Package jwt

// See func authHandler for an example auth handler that produces a token
res, err := http.PostForm(fmt.Sprintf("http://localhost:%v/authenticate", serverPort), url.Values{
    "user": {"test"},
    "pass": {"known"},
})
if err != nil {
    fatal(err)
}

if res.StatusCode != 200 {
    fmt.Println("Unexpected status code", res.StatusCode)
}

// Read the token out of the response body
buf := new(bytes.Buffer)
io.Copy(buf, res.Body)
res.Body.Close()
tokenString := strings.TrimSpace(buf.String())

// Parse the token
token, err := jwt.ParseWithClaims(tokenString, &CustomClaimsExample{}, func(token *jwt.Token) (interface{}, error) {
    // since we only use the one private key to sign the tokens,
    // we also only use its public counter part to verify
    return verifyKey, nil
})
fatal(err)

claims := token.Claims.(*CustomClaimsExample)
fmt.Println(claims.CustomerInfo.Name)

test

// Make a sample token
// In a real world situation, this token will have been acquired from
// some other API call (see Example_getTokenViaHTTP)
token, err := createToken("foo")
fatal(err)

// Make request.  See func restrictedHandler for example request processor
req, err := http.NewRequest("GET", fmt.Sprintf("http://localhost:%v/restricted", serverPort), nil)
fatal(err)
req.Header.Set("Authorization", fmt.Sprintf("Bearer %v", token))
res, err := http.DefaultClient.Do(req)
fatal(err)

// Read the response body
buf := new(bytes.Buffer)
io.Copy(buf, res.Body)
res.Body.Close()
fmt.Println(buf.String())

Welcome, foo

Constants

The errors that might occur when parsing and validating a token

const (
    ValidationErrorMalformed        uint32 = 1 << iota // Token is malformed
    ValidationErrorUnverifiable                        // Token could not be verified because of signing problems
    ValidationErrorSignatureInvalid                    // Signature validation failed

    // Standard Claim validation errors
    ValidationErrorAudience      // AUD validation failed
    ValidationErrorExpired       // EXP validation failed
    ValidationErrorIssuedAt      // IAT validation failed
    ValidationErrorIssuer        // ISS validation failed
    ValidationErrorNotValidYet   // NBF validation failed
    ValidationErrorId            // JTI validation failed
    ValidationErrorClaimsInvalid // Generic claims validation error
)

const UnsafeAllowNoneSignatureType unsafeNoneMagicConstant = "none signing method allowed"

Variables

var (
    ErrNotECPublicKey  = errors.New("Key is not a valid ECDSA public key")
    ErrNotECPrivateKey = errors.New("Key is not a valid ECDSA private key")
)

var (
    ErrNotEdPrivateKey = errors.New("Key is not a valid Ed25519 private key")
    ErrNotEdPublicKey  = errors.New("Key is not a valid Ed25519 public key")
)

Error constants

var (
    ErrInvalidKey      = errors.New("key is invalid")
    ErrInvalidKeyType  = errors.New("key is of invalid type")
    ErrHashUnavailable = errors.New("the requested hash function is unavailable")
)

var (
    ErrKeyMustBePEMEncoded = errors.New("Invalid Key: Key must be a PEM encoded PKCS1 or PKCS8 key")
    ErrNotRSAPrivateKey    = errors.New("Key is not a valid RSA private key")
    ErrNotRSAPublicKey     = errors.New("Key is not a valid RSA public key")
)

var (
    // Sadly this is missing from crypto/ecdsa compared to crypto/rsa
    ErrECDSAVerification = errors.New("crypto/ecdsa: verification error")
)

var (
    ErrEd25519Verification = errors.New("ed25519: verification error")
)

var NoneSignatureTypeDisallowedError error

Implements the none signing method. This is required by the spec but you probably should never use it.

var SigningMethodNone *signingMethodNone

TimeFunc provides the current time when parsing token to validate "exp" claim (expiration time). You can override it to use another time value. This is useful for testing or if your server uses a different time zone than your tokens.

