diff options
Diffstat (limited to 'vendor/golang.org/x/oauth2/jwt/jwt.go')
-rw-r--r-- | vendor/golang.org/x/oauth2/jwt/jwt.go | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/vendor/golang.org/x/oauth2/jwt/jwt.go b/vendor/golang.org/x/oauth2/jwt/jwt.go new file mode 100644 index 000000000..0783a94c4 --- /dev/null +++ b/vendor/golang.org/x/oauth2/jwt/jwt.go @@ -0,0 +1,162 @@ +// 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 jwt implements the OAuth 2.0 JSON Web Token flow, commonly +// known as "two-legged OAuth 2.0". +// +// See: https://tools.ietf.org/html/draft-ietf-oauth-jwt-bearer-12 +package jwt + +import ( + "context" + "encoding/json" + "fmt" + "io" + "io/ioutil" + "net/http" + "net/url" + "strings" + "time" + + "golang.org/x/oauth2" + "golang.org/x/oauth2/internal" + "golang.org/x/oauth2/jws" +) + +var ( + defaultGrantType = "urn:ietf:params:oauth:grant-type:jwt-bearer" + defaultHeader = &jws.Header{Algorithm: "RS256", Typ: "JWT"} +) + +// Config is the configuration for using JWT to fetch tokens, +// commonly known as "two-legged OAuth 2.0". +type Config struct { + // Email is the OAuth client identifier used when communicating with + // the configured OAuth provider. + Email string + + // PrivateKey contains the contents of an RSA private key or the + // contents of a PEM file that contains a private key. The provided + // private key is used to sign JWT payloads. + // PEM containers with a passphrase are not supported. + // Use the following command to convert a PKCS 12 file into a PEM. + // + // $ openssl pkcs12 -in key.p12 -out key.pem -nodes + // + PrivateKey []byte + + // PrivateKeyID contains an optional hint indicating which key is being + // used. + PrivateKeyID string + + // Subject is the optional user to impersonate. + Subject string + + // Scopes optionally specifies a list of requested permission scopes. + Scopes []string + + // TokenURL is the endpoint required to complete the 2-legged JWT flow. + TokenURL string + + // Expires optionally specifies how long the token is valid for. + Expires time.Duration +} + +// TokenSource returns a JWT TokenSource using the configuration +// in c and the HTTP client from the provided context. +func (c *Config) TokenSource(ctx context.Context) oauth2.TokenSource { + return oauth2.ReuseTokenSource(nil, jwtSource{ctx, c}) +} + +// Client returns an HTTP client wrapping the context's +// HTTP transport and adding Authorization headers with tokens +// obtained from c. +// +// The returned client and its Transport should not be modified. +func (c *Config) Client(ctx context.Context) *http.Client { + return oauth2.NewClient(ctx, c.TokenSource(ctx)) +} + +// jwtSource is a source that always does a signed JWT request for a token. +// It should typically be wrapped with a reuseTokenSource. +type jwtSource struct { + ctx context.Context + conf *Config +} + +func (js jwtSource) Token() (*oauth2.Token, error) { + pk, err := internal.ParseKey(js.conf.PrivateKey) + if err != nil { + return nil, err + } + hc := oauth2.NewClient(js.ctx, nil) + claimSet := &jws.ClaimSet{ + Iss: js.conf.Email, + Scope: strings.Join(js.conf.Scopes, " "), + Aud: js.conf.TokenURL, + } + if subject := js.conf.Subject; subject != "" { + claimSet.Sub = subject + // prn is the old name of sub. Keep setting it + // to be compatible with legacy OAuth 2.0 providers. + claimSet.Prn = subject + } + if t := js.conf.Expires; t > 0 { + claimSet.Exp = time.Now().Add(t).Unix() + } + h := *defaultHeader + h.KeyID = js.conf.PrivateKeyID + payload, err := jws.Encode(&h, claimSet, pk) + if err != nil { + return nil, err + } + v := url.Values{} + v.Set("grant_type", defaultGrantType) + v.Set("assertion", payload) + resp, err := hc.PostForm(js.conf.TokenURL, v) + if err != nil { + return nil, fmt.Errorf("oauth2: cannot fetch token: %v", err) + } + defer resp.Body.Close() + body, err := ioutil.ReadAll(io.LimitReader(resp.Body, 1<<20)) + if err != nil { + return nil, fmt.Errorf("oauth2: cannot fetch token: %v", err) + } + if c := resp.StatusCode; c < 200 || c > 299 { + return nil, &oauth2.RetrieveError{ + Response: resp, + Body: body, + } + } + // tokenRes is the JSON response body. + var tokenRes struct { + AccessToken string `json:"access_token"` + TokenType string `json:"token_type"` + IDToken string `json:"id_token"` + ExpiresIn int64 `json:"expires_in"` // relative seconds from now + } + if err := json.Unmarshal(body, &tokenRes); err != nil { + return nil, fmt.Errorf("oauth2: cannot fetch token: %v", err) + } + token := &oauth2.Token{ + AccessToken: tokenRes.AccessToken, + TokenType: tokenRes.TokenType, + } + raw := make(map[string]interface{}) + json.Unmarshal(body, &raw) // no error checks for optional fields + token = token.WithExtra(raw) + + if secs := tokenRes.ExpiresIn; secs > 0 { + token.Expiry = time.Now().Add(time.Duration(secs) * time.Second) + } + if v := tokenRes.IDToken; v != "" { + // decode returned id token to get expiry + claimSet, err := jws.Decode(v) + if err != nil { + return nil, fmt.Errorf("oauth2: error decoding JWT token: %v", err) + } + token.Expiry = time.Unix(claimSet.Exp, 0) + } + return token, nil +} |