JOSE v1.8.4 JOSE.JWE

JWE stands for JSON Web Encryption which is defined in RFC 7516.

Key Derivation Algorithms

The following key derivation algorithms for the "alg" field are currently supported by JOSE.JWE (some may need the JOSE.crypto_fallback/1 option to be enabled):

"A128GCMKW"
"A192GCMKW"
"A256GCMKW"
"A128KW"
"A192KW"
"A256KW"
"dir"
"ECDH-ES"
"ECDH-ES+A128KW"
"ECDH-ES+A192KW"
"ECDH-ES+A256KW"
"PBES2-HS256+A128KW"
"PBES2-HS384+A192KW"
"PBES2-HS512+A256KW"
"RSA1_5"
"RSA-OAEP"
"RSA-OAEP-256"

Encryption Algorithms

The following encryption algorithms for the "enc" field are currently supported by JOSE.JWE (some may need the JOSE.crypto_fallback/1 option to be enabled):

"A128CBC-HS256"
"A192CBC-HS384"
"A256CBC-HS512"
"A128GCM"
"A192GCM"
"A256GCM"
"ChaCha20/Poly1305"

Compression Algorithms

The following compression algorithms for the "zip" field are currently supported by JOSE.JWE:

"DEF"

Key Derivation Examples

All of the examples below will use "enc" set to "A128GCM", "A192GCM", or "A256GCM" depending on the derived key size.

The octet key used will typically be all zeroes of the required size in the form of <<0::128>> (for a 128-bit key).

All of the example keys generated below can be found here: https://gist.github.com/potatosalad/dd140560b2bdbdab886d

# octet keys we'll use below
jwk_oct128 = JOSE.JWK.from_oct(<<0::128>>)
jwk_oct192 = JOSE.JWK.from_oct(<<0::192>>)
jwk_oct256 = JOSE.JWK.from_oct(<<0::256>>)
jwk_secret = JOSE.JWK.from_oct("secret")

# EC keypairs we'll use below
jwk_ec256_alice_sk = JOSE.JWK.generate_key({:ec, :secp256r1})
jwk_ec256_alice_pk = JOSE.JWK.to_public(jwk_ec256_alice_sk)
jwk_ec256_bob_sk   = JOSE.JWK.generate_key({:ec, :secp256r1})
jwk_ec256_bob_pk   = JOSE.JWK.to_public(jwk_ec256_bob_sk)

# X25519 keypairs we'll use below
jwk_x25519_alice_sk = JOSE.JWK.generate_key({:okp, :X25519})
jwk_x25519_alice_pk = JOSE.JWK.to_public(jwk_x25519_alice_sk)
jwk_x25519_bob_sk   = JOSE.JWK.generate_key({:okp, :X25519})
jwk_x25519_bob_pk   = JOSE.JWK.to_public(jwk_x25519_bob_sk)

# X448 keypairs we'll use below
jwk_x448_alice_sk = JOSE.JWK.generate_key({:okp, :X448})
jwk_x448_alice_pk = JOSE.JWK.to_public(jwk_x448_alice_sk)
jwk_x448_bob_sk   = JOSE.JWK.generate_key({:okp, :X448})
jwk_x448_bob_pk   = JOSE.JWK.to_public(jwk_x448_bob_sk)

# RSA keypairs we'll use below
jwk_rsa_sk = JOSE.JWK.generate_key({:rsa, 4096})
jwk_rsa_pk = JOSE.JWK.to_public(jwk_rsa_sk)

A128GCMKW, A192GCMKW, and A256GCMKW

# A128GCMKW
iex> encrypted_a128gcmkw = JOSE.JWE.block_encrypt(jwk_oct128, "{}", %{ "alg" => "A128GCMKW", "enc" => "A128GCM" }) |> JOSE.JWE.compact |> elem(1)
"eyJhbGciOiJBMTI4R0NNS1ciLCJlbmMiOiJBMTI4R0NNIiwiaXYiOiJzODNFNjhPNjhsWlM5ZVprIiwidGFnIjoieF9Ea2M5dm1LMk5RQV8tU2hvTkFRdyJ9.8B2qX8fVEa-s61RsZXqkCg.J7yJ8sKLbUlzyor6.FRs.BhBwImTv9B14NwVuxmfU6A"
iex> JOSE.JWE.block_decrypt(jwk_oct128, encrypted_a128gcmkw) |> elem(0)
"{}"

# A192GCMKW
iex> encrypted_a192gcmkw = JOSE.JWE.block_encrypt(jwk_oct192, "{}", %{ "alg" => "A192GCMKW", "enc" => "A192GCM" }) |> JOSE.JWE.compact |> elem(1)
"eyJhbGciOiJBMTkyR0NNS1ciLCJlbmMiOiJBMTkyR0NNIiwiaXYiOiIxMkduZWQyTDB6NE5LZG83IiwidGFnIjoiM0thbG9iaER1Wmx5dE1YSjhjcXhZZyJ9.jJC4E1c6augIhvGDp3fquRfO-mnnud4F.S2NkKNGxBKTsCnKo.gZA.MvfhqSTeEN75H8HDyvfzRQ"
iex> JOSE.JWE.block_decrypt(jwk_oct192, encrypted_a192gcmkw) |> elem(0)
"{}"

# A256GCMKW
iex> encrypted_a256gcmkw = JOSE.JWE.block_encrypt(jwk_oct256, "{}", %{ "alg" => "A256GCMKW", "enc" => "A256GCM" }) |> JOSE.JWE.compact |> elem(1)
"eyJhbGciOiJBMjU2R0NNS1ciLCJlbmMiOiJBMjU2R0NNIiwiaXYiOiJHU3lFMTBLQURxZTczNUMzIiwidGFnIjoiR3dVbDJCbXRNWlVseDlXNEMtY0tQZyJ9.sSsbFw9z8WTkzBLvPMywSedTXXygFxfP9g5U2qpzUX8.eiVFfe7iojfK0AXb._v8.YVfk9dNrtS7wxbGqCVge-g"
iex> JOSE.JWE.block_decrypt(jwk_oct256, encrypted_a256gcmkw) |> elem(0)
"{}"