var TimeFunc = time.Now

func DecodeSegment ¶

func DecodeSegment(seg string) ([]byte, error)

Decode JWT specific base64url encoding with padding stripped

func EncodeSegment ¶

func EncodeSegment(seg []byte) string

Encode JWT specific base64url encoding with padding stripped

func ParseECPrivateKeyFromPEM ¶

func ParseECPrivateKeyFromPEM(key []byte) (*ecdsa.PrivateKey, error)

Parse PEM encoded Elliptic Curve Private Key Structure

func ParseECPublicKeyFromPEM ¶

func ParseECPublicKeyFromPEM(key []byte) (*ecdsa.PublicKey, error)

Parse PEM encoded PKCS1 or PKCS8 public key

func ParseEdPrivateKeyFromPEM ¶

func ParseEdPrivateKeyFromPEM(key []byte) (crypto.PrivateKey, error)

Parse PEM-encoded Edwards curve private key

func ParseEdPublicKeyFromPEM ¶

func ParseEdPublicKeyFromPEM(key []byte) (crypto.PublicKey, error)

Parse PEM-encoded Edwards curve public key

func ParseRSAPrivateKeyFromPEM ¶

func ParseRSAPrivateKeyFromPEM(key []byte) (*rsa.PrivateKey, error)

Parse PEM encoded PKCS1 or PKCS8 private key

func ParseRSAPrivateKeyFromPEMWithPassword ¶

func ParseRSAPrivateKeyFromPEMWithPassword(key []byte, password string) (*rsa.PrivateKey, error)

Parse PEM encoded PKCS1 or PKCS8 private key protected with password

func ParseRSAPublicKeyFromPEM ¶

func ParseRSAPublicKeyFromPEM(key []byte) (*rsa.PublicKey, error)

Parse PEM encoded PKCS1 or PKCS8 public key

func RegisterSigningMethod ¶

func RegisterSigningMethod(alg string, f func() SigningMethod)

Register the "alg" name and a factory function for signing method. This is typically done during init() in the method's implementation

type Claims ¶

For a type to be a Claims object, it must just have a Valid method that determines if the token is invalid for any supported reason

type Claims interface {
    Valid() error
}

type Keyfunc ¶

Parse methods use this callback function to supply the key for verification. The function receives the parsed, but unverified Token. This allows you to use properties in the Header of the token (such as `kid`) to identify which key to use.

type Keyfunc func(*Token) (interface{}, error)

type MapClaims ¶

Claims type that uses the map[string]interface{} for JSON decoding This is the default claims type if you don't supply one

type MapClaims map[string]interface{}

func (MapClaims) Valid ¶

func (m MapClaims) Valid() error

Validates time based claims "exp, iat, nbf". There is no accounting for clock skew. As well, if any of the above claims are not in the token, it will still be considered a valid claim.

func (MapClaims) VerifyAudience ¶

func (m MapClaims) VerifyAudience(cmp string, req bool) bool

VerifyAudience Compares the aud claim against cmp. If required is false, this method will return true if the value matches or is unset

func (MapClaims) VerifyExpiresAt ¶

func (m MapClaims) VerifyExpiresAt(cmp int64, req bool) bool

Compares the exp claim against cmp. If required is false, this method will return true if the value matches or is unset

func (MapClaims) VerifyIssuedAt ¶

func (m MapClaims) VerifyIssuedAt(cmp int64, req bool) bool

Compares the iat claim against cmp. If required is false, this method will return true if the value matches or is unset

func (MapClaims) VerifyIssuer ¶

func (m MapClaims) VerifyIssuer(cmp string, req bool) bool

Compares the iss claim against cmp. If required is false, this method will return true if the value matches or is unset

func (MapClaims) VerifyNotBefore ¶

func (m MapClaims) VerifyNotBefore(cmp int64, req bool) bool

Compares the nbf claim against cmp. If required is false, this method will return true if the value matches or is unset

type Parser ¶

type Parser struct {
    ValidMethods         []string // If populated, only these methods will be considered valid
    UseJSONNumber        bool     // Use JSON Number format in JSON decoder
    SkipClaimsValidation bool     // Skip claims validation during token parsing
}

func (*Parser) Parse ¶

func (p *Parser) Parse(tokenString string, keyFunc Keyfunc) (*Token, error)

