JWT

Description

The jwt vmod allows for the manipulation, creation, and verification of JWT and JWS tokens.

Examples

Verifying HS256

The following example verifies a token signed with the HS256 algorithm that is in the Authorization header.

vcl 4.1;

import jwt;

backend default none;

sub vcl_init {
  new jwt_reader = jwt.reader();
}

sub vcl_recv {
  if (!jwt_reader.parse(req.http.Authorization)) {
    return (synth(401, "Invalid Authorization Token"));
  }

  if (!jwt_reader.set_key("secret")) {
    return (synth(401, "Invalid Authorization Token"));
  }

  if (!jwt_reader.verify("HS256")) {
    return (synth(401, "Invalid Authorization Token"));
  }

  # JWT token was valid
}

Creating HS256

The following example generates a token signed with the HS256 algorithm.

vcl 4.1;

import jwt;

backend default none;

sub vcl_init {
  new jwt_writer = jwt.writer();
}

sub vcl_recv {
  jwt_writer.set_sub(req.method + " " + req.http.host + req.url);
  jwt_writer.set_alg("HS256");

  # Shortlived token that allows 30 seconds clock skew.
  jwt_writer.set_nbf(now - 30s);
  jwt_writer.set_exp(now + 30s);
  jwt_writer.set_iss(server.identity);
  set req.http.jwt = jwt_writer.generate("secret");
  if (jwt_writer.error()) {
    # Something went wrong generating the new token.
  }
}

Modifying

The following example takes an existing token, verifies it, extends its expiration to 6 hours from the current time, then sets the new token on the request Authorization header.

vcl 4.1;

import jwt;

backend default none;

sub vcl_init {
  new jwt_reader = jwt.reader();
  new jwt_writer = jwt.writer();
}

sub vcl_recv {
  if (!jwt_reader.parse(req.http.Authorization)) {
    return (synth(401, "Invalid Authorization Token"));
  }

  if (!jwt_reader.set_key("secret")) {
    return (synth(401, "Invalid Authorization Token"));
  }

  if (!jwt_reader.verify("HS256")) {
    return (synth(401, "Invalid Authorization Token"));
  }

  # JWT token was valid, extend the lifetime.
  jwt_writer.from_string(jwt_reader.to_string());
  jwt_writer.set_exp(now + 6h);
  if (jwt_writer.error()) {
    # Something went wrong extending the expiration date.
  }

  set req.http.Authorization = jwt_writer.generate("secret");
  if (jwt_writer.error()) {
    # Something went wrong generating the new token.
  }
}

Using RSA Key Pair

The following example uses an RSA 512-bit public/private key pair and the RS256 algorithm. It generates a token signed with the private key, then verifies it with the public key.

vcl 4.1;

import jwt;

backend default none;

sub vcl_init {
  new jwt_reader = jwt.reader();
  new jwt_writer = jwt.writer();
}

sub vcl_recv {
  # set the JWT header ``alg`` field
  jwt_writer.set_alg("RS256");
  # set the JWT payload ``sub`` and ``iss`` claims
  jwt_writer.set_sub(req.method + " " + req.http.host + req.url);
  jwt_writer.set_iss(server.identity);

  # Generate the JWT token. Note how the key is wrapped.
  set req.http.jwt = jwt_writer.generate({"-----BEGIN PRIVATE KEY-----
MIIBUwIBADANBgkqhkiG9w0BAQEFAASCAT0wggE5AgEAAkEAmQgArH6JVVRDuJEE
yXeiMAPXYyP7O4R/lFTxDisbUCIXbjMQnhH7ImeLBjw+g5OzNXb2olkzXBy9l2sZ
ECc/LQIDAQABAkBtkutYl6oiLRnod/4je8Pn+XgqBsOHVFI9layc5oTCFOs1qiJi
oJr7RCejqNOp1dXDN5aLFLcrEQJohxMPxosBAiEA0K8gGm2EnkNbTw2SnWoiTbz3
bR1/gR1AiQYbkdsIPs0CIQC7uo+CFW73qdcuWEKtwJaSV0+j3WgMTfAcCCHNoc5B
4QIgUI66EtmiL0ILNnoj1faJpX7D+PBBL0NujTa5X9Ww2iUCIBzYX7CnRnO7nxq5
6RT1oK0/yTbukExDtX85KKiGEkFBAiAri8SzhNNOGBtNXhqC94Cp/Aj9J5mN2kTA
ANUlyKgK8w==
-----END PRIVATE KEY-----"});