A128KW, A192KW, and A256KW

# A128KW
iex> encrypted_a128kw = JOSE.JWE.block_encrypt(jwk_oct128, "{}", %{ "alg" => "A128KW", "enc" => "A128GCM" }) |> JOSE.JWE.compact |> elem(1)
"eyJhbGciOiJBMTI4S1ciLCJlbmMiOiJBMTI4R0NNIn0.t4_Fb4kCl6BcS1cXnR4P4Xgm-jwVNsFl.RerKfWjzqqtLIUrz.JmE.ZDpVlWo-aQYM5la9eshwWw"
iex> JOSE.JWE.block_decrypt(jwk_oct128, encrypted_a128kw) |> elem(0)
"{}"

# A192KW
iex> encrypted_a192kw = JOSE.JWE.block_encrypt(jwk_oct192, "{}", %{ "alg" => "A192KW", "enc" => "A192GCM" }) |> JOSE.JWE.compact |> elem(1)
"eyJhbGciOiJBMTkyS1ciLCJlbmMiOiJBMTkyR0NNIn0.edpvNrztlNADbkwfq5YBJgqFBSH_Znv1Y1uXKNQ_13w.yCkEYTCPOKH6CoxZ.siw.zP_ZM9OEeX1FIdFjqNawtQ"
iex> JOSE.JWE.block_decrypt(jwk_oct192, encrypted_a192kw) |> elem(0)
"{}"

# A256KW
iex> encrypted_a256kw = JOSE.JWE.block_encrypt(jwk_oct256, "{}", %{ "alg" => "A256KW", "enc" => "A256GCM" }) |> JOSE.JWE.compact |> elem(1)
"eyJhbGciOiJBMjU2S1ciLCJlbmMiOiJBMjU2R0NNIn0.OvAhC1a2BoP_2SMIiZXwIHWPoIkD-Cosgp3nlpiTs8ySUBPfPzwG1g.4GeackYJbuBksAWA.HPE.vG0sGC2kuklH5xk8KXhyNA"
iex> JOSE.JWE.block_decrypt(jwk_oct256, encrypted_a256kw) |> elem(0)
"{}"

dir

The "dir" key derivation algorithm is essentially just a pass-through to the underlying "enc" algorithm.

The "encrypted_key" is not included in the protected header, so the key must be fully known by both parties.

# dir
iex> encrypted_dir = JOSE.JWE.block_encrypt(jwk_oct128, "{}", %{ "alg" => "dir", "enc" => "A128GCM" }) |> JOSE.JWE.compact |> elem(1)
"eyJhbGciOiJkaXIiLCJlbmMiOiJBMTI4R0NNIn0..HdRR8O0kk_SvOjAS.rxo.JTMPGPKZZKVNlWV0RexsmQ"
iex> JOSE.JWE.block_decrypt(jwk_oct128, encrypted_dir) |> elem(0)
"{}"

ECDH-ES, ECDH-ES+A128KW, ECDH-ES+A192KW, and ECDH-ES+A256KW

The "ECDH-ES" key derivation algorithm does not include the "encrypted_key" field in the protected header, similar to how "dir" functions.

The size of the generated key is dependent on the "enc" setting (for example, "A128GCM" will generate a 128-bit key, "A256GCM" a 256-bit key, etc).

# ECDH-ES with EC keypairs
iex> encrypted_ecdhes_ec256_alice2bob = JOSE.JWE.block_encrypt({jwk_ec256_bob_pk, jwk_ec256_alice_sk}, "{}", %{ "alg" => "ECDH-ES", "enc" => "A128GCM" }) |> JOSE.JWE.compact |> elem(1)
"eyJhbGciOiJFQ0RILUVTIiwiZW5jIjoiQTEyOEdDTSIsImVwayI6eyJjcnYiOiJQLTI1NiIsImt0eSI6IkVDIiwieCI6IjQ4UVUzUTBDeVN4d0piRXdXckpyWVhscDg4X2RWcEhUeHE0YXZjNjZoNVEiLCJ5IjoiWnpxcklOdE1NeEh4US1RQjcyUk1jZGxtRHNPSXdsS2hNcVZtX2dZV0MxNCJ9fQ..UssNrY5qEeFdluZY.R6g.32nlr0wHF2TwfL1UnBtIow"
iex> JOSE.JWE.block_decrypt({jwk_ec256_alice_pk, jwk_ec256_bob_sk}, encrypted_ecdhes_ec256_alice2bob) |> elem(0)
"{}"

# ECDH-ES with X25519 keypairs
iex> encrypted_ecdhes_x25519_alice2bob = JOSE.JWE.block_encrypt({jwk_x25519_bob_pk, jwk_x25519_alice_sk}, "{}", %{ "alg" => "ECDH-ES", "enc" => "A128GCM" }) |> JOSE.JWE.compact |> elem(1)
"eyJhbGciOiJFQ0RILUVTIiwiZW5jIjoiQTEyOEdDTSIsImVwayI6eyJjcnYiOiJYMjU1MTkiLCJrdHkiOiJPS1AiLCJ4IjoiZ0g3TjJwT0duenZfd0tBLUhqREZKTlVSZVhfdG05XzdiMkZSUjI3cXFYcyJ9fQ..T-0q42FPCUy3hlla.MHU.9TNP2jG5bN1vSvaesijdww"
iex> JOSE.JWE.block_decrypt({jwk_x25519_alice_pk, jwk_x25519_bob_sk}, encrypted_ecdhes_x25519_alice2bob) |> elem(0)
"{}"

# ECDH-ES with X448 keypairs
iex> encrypted_ecdhes_x448_alice2bob = JOSE.JWE.block_encrypt({jwk_x448_bob_pk, jwk_x448_alice_sk}, "{}", %{ "alg" => "ECDH-ES", "enc" => "A128GCM" }) |> JOSE.JWE.compact |> elem(1)
"eyJhbGciOiJFQ0RILUVTIiwiZW5jIjoiQTEyOEdDTSIsImVwayI6eyJjcnYiOiJYNDQ4Iiwia3R5IjoiT0tQIiwieCI6ImFFaHZISGxFM2V1Y3lsY0RNNzBMd1paY2dDRk9acXExNWM3YXZNMjJkcWZIUEtja1FZNmo3LXFfM19kMGI1cGVWZEFoNVoyQWZIWSJ9fQ..T-UNE-wOApuRH71r.Uj8.l8bIfhC1UPAPVWBV3wkc6A"
iex> JOSE.JWE.block_decrypt({jwk_x448_alice_pk, jwk_x448_bob_sk}, encrypted_ecdhes_x448_alice2bob) |> elem(0)
"{}"