Parse, validate, and return a token. keyFunc will receive the parsed token and should return the key for validating. If everything is kosher, err will be nil

func (*Parser) ParseUnverified ¶

func (p *Parser) ParseUnverified(tokenString string, claims Claims) (token *Token, parts []string, err error)

WARNING: Don't use this method unless you know what you're doing

This method parses the token but doesn't validate the signature. It's only ever useful in cases where you know the signature is valid (because it has been checked previously in the stack) and you want to extract values from it.

func (*Parser) ParseWithClaims ¶

func (p *Parser) ParseWithClaims(tokenString string, claims Claims, keyFunc Keyfunc) (*Token, error)

type SigningMethod ¶

Implement SigningMethod to add new methods for signing or verifying tokens.

type SigningMethod interface {
    Verify(signingString, signature string, key interface{}) error // Returns nil if signature is valid
    Sign(signingString string, key interface{}) (string, error)    // Returns encoded signature or error
    Alg() string                                                   // returns the alg identifier for this method (example: 'HS256')
}

func GetSigningMethod ¶

func GetSigningMethod(alg string) (method SigningMethod)

Get a signing method from an "alg" string

type SigningMethodECDSA ¶

Implements the ECDSA family of signing methods signing methods Expects *ecdsa.PrivateKey for signing and *ecdsa.PublicKey for verification

type SigningMethodECDSA struct {
    Name      string
    Hash      crypto.Hash
    KeySize   int
    CurveBits int
}

Specific instances for EC256 and company

var (
    SigningMethodES256 *SigningMethodECDSA
    SigningMethodES384 *SigningMethodECDSA
    SigningMethodES512 *SigningMethodECDSA
)

func (*SigningMethodECDSA) Alg ¶

func (m *SigningMethodECDSA) Alg() string

func (*SigningMethodECDSA) Sign ¶

func (m *SigningMethodECDSA) Sign(signingString string, key interface{}) (string, error)

Implements the Sign method from SigningMethod For this signing method, key must be an ecdsa.PrivateKey struct

func (*SigningMethodECDSA) Verify ¶

func (m *SigningMethodECDSA) Verify(signingString, signature string, key interface{}) error

Implements the Verify method from SigningMethod For this verify method, key must be an ecdsa.PublicKey struct

type SigningMethodEd25519 ¶

Implements the EdDSA family Expects ed25519.PrivateKey for signing and ed25519.PublicKey for verification

type SigningMethodEd25519 struct{}

Specific instance for EdDSA

var (
    SigningMethodEdDSA *SigningMethodEd25519
)

func (*SigningMethodEd25519) Alg ¶

func (m *SigningMethodEd25519) Alg() string

func (*SigningMethodEd25519) Sign ¶

func (m *SigningMethodEd25519) Sign(signingString string, key interface{}) (string, error)

Implements the Sign method from SigningMethod For this signing method, key must be an ed25519.PrivateKey

func (*SigningMethodEd25519) Verify ¶

func (m *SigningMethodEd25519) Verify(signingString, signature string, key interface{}) error

Implements the Verify method from SigningMethod For this verify method, key must be an ed25519.PublicKey

type SigningMethodHMAC ¶

Implements the HMAC-SHA family of signing methods signing methods Expects key type of []byte for both signing and validation

type SigningMethodHMAC struct {
    Name string
    Hash crypto.Hash
}

Specific instances for HS256 and company

var (
    SigningMethodHS256  *SigningMethodHMAC
    SigningMethodHS384  *SigningMethodHMAC
    SigningMethodHS512  *SigningMethodHMAC
    ErrSignatureInvalid = errors.New("signature is invalid")
)

func (*SigningMethodHMAC) Alg ¶

func (m *SigningMethodHMAC) Alg() string

func (*SigningMethodHMAC) Sign ¶

func (m *SigningMethodHMAC) Sign(signingString string, key interface{}) (string, error)