  # always check if there was a generate error
  if (jwt_writer.error()) {
    return (synth(401, "Failed to generate token"));
  }

  # token successfully generated, now verify it.
  if (!jwt_reader.parse(req.http.jwt)) {
    return (synth(401, "Failed to parse the token"));
  }

  if (!jwt_reader.set_key({"-----BEGIN PUBLIC KEY-----
MFwwDQYJKoZIhvcNAQEBBQADSwAwSAJBAJkIAKx+iVVUQ7iRBMl3ojAD12Mj+zuE
f5RU8Q4rG1AiF24zEJ4R+yJniwY8PoOTszV29qJZM1wcvZdrGRAnPy0CAwEAAQ==
-----END PUBLIC KEY-----"})) {
    return (synth(401, "Invalid RSA public key"));
  }

  if (!jwt_reader.verify("RS256")) {
    return (synth(401, "Invalid Authorization Token"));
  }

  # JWT token is valid
}

Using RSA JWK

The following example uses an RSA 512-bit public/private key pair and the RS256 algorithm. It generates a token signed with the private key, then verifies it with the public key as a JWK.

vcl 4.1;

import jwt;

backend default none;

sub vcl_init {
  new jwt_reader = jwt.reader();
  new jwt_writer = jwt.writer();
}

sub vcl_recv {
  # set the JWT header ``alg`` field
  jwt_writer.set_alg("RS256");
  # set the JWT payload ``sub`` and ``iss`` claims
  jwt_writer.set_sub(req.method + " " + req.http.host + req.url);
  jwt_writer.set_iss(server.identity);

  # Generate the JWT token. Note how the key is wrapped.
  set req.http.jwt = jwt_writer.generate({"-----BEGIN PRIVATE KEY-----
MIIBUwIBADANBgkqhkiG9w0BAQEFAASCAT0wggE5AgEAAkEAmQgArH6JVVRDuJEE
yXeiMAPXYyP7O4R/lFTxDisbUCIXbjMQnhH7ImeLBjw+g5OzNXb2olkzXBy9l2sZ
ECc/LQIDAQABAkBtkutYl6oiLRnod/4je8Pn+XgqBsOHVFI9layc5oTCFOs1qiJi
oJr7RCejqNOp1dXDN5aLFLcrEQJohxMPxosBAiEA0K8gGm2EnkNbTw2SnWoiTbz3
bR1/gR1AiQYbkdsIPs0CIQC7uo+CFW73qdcuWEKtwJaSV0+j3WgMTfAcCCHNoc5B
4QIgUI66EtmiL0ILNnoj1faJpX7D+PBBL0NujTa5X9Ww2iUCIBzYX7CnRnO7nxq5
6RT1oK0/yTbukExDtX85KKiGEkFBAiAri8SzhNNOGBtNXhqC94Cp/Aj9J5mN2kTA
ANUlyKgK8w==
-----END PRIVATE KEY-----"});

  # always check if there was a generate error
  if (jwt_writer.error()) {
    return (synth(401, "Failed to generate token"));
  }

  # token successfully generated, now verify it.
  if (!jwt_reader.parse(req.http.jwt)) {
    return (synth(401, "Failed to parse the token"));
  }

  if (!jwt_reader.set_jwk({"
      {
        "keys": [
          {
            "alg": "RS256",
            "kty": "RSA",
            "e": "AQAB",
            "n": "mQgArH6JVVRDuJEEyXeiMAPXYyP7O4R_lFTxDisbUCIXbjMQnhH7ImeLBjw-g5OzNXb2olkzXBy9l2sZECc_LQ"
          }
        ]
      }"})) {
    return (synth(401, "Invalid JWK"));
  }

  if (!jwt_reader.verify("RS256")) {
    return (synth(401, "Invalid Authorization Token"));
  }

