Merge branch 'release_3_0_0' into dg/request

.travis.yml

@@ -1,7 +1,8 @@
 language: go
 
 go:
-  - 1.3.3
-  - 1.4.2
+  - 1.3
+  - 1.4
   - 1.5
+  - 1.6
   - tip

README.md

@@ -4,6 +4,7 @@ A [go](http://www.golang.org) (or 'golang' for search engine friendliness) imple
 
 **NOTICE:** A vulnerability in JWT was [recently published](https://auth0.com/blog/2015/03/31/critical-vulnerabilities-in-json-web-token-libraries/).  As this library doesn't force users to validate the `alg` is what they expected, it's possible your usage is effected.  There will be an update soon to remedy this, and it will likey require backwards-incompatible changes to the API.  In the short term, please make sure your implementation verifies the `alg` is what you expect.
 
+
 ## What the heck is a JWT?
 
 In short, it's a signed JSON object that does something useful (for example, authentication).  It's commonly used for `Bearer` tokens in Oauth 2.  A token is made of three parts, separated by `.`'s.  The first two parts are JSON objects, that have been [base64url](http://tools.ietf.org/html/rfc4648) encoded.  The last part is the signature, encoded the same way.
@@ -14,7 +15,7 @@ The part in the middle is the interesting bit.  It's called the Claims and conta
 
 ## What's in the box?
 
-This library supports the parsing and verification as well as the generation and signing of JWTs.  Current supported signing algorithms are RSA256 and HMAC SHA256, though hooks are present for adding your own.
+This library supports the parsing and verification as well as the generation and signing of JWTs.  Current supported signing algorithms are HMAC SHA, RSA, RSA-PSS, and ECDSA, though hooks are present for adding your own.
 
 ## Parse and Verify
 
@@ -26,7 +27,7 @@ Parsing and verifying tokens is pretty straight forward.  You pass in the token
 		if _, ok := token.Method.(*jwt.SigningMethodRSA); !ok {
 			return nil, fmt.Errorf("Unexpected signing method: %v", token.Header["alg"])
 		}
-		return myLookupKey(token.Header["kid"])
+		return myLookupKey(token.Header["kid"]), nil
 	})
 
 	if err == nil && token.Valid {
@@ -35,18 +36,18 @@ Parsing and verifying tokens is pretty straight forward.  You pass in the token
 		deliverUtterRejection(":(")
 	}
 ```
-	
+
 ## Create a token
 
 ```go
 	// Create the token
-	token := jwt.New(jwt.SigningMethodHS256)
-	// Set some claims
-	token.Claims["foo"] = "bar"
-	token.Claims["exp"] = time.Now().Add(time.Hour * 72).Unix()
+	token := jwt.NewWithClaims(jwt.SigningMethodHS256, jwt.MapClaims{
+		"foo": "bar",
+		"exp": time.Now().Add(time.Hour * 72).Unix(),
+	})
 	// Sign and get the complete encoded token as a string
 	tokenString, err := token.SignedString(mySigningKey)
-```	
+```
 
 ## Extensions
 
@@ -62,6 +63,92 @@ This project uses [Semantic Versioning 2.0.0](http://semver.org).  Accepted pull
 
 While we try to make it obvious when we make breaking changes, there isn't a great mechanism for pushing announcements out to users.  You may want to use this alternative package include: `gopkg.in/dgrijalva/jwt-go.v2`.  It will do the right thing WRT semantic versioning.
 
