Make client a top-level package for consistency

1 files changed, 113 insertions, 0 deletions

diff --git a/client/client.go b/client/client.go
new file mode 100644
index 0000000..ba5b900
--- /dev/null
+++ b/client/client.go
@@ -0,0 +1,113 @@
+package client
+
+import (
+	"bytes"
+	"crypto/tls"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"path"
+	"time"
+
+	"github.com/nsheridan/cashier/lib"
+	"golang.org/x/crypto/ssh"
+	"golang.org/x/crypto/ssh/agent"
+)
+
+// InstallCert adds the private key and signed certificate to the ssh agent.
+func InstallCert(a agent.Agent, cert *ssh.Certificate, key Key) error {
+	t := time.Unix(int64(cert.ValidBefore), 0)
+	lifetime := t.Sub(time.Now()).Seconds()
+	comment := fmt.Sprintf("%s [Expires %s]", cert.KeyId, t)
+	pubcert := agent.AddedKey{
+		PrivateKey:   key,
+		Certificate:  cert,
+		Comment:      comment,
+		LifetimeSecs: uint32(lifetime),
+	}
+	if err := a.Add(pubcert); err != nil {
+		return fmt.Errorf("error importing certificate: %s", err)
+	}
+	privkey := agent.AddedKey{
+		PrivateKey:   key,
+		Comment:      comment,
+		LifetimeSecs: uint32(lifetime),
+	}
+	if err := a.Add(privkey); err != nil {
+		return fmt.Errorf("error importing key: %s", err)
+	}
+	return nil
+}
+
+// send the signing request to the CA.
+func send(s []byte, token, ca string, ValidateTLSCertificate bool) (*lib.SignResponse, error) {
+	transport := &http.Transport{
+		TLSClientConfig: &tls.Config{InsecureSkipVerify: !ValidateTLSCertificate},
+	}
+	client := &http.Client{Transport: transport}
+	u, err := url.Parse(ca)
+	if err != nil {
+		return nil, err
+	}
+	u.Path = path.Join(u.Path, "/sign")
+	req, err := http.NewRequest("POST", u.String(), bytes.NewReader(s))
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Add("Accept", "application/json")
+	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token))
+	resp, err := client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("Bad response from server: %s", resp.Status)
+	}
+	defer resp.Body.Close()
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+	c := &lib.SignResponse{}
+	if err := json.Unmarshal(body, c); err != nil {
+		return nil, err
+	}
+	return c, nil
+}
+
+// Sign sends the public key to the CA to be signed.
+func Sign(pub ssh.PublicKey, token string, conf *Config) (*ssh.Certificate, error) {
+	validity, err := time.ParseDuration(conf.Validity)
+	if err != nil {
+		return nil, err
+	}
+	marshaled := ssh.MarshalAuthorizedKey(pub)
+	// Remove the trailing newline.
+	marshaled = marshaled[:len(marshaled)-1]
+	s, err := json.Marshal(&lib.SignRequest{
+		Key:        string(marshaled),
+		ValidUntil: time.Now().Add(validity),
+	})
+	if err != nil {
+		return nil, err
+	}
+	resp, err := send(s, token, conf.CA, conf.ValidateTLSCertificate)
+	if err != nil {
+		return nil, err
+	}
+	if resp.Status != "ok" {
+		return nil, fmt.Errorf("error: %s", resp.Response)
+	}
+	k, _, _, _, err := ssh.ParseAuthorizedKey([]byte(resp.Response))
+	if err != nil {
+		return nil, err
+	}
+	cert, ok := k.(*ssh.Certificate)
+	if !ok {
+		return nil, fmt.Errorf("did not receive a certificate from server")
+	}
+	return cert, nil
+}