Golang Docusign support

Signed-off-by: Harold Wanyama <hwanyama@contractor.linuxfoundation.org>

cla-backend-go/go.mod

@@ -84,6 +84,7 @@ require (
 	github.com/go-openapi/jsonreference v0.20.0 // indirect
 	github.com/go-playground/locales v0.13.0 // indirect
 	github.com/go-playground/universal-translator v0.17.0 // indirect
+	github.com/golang-jwt/jwt v3.2.2+incompatible // indirect
 	github.com/golang/protobuf v1.5.3 // indirect
 	github.com/google/go-github/v50 v50.2.0 // indirect
 	github.com/google/go-querystring v1.1.0 // indirect

cla-backend-go/go.sum

@@ -271,6 +271,8 @@ github.com/gobuffalo/packr/v2 v2.2.0/go.mod h1:CaAwI0GPIAv+5wKLtv8Afwl+Cm78K/I/V
 github.com/gobuffalo/syncx v0.0.0-20190224160051-33c29581e754/go.mod h1:HhnNqWY95UYwwW3uSASeV7vtgYkT2t16hJgV3AEPUpw=
 github.com/gofrs/uuid v4.0.0+incompatible h1:1SD/1F5pU8p29ybwgQSwpQk+mwdRrXCYuPhW6m+TnJw=
 github.com/gofrs/uuid v4.0.0+incompatible/go.mod h1:b2aQJv3Z4Fp6yNu3cdSllBxTCLRxnplIgP/c0N/04lM=
+github.com/golang-jwt/jwt v3.2.2+incompatible h1:IfV12K8xAKAnZqdXVzCZ+TOjboZ2keLg81eXfW3O+oY=
+github.com/golang-jwt/jwt v3.2.2+incompatible/go.mod h1:8pz2t5EyA70fFQQSrl6XZXzqecmYZeUEB8OUGHkxJ+I=
 github.com/golang-jwt/jwt/v4 v4.5.0 h1:7cYmW1XlMY7h7ii7UhUyChSgS5wUJEnm9uZVTGqOWzg=
 github.com/golang-jwt/jwt/v4 v4.5.0/go.mod h1:m21LjoU+eqJr34lmDMbreY2eSTRJ1cv77w39/MY0Ch0=
 github.com/golang/dep v0.5.4/go.mod h1:6RZ2Wai7dSWk7qL55sDYk+8UPFqcW7all2KDBraPPFA=

cla-backend-go/v2/docusign_auth/auth.go

@@ -4,7 +4,9 @@
 package docusignauth
 
 import (
+	"crypto/x509"
 	"encoding/json"
+	"encoding/pem"
 	"fmt"
 	"io"
 	"net/http"
@@ -16,7 +18,7 @@ import (
 )
 
 var (
-	baseURL           = os.Getenv("DOCUSIGN_BASE_URL")
+	baseURL           = os.Getenv("DOCUSIGN_AUTH_SERVER")
 	oauthTokenURL     = baseURL + "/oauth/token"
 	jwtGrantAssertion = "urn:ietf:params:oauth:grant-type:jwt-bearer"
 )
@@ -27,8 +29,18 @@ type TokenResponse struct {
 }
 
 func GetAccessToken(integrationKey, userGUID, privateKey string) (string, error) {
+	block, _ := pem.Decode([]byte(privateKey))
+	if block == nil {
+		return "", fmt.Errorf("failed to parse private key")
+	}
+
+	privateKeyParsed, err := x509.ParsePKCS1PrivateKey(block.Bytes)
+	if err != nil {
+		return "", err
+	}
+
 	// Generate the JWT token
-	tokenString, err := generateJWT(integrationKey, userGUID, privateKey)
+	tokenString, err := generateJWT(integrationKey, userGUID, privateKeyParsed.D.String())
 	if err != nil {
 		return "", err
 	}

