diff options
Diffstat (limited to 'vendor/golang.org/x/oauth2/jws/jws.go')
-rw-r--r-- | vendor/golang.org/x/oauth2/jws/jws.go | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/vendor/golang.org/x/oauth2/jws/jws.go b/vendor/golang.org/x/oauth2/jws/jws.go new file mode 100644 index 000000000..683d2d271 --- /dev/null +++ b/vendor/golang.org/x/oauth2/jws/jws.go @@ -0,0 +1,182 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package jws provides a partial implementation +// of JSON Web Signature encoding and decoding. +// It exists to support the golang.org/x/oauth2 package. +// +// See RFC 7515. +// +// Deprecated: this package is not intended for public use and might be +// removed in the future. It exists for internal use only. +// Please switch to another JWS package or copy this package into your own +// source tree. +package jws // import "golang.org/x/oauth2/jws" + +import ( + "bytes" + "crypto" + "crypto/rand" + "crypto/rsa" + "crypto/sha256" + "encoding/base64" + "encoding/json" + "errors" + "fmt" + "strings" + "time" +) + +// ClaimSet contains information about the JWT signature including the +// permissions being requested (scopes), the target of the token, the issuer, +// the time the token was issued, and the lifetime of the token. +type ClaimSet struct { + Iss string `json:"iss"` // email address of the client_id of the application making the access token request + Scope string `json:"scope,omitempty"` // space-delimited list of the permissions the application requests + Aud string `json:"aud"` // descriptor of the intended target of the assertion (Optional). + Exp int64 `json:"exp"` // the expiration time of the assertion (seconds since Unix epoch) + Iat int64 `json:"iat"` // the time the assertion was issued (seconds since Unix epoch) + Typ string `json:"typ,omitempty"` // token type (Optional). + + // Email for which the application is requesting delegated access (Optional). + Sub string `json:"sub,omitempty"` + + // The old name of Sub. Client keeps setting Prn to be + // complaint with legacy OAuth 2.0 providers. (Optional) + Prn string `json:"prn,omitempty"` + + // See http://tools.ietf.org/html/draft-jones-json-web-token-10#section-4.3 + // This array is marshalled using custom code (see (c *ClaimSet) encode()). + PrivateClaims map[string]interface{} `json:"-"` +} + +func (c *ClaimSet) encode() (string, error) { + // Reverting time back for machines whose time is not perfectly in sync. + // If client machine's time is in the future according + // to Google servers, an access token will not be issued. + now := time.Now().Add(-10 * time.Second) + if c.Iat == 0 { + c.Iat = now.Unix() + } + if c.Exp == 0 { + c.Exp = now.Add(time.Hour).Unix() + } + if c.Exp < c.Iat { + return "", fmt.Errorf("jws: invalid Exp = %v; must be later than Iat = %v", c.Exp, c.Iat) + } + + b, err := json.Marshal(c) + if err != nil { + return "", err + } + + if len(c.PrivateClaims) == 0 { + return base64.RawURLEncoding.EncodeToString(b), nil + } + + // Marshal private claim set and then append it to b. + prv, err := json.Marshal(c.PrivateClaims) + if err != nil { + return "", fmt.Errorf("jws: invalid map of private claims %v", c.PrivateClaims) + } + + // Concatenate public and private claim JSON objects. + if !bytes.HasSuffix(b, []byte{'}'}) { + return "", fmt.Errorf("jws: invalid JSON %s", b) + } + if !bytes.HasPrefix(prv, []byte{'{'}) { + return "", fmt.Errorf("jws: invalid JSON %s", prv) + } + b[len(b)-1] = ',' // Replace closing curly brace with a comma. + b = append(b, prv[1:]...) // Append private claims. + return base64.RawURLEncoding.EncodeToString(b), nil +} + +// Header represents the header for the signed JWS payloads. +type Header struct { + // The algorithm used for signature. + Algorithm string `json:"alg"` + + // Represents the token type. + Typ string `json:"typ"` + + // The optional hint of which key is being used. + KeyID string `json:"kid,omitempty"` +} + +func (h *Header) encode() (string, error) { + b, err := json.Marshal(h) + if err != nil { + return "", err + } + return base64.RawURLEncoding.EncodeToString(b), nil +} + +// Decode decodes a claim set from a JWS payload. +func Decode(payload string) (*ClaimSet, error) { + // decode returned id token to get expiry + s := strings.Split(payload, ".") + if len(s) < 2 { + // TODO(jbd): Provide more context about the error. + return nil, errors.New("jws: invalid token received") + } + decoded, err := base64.RawURLEncoding.DecodeString(s[1]) + if err != nil { + return nil, err + } + c := &ClaimSet{} + err = json.NewDecoder(bytes.NewBuffer(decoded)).Decode(c) + return c, err +} + +// Signer returns a signature for the given data. +type Signer func(data []byte) (sig []byte, err error) + +// EncodeWithSigner encodes a header and claim set with the provided signer. +func EncodeWithSigner(header *Header, c *ClaimSet, sg Signer) (string, error) { + head, err := header.encode() + if err != nil { + return "", err + } + cs, err := c.encode() + if err != nil { + return "", err + } + ss := fmt.Sprintf("%s.%s", head, cs) + sig, err := sg([]byte(ss)) + if err != nil { + return "", err + } + return fmt.Sprintf("%s.%s", ss, base64.RawURLEncoding.EncodeToString(sig)), nil +} + +// Encode encodes a signed JWS with provided header and claim set. +// This invokes EncodeWithSigner using crypto/rsa.SignPKCS1v15 with the given RSA private key. +func Encode(header *Header, c *ClaimSet, key *rsa.PrivateKey) (string, error) { + sg := func(data []byte) (sig []byte, err error) { + h := sha256.New() + h.Write(data) + return rsa.SignPKCS1v15(rand.Reader, key, crypto.SHA256, h.Sum(nil)) + } + return EncodeWithSigner(header, c, sg) +} + +// Verify tests whether the provided JWT token's signature was produced by the private key +// associated with the supplied public key. +func Verify(token string, key *rsa.PublicKey) error { + parts := strings.Split(token, ".") + if len(parts) != 3 { + return errors.New("jws: invalid token received, token must have 3 parts") + } + + signedContent := parts[0] + "." + parts[1] + signatureString, err := base64.RawURLEncoding.DecodeString(parts[2]) + if err != nil { + return err + } + + h := sha256.New() + h.Write([]byte(signedContent)) + return rsa.VerifyPKCS1v15(key, crypto.SHA256, h.Sum(nil), []byte(signatureString)) +} |