When decrypting with any of the "ECDH-ES" related algorithms, the other party’s public key is recommended, but not required for decryption (the embedded Ephemeral Public Key will be used instead):

# decrypting the X448 example with and without the public key specified
iex> JOSE.JWE.block_decrypt({jwk_x448_alice_pk, jwk_x448_bob_sk}, encrypted_ecdhes_x448_alice2bob) |> elem(0)
"{}"
iex> JOSE.JWE.block_decrypt(jwk_x448_bob_sk, encrypted_ecdhes_x448_alice2bob) |> elem(0)
"{}"

The "ECDH-ES+A128KW", "ECDH-ES+A192KW", and "ECDH-ES+A256KW" key derivation algorithms do include the "encrypted_key" and the suffix after "ECDH-ES+" determines the key size (so "ECDH-ES+A128KW" computes a 128-bit key).

# ECDH-ES+A128KW with EC keypairs
iex> encrypted_ecdhesa128kw_alice2bob = JOSE.JWE.block_encrypt({jwk_ec256_bob_pk, jwk_ec256_alice_sk}, "{}", %{ "alg" => "ECDH-ES+A128KW", "enc" => "A128GCM" }) |> JOSE.JWE.compact |> elem(1)
"eyJhbGciOiJFQ0RILUVTK0ExMjhLVyIsImVuYyI6IkExMjhHQ00iLCJlcGsiOnsiY3J2IjoiUC0yNTYiLCJrdHkiOiJFQyIsIngiOiI0OFFVM1EwQ3lTeHdKYkV3V3JKcllYbHA4OF9kVnBIVHhxNGF2YzY2aDVRIiwieSI6Ilp6cXJJTnRNTXhIeFEtUUI3MlJNY2RsbURzT0l3bEtoTXFWbV9nWVdDMTQifX0.ZwuqXf7svd3SH0M-XYLjWz5JsN6xX03C.l8tt83EJjy86IovL.i5A.nw05dPUA0a18xdtvmHbhHA"
iex> JOSE.JWE.block_decrypt({jwk_ec256_alice_pk, jwk_ec256_bob_sk}, encrypted_ecdhesa128kw_alice2bob) |> elem(0)
"{}"

# ECDH-ES+A192KW with EC keypairs
iex> encrypted_ecdhesa192kw_alice2bob = JOSE.JWE.block_encrypt({jwk_ec256_bob_pk, jwk_ec256_alice_sk}, "{}", %{ "alg" => "ECDH-ES+A192KW", "enc" => "A192GCM" }) |> JOSE.JWE.compact |> elem(1)
"eyJhbGciOiJFQ0RILUVTK0ExOTJLVyIsImVuYyI6IkExOTJHQ00iLCJlcGsiOnsiY3J2IjoiUC0yNTYiLCJrdHkiOiJFQyIsIngiOiI0OFFVM1EwQ3lTeHdKYkV3V3JKcllYbHA4OF9kVnBIVHhxNGF2YzY2aDVRIiwieSI6Ilp6cXJJTnRNTXhIeFEtUUI3MlJNY2RsbURzT0l3bEtoTXFWbV9nWVdDMTQifX0.S9LZ1i_Lua_if4I83WcaCQ9yT5qqPI_NhCFR7tMiZDQ.kG3taKEjGeKDRTzs.H1s.oVGBFP63z4gd3e-R2d1cmA"
iex> JOSE.JWE.block_decrypt({jwk_ec256_alice_pk, jwk_ec256_bob_sk}, encrypted_ecdhesa192kw_alice2bob) |> elem(0)
"{}"

# ECDH-ES+A256KW with EC keypairs
iex> encrypted_ecdhesa256kw_alice2bob = JOSE.JWE.block_encrypt({jwk_ec256_bob_pk, jwk_ec256_alice_sk}, "{}", %{ "alg" => "ECDH-ES+A256KW", "enc" => "A256GCM" }) |> JOSE.JWE.compact |> elem(1)
"eyJhbGciOiJFQ0RILUVTK0EyNTZLVyIsImVuYyI6IkEyNTZHQ00iLCJlcGsiOnsiY3J2IjoiUC0yNTYiLCJrdHkiOiJFQyIsIngiOiI0OFFVM1EwQ3lTeHdKYkV3V3JKcllYbHA4OF9kVnBIVHhxNGF2YzY2aDVRIiwieSI6Ilp6cXJJTnRNTXhIeFEtUUI3MlJNY2RsbURzT0l3bEtoTXFWbV9nWVdDMTQifX0.4KWy1-vRiJyNINF6mWYbUPPTVNG9ADfvvfpSDbddPTftz7GmUHUsuQ.IkRhtGH23R-9dFF3.9yk.RnALhnqWMHWCZFxqc-DU4A"
iex> JOSE.JWE.block_decrypt({jwk_ec256_alice_pk, jwk_ec256_bob_sk}, encrypted_ecdhesa256kw_alice2bob) |> elem(0)
"{}"

See JOSE.JWK.box_encrypt/2 for generating an Ephemeral Public Key based on the same curve as the supplied other party key in the same step.

