lego/vendor/github.com/ldez/go-auroradns/auth.go
2018-10-22 20:42:22 +02:00

98 lines
2.5 KiB
Go

package auroradns
import (
"crypto/hmac"
"crypto/sha256"
"encoding/base64"
"fmt"
"net/http"
"strings"
"time"
)
// TokenTransport HTTP transport for API authentication
type TokenTransport struct {
userID string
key string
// Transport is the underlying HTTP transport to use when making requests.
// It will default to http.DefaultTransport if nil.
Transport http.RoundTripper
}
// NewTokenTransport Creates a new TokenTransport
func NewTokenTransport(userID, key string) (*TokenTransport, error) {
if userID == "" || key == "" {
return nil, fmt.Errorf("credentials missing")
}
return &TokenTransport{userID: userID, key: key}, nil
}
// RoundTrip executes a single HTTP transaction
func (t *TokenTransport) RoundTrip(req *http.Request) (*http.Response, error) {
enrichedReq := &http.Request{}
*enrichedReq = *req
enrichedReq.Header = make(http.Header, len(req.Header))
for k, s := range req.Header {
enrichedReq.Header[k] = append([]string(nil), s...)
}
if t.userID != "" && t.key != "" {
timestamp := time.Now().UTC()
fmtTime := timestamp.Format("20060102T150405Z")
req.Header.Set("X-AuroraDNS-Date", fmtTime)
token, err := newToken(t.userID, t.key, req.Method, req.URL.Path, timestamp)
if err == nil {
req.Header.Set("Authorization", fmt.Sprintf("AuroraDNSv1 %s", token))
}
}
return t.transport().RoundTrip(enrichedReq)
}
// Wrap Wrap a HTTP client Transport with the TokenTransport
func (t *TokenTransport) Wrap(client *http.Client) *http.Client {
backup := client.Transport
t.Transport = backup
client.Transport = t
return client
}
// Client Creates a new HTTP client
func (t *TokenTransport) Client() *http.Client {
return &http.Client{
Transport: t,
Timeout: 30 * time.Second,
}
}
func (t *TokenTransport) transport() http.RoundTripper {
if t.Transport != nil {
return t.Transport
}
return http.DefaultTransport
}
// newToken generates a token for accessing a specific method of the API
func newToken(userID string, key string, method string, action string, timestamp time.Time) (string, error) {
fmtTime := timestamp.Format("20060102T150405Z")
message := strings.Join([]string{method, action, fmtTime}, "")
signatureHmac := hmac.New(sha256.New, []byte(key))
_, err := signatureHmac.Write([]byte(message))
if err != nil {
return "", err
}
signature := base64.StdEncoding.EncodeToString(signatureHmac.Sum(nil))
userIDAndSignature := fmt.Sprintf("%s:%s", userID, signature)
token := base64.StdEncoding.EncodeToString([]byte(userIDAndSignature))
return token, nil
}