Implements the Sign method from SigningMethod for this signing method. Key must be []byte

func (*SigningMethodHMAC) Verify ¶

func (m *SigningMethodHMAC) Verify(signingString, signature string, key interface{}) error

Verify the signature of HSXXX tokens. Returns nil if the signature is valid.

type SigningMethodRSA ¶

Implements the RSA family of signing methods signing methods Expects *rsa.PrivateKey for signing and *rsa.PublicKey for validation

type SigningMethodRSA struct {
    Name string
    Hash crypto.Hash
}

Specific instances for RS256 and company

var (
    SigningMethodRS256 *SigningMethodRSA
    SigningMethodRS384 *SigningMethodRSA
    SigningMethodRS512 *SigningMethodRSA
)

func (*SigningMethodRSA) Alg ¶

func (m *SigningMethodRSA) Alg() string

func (*SigningMethodRSA) Sign ¶

func (m *SigningMethodRSA) Sign(signingString string, key interface{}) (string, error)

Implements the Sign method from SigningMethod For this signing method, must be an *rsa.PrivateKey structure.

func (*SigningMethodRSA) Verify ¶

func (m *SigningMethodRSA) Verify(signingString, signature string, key interface{}) error

Implements the Verify method from SigningMethod For this signing method, must be an *rsa.PublicKey structure.

type SigningMethodRSAPSS ¶

Implements the RSAPSS family of signing methods signing methods

type SigningMethodRSAPSS struct {
    *SigningMethodRSA
    Options *rsa.PSSOptions
    // VerifyOptions is optional. If set overrides Options for rsa.VerifyPPS.
    // Used to accept tokens signed with rsa.PSSSaltLengthAuto, what doesn't follow
    // https://tools.ietf.org/html/rfc7518#section-3.5 but was used previously.
    // See https://github.com/dgrijalva/jwt-go/issues/285#issuecomment-437451244 for details.
    VerifyOptions *rsa.PSSOptions
}

Specific instances for RS/PS and company.

var (
    SigningMethodPS256 *SigningMethodRSAPSS
    SigningMethodPS384 *SigningMethodRSAPSS
    SigningMethodPS512 *SigningMethodRSAPSS
)

func (*SigningMethodRSAPSS) Sign ¶

func (m *SigningMethodRSAPSS) Sign(signingString string, key interface{}) (string, error)

Implements the Sign method from SigningMethod For this signing method, key must be an rsa.PrivateKey struct

func (*SigningMethodRSAPSS) Verify ¶

func (m *SigningMethodRSAPSS) Verify(signingString, signature string, key interface{}) error

Implements the Verify method from SigningMethod For this verify method, key must be an rsa.PublicKey struct

type StandardClaims ¶

Structured version of Claims Section, as referenced at https://tools.ietf.org/html/rfc7519#section-4.1 See examples for how to use this with your own claim types

type StandardClaims struct {
    Audience  string `json:"aud,omitempty"`
    ExpiresAt int64  `json:"exp,omitempty"`
    Id        string `json:"jti,omitempty"`
    IssuedAt  int64  `json:"iat,omitempty"`
    Issuer    string `json:"iss,omitempty"`
    NotBefore int64  `json:"nbf,omitempty"`
    Subject   string `json:"sub,omitempty"`
}

func (StandardClaims) Valid ¶

func (c StandardClaims) Valid() error

Validates time based claims "exp, iat, nbf". There is no accounting for clock skew. As well, if any of the above claims are not in the token, it will still be considered a valid claim.

