lego/providers/dns/constellix/internal/auth.go
2020-10-17 14:51:55 +02:00

91 lines
2.3 KiB
Go

package internal
import (
"crypto/hmac"
"crypto/sha1"
"encoding/base64"
"errors"
"fmt"
"net/http"
"strconv"
"time"
)
const securityTokenHeader = "x-cns-security-token"
// TokenTransport HTTP transport for API authentication.
type TokenTransport struct {
apiKey string
secretKey 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 HTTP transport for API authentication.
func NewTokenTransport(apiKey, secretKey string) (*TokenTransport, error) {
if apiKey == "" {
return nil, errors.New("credentials missing: API key")
}
if secretKey == "" {
return nil, errors.New("credentials missing: secret key")
}
return &TokenTransport{apiKey: apiKey, secretKey: secretKey}, 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.apiKey != "" && t.secretKey != "" {
securityToken := createCnsSecurityToken(t.apiKey, t.secretKey)
enrichedReq.Header.Set(securityTokenHeader, securityToken)
}
return t.transport().RoundTrip(enrichedReq)
}
func (t *TokenTransport) transport() http.RoundTripper {
if t.Transport != nil {
return t.Transport
}
return http.DefaultTransport
}
// Client Creates a new HTTP client.
func (t *TokenTransport) Client() *http.Client {
return &http.Client{Transport: t}
}
// 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
}
func createCnsSecurityToken(apiKey, secretKey string) string {
timestamp := time.Now().Round(time.Millisecond).UnixNano() / int64(time.Millisecond)
hm := encodedHmac(timestamp, secretKey)
requestDate := strconv.FormatInt(timestamp, 10)
return fmt.Sprintf("%s:%s:%s", apiKey, hm, requestDate)
}
func encodedHmac(message int64, secret string) string {
h := hmac.New(sha1.New, []byte(secret))
_, _ = h.Write([]byte(strconv.FormatInt(message, 10)))
return base64.StdEncoding.EncodeToString(h.Sum(nil))
}