PBES2-HS256+A128KW, PBES2-HS384+A192KW, and PBES2-HS512+A256KW

# PBES2-HS256+A128KW
iex> encrypted_pbes2hs256a128kw = JOSE.JWE.block_encrypt(jwk_secret, "{}", %{ "alg" => "PBES2-HS256+A128KW", "enc" => "A128GCM" }) |> JOSE.JWE.compact |> elem(1)
"eyJhbGciOiJQQkVTMi1IUzI1NitBMTI4S1ciLCJlbmMiOiJBMTI4R0NNIiwicDJjIjo0MDk2LCJwMnMiOiJRR0laNTlzbjRnQThySHBWYjFrSkd3In0.8WMQ0fysLiHU8AjpjkcqJGpYe53VRf2s.vVEb2ZtKmtPIw8M-.Cmg.GCjDtdKV6khqEuyZy2gUxw"
iex> JOSE.JWE.block_decrypt(jwk_secret, encrypted_pbes2hs256a128kw) |> elem(0)
"{}"

# PBES2-HS384+A192KW
iex> encrypted_pbes2hs384a192kw = JOSE.JWE.block_encrypt(jwk_secret, "{}", %{ "alg" => "PBES2-HS384+A192KW", "enc" => "A192GCM" }) |> JOSE.JWE.compact |> elem(1)
"eyJhbGciOiJQQkVTMi1IUzM4NCtBMTkyS1ciLCJlbmMiOiJBMTkyR0NNIiwicDJjIjo2MTQ0LCJwMnMiOiJKSDRjZ0hlNTZiU0prZ1d6VktpWWJCb0FzWEJBY1A1NiJ9.Ck5GvgXxmyac3jzs0lRavoRh6tI9nEs3lYkx8sdDzGw.IdxaPATMkQ8FYiYQ.uHk.rDU6ltWsTsw9vuvA73bgJQ"
iex> JOSE.JWE.block_decrypt(jwk_secret, encrypted_pbes2hs384a192kw) |> elem(0)
"{}"

# PBES2-HS512+A256KW
iex> encrypted_pbes2hs512a256kw = JOSE.JWE.block_encrypt(jwk_secret, "{}", %{ "alg" => "PBES2-HS512+A256KW", "enc" => "A256GCM" }) |> JOSE.JWE.compact |> elem(1)
"eyJhbGciOiJQQkVTMi1IUzUxMitBMjU2S1ciLCJlbmMiOiJBMjU2R0NNIiwicDJjIjo4MTkyLCJwMnMiOiJ6YWRiMVNmT1F4V1gyTHJrSVgwWDFGM2QzNlBIdUdxRVFzUDVhbWVnTk00In0.6SUVO9sSevqZrZ5yPX-JvJNJrzfIQeTTzrkWBHEqHra1_AITtwEe0A.0AaF_3ZlJOkRlqgb.W8I.jFWob73QTn52IFSIPEWHFA"
iex> JOSE.JWE.block_decrypt(jwk_secret, encrypted_pbes2hs512a256kw) |> elem(0)
"{}"

The "p2s" and "p2i" fields may also be specified to control the Salt and Iterations of the PBES2 Key Derivation Function, respectively.

The default Salt is a randomly generated binary the same length of bytes as the key wrap (for example, "PBES2-HS256+A128KW" will generate a 16-byte Salt).

The default Iterations is 32 times the number of bits specified by the key wrap (for example, "PBES2-HS256+A128KW" will have 4096 Iterations).

# let's setup the JWE header
iterations = 8192
salt = <<0::256>> # all zero salt, for example usage only
jwe = %{
  "alg" => "PBES2-HS256+A128KW",
  "enc" => "A128GCM",
  "p2i" => iterations,
  "p2s" => :base64url.encode(salt)
}
# PBES2-HS256+A128KW
iex> encrypted_pbes2 = JOSE.JWE.block_encrypt(jwk_secret, "{}", jwe) |> JOSE.JWE.compact |> elem(1)
"eyJhbGciOiJQQkVTMi1IUzI1NitBMTI4S1ciLCJlbmMiOiJBMTI4R0NNIiwicDJjIjo0MDk2LCJwMmkiOjgxOTIsInAycyI6IkFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUFBQUEifQ.I7wcBmg7O_rOWpg1aak7wQWX84YtED6k.Rgh3f6Kzl5SZ1z7x.FNo.eyK1ySx4SGR-xC2EYNySQA"
iex> JOSE.JWE.block_decrypt(jwk_secret, encrypted_pbes2) |> elem(0)
"{}"

RSA1_5, RSA-OAEP, and RSA-OAEP-256

# RSA1_5
iex> encrypted_rsa1_5 = JOSE.JWE.block_encrypt(jwk_rsa_pk, "{}", %{ "alg" => "RSA1_5", "enc" => "A128GCM" }) |> JOSE.JWE.compact |> elem(1)
"eyJhbGciOiJSU0ExXzUiLCJlbmMiOiJBMTI4R0NNIn0.NlndPTqULN1vArshEzfEXY0nHCf4ubsTK9iHAeIxL85fReYrYG8EDB2_IirUneavvHSa-hsVLXNzBu0F9OY3TRFAIuJ8Jt1tqZZEhHZ97vzTEIjdlPNctGNI11-mhNCJ0doSvx9T4ByngaAFtJnRoR2cqbJkJFGja60fHtO0CfKLW5XzPf0NAhr8Tof-5IJfbNpMcC_LdCItJ6i8cuj4i5pG_CikOKDrNzbaBP72200_kl_-YaLDMA4tVb2YjWksY5Vau0Hz16QvI9QwDIcIDLYPAlTlDrU7s_FfmO_89S9Z69-lc_OBG7x2CYzIhB-0wzx753nZRl_WNJKi1Ya_AV552FEqVUhR-SuKcyrTA9OwkKC2JoL3lFqsCL9jkZkBrVREQlT0cxNI_AInyx5FHNLBbdtkz0JQbvzMJ854RP0V_eTlI5u8DZ42aOTRMBLHPi-4gP0J_CGWyKDQreXEEF6LSuLJb1cGk-NX1Vd85aARstQPuOoy7pWJjPvBEKEib70fjkUuMA0Atid-5BusQLKc1H-D6c5HIFH0DgYtXhN6AtQ_fmqw1F_X1JrGnYiYGzJCD2hh0Yt2UJZoCuHlPKk8aM5L3lNU3AISb1soSQl3hfX8Skb817ffC7jYezdhZc12cRNzOPAYqJYjN2eDlQhx-gpFjVzc-W1bFG8Yijo.grliT3M1iZ48aSY9.F4Y.pBRqIGZ4Q_fI1kmeAggvRg"
iex> JOSE.JWE.block_decrypt(jwk_rsa_sk, encrypted_rsa1_5) |> elem(0)
"{}"

