JOSE v1.8.4 JOSE.JWA

JWA stands for JSON Web Algorithms which is defined in RFC 7518.

Cryptographic Algorithm Fallback

Native implementations of all cryptographic and public key algorithms required by the JWA specifications are not present in current versions of Elixir and OTP.

JOSE will detect whether a specific algorithm is natively supported or not and, by default, it will mark the algorithm as unsupported if a native implementation is not found.

However, JOSE also has pure Erlang versions of many of the missing algorithms which can be used as a fallback by calling JOSE.crypto_fallback/1 and passing true.

Summary

Functions

Returns the current module and first argument for the specified cipher

Decrypts cipher_text according to cipher block cipher

Decrypts cipher_text according to cipher block cipher

Encrypts plain_text according to cipher block cipher

Encrypts plain_text according to cipher block cipher

Performs a constant time comparison between two binaries to help avoid timing attacks

Returns the current block ciphers and their associated modules

Returns the current listing of supported :crypto and :public_key algorithms

Decrypts cipher_text using the private_key

Returns either :binary or :list depending on the detected runtime behavior for EC keys

Encrypts plain_text using the public_key

Checks whether the cipher is natively supported by :crypto or not

Checks whether ChaCha20/Poly1305 support is available or not

Checks whether the padding is natively supported by :public_key or not

Checks whether the padding is natively supported by :public_key or not

Signs the digested message using the digest_type and private_key

Returns the current listing of supported JOSE algorithms

Verifies the signature with the digested message using the digest_type and public_key

Functions

block_cipher(cipher)

Returns the current module and first argument for the specified cipher.

iex> JOSE.JWA.block_cipher({:aes_cbc, 128})
{:crypto, :aes_cbc128}
iex> JOSE.JWA.block_cipher({:aes_cbc, 192})
{:jose_jwa_unsupported, {:aes_cbc, 192}}
iex> JOSE.crypto_fallback(true)
:ok
iex> JOSE.JWA.block_cipher({:aes_cbc, 192})
{:jose_jwa_aes, {:aes_cbc, 192}}
block_decrypt(cipher, key, cipher_text)

Decrypts cipher_text according to cipher block cipher.

Currently supported block ciphers:

  • {:aes_ecb, 128} - AES ECB with 128-bit key size
  • {:aes_ecb, 192} - AES ECB with 192-bit key size
  • {:aes_ecb, 256} - AES ECB with 256-bit key size
block_decrypt(cipher, key, iv, cipher_text)

Decrypts cipher_text according to cipher block cipher.

Currently supported block ciphers:

  • {:aes_cbc, 128} - AES CBC with 128-bit key size and 128-bit iv size
  • {:aes_cbc, 192} - AES CBC with 192-bit key size and 128-bit iv size
  • {:aes_cbc, 256} - AES CBC with 256-bit key size and 128-bit iv size
  • {:aes_gcm, 128} - AES GCM with 128-bit key size and variable iv size
  • {:aes_gcm, 192} - AES GCM with 192-bit key size and variable iv size
  • {:aes_gcm, 256} - AES GCM with 256-bit key size and variable iv size
  • {:chacha20_poly1305, 256} - ChaCha20/Poly1305 with 256-bit key size and 96-bit iv size
block_encrypt(cipher, key, plain_text)

Encrypts plain_text according to cipher block cipher.

Currently supported block ciphers:

  • {:aes_ecb, 128} - AES ECB with 128-bit key size
  • {:aes_ecb, 192} - AES ECB with 192-bit key size
  • {:aes_ecb, 256} - AES ECB with 256-bit key size
block_encrypt(cipher, key, iv, plain_text)

Encrypts plain_text according to cipher block cipher.

Currently supported block ciphers:

  • {:aes_cbc, 128} - AES CBC with 128-bit key size and 128-bit iv size
  • {:aes_cbc, 192} - AES CBC with 192-bit key size and 128-bit iv size
  • {:aes_cbc, 256} - AES CBC with 256-bit key size and 128-bit iv size
  • {:aes_gcm, 128} - AES GCM with 128-bit key size and variable iv size
  • {:aes_gcm, 192} - AES GCM with 192-bit key size and variable iv size
  • {:aes_gcm, 256} - AES GCM with 256-bit key size and variable iv size
  • {:chacha20_poly1305, 256} - ChaCha20/Poly1305 with 256-bit key size and 96-bit iv size
constant_time_compare(a, b)

Performs a constant time comparison between two binaries to help avoid timing attacks.

crypto_ciphers()

Returns the current block ciphers and their associated modules.

iex> JOSE.JWA.crypto_ciphers()
[{{:aes_cbc, 128}, :crypto}, {{:aes_cbc, 192}, :crypto},
 {{:aes_cbc, 256}, :crypto}, {{:aes_ecb, 128}, :crypto},
 {{:aes_ecb, 192}, :crypto}, {{:aes_ecb, 256}, :crypto},
 {{:aes_gcm, 128}, :crypto}, {{:aes_gcm, 192}, :crypto},
 {{:aes_gcm, 256}, :crypto},
 {{:chacha20_poly1305, 256}, :jose_chacha20_poly1305}]
crypto_fallback()

