Add support for rekeying Fixes #292

api/rekey.go

@@ -0,0 +1,65 @@
+package api
+
+import (
+	"net/http"
+
+	"github.com/smallstep/certificates/errs"
+)
+
+// RekeyRequest is the request body for a certificate rekey request.
+type RekeyRequest struct {
+	CsrPEM    CertificateRequest `json:"csr"`
+}
+
+// Validate checks the fields of the RekeyRequest and returns nil if they are ok
+// or an error if something is wrong.
+func (s *RekeyRequest) Validate() error {
+	if s.CsrPEM.CertificateRequest == nil {
+		return errs.BadRequest("missing csr")
+	}
+	if err := s.CsrPEM.CertificateRequest.CheckSignature(); err != nil {
+		return errs.Wrap(http.StatusBadRequest, err, "invalid csr")
+	}
+
+	return nil
+}
+
+
+// Rekey is similar to renew except that the certificate will be renewed with new key from csr.
+func (h *caHandler) Rekey(w http.ResponseWriter, r *http.Request) {
+
+	var body RekeyRequest
+	if err := ReadJSON(r.Body, &body); err != nil {
+		WriteError(w, errs.Wrap(http.StatusBadRequest, err, "error reading request body"))
+		return
+	}
+
+	if err := body.Validate(); err != nil {
+		WriteError(w, err)
+		return
+	}
+
+	if r.TLS == nil || len(r.TLS.PeerCertificates) == 0 {
+		WriteError(w, errs.BadRequest("missing peer certificate"))
+		return
+	}
+
+	certChain, err := h.Authority.Rekey(r.TLS.PeerCertificates[0],body.CsrPEM.CertificateRequest)
+	if err != nil {
+		WriteError(w, errs.Wrap(http.StatusInternalServerError, err, "cahandler.Rekey"))
+		return
+	}
+	certChainPEM := certChainToPEM(certChain)
+	var caPEM Certificate
+	if len(certChainPEM) > 1 {
+		caPEM = certChainPEM[1]
+	}
+
+	logCertificate(w, certChain[0])
+	JSONStatus(w, &SignResponse{
+		ServerPEM:    certChainPEM[0],
+		CaPEM:        caPEM,
+		CertChainPEM: certChainPEM,
+		TLSOptions:   h.Authority.GetTLSOptions(),
+	}, http.StatusCreated)
+}