  # JWT token is valid
}

API

Encoded Keys

The JWT methods that have a key parameter can accept an HMAC, RSA, or ECDSA key. Care must be taken when using HMAC keys (secrets) that are binary data. Such binary secrets can contain embedded null (\0) bytes and MUST NOT be passed as simple ASCII strings. Passing HMAC binary secrets as simple strings can cause a truncated secret to be used to generate a token or signature, making it insecure. Likewise, a binary secret can cause a truncated secret to be used when verifying a token or signature. It is strongly suggested that HMAC binary secrets be encoded before passing as a key. These JWT methods have an optional encoding parameter to indicate how the key is encoded. If the encoding is anything other than ascii (default), the key will be decoded to its binary form before generating or verifying the token or signature. Note that the encoding parameter is ignored for RSA and ECDSA keys.

Valid encoding values:

ascii: the key is a simple ASCII string and no decoding is required. Default.
base64url: the key is a base64url encoded string.

reader

OBJECT reader()

Creates a JWT Reader Object. must be called in sub vcl_init.

Arguments: None

Type: Object

Returns: Object.

.parse

BOOL .parse(STRING token)

Parse a JWT/JWS token into the reader and return whether it was able to be parsed successfully. You should always check the return of this method before calling any of the methods below.

Arguments:

token accepts type STRING

Type: Method

Returns: Bool

.from_string

BOOL .from_string(STRING token)

Parse a JWT/JWS token into the reader and return whether it was able to be parsed successfully. Primarily an alias to keep convention with the reader/writer to and from methods. You should always check the return of this method before calling any of the other reader methods.

Arguments:

token accepts type STRING

Type: Method

Returns: Bool

.get_alg

STRING .get_alg()

Get the alg parameter parsed from the JWT header (e.g. HS256) or return NULL if it does not exist.

Arguments: None

Type: Method

Returns: String

.get_typ

STRING .get_typ()

Get the typ parameter parsed from the JWT header (e.g. JWT) or return NULL if it does not exist.

Arguments: None

Type: Method

Returns: String

.get_b64

BOOL .get_b64()

Get the b64 parameter parsed from the JWT header (e.g. TRUE) or return 0 if it does not exist.

Arguments: None

Type: Method

Returns: Bool

.get_kid

STRING .get_kid()

Get the kid parameter parsed from the JWT header or return NULL if it does not exist. The value of the kid is application-specific.

Arguments: None

Type: Method

Returns: String

.is_jwt

BOOL .is_jwt()

Tell whether the token is a JWT or a JWS. A JWT token will either have the typ header parameter equal to JWT or have a payload that is base64url encoded JSON, if both of these requirements aren’t met it is a JWS and this method will return false.

Arguments: None

Type: Method

Returns: Bool

.get_sub

STRING .get_sub(STRING default = 0)

Get the sub claim parsed from the JWT payload or return default if it does not exist.

Arguments:

default accepts type STRING with a default value of 0 optional

Type: Method

Returns: String

.get_iss

STRING .get_iss(STRING default = 0)

Get the iss claim parsed from the JWT payload or return default if it does not exist.

Arguments:

default accepts type STRING with a default value of 0 optional

Type: Method

Returns: String

.get_jti

STRING .get_jti(STRING default = 0)

Get the jti claim parsed from the JWT payload or return default if it does not exist.

Arguments:

default accepts type STRING with a default value of 0 optional

Type: Method

Returns: String

.get_exp

TIME .get_exp()

Get the exp claim parsed from the JWT payload. You must call reader.has_exp() before calling this function to make sure you have an exp to get.

Arguments: None

Type: Method

Returns: Time

.has_exp

BOOL .has_exp()

Check whether the JWT payload has an exp claim. This must be called before reader.get_exp() to make sure you have an exp to return.