# RSA-OAEP
iex> encrypted_rsaoaep = JOSE.JWE.block_encrypt(jwk_rsa_pk, "{}", %{ "alg" => "RSA-OAEP", "enc" => "A128GCM" }) |> JOSE.JWE.compact |> elem(1)
"eyJhbGciOiJSU0EtT0FFUCIsImVuYyI6IkExMjhHQ00ifQ.YZfGKTTU2KuvwIMpSYadbNmGzWIbLrwRYD8JvZAWkvcnFeky09S04VadRNPXmCBSl4EF1K7oBm0fiYXuvNbLFNKYT_Jo_y6Lb-XsP--BZKaEcq6wIdZ4-xTJ7YYX5dfco_cMknZLG8W2sQRwtWopisn9NyzSpfGNlYqeJqjpoJy0qnO8yZeEYeadwoVF9-XZfYwvMjEt7HORqBIPF1JIaOYTQ-LQBvya6XYhOR7dkSnuCZ_ITGW5ZbPvzOILSMW_3Ixe78ncfO2gxF6AiLh02oTLsOSrF9xDlJvuU0k1TdkNWtGroeP_WVbXEO7O_GI5LVW-cDzoVm5ZCQs2Df0018-qDxFyY9xhKS9aNDi_btiarstXMSz3EkOfPhWR_IzlVyUkYnzs3GS993gKLQ0Tk-ipvOT9Bcw9VTLLK3-f5YSkf51IA---hPFlxVlboH9bmTXlT4JzSbErQEYp3JuXjOP7FQn0OPko5Utqbbm41XBEJhUpBNhjrBGDspsMxML_eJdyzBgA5UyNfdCEQ2vM1pCegxG_hSKAhCKVNn71wW4O_y_eqUcoyhjB7HtVxiF29jzNUKF-y14171L4-mxsIpixaM1ofnayWMiherVP0Wz2MXkzWB0AUv8c3kNEJIh3oeyrczWwzpmeCh1Bq7-J4D6aaFjyGFcm-03_QZmfwho.ymxveKBeRuaZ8HzD.3H4.6oKLh2NouhPGpO1dmA-tTg"
iex> JOSE.JWE.block_decrypt(jwk_rsa_sk, encrypted_rsaoaep) |> elem(0)
"{}"

# RSA-OAEP-256
iex> encrypted_rsaoaep256 = JOSE.JWE.block_encrypt(jwk_rsa_pk, "{}", %{ "alg" => "RSA-OAEP-256", "enc" => "A128GCM" }) |> JOSE.JWE.compact |> elem(1)
"eyJhbGciOiJSU0EtT0FFUC0yNTYiLCJlbmMiOiJBMTI4R0NNIn0.OW9Hy9qpOIgVueODQXcWIUw_-Sm3UFGtxosyOAaI6JUQFt8q-iEtKkUp4NHrOlczO6tP5t8zRKdNXFfCm9QZk6F9PsSO-NzE2-DV1ANAMck-CDfGTK0mwG5U_KZwlObSgU0gxf87K49Wuno1rWlHWzJb__C_hCJXi_aQW17tLmbuTpJMkB0NTCKX3y6QaxvynP98jqwMJT6uGmE3AeuZYhPGzAOWbltbWyw-TqWqyLJirAUY_fvDNsKt1TDrTd9216TK5y7RQeUtdGfbuYK9lt2TIwfh9ycAHd7SANH_YJc2cKYa3e6CgqnQAjVpbhpogBz5sz5HaK95XYbXOdnYyHQ00gS44YquiQCvX331UgEWnthtmYwDZfnCxTkPydafGOBsjaagGvV2tQtxUKW3JmVChF97bNj5lQZ7rAkyooxx-k3IMT0005x6_74O5tXGN5fb7oyT3Mx_NZ5dKzlYAA_V8oOpNslaFhV5K5Q_-hRkUsEPWdaD5s2uS9Z7l7ot39CzzTKDj65f2eCTWFReFKOjhabCL4ZiFXbElB3dA3y5FdxXPAfe6N31G9ynalx1JIcrEaRb8sdqk6U6uC3s3DpkoRSnp3osBJOxxuk_Lgb-ZM9d8UuRVj4W78-qjfX_lcG1RlRmlYoDIU03ly0UfRWi-7HmpPECrGTsGZEfULg.J-txckmMXEi-bZVh.Rbw.D7UpSkticmDCGiNyLVggLg"
iex> JOSE.JWE.block_decrypt(jwk_rsa_sk, encrypted_rsaoaep256) |> elem(0)
"{}"

Encryption Examples

All of the examples below will use "alg" set to "dir" passing the key directly to the Encryption Algorithm.

The octet key used will typically be all zeroes of the required size in the form of <<0::128>> (for a 128-bit key).

All of the example keys generated below can be found here: https://gist.github.com/potatosalad/dd140560b2bdbdab886d

# octet keys we'll use below
jwk_oct128 = JOSE.JWK.from_oct(<<0::128>>)
jwk_oct192 = JOSE.JWK.from_oct(<<0::192>>)
jwk_oct256 = JOSE.JWK.from_oct(<<0::256>>)
jwk_oct384 = JOSE.JWK.from_oct(<<0::384>>)
jwk_oct512 = JOSE.JWK.from_oct(<<0::512>>)

A128CBC-HS256, A192CBC-HS384, and A256CBC-HS512

# A128CBC-HS256
iex> encrypted_a128cbchs256 = JOSE.JWE.block_encrypt(jwk_oct256, "{}", %{ "alg" => "dir", "enc" => "A128CBC-HS256" }) |> JOSE.JWE.compact |> elem(1)
"eyJhbGciOiJkaXIiLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0..bxps64-UIQoFvhkjr05e9A.HrtJ3AqrqJ4f5PHjGseHYw.kopJoTDxk34IVhheoToLSA"
iex> JOSE.JWE.block_decrypt(jwk_oct256, encrypted_a128cbchs256) |> elem(0)
"{}"