func (*StandardClaims) VerifyAudience ¶

func (c *StandardClaims) VerifyAudience(cmp string, req bool) bool

Compares the aud claim against cmp. If required is false, this method will return true if the value matches or is unset

func (*StandardClaims) VerifyExpiresAt ¶

func (c *StandardClaims) VerifyExpiresAt(cmp int64, req bool) bool

Compares the exp claim against cmp. If required is false, this method will return true if the value matches or is unset

func (*StandardClaims) VerifyIssuedAt ¶

func (c *StandardClaims) VerifyIssuedAt(cmp int64, req bool) bool

Compares the iat claim against cmp. If required is false, this method will return true if the value matches or is unset

func (*StandardClaims) VerifyIssuer ¶

func (c *StandardClaims) VerifyIssuer(cmp string, req bool) bool

Compares the iss claim against cmp. If required is false, this method will return true if the value matches or is unset

func (*StandardClaims) VerifyNotBefore ¶

func (c *StandardClaims) VerifyNotBefore(cmp int64, req bool) bool

Compares the nbf claim against cmp. If required is false, this method will return true if the value matches or is unset

type Token ¶

A JWT Token. Different fields will be used depending on whether you're creating or parsing/verifying a token.

type Token struct {
    Raw       string                 // The raw token.  Populated when you Parse a token
    Method    SigningMethod          // The signing method used or to be used
    Header    map[string]interface{} // The first segment of the token
    Claims    Claims                 // The second segment of the token
    Signature string                 // The third segment of the token.  Populated when you Parse a token
    Valid     bool                   // Is the token valid?  Populated when you Parse/Verify a token
}

func New ¶

func New(method SigningMethod) *Token

Create a new Token. Takes a signing method

// Create a new token object, specifying signing method and the claims
// you would like it to contain.
token := jwt.NewWithClaims(jwt.SigningMethodHS256, jwt.MapClaims{
    "foo": "bar",
    "nbf": time.Date(2015, 10, 10, 12, 0, 0, 0, time.UTC).Unix(),
})

// Sign and get the complete encoded token as a string using the secret
tokenString, err := token.SignedString(hmacSampleSecret)

fmt.Println(tokenString, err)

eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJmb28iOiJiYXIiLCJuYmYiOjE0NDQ0Nzg0MDB9.u1riaD1rW97opCoAuRCTy4w58Br-Zk-bh7vLiRIsrpU <nil>

func NewWithClaims ¶

func NewWithClaims(method SigningMethod, claims Claims) *Token

mySigningKey := []byte("AllYourBase")

type MyCustomClaims struct {
    Foo string `json:"foo"`
    jwt.StandardClaims
}

// Create the Claims
claims := MyCustomClaims{
    "bar",
    jwt.StandardClaims{
        ExpiresAt: 15000,
        Issuer:    "test",
    },
}

token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
ss, err := token.SignedString(mySigningKey)
fmt.Printf("%v %v", ss, err)

eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJmb28iOiJiYXIiLCJleHAiOjE1MDAwLCJpc3MiOiJ0ZXN0In0.HE7fK0xOQwFEr4WDgRWj4teRPZ6i3GLwD5YCm6Pwu_c <nil>

mySigningKey := []byte("AllYourBase")

// Create the Claims
claims := &jwt.StandardClaims{
    ExpiresAt: 15000,
    Issuer:    "test",
}

token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
ss, err := token.SignedString(mySigningKey)
fmt.Printf("%v %v", ss, err)

eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJleHAiOjE1MDAwLCJpc3MiOiJ0ZXN0In0.QsODzZu3lUZMVdhbO76u3Jv02iYCvEHcYVUI1kOWEU0 <nil>

func Parse ¶

func Parse(tokenString string, keyFunc Keyfunc) (*Token, error)

Parse, validate, and return a token. keyFunc will receive the parsed token and should return the key for validating. If everything is kosher, err will be nil