Arguments: None

Type: Method

Returns: Bool

.get_nbf

TIME .get_nbf()

Get the nbf claim parsed from the JWT payload. You must call reader.has_nbf() before calling this function to make sure you have an nbf to get.

Arguments: None

Type: Method

Returns: Time

.has_nbf

BOOL .has_nbf()

Check whether the JWT payload has an nbf claim. This must be called before reader.get_nbf() to make sure you have an nbf to return.

Arguments: None

Type: Method

Returns: Bool

.get_iat

TIME .get_iat()

Get the iat claim parsed from the JWT payload. You must call reader.has_iat() before calling this function to make sure you have an iat to get.

Arguments: None

Type: Method

Returns: Time

.has_iat

BOOL .has_iat()

Check whether the JWT payload has an iat claim. This must be called before reader.get_iat() to make sure you have an iat to return.

Arguments: None

Type: Method

Returns: Bool

.get_header

STRING .get_header()

Get the JWT header as a JSON string.

Arguments: None

Type: Method

Returns: String

.get_header_encoded

STRING .get_header_encoded()

Get the JWT header as a JSON string that is base64url encoded.

Arguments: None

Type: Method

Returns: String

.get_payload

STRING .get_payload()

Get the JWT payload as a JSON string.

Arguments: None

Type: Method

Returns: String

.get_payload_encoded

STRING .get_payload_encoded()

Get the JWT payload as a JSON string that is base64url encoded.

Arguments: None

Type: Method

Returns: String

.get_signature

STRING .get_signature()

Get the base64url encoded signature of the JWT token.

Arguments: None

Type: Method

Returns: String

.get_claim_string

STRING .get_claim_string(STRING claim, STRING def = 0)

Get the string value of the claim from the JWT payload. If the claim does not exist, the payload did not parse, or the claim is not a string type, the def value is returned.

Arguments:

claim accepts type STRING
def accepts type STRING with a default value of 0 optional

Type: Method

Returns: String

.get_claim_bool

BOOL .get_claim_bool(STRING claim, BOOL def = 0)

Get the boolean value of the claim from the JWT payload. Returns 1 for true and 0 for false. If the claim does not exist, the payload did not parse, or the claim is not a boolean type, the def value is returned.

Arguments:

claim accepts type STRING
def accepts type BOOL with a default value of 0 optional

Type: Method

Returns: Bool

.get_claim_number

REAL .get_claim_number(STRING claim, REAL def = 0.0)

Get the number value of the claim from the JWT payload. If the claim does not exist, the payload did not parse, or the claim is not a number type, the def value is returned.

Arguments:

claim accepts type STRING
def accepts type REAL with a default value of 0 optional

Type: Method

Returns: Real

.get_claim_integer

INT .get_claim_integer(STRING claim, INT def = 0)

Get the integer value of the claim from the JWT payload. If the claim does not exist, the payload did not parse, or the claim is not a number type, the def value is returned. This is a convenience wrapper for .get_claim_number, rounding the claim number to the nearest integer.

Arguments:

claim accepts type STRING
def accepts type INT with a default value of 0 optional

Type: Method

Returns: Int

.get_claim

STRING .get_claim(STRING claim, STRING def = 0)

Get the value of the claim from the JWT payload. If the claim does not exist or the payload did not parse, the def value is returned. This is a general purpose get method that is not type specific. It is useful, for example, to get object or array claims as a string.

Arguments:

claim accepts type STRING
def accepts type STRING with a default value of 0 optional

Type: Method

Returns: String

.to_string

STRING .to_string()

Get the JWT token as a string. The string will have the expected JWT token format: header.payload.signature. The header, payload, and signature are each base64url encoded. This token string can, for example, be passed to a jwt_writer.from_string() method.

Arguments: None

Type: Method

Returns: String

.set_key

BOOL .set_key(STRING key, ENUM {ascii, base64url} encoding = ascii)

Set the HMAC secret, RSA public key, or ECDSA public key to use to verify the token or signature. The RSA and ECDSA keys must be in PEM format without newlines.