cla-backend-go/v2/main/main.go

@@ -0,0 +1,47 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/communitybridge/easycla/cla-backend-go/v2/docusign_auth"
+)
+
+func main() {
+	integrationKey := "557677f2-1e2f-4955-aaa6-1ef44630e01d"
+	userID := "3a1d118f-3083-4c25-8306-11b7400f7c03"
+	privateKey :=`
+	-----BEGIN RSA PRIVATE KEY-----
+	MIIEogIBAAKCAQEAh0M2mIGaJjP8S/FxZR7nRsatCR/KpCPBFBbxalZffykqtTID
+	KNeDhJ5RvJKAVoJlLaLoUYSYloVaeSAwQdbn4F+Lsnll3mCGocwdl/W8998Lc/Ln
+	MaNQhpekBoXaq8vbj251jxnRcsdI9yl/YyQo3jZnM77OWtEF7dyvS6V9cMprT2Ca
+	eIJPj0Ck3/P9rGwE3DdiEXZDetgkuNQyMavfvLKltCNu3qQXFA95PXlHs2E57OrS
+	CNIQT37jfInXuIyCoGjDSq+U3ZE047UG5Id8/OFvcP1z5iUdwvueoEximt/kSvR0
+	ZcNfjqyJnnYq80OKwTdalZEOzAEkt/U2QuB9jwIDAQABAoIBAB01GstopOgd7ptZ
+	efJrb2ZdjUy8lC3IWK9lWuDq4LkdIw84Su1dSBVxeFXfTp4fjwiBNmgv2SEbj5M7
+	K6Bz7uMIzqoNw7z2m+vBHxzKn/DoNVlmuJyD1uYRRYZxDext2y3IHNN3MD54IN3a
+	FJtMWhTNq5BFYdrDauPXdPTBOeqKQgMoQl6OwHIx4WJXYxRgIgrvBYRzLSwG/u4V
+	tAvj1/J0PSSOY5A1qn6L2ii9abVElFr2zZC5MtG3oG1TLCidzxZFt/5qSHGo+0tU
+	l/7YRXWxadfYrPmS9akbC7SQn9WJQdIlfejtuQ6hmKTCCjhTp2BUba3kTI3PcM46
+	GzW3WQECgYEA08lwWFZng3bm3KrDx3ljjZ+cuL8vOXfLeYuaIPmNu5eXrR5ZR9Ar
+	UyUmnZbL8rhK9dNCmRGX293uuppwJolfMAy+kcvQ4HsRQ5tOgXmP8VhKzA4RRc+h
+	I7uIGQ7NmKI6Wm/wJ+T3Okw0h8ze8MW66/D5IHDQSoGQZH9kkA9+MQECgYEAo4AS
+	jB/b/SWhwrRUI8m+5Tjy5WO9ZkRZ54zpRnAr5HsjSBgb72IGbJKwleKwb3FxwPTQ
+	ZlgKP2O5rGzZOEZcIryIliCpV4C/XeFVwUKxo/A5jkL+U9ZQwoA0/0ssdE/7uLzG
+	FiKcFK7OhsFg+dNEX1ForM9cGN5OzY8sGzylHo8CgYAc0Nq1WkRJUeNFgQKUYILY
+	ITB8vp6ZTiBkUEdPV0Uekhi0GF4DdGKAtJxVctAbHVItsmnsU8V6x+6UezDpPWWz
+	Lvi686Ve9b+6mCYNXdHk/6NlskBNZFvDdd+lsSruKpyP840UkIXG69l15L0su2qc
+	cbQj4tWkXY6c7exr4X/FAQKBgDmGTABFDU9puBoa/CeDSci4Wq1ehDrA/ai8KS8B
+	NFA1CtrIsLtuj7gPfFWf5levYEh1WgVIIILhAWiq+1oTV0NZdezsHOiOgcX0DAns
+	/zcgw/9LjtPMaamlFgBkYIWjxnre4ArVrniQcFV1IDuFm16189ApPMv7G1qzbt8+
+	XRH9AoGAceSrZLbceDkqgprTTV1BEOFY+Ti9edBIUW+CqN6KkB66OXHGWlab/PZc
+	OCHRPAjEijZcVXm8IPC2yi/s0agQAB8dKO2L1X0EtvxkWSg2s/YXFpp0QccQToTo
+	lRFb9injNzixUOq18Z62XcC/yqMB7QtgRw5x5OQk0HNWpL7h6KM=
+	-----END RSA PRIVATE KEY-----
+	`
+	token, err := docusignauth.GetAccessToken(integrationKey, userID, privateKey)
+	if err != nil {
+		fmt.Println(err)
+	}
+
+	fmt.Println(token)
+}

cla-backend-go/v2/sign/docusign.go

@@ -0,0 +1,18 @@
+// Copyright The Linux Foundation and each contributor to LFX.
+// SPDX-License-Identifier: MIT
+
+package sign
+
+import (
+	"context"
+	"log"
+)
+
+func (s *service) getAccessToken(ctx context.Context) (string, error) {
+	f := logrus.Fields{
+		"functionName": "sign.getAccessToken",
+	}
+
+	// Get the access token
+	jwtAssertion, jwterr := jwtToken()
+}

cla-backend-go/v2/sign/jwt.go

@@ -0,0 +1,17 @@
+// Copyright The Linux Foundation and each contributor to LFX.
+// SPDX-License-Identifier: MIT
+
+package sign
+
+import (
+	"github.com/golang-jwt/jwt"
+	"github.com/sirupsen/logrus"
+)
+
+const 
+
+func jwtToken() (string, error) {
+	claims := jwt.MapClaims{
+		"iss": ,
+	}
+}