Yet another JWT lib for Elixir

This is a rewrite of json_web_token_ex with jwt_claims_ex merged in, both created by @garyf.

Many things were simplified during the rewrite, code was cleaned up as well.

Installation

The package can be installed by adding yajwt to your list of dependencies in mix.exs:

def deps do
  [{:yajwt, "~> 1.0"}]
end

Usage

JWT.sign(claims, options)

Returns a JSON Web Token string

claims (required) map

options (required) map

• alg (optional, default: "HS256")
• key (required unless alg is "none")

Include any JWS JOSE header parameters (RFC 7515) in the options map

Example

# sign with default algorithm, HMAC SHA256
jwt = JWT.sign(%{foo: "bar"}, %{key: "gZH75aKtMN3Yj0iPS4hcgUuTwjAzZr9C"})

# sign with RSA SHA256 algorithm
private_key = JWT.Algorithm.RsaUtil.private_key("path/to/", "key.pem")
opts = %{
  alg: "RS256",
  key: private_key
}

jwt = JWT.sign(%{foo: "bar"}, opts)

# unsecured token (algorithm is "none")
jwt = JWT.sign(%{foo: "bar"}, %{alg: "none"})

JWT.verify(jwt, options)

Returns a tuple, either:

• {:ok, claims}, a JWT claims set map, if the Message Authentication Code (MAC), or signature, is verified
• {:error, "invalid"}, otherwise

"jwt" (required) is a JSON web token string

options (required) map

• alg (optional, default: "HS256")
• key (required unless alg is "none")

Example

secure_jwt_example = "eyJ0eXAiOiJKV1QiLA0KICJhbGciOiJIUzI1NiJ9.eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt.cGxlLmNvbS9pc19yb290Ijp0cnVlfQ.dBjftJeZ4CVP-mB92K27uhbUJU1p1r_wW1gFWFOEjXk"

# verify with default algorithm, HMAC SHA256
{:ok, claims} = JWT.verify(secure_jwt_example, %{key: "gZH75aKtMN3Yj0iPS4hcgUuTwjAzZr9C"})

# Or with the bang version
claims = JWT.verify!(secure_jwt_example, %{key: "gZH75aKtMN3Yj0iPS4hcgUuTwjAzZr9C"})

# verify with RSA SHA256 algorithm
opts = %{
  alg: "RS256",
  key: < RSA public key >
}

{:ok, claims} = JWT.verify(jwt, opts)

# unsecured token (algorithm is "none")
unsecured_jwt_example = "eyJ0eXAiOiJKV1QiLA0KICJhbGciOiJIUzI1NiJ9.eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt."

{:ok, claims} = JWT.verify(unsecured_jwt_example, %{alg: "none"})

Supported encryption algorithms

alg Param Value	Digital Signature or MAC Algorithm
HS256	HMAC using SHA-256 per RFC 2104
HS384	HMAC using SHA-384
HS512	HMAC using SHA-512
RS256	RSASSA-PKCS-v1_5 using SHA-256 per RFC3447
RS384	RSASSA-PKCS-v1_5 using SHA-384
RS512	RSASSA-PKCS-v1_5 using SHA-512
ES256	ECDSA using P-256 and SHA-256 per DSS
ES384	ECDSA using P-384 and SHA-384
ES512	ECDSA using P-521 and SHA-512
none	No digital signature or MAC performed (unsecured)

Registered claim names

The following claims are supported. They are validated when the JWT is verified.

• iss (Issuer)
• sub (Subject)
• aud (Audience)
• exp (Expiration Time)
• nbf (Not Before)
• iat (Issued At)
• jti (JWT ID)