The optional encoding parameter indicates whether the key is encoded with one of the defined methods. See Encoded Keys.

Arguments:

key accepts type STRING
encoding is an ENUM that accepts values of ascii, and base64url with a default value of ascii optional

Type: Method

Returns: Bool

.set_jwk

INT .set_jwk(STRING jwk)

Set the HMAC, RSA, or ECDSA public key(s) for the token via a JWK. The jwk can be a single key or an array of keys.

An array of keys can include a mix of HMAC, RSA, and ECDSA keys, including multiple keys of the same type. For example, an array with both current and previous RSA keys can be useful for key rotation.

Each key must have a kty and/or alg field. The supported kty values are oct, RSA, and EC. The supported alg values are HS256, HS384, HS512, RS256, RS384, RS512, ES256, ES384, and ES512. Also, the key must have fields specific to an HMAC, RSA, or ECDSA key. The key can have an optional kid field to be used for key selection during verification (see reader.verify()). All other fields in the key are ignored.

A valid HMAC key has these fields:

kty (if present) is oct.
alg (if present) is HS256, HS384, or HS512.
k is required (base64url encoded secret).

A valid RSA key has these fields:

kty (if present) is RSA.
alg (if present) is RS256, RS384, or RS512.
n and e are required.

A valid ECDSA key has these fields:

kty (if present) is EC.
alg (if present) is ES256, ES384, or ES512.
crv must be P-256, P-384, or P-521.
x and y are required.

This returns a count of valid keys.

Arguments:

jwk accepts type STRING

Type: Method

Returns: Int

.verify

BOOL .verify(STRING expected_alg, ENUM {none, optional, required} check_kid = none, BOOL check_exp = 1, BOOL check_nbf = 1)

Verify the JWT/JWS token. This method supports verifying the signature with algorithms none, HS256, HS384, HS512, RS256, RS384, RS512, ES256, ES384, and ES512. The exp and nbf payload parameters are also checked when this method is called if they are present (see the check_exp and check_nbf parameters).

You must call reader.set_key() or reader.set_jwk(), before calling this function, to provide the public key(s) or secret(s) used for verification.

If expected_alg does not match the algorithm of the passed in token verification will fail. DO NOT USE get_alg() to populate this argument as this will allow an attacker to forge tokens by claiming the algorithm of the token is none, which does not require signature verification. The possible values for this argument are none, HS256, HS384, HS512, RS256, RS384, RS512, ES256, ES384, and ES512.

The optional check_kid parameter can be used with JWKs to indicate whether the kid field should be used for JWK selection. The request kid comes from the JWS/JWT header field or by calling .set_kid(), and is compared against the JWK kid field. The kid are case-sensitive strings and compared accordingly. A JWK with a matching kid must also have the expected algorithm. If more than one JWK has the same kid, each is tried until a successful verifification result. The check_kid parameter is ignored when verifying with a public key string (instead of JWKs).

Valid check_kid values:

none: ignore the kid fields and do JWK selection using algorithm matching. Default.
optional: if there is a request kid and a JWK has a kid field, compare them. Otherwise, do JWK selection using algorithm matching.
required: there must be a request kid and a JWK must have a matching kid field. If no matching kid is found in the JWKs, .verify() fails.

If check_exp is 1 (default), the exp claim, if present, is validated against the current time. Passing 0 causes the exp check to be skipped.

If check_nbf is 1 (default), the nbf claim, if present, is validated against the current time. Passing 0 causes the nbf check to be skipped.

This returns true if the expected_alg matches the token’s algorithm, the signature algorithm is one of the supported ones listed above, the signature is valid, and the exp and nbf claims are valid if they are present. If any of the aforementioned conditions are not met, the return value will be false.

Arguments:

expected_alg accepts type STRING
check_exp accepts type BOOL with a default value of 1 optional
check_nbf accepts type BOOL with a default value of 1 optional
check_kid is an ENUM that accepts values of none, optional, and required with a default value of none optional

Type: Method

Returns: Bool

.verify_raw

BOOL .verify_raw(STRING alg, STRING data, STRING signature)

Verify the signature of the data. This method supports verifying with a public key or with JWKs. A public key can be provided with .set_key(). JWKs can be provided with .set_jwk(). This method is useful when the alg, data, or signature do not come from the traditional JWT/JWS header, payload, or token.