See JOSE.crypto_fallback/0

crypto_fallback(boolean)

See JOSE.crypto_fallback/1

crypto_supports()

Returns the current listing of supported :crypto and :public_key algorithms.

iex> JOSE.JWA.crypto_supports()
[ciphers: [aes_cbc: 128, aes_cbc: 192, aes_cbc: 256, aes_ecb: 128, aes_ecb: 192,
  aes_ecb: 256, aes_gcm: 128, aes_gcm: 192, aes_gcm: 256,
  chacha20_poly1305: 256],
 hashs: [:md5, :poly1305, :sha, :sha256, :sha384, :sha512, :shake256],
 public_keys: [:ec_gf2m, :ecdh, :ecdsa, :ed25519, :ed25519ph, :ed448, :ed448ph,
  :rsa, :x25519, :x448], rsa_crypt: [:rsa1_5, :rsa_oaep, :rsa_oaep_256],
 rsa_sign: [:rsa_pkcs1_padding, :rsa_pkcs1_pss_padding]]
decrypt_private(cipher_text, private_key, options)

Decrypts cipher_text using the private_key.

Options

  • :rsa_padding - one of :rsa_pkcs1_oaep_padding or :rsa_pkcs1_padding
  • :rsa_oaep_md - sets the hashing algorithm for :rsa_pkcs1_oaep_padding, defaults to :sha
  • :rsa_oaep_label - sets the label for :rsa_pkcs1_oaep_padding, defaults to <<>>
ec_key_mode()

Returns either :binary or :list depending on the detected runtime behavior for EC keys.

encrypt_public(plain_text, public_key, options)

Encrypts plain_text using the public_key.

Options

  • :rsa_padding - one of :rsa_pkcs1_oaep_padding or :rsa_pkcs1_padding
  • :rsa_oaep_md - sets the hashing algorithm for :rsa_pkcs1_oaep_padding, defaults to :sha
  • :rsa_oaep_label - sets the label for :rsa_pkcs1_oaep_padding, defaults to <<>>
is_block_cipher_supported(cipher)

Checks whether the cipher is natively supported by :crypto or not.

is_chacha20_poly1305_supported()

Checks whether ChaCha20/Poly1305 support is available or not.

is_rsa_crypt_supported(padding)

Checks whether the padding is natively supported by :public_key or not.

is_rsa_sign_supported(padding)

Checks whether the padding is natively supported by :public_key or not.

sign(message, digest_type, private_key, options)

Signs the digested message using the digest_type and private_key.

Options

  • :rsa_padding - one of :rsa_pkcs1_pss_padding or :rsa_pkcs1_padding
  • :rsa_pss_saltlen - sets the salt length for :rsa_pkcs1_pss_padding, defaults to -2

    • -2 - use maximum for salt length
    • -1 - use hash length for salt length
    • any number higher than -1 is used as the actual salt length
supports()

Returns the current listing of supported JOSE algorithms.

iex> JOSE.JWA.supports()
[{:jwe,
  {:alg,
   ["A128GCMKW", "A128KW", "A192GCMKW", "A192KW", "A256GCMKW", "A256KW",
    "ECDH-ES", "ECDH-ES+A128KW", "ECDH-ES+A192KW", "ECDH-ES+A256KW",
    "PBES2-HS256+A128KW", "PBES2-HS384+A192KW", "PBES2-HS512+A256KW",
    "RSA-OAEP", "RSA-OAEP-256", "RSA1_5", "dir"]},
  {:enc,
   ["A128CBC-HS256", "A128GCM", "A192CBC-HS384", "A192GCM", "A256CBC-HS512",
    "A256GCM", "ChaCha20/Poly1305"]}, {:zip, ["DEF"]}},
 {:jwk, {:kty, ["EC", "OKP", "RSA", "oct"]},
  {:kty_OKP_crv,
   ["Ed25519", "Ed25519ph", "Ed448", "Ed448ph", "X25519", "X448"]}},
 {:jws,
  {:alg,
   ["ES256", "ES384", "ES512", "Ed25519", "Ed25519ph", "Ed448", "Ed448ph",
    "HS256", "HS384", "HS512", "PS256", "PS384", "PS512", "Poly1305", "RS256",
    "RS384", "RS512", "none"]}}]
unsecured_signing()

See JOSE.unsecured_signing/0

unsecured_signing(boolean)

See JOSE.unsecured_signing/1

verify(message, digest_type, signature, public_key, options)

Verifies the signature with the digested message using the digest_type and public_key.

Options

  • :rsa_padding - one of :rsa_pkcs1_pss_padding or :rsa_pkcs1_padding
  • :rsa_pss_saltlen - sets the salt length for :rsa_pkcs1_pss_padding, defaults to -2

    • -2 - use maximum for salt length
    • -1 - use hash length for salt length
    • any number higher than -1 is used as the actual salt length