. When data is read, the authentication tag is checked for tampering.

Encryption in transit

Data in transit is protected by Transport Layer Security (TLS). See our lab's SSL Labs report .

Downstream TLS

For downstream TLS (connections from the user's client to Pomerium)

• The minimum accepted version of TLS is 1.2.

• For TLS 1.2, the following cipher suites are offered, in this order:

  • ECDHE-ECDSA-AES256-GCM-SHA384
  • ECDHE-RSA-AES256-GCM-SHA384
  • ECDHE-ECDSA-AES128-GCM-SHA256
  • ECDHE-RSA-AES128-GCM-SHA256
  • ECDHE-ECDSA-CHACHA20-POLY1305
  • ECDHE-RSA-CHACHA20-POLY1305

• The following elliptic curves are offered, in this order:

  • X25519
  • secp256r1

Upstream TLS

For upstream TLS (connections from Pomerium to the application or service)

• The minimum accepted version of TLS is 1.2.

• For TLS 1.2, the following cipher suites are supported:

  • ECDHE-ECDSA-AES256-GCM-SHA384
  • ECDHE-RSA-AES256-GCM-SHA384
  • ECDHE-ECDSA-AES128-GCM-SHA256
  • ECDHE-RSA-AES128-GCM-SHA256
  • ECDHE-ECDSA-CHACHA20-POLY1305
  • ECDHE-RSA-CHACHA20-POLY1305
  • ECDHE-ECDSA-AES128-SHA
  • ECDHE-RSA-AES128-SHA
  • AES128-GCM-SHA256
  • AES128-SHA
  • ECDHE-ECDSA-AES256-SHA
  • ECDHE-RSA-AES256-SHA
  • AES256-GCM-SHA384
  • AES256-SHA

• The following elliptic curves are supported:

  • X25519
  • P-256
  • P-384
  • P-521

• HTTP Strict Transport Security (HSTS) with a long duration is used by default.

• Mutually authenticated TLS is used when client side certificates are provided.