# A192CBC-HS384
iex> encrypted_a192cbchs384 = JOSE.JWE.block_encrypt(jwk_oct384, "{}", %{ "alg" => "dir", "enc" => "A192CBC-HS384" }) |> JOSE.JWE.compact |> elem(1)
"eyJhbGciOiJkaXIiLCJlbmMiOiJBMTkyQ0JDLUhTMzg0In0..3zSCHwvHrcxsNyssIgEBRA.XB70tUoQZlnOgY5ygMxfKA.Avl7Z8jCpShh3_iTcPcU3Woh6E9ykNyB"
iex> JOSE.JWE.block_decrypt(jwk_oct384, encrypted_a192cbchs384) |> elem(0)
"{}"

# A256CBC-HS512
iex> encrypted_a256cbchs512 = JOSE.JWE.block_encrypt(jwk_oct512, "{}", %{ "alg" => "dir", "enc" => "A256CBC-HS512" }) |> JOSE.JWE.compact |> elem(1)
"eyJhbGciOiJkaXIiLCJlbmMiOiJBMjU2Q0JDLUhTNTEyIn0..mqMhkWAMF7HmW_Nu1ERUzQ.bzd-tmykuru0Lu_rsNZ2ow.mlOFO8JcC_UJ35TsZgiUeEwAjRDs6cwfN7Umyzm7mmY"
iex> JOSE.JWE.block_decrypt(jwk_oct512, encrypted_a256cbchs512) |> elem(0)
"{}"

A128GCM, A192GCM, and A256GCM

# A128GCM
iex> encrypted_a128gcm = JOSE.JWE.block_encrypt(jwk_oct128, "{}", %{ "alg" => "dir", "enc" => "A128GCM" }) |> JOSE.JWE.compact |> elem(1)
"eyJhbGciOiJkaXIiLCJlbmMiOiJBMTI4R0NNIn0..pPF4SbzGZwxS1J-M.Ic0.qkHuC-hOO44HPlykBJLSsA"
iex> JOSE.JWE.block_decrypt(jwk_oct128, encrypted_a128gcm) |> elem(0)
"{}"

# A192GCM
iex> encrypted_a192gcm = JOSE.JWE.block_encrypt(jwk_oct192, "{}", %{ "alg" => "dir", "enc" => "A192GCM" }) |> JOSE.JWE.compact |> elem(1)
"eyJhbGciOiJkaXIiLCJlbmMiOiJBMTkyR0NNIn0..muNgk2GFW9ATwqqZ.bvE.gYvC0G6DAodJdyrUqLw7Iw"
iex> JOSE.JWE.block_decrypt(jwk_oct192, encrypted_a192gcm) |> elem(0)
"{}"

# A256GCM
iex> encrypted_a256gcm = JOSE.JWE.block_encrypt(jwk_oct256, "{}", %{ "alg" => "dir", "enc" => "A256GCM" }) |> JOSE.JWE.compact |> elem(1)
"eyJhbGciOiJkaXIiLCJlbmMiOiJBMjU2R0NNIn0..rDTJhd5ja5pDAYtn.PrM.MQdLgiVXQsG_cLas93ZEHw"
iex> JOSE.JWE.block_decrypt(jwk_oct256, encrypted_a256gcm) |> elem(0)
"{}"

ChaCha20/Poly1305

This is highly experimental and based on RFC 7539.

# ChaCha20/Poly1305
iex> encrypted_chacha20_poly1305 = JOSE.JWE.block_encrypt(jwk_oct256, "{}", %{ "alg" => "dir", "enc" => "ChaCha20/Poly1305" }) |> JOSE.JWE.compact |> elem(1)
"eyJhbGciOiJkaXIiLCJlbmMiOiJDaGFDaGEyMC9Qb2x5MTMwNSJ9..gunc-Xr1t1jqZX1l.8Yc.yi9qKB4ANjfQCPjgYwf-zQ"
iex> JOSE.JWE.block_decrypt(jwk_oct256, encrypted_chacha20_poly1305) |> elem(0)
"{}"

Compression Examples

All of the examples below will use "alg" set to "dir" passing the key directly to the Encryption Algorithm ("enc" is set to "A128GCM").

The octet key used will typically be all zeroes of the required size in the form of <<0::128>> (for a 128-bit key).

All of the example keys generated below can be found here: https://gist.github.com/potatosalad/dd140560b2bdbdab886d

# octet keys we'll use below
jwk_oct128 = JOSE.JWK.from_oct(<<0::128>>)

DEF

# DEF
iex> encrypted_def = JOSE.JWE.block_encrypt(jwk_oct128, "{}", %{ "alg" => "dir", "enc" => "A128GCM", "zip" => "DEF" }) |> JOSE.JWE.compact |> elem(1)
"eyJhbGciOiJkaXIiLCJlbmMiOiJBMTI4R0NNIiwiemlwIjoiREVGIn0..Vvr0vlKWE9rAJ8CR.UpOz7w10Uc9pMg.Pctxzz0ijPSOY8zyRcbjww"
iex> JOSE.JWE.block_decrypt(jwk_oct128, encrypted_def) |> elem(0)
"{}"

Summary

Types

t()

Functions

block_decrypt(jwk, encrypted)

Decrypts the encrypted binary or map using the jwk

block_encrypt(jwk, plain_text, jwe)

Encrypts plain_text using the jwk and algorithm specified by the jwe by getting the cek for block_encrypt/4

block_encrypt(jwk, plain_text, cek, jwe)

Encrypts plain_text using the jwk, cek, and algorithm specified by the jwe by getting the iv for block_encrypt/5

block_encrypt(jwk, plain_text, cek, iv, jwe)

Encrypts the plain_text using the jwk, cek, iv, and algorithm specified by the jwe

compact(encrypted)

Compacts an expanded encrypted map into a binary

compress(plain_text, jwe)

Compresses the plain_text using the "zip" algorithm specified by the jwe

expand(encrypted)

Expands a compacted encrypted binary into a map

from(list)

Converts a binary or map into a JOSE.JWE

from_binary(list)

Converts a binary into a JOSE.JWE

from_file(file)