The possible values for alg are none, HS256, HS384, HS512, RS256, RS384, RS512, ES256, ES384, and ES512.

The data can be any arbitrary string and it is used as is.

The signature is a base64url encoded signature.

This returns true if the alg is one of the supported ones listed above and the signature is valid. If any of the aforementioned conditions are not met, the return value will be false.

Arguments:

alg accepts type STRING
data accepts type STRING
signature accepts type STRING

Type: Method

Returns: Bool

writer

OBJECT writer()

Creates a JWT Writer Object. must be called in sub vcl_init.

Arguments: None

Type: Object

Returns: Object.

.parse

VOID .parse(STRING token)

Parse the JWT/JWS header and payload from the token into the writer. You should always check for a parsing error with writer.error() before calling any other writer methods.

The token should be in the JWT/JWS token format: header.payload.signature. The header, payload, and signature are each base64url encoded. The signature is ignored.

Arguments:

token accepts type STRING

Type: Method

Returns: None

.from_string

VOID .from_string(STRING token)

Parse the JWT/JWS header and payload from the token into the writer. You should always check for a parsing error with writer.error() before calling any other writer methods. Primarily an alias of writer.parse() to keep convention with the reader/writer to and from methods. Can be used with the reader.to_string() method.

Arguments:

token accepts type STRING

Type: Method

Returns: None

.set_header

VOID .set_header(STRING header)

Set the JWT/JWS header in the writer from the JSON header string.

Arguments:

header accepts type STRING

Type: Method

Returns: None

.set_payload

VOID .set_payload(STRING payload)

Set the JWT/JWS payload in the writer from the JSON payload string.

Arguments:

payload accepts type STRING

Type: Method

Returns: None

.set_header_encoded

VOID .set_header_encoded(STRING header)

Set the JWT/JWS header in the writer from the base64url encoded JSON header string.

Arguments:

header accepts type STRING

Type: Method

Returns: None

.set_payload_encoded

VOID .set_payload_encoded(STRING payload)

Set the JWT/JWS payload in the writer from the base64url encoded JSON payload string.

Arguments:

payload accepts type STRING

Type: Method

Returns: None

.set_alg

VOID .set_alg(STRING alg)

Set the signature algorithm alg parameter of the token header. This method supports values of none, HS256, HS384, HS512, RS256, RS384, RS512, ES256, ES384, or ES512.

Arguments:

alg accepts type STRING

Type: Method

Returns: None

.set_typ

VOID .set_typ(STRING typ)

Set the typ parameter of the token header.

Arguments:

typ accepts type STRING

Type: Method

Returns: None

.set_b64

VOID .set_b64(BOOL is_b64)

Set the b64 parameter of the token header.

Arguments:

is_b64 accepts type BOOL

Type: Method

Returns: None

.set_kid

VOID .set_kid(STRING kid)

Set the kid parameter of the token header. The value of the kid is application-specific.

Arguments:

kid accepts type STRING

Type: Method

Returns: None

.set_sub

VOID .set_sub(STRING sub)

Set the sub claim of the token payload.

Arguments:

sub accepts type STRING

Type: Method

Returns: None

.set_iss

VOID .set_iss(STRING iss)

Set the iss claim of the token payload.

Arguments:

iss accepts type STRING

Type: Method

Returns: None

.set_jti

VOID .set_jti(STRING jti)

Set the jti claim of the token payload.

Arguments:

jti accepts type STRING

Type: Method

Returns: None

.set_exp

VOID .set_exp(TIME time)

Set the exp claim of the token payload.

Arguments:

time accepts type TIME

Type: Method

Returns: None

.set_nbf

VOID .set_nbf(TIME time)

Set the nbf claim of the token payload.

