Algorithms

Oberon PSA Crypto supports the following cryptographic algorithms, conforming to the relevant parts of the PSA Certified Crypto API specification:

Message digests (hashes)

  • SHA1
  • SHA2 (224, 256, 384, 512)
  • SHA3 (224, 256, 384, 512)
  • SHAKE256-512

Message authentication codes (MAC)

  • HMAC
  • AES-CMAC 

Unauthenticated ciphers

  • ChaCha20, XChaCha20
  • AES (CTR, ECB no padding, CBC no padding, CBC PKCS7, CCM* tag, KW, KWP)

Authenticated encryption with associated data (AEAD)

  • AES (CCM, GCM)
  • ChaCha20-Poly1305, XChaCha20-Poly1305

Key derivation

  • HKDF / HKDF extract / HKDF expand
  • PBKDF2-HMAC
  • PBKDF2-CMAC-PRF128
  • TLS-1.2 PRF
  • TLS-1.2 PSK-to-Mastersecret
  • NIST SP 800-108 counter-mode KDF (CMAC, HMAC)

Asymmetric signature

  • RSASSA (PKCS-v1.5, PSS)
  • ECDSA / deterministic ECDSA (P-224, P-256, P-384, P-521, secp256k1)
  • EdDSA (Ed25519, Ed448)
  • LMS / HSS signature verification only (SHA256, SHAKE256)
  • XMSS / XMSS^MT signature verification only (SHA256, SHAKE256)

Asymmetric encryption

  • RSAES (PKCS-v1.5, OAEP)

Key agreement

  • ECDH (P-224, P-256, P-384, P-521)
  • ECDH (X25519, X448)

Password-authenticated key exchange (PAKE)

  • EC-JPAKE (P-256)
  • SPAKE2+ (P-256, HMAC)
  • SRP-6 (SHA512)
  • WPA3-SAE

Random number generation

  • CTR-DRBG
  • HMAC-DRBG

The following cryptographic key sizes are supported:

  • AES: 128, 192, and 256 bit keys are supported for all uses of AES, except for PBKDF2-AES-CMAC-PRF128 which uses 128 bit keys.
  • RSA: 1, 1.5, 2, 3, 4, 6, and 8 kbit keys are supported for all uses of RSA.
  • NIST curves: P-224 (aka secp224r1), P-256 (aka secp256r1) and P-384 (aka secp384r1) support 224/256/384 bit keys.
  • Twisted Edwards curves: Ed25519 supports 255 bit keys.
  • Montgomery curves: X25519 supports 255 bit keys.
  • SRP-6: 3072 bit keys are supported.