Reads file and calls from_binary/1 to convert into a JOSE.JWE

from_map(list)

Converts a map into a JOSE.JWE

from_record(jose_jwe)

Converts a :jose_jwe record into a JOSE.JWE

generate_key(list)

Generates a new JOSE.JWK based on the algorithms of the specified JOSE.JWE

key_decrypt(jwk, encrypted_key, jwe)

Decrypts the encrypted_key using the jwk and the "alg" and "enc" specified by the jwe

key_encrypt(jwk, decrypted_key, jwe)

Encrypts the decrypted_key using the jwk and the "alg" and "enc" specified by the jwe

merge(left, right)

Merges map on right into map on left

next_cek(jwk, jwe)

Returns the next cek using the jwk and the "alg" and "enc" specified by the jwe

next_iv(jwe)

Returns the next iv the "alg" and "enc" specified by the jwe

to_binary(list)

Converts a JOSE.JWE into a binary

to_file(file, any)

Calls to_binary/1 on a JOSE.JWE and then writes the binary to file

to_map(list)

Converts a JOSE.JWE into a map

to_record(list)

Converts a JOSE.JWE struct to a :jose_jwe record

uncompress(cipher_text, jwe)

Uncompresses the cipher_text using the "zip" algorithm specified by the jwe

Types

t()

t() :: %JOSE.JWE{alg: term, enc: term, fields: term, zip: term}

Functions

block_decrypt(jwk, encrypted)

Decrypts the encrypted binary or map using the jwk.

iex> jwk = JOSE.JWK.from(%{"k" => "STlqtIOhWJjoVnYjUjxFLZ6oN1oB70QARGSTWQ_5XgM", "kty" => "oct"})
%JOSE.JWK{fields: %{}, keys: :undefined,
 kty: {:jose_jwk_kty_oct,
  <<73, 57, 106, 180, 131, 161, 88, 152, 232, 86, 118, 35, 82, 60, 69, 45, 158, 168, 55, 90, 1, 239, 68, 0, 68, 100, 147, 89, 15, 249, 94, 3>>}}
iex> JOSE.JWE.block_decrypt(jwk, "eyJhbGciOiJkaXIiLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0..jBt5tTa1Q0N3uFPEkf30MQ.Ei49MvTLLje7bsZ5EZCZMA.gMWOAmhZSq9ksHCZm6VSoA")
{"{}",
 %JOSE.JWE{alg: {:jose_jwe_alg_dir, :dir},
  enc: {:jose_jwe_enc_aes,
   {:jose_jwe_enc_aes, {:aes_cbc, 128}, 256, 32, 16, 16, 16, 16, :sha256}},
  fields: %{}, zip: :undefined}}

See block_encrypt/2.

block_encrypt(jwk, plain_text, jwe)

Encrypts plain_text using the jwk and algorithm specified by the jwe by getting the cek for block_encrypt/4.

block_encrypt(jwk, plain_text, cek, jwe)

Encrypts plain_text using the jwk, cek, and algorithm specified by the jwe by getting the iv for block_encrypt/5.

block_encrypt(jwk, plain_text, cek, iv, jwe)

Encrypts the plain_text using the jwk, cek, iv, and algorithm specified by the jwe.

iex> jwk = JOSE.JWK.from(%{"k" => "STlqtIOhWJjoVnYjUjxFLZ6oN1oB70QARGSTWQ_5XgM", "kty" => "oct"})
%JOSE.JWK{fields: %{}, keys: :undefined,
 kty: {:jose_jwk_kty_oct,
  <<73, 57, 106, 180, 131, 161, 88, 152, 232, 86, 118, 35, 82, 60, 69, 45, 158, 168, 55, 90, 1, 239, 68, 0, 68, 100, 147, 89, 15, 249, 94, 3>>}}
iex> JOSE.JWE.block_encrypt(jwk, "{}", %{ "alg" => "dir", "enc" => "A128CBC-HS256" })
{%{alg: :jose_jwe_alg_dir, enc: :jose_jwe_enc_aes},
 %{"ciphertext" => "Ei49MvTLLje7bsZ5EZCZMA", "encrypted_key" => "",
   "iv" => "jBt5tTa1Q0N3uFPEkf30MQ",
   "protected" => "eyJhbGciOiJkaXIiLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0",
   "tag" => "gMWOAmhZSq9ksHCZm6VSoA"}}

See block_decrypt/2.

compact(encrypted)

Compacts an expanded encrypted map into a binary.

iex> JOSE.JWE.compact(%{"ciphertext" => "Ei49MvTLLje7bsZ5EZCZMA", "encrypted_key" => "",
 "iv" => "jBt5tTa1Q0N3uFPEkf30MQ",
 "protected" => "eyJhbGciOiJkaXIiLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0",
 "tag" => "gMWOAmhZSq9ksHCZm6VSoA"})
{%{},
 "eyJhbGciOiJkaXIiLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0..jBt5tTa1Q0N3uFPEkf30MQ.Ei49MvTLLje7bsZ5EZCZMA.gMWOAmhZSq9ksHCZm6VSoA"}

See expand/1.

compress(plain_text, jwe)

Compresses the plain_text using the "zip" algorithm specified by the jwe.

iex> JOSE.JWE.compress("{}", %{ "alg" => "dir", "zip" => "DEF" })
<<120, 156, 171, 174, 5, 0, 1, 117, 0, 249>>

See uncompress/2.

expand(encrypted)

Expands a compacted encrypted binary into a map.

iex> JOSE.JWE.expand("eyJhbGciOiJkaXIiLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0..jBt5tTa1Q0N3uFPEkf30MQ.Ei49MvTLLje7bsZ5EZCZMA.gMWOAmhZSq9ksHCZm6VSoA")
{%{},
 %{"ciphertext" => "Ei49MvTLLje7bsZ5EZCZMA", "encrypted_key" => "",
   "iv" => "jBt5tTa1Q0N3uFPEkf30MQ",
   "protected" => "eyJhbGciOiJkaXIiLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0",
   "tag" => "gMWOAmhZSq9ksHCZm6VSoA"}}

See compact/1.

from(list)

Converts a binary or map into a JOSE.JWE.