+## Migration Guide from v2 -> v3
+
+Added the ability to supply a typed object for the claims section of the token.
+
+Unfortunately this requires a breaking change. A few new methods were added to support this,
+and the old default of `map[string]interface{}` was changed to `jwt.MapClaims`.
+
+The old example for creating a token looked like this..
+
+```go
+	token := jwt.New(jwt.SigningMethodHS256)
+	token.Claims["foo"] = "bar"
+	token.Claims["exp"] = time.Now().Add(time.Hour * 72).Unix()
+```
+
+is now directly mapped to...
+
+```go
+	token := jwt.New(jwt.SigningMethodHS256)
+	claims := token.Claims.(jwt.MapClaims)
+	claims["foo"] = "bar"
+	claims["exp"] = time.Now().Add(time.Hour * 72).Unix()
+```
+
+However, we added a helper `jwt.NewWithClaims` which accepts a claims object.
+
+Any type can now be used as the claim object for inside a token so long as it implements the interface `jwt.Claims`.
+
+So, we added an additional claim type `jwt.StandardClaims` was added.
+This is intended to be used as a base for creating your own types from,
+and includes a few helper functions for verifying the claims defined [here](https://tools.ietf.org/html/rfc7519#section-4.1).
+
+```go
+	claims := jwt.StandardClaims{
+		Audience: "myapi"
+		ExpiresAt: time.Now().Add(time.Hour * 72).Unix(),
+	}
+	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
+```
+
+On the other end of usage all of the `jwt.Parse` and friends got a `WithClaims` suffix added to them.
+
+```go
+	token, err := jwt.Parse(token, keyFunc)
+	claims := token.Claims.(jwt.MapClaim)
+	//like you used to..
+	claims["foo"]
+	claims["bar"]
+```
+
+New method usage:
+```go
+	token, err := jwt.ParseWithClaims(token, keyFunc, &jwt.StandardClaims{})
+	claims := token.Claims.(jwt.StandardClaims)
+	fmt.Println(claims.IssuedAt)
+```
+
+## Usage Tips
+
+### Signing vs Encryption
+
+A token is simply a JSON object that is signed by its author. this tells you exactly two things about the data:
+
+* The author of the token was in the possession of the signing secret
+* The data has not been modified since it was signed
+
+It's important to know that JWT does not provide encryption, which means anyone who has access to the token can read its contents. If you need to protect (encrypt) the data, there is a companion spec, `JWE`, that provides this functionality. JWE is currently outside the scope of this library.
+
+### Choosing a Signing Method
+
+There are several signing methods available, and you should probably take the time to learn about the various options before choosing one.  The principal design decision is most likely going to be symmetric vs asymmetric.
+
+Symmetric signing methods, such as HSA, use only a single secret. This is probably the simplest signing method to use since any `[]byte` can be used as a valid secret. They are also slightly computationally faster to use, though this rarely is enough to matter. Symmetric signing methods work the best when both producers and consumers of tokens are trusted, or even the same system. Since the same secret is used to both sign and validate tokens, you can't easily distribute the key for validation.
+
+Asymmetric signing methods, such as RSA, use different keys for signing and verifying tokens. This makes it possible to produce tokens with a private key, and allow any consumer to access the public key for verification.
+
+### JWT and OAuth
+
+It's worth mentioning that OAuth and JWT are not the same thing. A JWT token is simply a signed JSON object. It can be used anywhere such a thing is useful. There is some confusion, though, as JWT is the most common type of bearer token used in OAuth2 authentication.
+
+Without going too far down the rabbit hole, here's a description of the interaction of these technologies:
+
+* OAuth is a protocol for allowing an identity provider to be separate from the service a user is logging in to.  For example, whenever you use Facebook to log into a different service (Yelp, Spotify, etc), you are using OAuth.
+* OAuth defines several options for passing around authentication data. One popular method is called a "bearer token". A bearer token is simply a string that _should_ only be held by an authenticated user. Thus, simply presenting this token proves your identity. You can probably derive from here why a JWT might make a good bearer token.
+* Because bearer tokens are used for authentication, it's important they're kept secret. This is why transactions that use bearer tokens typically happen over SSL.
+
 ## More
 
 Documentation can be found [on godoc.org](http://godoc.org/github.com/dgrijalva/jwt-go).

VERSION_HISTORY.md

@@ -1,5 +1,20 @@
 ## `jwt-go` Version History
 
+#### 3.0.0
+
+* Dropped support for `[]byte` keys when using RSA signing methods.  This convenience feature could contribute to security vulnerabilities involving mismatched key types with signing methods.
+* Added `Claims` interface type to allow users to decode the claims into a custom type
+* The `Claims` property on `Token` is now type `Claims` instead of `map[string]interface{}`.  The default value is type `MapClaims`, which is an alias to `map[string]interface{}`.  This makes it possible to use a custom type when decoding claims.
+* Added `ParseWithClaims`, which takes a third argument of type `Claims`.  Use this function instead of `Parse` if you have a custom type you'd like to decode into.
+
+#### 2.5.0
+
+This will likely be the last backwards compatible release before 3.0.0.
+
+* Added support for signing method none.  You shouldn't use this.  The API tries to make this clear.
+* Updated/fixed some documentation
+* Added more helpful error message when trying to parse tokens that begin with `BEARER `
+
 #### 2.4.0
 
 * Added new type, Parser, to allow for configuration of various parsing parameters