// Token from another example.  This token is expired
var tokenString = "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJmb28iOiJiYXIiLCJleHAiOjE1MDAwLCJpc3MiOiJ0ZXN0In0.HE7fK0xOQwFEr4WDgRWj4teRPZ6i3GLwD5YCm6Pwu_c"

token, err := jwt.Parse(tokenString, func(token *jwt.Token) (interface{}, error) {
    return []byte("AllYourBase"), nil
})

if token.Valid {
    fmt.Println("You look nice today")
} else if ve, ok := err.(*jwt.ValidationError); ok {
    if ve.Errors&jwt.ValidationErrorMalformed != 0 {
        fmt.Println("That's not even a token")
    } else if ve.Errors&(jwt.ValidationErrorExpired|jwt.ValidationErrorNotValidYet) != 0 {
        // Token is either expired or not active yet
        fmt.Println("Timing is everything")
    } else {
        fmt.Println("Couldn't handle this token:", err)
    }
} else {
    fmt.Println("Couldn't handle this token:", err)
}

Timing is everything

// sample token string taken from the New example
tokenString := "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJmb28iOiJiYXIiLCJuYmYiOjE0NDQ0Nzg0MDB9.u1riaD1rW97opCoAuRCTy4w58Br-Zk-bh7vLiRIsrpU"

// Parse takes the token string and a function for looking up the key. The latter is especially
// useful if you use multiple keys for your application.  The standard is to use 'kid' in the
// head of the token to identify which key to use, but the parsed token (head and claims) is provided
// to the callback, providing flexibility.
token, err := jwt.Parse(tokenString, func(token *jwt.Token) (interface{}, error) {
    // Don't forget to validate the alg is what you expect:
    if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
        return nil, fmt.Errorf("Unexpected signing method: %v", token.Header["alg"])
    }

    // hmacSampleSecret is a []byte containing your secret, e.g. []byte("my_secret_key")
    return hmacSampleSecret, nil
})

if claims, ok := token.Claims.(jwt.MapClaims); ok && token.Valid {
    fmt.Println(claims["foo"], claims["nbf"])
} else {
    fmt.Println(err)
}

bar 1.4444784e+09

func ParseWithClaims ¶

func ParseWithClaims(tokenString string, claims Claims, keyFunc Keyfunc) (*Token, error)

tokenString := "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJmb28iOiJiYXIiLCJleHAiOjE1MDAwLCJpc3MiOiJ0ZXN0In0.HE7fK0xOQwFEr4WDgRWj4teRPZ6i3GLwD5YCm6Pwu_c"

type MyCustomClaims struct {
    Foo string `json:"foo"`
    jwt.StandardClaims
}

// sample token is expired.  override time so it parses as valid
at(time.Unix(0, 0), func() {
    token, err := jwt.ParseWithClaims(tokenString, &MyCustomClaims{}, func(token *jwt.Token) (interface{}, error) {
        return []byte("AllYourBase"), nil
    })

    if claims, ok := token.Claims.(*MyCustomClaims); ok && token.Valid {
        fmt.Printf("%v %v", claims.Foo, claims.StandardClaims.ExpiresAt)
    } else {
        fmt.Println(err)
    }
})

bar 15000

func (*Token) SignedString ¶

func (t *Token) SignedString(key interface{}) (string, error)

Get the complete, signed token

func (*Token) SigningString ¶

func (t *Token) SigningString() (string, error)

Generate the signing string. This is the most expensive part of the whole deal. Unless you need this for something special, just go straight for the SignedString.

type ValidationError ¶

The error from Parse if token is not valid

type ValidationError struct {
    Inner  error  // stores the error returned by external dependencies, i.e.: KeyFunc
    Errors uint32 // bitfield.  see ValidationError... constants
    // contains filtered or unexported fields
}

func NewValidationError ¶

func NewValidationError(errorText string, errorFlags uint32) *ValidationError

Helper for constructing a ValidationError with a string error message

func (ValidationError) Error ¶

func (e ValidationError) Error() string

Validation error is an error type

Subdirectories