iex> JOSE.JWE.from(%{ "alg" => "dir" })
%JOSE.JWE{alg: {:jose_jwe_alg_dir, :dir}, enc: :undefined, fields: %{},
 zip: :undefined}
iex> JOSE.JWE.from("{"alg":"dir"}")
%JOSE.JWE{alg: {:jose_jwe_alg_dir, :dir}, enc: :undefined, fields: %{},
 zip: :undefined}

There are 3 keys which can have custom modules defined for them:

"alg" - must implement :jose_jwe and :jose_jwe_alg behaviours
"enc" - must implement :jose_jwe and :jose_jwe_enc behaviours
"zip" - must implement :jose_jwe and :jose_jwe_zip behaviours

For example:

iex> JOSE.JWE.from({%{ zip: MyCustomCompress }, %{ "alg" => "dir", "zip" => "custom" }})
%JOSE.JWE{alg: {:jose_jwe_alg_dir, :dir}, enc: :undefined, fields: %{},
 zip: {MyCustomCompress, :state}}

from_binary(list)

Converts a binary into a JOSE.JWE.

from_file(file)

Reads file and calls from_binary/1 to convert into a JOSE.JWE.

from_map(list)

Converts a map into a JOSE.JWE.

from_record(jose_jwe)

Converts a :jose_jwe record into a JOSE.JWE.

generate_key(list)

Generates a new JOSE.JWK based on the algorithms of the specified JOSE.JWE.

iex> JOSE.JWE.generate_key(%{"alg" => "dir", "enc" => "A128GCM"})
%JOSE.JWK{fields: %{"alg" => "dir", "enc" => "A128GCM", "use" => "enc"},
 keys: :undefined,
 kty: {:jose_jwk_kty_oct,
  <<188, 156, 171, 224, 232, 231, 41, 250, 210, 117, 112, 219, 134, 218, 94, 50>>}}

key_decrypt(jwk, encrypted_key, jwe)

Decrypts the encrypted_key using the jwk and the "alg" and "enc" specified by the jwe.

# let's define our jwk and encrypted_key
jwk = JOSE.JWK.from(%{"k" => "idN_YyeYZqEE7BkpexhA2Q", "kty" => "oct"})
enc = <<27, 123, 126, 121, 56, 105, 105, 81, 140, 76, 30, 2, 14, 92, 231, 174, 203, 196, 110, 204, 57, 238, 248, 73>>

iex> JOSE.JWE.key_decrypt(jwk, enc, %{ "alg" => "A128KW", "enc" => "A128CBC-HS256" })
<<134, 82, 15, 176, 181, 115, 173, 19, 13, 44, 189, 185, 187, 125, 28, 240>>

See key_encrypt/3.

key_encrypt(jwk, decrypted_key, jwe)

Encrypts the decrypted_key using the jwk and the "alg" and "enc" specified by the jwe.

# let's define our jwk and cek (or decrypted_key)
jwk = JOSE.JWK.from(%{"k" => "idN_YyeYZqEE7BkpexhA2Q", "kty" => "oct"})            # JOSE.JWK.generate_key({:oct, 16})
cek = <<134, 82, 15, 176, 181, 115, 173, 19, 13, 44, 189, 185, 187, 125, 28, 240>> # :crypto.rand_bytes(16)

iex> JOSE.JWE.key_encrypt(jwk, cek, %{ "alg" => "A128KW", "enc" => "A128CBC-HS256" })
{<<27, 123, 126, 121, 56, 105, 105, 81, 140, 76, 30, 2, 14, 92, 231, 174, 203, 196, 110, 204, 57, 238, 248, 73>>,
 %JOSE.JWE{alg: {:jose_jwe_alg_aes_kw,
   {:jose_jwe_alg_aes_kw, 128, false, :undefined, :undefined}},
  enc: {:jose_jwe_enc_aes,
   {:jose_jwe_enc_aes, {:aes_cbc, 128}, 256, 32, 16, 16, 16, 16, :sha256}},
  fields: %{}, zip: :undefined}}

See key_decrypt/3.

merge(left, right)

Merges map on right into map on left.

next_cek(jwk, jwe)

Returns the next cek using the jwk and the "alg" and "enc" specified by the jwe.

# let's define our jwk
jwk = JOSE.JWK.from(%{"k" => "idN_YyeYZqEE7BkpexhA2Q", "kty" => "oct"}) # JOSE.JWK.generate_key({:oct, 16})

iex> JOSE.JWE.next_cek(jwk, %{ "alg" => "A128KW", "enc" => "A128CBC-HS256" })
<<37, 83, 139, 165, 44, 23, 163, 186, 255, 155, 183, 17, 220, 211, 80, 247, 239, 149, 194, 53, 134, 41, 254, 176, 0, 247, 66, 38, 217, 252, 82, 233>>

# when using the "dir" algorithm, the jwk itself will be used
iex> JOSE.JWE.next_cek(jwk, %{ "alg" => "dir", "enc" => "A128GCM" })
<<137, 211, 127, 99, 39, 152, 102, 161, 4, 236, 25, 41, 123, 24, 64, 217>>

next_iv(jwe)

Returns the next iv the "alg" and "enc" specified by the jwe.

# typically just returns random bytes for the specified "enc" algorithm
iex> bit_size(JOSE.JWE.next_iv(%{ "alg" => "dir", "enc" => "A128CBC-HS256" }))
128
iex> bit_size(JOSE.JWE.next_iv(%{ "alg" => "dir", "enc" => "A128GCM" }))
96

to_binary(list)

Converts a JOSE.JWE into a binary.

to_file(file, any)

Calls to_binary/1 on a JOSE.JWE and then writes the binary to file.

to_map(list)

Converts a JOSE.JWE into a map.

to_record(list)

Converts a JOSE.JWE struct to a :jose_jwe record.

uncompress(cipher_text, jwe)

Uncompresses the cipher_text using the "zip" algorithm specified by the jwe.

iex> JOSE.JWE.uncompress(<<120, 156, 171, 174, 5, 0, 1, 117, 0, 249>>, %{ "alg" => "dir", "zip" => "DEF" })
"{}"

See compress/2.