Update Lego

vendor/github.com/xenolf/lego/acme/api/internal/nonces/nonce_manager.go

@@ -0,0 +1,78 @@
+package nonces
+
+import (
+	"errors"
+	"fmt"
+	"net/http"
+	"sync"
+
+	"github.com/xenolf/lego/acme/api/internal/sender"
+)
+
+// Manager Manages nonces.
+type Manager struct {
+	do       *sender.Doer
+	nonceURL string
+	nonces   []string
+	sync.Mutex
+}
+
+// NewManager Creates a new Manager.
+func NewManager(do *sender.Doer, nonceURL string) *Manager {
+	return &Manager{
+		do:       do,
+		nonceURL: nonceURL,
+	}
+}
+
+// Pop Pops a nonce.
+func (n *Manager) Pop() (string, bool) {
+	n.Lock()
+	defer n.Unlock()
+
+	if len(n.nonces) == 0 {
+		return "", false
+	}
+
+	nonce := n.nonces[len(n.nonces)-1]
+	n.nonces = n.nonces[:len(n.nonces)-1]
+	return nonce, true
+}
+
+// Push Pushes a nonce.
+func (n *Manager) Push(nonce string) {
+	n.Lock()
+	defer n.Unlock()
+	n.nonces = append(n.nonces, nonce)
+}
+
+// Nonce implement jose.NonceSource
+func (n *Manager) Nonce() (string, error) {
+	if nonce, ok := n.Pop(); ok {
+		return nonce, nil
+	}
+	return n.getNonce()
+}
+
+func (n *Manager) getNonce() (string, error) {
+	resp, err := n.do.Head(n.nonceURL)
+	if err != nil {
+		return "", fmt.Errorf("failed to get nonce from HTTP HEAD -> %v", err)
+	}
+
+	return GetFromResponse(resp)
+}
+
+// GetFromResponse Extracts a nonce from a HTTP response.
+func GetFromResponse(resp *http.Response) (string, error) {
+	if resp == nil {
+		return "", errors.New("nil response")
+	}
+
+	nonce := resp.Header.Get("Replay-Nonce")
+	if nonce == "" {
+		return "", fmt.Errorf("server did not respond with a proper nonce header")
+	}
+
+	return nonce, nil
+}