Arguments:

time accepts type TIME

Type: Method

Returns: None

.set_iat

VOID .set_iat(TIME time)

Set the iat claim of the token payload.

Arguments:

time accepts type TIME

Type: Method

Returns: None

.set_duration

VOID .set_duration(DURATION duration)

Set the exp claim of the token payload to current time plus duration, so that exp is in the future.

Arguments:

duration accepts type DURATION

Type: Method

Returns: None

.delete_sub

VOID .delete_sub()

Delete the sub claim from the token payload.

Arguments: None

Type: Method

Returns: None

.delete_iss

VOID .delete_iss()

Delete the iss claim from the token payload.

Arguments: None

Type: Method

Returns: None

.delete_jti

VOID .delete_jti()

Delete the jti claim from the token payload.

Arguments: None

Type: Method

Returns: None

.delete_exp

VOID .delete_exp()

Delete the exp claim from the token payload.

Arguments: None

Type: Method

Returns: None

.delete_nbf

VOID .delete_nbf()

Delete the nbf claim from the token payload.

Arguments: None

Type: Method

Returns: None

.delete_iat

VOID .delete_iat()

Delete the iat claim from the token payload.

Arguments: None

Type: Method

Returns: None

.generate

STRING .generate(STRING key, ENUM {ascii, base64url} encoding = ascii)

Generate the full JWT/JWS token. This method supports creating with the signature algorithms none, HS256, HS384, HS512, RS256, RS384, RS512, ES256, ES384, and ES512. The algorithm must be set with the .parse(), .from_string(), or .set_alg() method.

The key can be an HMAC secret, RSA private key, or ECDSA private key. The RSA and ECDSA keys must be in PEM format without newlines.

The optional encoding parameter indicates whether the key is encoded with one of the defined methods. See Encoded Keys.

This returns the token as a string in the typical JWT token format: header.payload.signature. The header, payload, and signature are each base64url encoded.

Arguments:

key accepts type STRING
encoding is an ENUM that accepts values of ascii, and base64url with a default value of ascii optional

Type: Method

Returns: String

.to_string

STRING .to_string(STRING key, ENUM {ascii, base64url} encoding = ascii)

The key can be an HMAC secret, RSA private key, or ECDSA private key. The RSA and ECDSA keys must be in PEM format without newlines.

The optional encoding parameter indicates whether the key is encoded with one of the defined methods. See Encoded Keys.

This returns the token as a string in the typical JWT token format: header.payload.signature. The header, payload, and signature are each base64url encoded.

Arguments:

key accepts type STRING
encoding is an ENUM that accepts values of ascii, and base64url with a default value of ascii optional

Type: Method

Returns: String

.generate_raw

STRING .generate_raw(STRING alg, STRING data, STRING key, ENUM {ascii, base64url} encoding = ascii)

Generate a signature for the data with the alg and private key. This method is useful when the alg or data do not come from the traditional JWT/JWS header or payload.

The possible values for alg are none, HS256, HS384, HS512, RS256, RS384, RS512, ES256, ES384, and ES512.

The data can be any arbitrary string and it is used as-is. This data is treated as an ASCII string. Do not pass binary data, as there is the risk it could contain embedded null (\0) bytes, resulting in truncated data being used to generate the signature.

The key can be an HMAC secret, RSA private key, or ECDSA private key. The RSA and ECDSA keys must be in PEM format without newlines.

The optional encoding parameter indicates whether the key is encoded with one of the defined methods. See Encoded Keys.

This returns the signature as a base64url encoded string.

Arguments:

alg accepts type STRING
data accepts type STRING
key accepts type STRING
encoding is an ENUM that accepts values of ascii, and base64url with a default value of ascii optional

Type: Method

Returns: String

.reset

VOID .reset()

Reset all data on the writer including the error flag.

Arguments: None

Type: Method

Returns: None

.error

BOOL .error()

Did any of the method calls above result in an error

Arguments: None

Type: Method

Returns: Bool

Availability

The jwt VMOD is available in Varnish Enterprise version 6.0.6r2 and later.