claims.go

@@ -0,0 +1,193 @@
+package jwt
+
+import "crypto/subtle"
+
+// 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
+}
+
+// Structured version of Claims Section, as referenced at
+// https://tools.ietf.org/html/rfc7519#section-4.1
+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"`
+}
+
+// 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 (c StandardClaims) Valid() error {
+	vErr := new(ValidationError)
+	now := TimeFunc().Unix()
+
+	// The claims below are optional, by default, so if they are set to the
+	// default value in Go, let's not fail the verification for them.
+	if c.VerifyExpiresAt(now, false) == false {
+		vErr.err = "Token is expired"
+		vErr.Errors |= ValidationErrorExpired
+	}
+
+	if c.VerifyIssuedAt(now, false) == false {
+		vErr.err = "Token used before issued, clock skew issue?"
+		vErr.Errors |= ValidationErrorIssuedAt
+	}
+
+	if c.VerifyNotBefore(now, false) == false {
+		vErr.err = "Token is not valid yet"
+		vErr.Errors |= ValidationErrorNotValidYet
+	}
+
+	if vErr.valid() {
+		return nil
+	}
+
+	return vErr
+}
+
+// Compares the aud claim against cmp.
+// If required is false, this method will return true if the value matches or is unset
+func (c *StandardClaims) VerifyAudience(cmp string, req bool) bool {
+	return verifyAud(c.Audience, cmp, req)
+}
+
+// Compares the exp claim against cmp.
+// If required is false, this method will return true if the value matches or is unset
+func (c *StandardClaims) VerifyExpiresAt(cmp int64, req bool) bool {
+	return verifyExp(c.ExpiresAt, cmp, req)
+}
+
+// Compares the iat claim against cmp.
+// If required is false, this method will return true if the value matches or is unset
+func (c *StandardClaims) VerifyIssuedAt(cmp int64, req bool) bool {
+	return verifyIat(c.IssuedAt, cmp, req)
+}
+
+// Compares the iss claim against cmp.
+// If required is false, this method will return true if the value matches or is unset
+func (c *StandardClaims) VerifyIssuer(cmp string, req bool) bool {
+	return verifyIss(c.Issuer, cmp, req)
+}
+
+// Compares the nbf claim against cmp.
+// If required is false, this method will return true if the value matches or is unset
+func (c *StandardClaims) VerifyNotBefore(cmp int64, req bool) bool {
+	return verifyNbf(c.NotBefore, cmp, req)
+}
+
+type MapClaims map[string]interface{}
+
+// Compares the aud claim against cmp.
+// If required is false, this method will return true if the value matches or is unset
+func (m MapClaims) VerifyAudience(cmp string, req bool) bool {
+	aud, _ := m["aud"].(string)
+	return verifyAud(aud, cmp, req)
+}
+
+// Compares the exp claim against cmp.
+// If required is false, this method will return true if the value matches or is unset
+func (m MapClaims) VerifyExpiresAt(cmp int64, req bool) bool {
+	exp, _ := m["exp"].(float64)
+	return verifyExp(int64(exp), cmp, req)
+}
+
+// Compares the iat claim against cmp.
+// If required is false, this method will return true if the value matches or is unset
+func (m MapClaims) VerifyIssuedAt(cmp int64, req bool) bool {
+	iat, _ := m["iat"].(float64)
+	return verifyIat(int64(iat), cmp, req)
+}
+
+// Compares the iss claim against cmp.
+// If required is false, this method will return true if the value matches or is unset
+func (m MapClaims) VerifyIssuer(cmp string, req bool) bool {
+	iss, _ := m["iss"].(string)
+	return verifyIss(iss, cmp, req)
+}
+
+// Compares the nbf claim against cmp.
+// If required is false, this method will return true if the value matches or is unset
+func (m MapClaims) VerifyNotBefore(cmp int64, req bool) bool {
+	nbf, _ := m["nbf"].(float64)
+	return verifyNbf(int64(nbf), cmp, req)
+}
+
+// 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 (m MapClaims) Valid() error {
+	vErr := new(ValidationError)
+	now := TimeFunc().Unix()
+
+	if m.VerifyExpiresAt(now, false) == false {
+		vErr.err = "Token is expired"
+		vErr.Errors |= ValidationErrorExpired
+	}
+
+	if m.VerifyIssuedAt(now, false) == false {
+		vErr.err = "Token used before issued, clock skew issue?"
+		vErr.Errors |= ValidationErrorIssuedAt
+	}
+
+	if m.VerifyNotBefore(now, false) == false {
+		vErr.err = "Token is not valid yet"
+		vErr.Errors |= ValidationErrorNotValidYet
+	}
+
+	if vErr.valid() {
+		return nil
+	}
+
+	return vErr
+}
+
+func verifyAud(aud string, cmp string, required bool) bool {
+	if aud == "" {
+		return !required
+	}
+	if subtle.ConstantTimeCompare([]byte(aud), []byte(cmp)) != 0 {
+		return true
+	} else {
+		return false
+	}
+}
+
+func verifyExp(exp int64, now int64, required bool) bool {
+	if exp == 0 {
+		return !required
+	}
+	return now <= exp
+}
+
+func verifyIat(iat int64, now int64, required bool) bool {
+	if iat == 0 {
+		return !required
+	}
+	return now >= iat
+}
+
+func verifyIss(iss string, cmp string, required bool) bool {
+	if iss == "" {
+		return !required
+	}
+	if subtle.ConstantTimeCompare([]byte(iss), []byte(cmp)) != 0 {
+		return true
+	} else {
+		return false
+	}
+}
+
+func verifyNbf(nbf int64, now int64, required bool) bool {
+	if nbf == 0 {
+		return !required
+	}
+	return now >= nbf
+}

cmd/jwt/app.go

@@ -163,7 +163,7 @@ func signToken() error {
 	}
 
 	// parse the JSON of the claims
-	var claims map[string]interface{}
+	var claims jwt.MapClaims
 	if err := json.Unmarshal(tokData, &claims); err != nil {
 		return fmt.Errorf("Couldn't parse claims JSON: %v", err)
 	}
@@ -182,8 +182,7 @@ func signToken() error {
 	}
 
 	// create a new token
-	token := jwt.New(alg)
-	token.Claims = claims
+	token := jwt.NewWithClaims(alg, claims)
 
 	if isEs() {
 		if k, ok := key.([]byte); !ok {