diff --git a/authapi/authapi.go b/authapi/authapi.go
index c91eca6..c782651 100644
--- a/authapi/authapi.go
+++ b/authapi/authapi.go
@@ -5,7 +5,7 @@ import (
 	"net/url"
 	"strconv"
 
-	"github.com/duosecurity/duo_api_golang"
+	duoapi "github.com/duosecurity/duo_api_golang"
 )
 
 type AuthApi struct {
@@ -313,7 +313,7 @@ type AuthResult struct {
 // Duo's Auth method. https://www.duosecurity.com/docs/authapi#/auth
 // Factor must be one of 'auto', 'push', 'passcode', 'sms' or 'phone'.
 // Use AuthUserId to specify the user_id.
-// Use AuthUsername to speicy the username.  You must specify either AuthUserId
+// Use AuthUsername to specify the username.  You must specify either AuthUserId
 // or AuthUsername, but not both.
 // Use AuthIpAddr to include the client's IP address.
 // Use AuthAsync to toggle whether the call blocks for the user's response or not.
diff --git a/duo_test.go b/duo_test.go
index f1540d6..ecd9f05 100644
--- a/duo_test.go
+++ b/duo_test.go
@@ -6,6 +6,7 @@ import (
 	"io/ioutil"
 	"net/http"
 	"net/url"
+	"reflect"
 	"strconv"
 	"strings"
 	"testing"
@@ -131,7 +132,26 @@ func TestSign(t *testing.T) {
 	}
 }
 
-func TestV2Canonicalize(t *testing.T) {
+func TestSignV5(t *testing.T) {
+	values := url.Values{}
+	values.Set("realname", "First Last")
+	body := "{\"txid\":\"f22b1678-252a-4070-b176-0ca2be7319fd\"}"
+	res := signV5("DIWJ8X6AEYOR5OMC6TQ1",
+		"Zh5eGmUq9zpfQnyUIu5OL9iWoMMv5ZNmk3zLJ4Ep",
+		"POST",
+		"api-XXXXXXXX.duosecurity.com",
+		"/accounts/v1/account/list",
+		"Tue, 21 Aug 2012 17:29:18 -0000",
+		values,
+		body)
+	expected := "Basic RElXSjhYNkFFWU9SNU9NQzZUUTE6NzhmNDMyN2Y4MzExNzNjYzc4ZDA5MDdlOTEzZTNjNWEyOGZlNzJkZDQ1NDVhMzQyNTg2YmI2NzE4MWYyYmEzOTNkMjA5MTFlODcwMzYyZjZmYWJhM2RjNmY3ZTlkYjVlOTNhZWQyZjNiZmMxMTBjNmRhZGFmZjRkYzYxNzllMGI="
+	if res != expected {
+		t.Error("Mismatch between expected and received\n" + "Expected: " + expected + "\nReceived: " + res)
+	}
+
+}
+
+func TestCanonicalizeV2(t *testing.T) {
 	values := url.Values{}
 	values.Set("䚚⡻㗐軳朧倪ࠐ킑È셰",
 		"ཅ᩶㐚敌숿鬉ꯢ荃ᬧ惐")
@@ -153,6 +173,29 @@ func TestV2Canonicalize(t *testing.T) {
 	}
 }
 
+func TestCanonicalizeV5(t *testing.T) {
+	values := url.Values{}
+	values.Set("username", "H ell?o")
+	body := "{\"activation_code\":\"duo://x1bTAIQGWXppdi2ctPVn-YXBpLWR1bzEuZHVvLnRlc3Q\",\"user_id\":\"DU439XKOX2W6LMYHWLEV\"}"
+	canon := canonicalizeV5(
+		"post",
+		"FOO.example.CoM",
+		"/Foo/BaR2/qux",
+		values,
+		body,
+		"Fri, 07 Dec 2012 17:18:00 -0000")
+	expected := `Fri, 07 Dec 2012 17:18:00 -0000
+POST
+foo.example.com
+/Foo/BaR2/qux
+username=H%20ell%3Fo
+9ddab7d898836a76fafbb0dcef7bc83f14036b39bbb1ebbe43044f7c76338fa699eba8f0d3ecb329a084f32ef23c8a1609efad25032923b651e6f3f6d2f7b773
+cf83e1357eefb8bdf1542850d66d8007d620e4050b5715dc83f4a921d36ce9ce47d0d13c5d85f2b0ff8318d2877eec2f63b931bd47417a81a538327af927da3e`
+	if canon != expected {
+		t.Error("Mismatch between expected and received\n" + "Expected: " + expected + "\nReceived: " + canon)
+	}
+}
+
 func TestNewDuo(t *testing.T) {
 	duo := NewDuoApi("ABC", "123", "api-XXXXXXX.duosecurity.com", "go-client")
 	if duo == nil {
@@ -174,7 +217,7 @@ func TestSetTransport(t *testing.T) {
 	}
 }
 
-func TestDupApiCallHttpErr(t *testing.T) {
+func TestDuoApiCallHttpErr(t *testing.T) {
 	httpClient := &mockHttpClient{doError: true}
 	sleepSvc := &mockSleepService{}
 
@@ -312,6 +355,47 @@ func TestSignedCallCompletelyRateLimited(t *testing.T) {
 		7, rateLimitResp, completeRateLimitSleepDurations)
 }
 
+func TestHashString(t *testing.T) {
+	body := `{"limit":10,"offset":2}`
+	expected := "66fabab062974c3dd3f4d27284e41bf8121d71c0e63e95631992062ef5d1a4058403af3482c8c32ae63cd724cbf0aa793a931ef273539ef6f3745751c22f25f6"
+	res := hashString(body)
+	if res != expected {
+		t.Error("Expected hash of body params but got:\n" + res)
+	}
+}
+
+func TestJSONToValues(t *testing.T) {
+	json := JSONParams{
+		"user_id":         "1234",
+		"activation_code": "1234567890-abcdef",
+	}
+	expected := url.Values{
+		"activation_code": []string{"1234567890-abcdef"},
+		"user_id":         []string{"1234"},
+	}
+	res, _ := jsonToValues(json)
+	if !reflect.DeepEqual(res, expected) {
+		t.Error("Expected parsed JSON params but got:\n" + res.Encode())
+	}
+
+	empty_json := JSONParams{}
+	empty_expected := url.Values{}
+	empty_res, _ := jsonToValues(empty_json)
+	if !reflect.DeepEqual(empty_res, empty_expected) {
+		t.Error("Expected empty result but got:\n" + res.Encode())
+	}
+
+	bad_json := JSONParams{
+		"user_id": 1234,
+	}
+	expected_err := "JSON value not a string"
+	_, err := jsonToValues(bad_json)
+	if err.Error() != expected_err {
+		t.Error("Expected not a string error but received " + err.Error())
+	}
+
+}
+
 type mockHttpClient struct {
 	responses      []http.Response
 	actualRequests []*http.Request
diff --git a/duoapi.go b/duoapi.go
index c4ba5f7..5932b59 100644
--- a/duoapi.go
+++ b/duoapi.go
@@ -7,6 +7,8 @@ import (
 	"crypto/x509"
 	"encoding/base64"
 	"encoding/hex"
+	"encoding/json"
+	"errors"
 	"io"
 	"io/ioutil"
 	"math/rand"
@@ -54,6 +56,42 @@ func canonicalize(method string,
 	return strings.Join(canon[:], "\n")
 }
 
+func canonicalizeV5(method string,
+	host string,
+	uri string,
+	params url.Values,
+	body string,
+	date string) string {
+	var canon [7]string
+	canon[0] = date
+	canon[1] = strings.ToUpper(method)
+	canon[2] = strings.ToLower(host)
+	canon[3] = uri
+	canon[4] = canonParams(params)
+	canon[5] = hashString(body)
+	canon[6] = hashString("") // additional headers not needed at this time
+	return strings.Join(canon[:], "\n")
+}
+
+func hashString(to_hash string) string {
+	hash := sha512.New()
+	hash.Write([]byte(to_hash))
+	return hex.EncodeToString(hash.Sum(nil))
+}
+
+func jsonToValues(json JSONParams) (url.Values, error) {
+	params := url.Values{}
+	for key, val := range json {
+		s, ok := val.(string)
+		if ok {
+			params[key] = []string{s}
+		} else {
+			return nil, errors.New("JSON value not a string")
+		}
+	}
+	return params, nil
+}
+
 func sign(ikey string,
 	skey string,
 	method string,
@@ -69,6 +107,23 @@ func sign(ikey string,
 	return "Basic " + base64.StdEncoding.EncodeToString([]byte(auth))
 }
 
+func signV5(ikey string,
+	skey string,
+	method string,
+	host string,
+	uri string,
+	date string,
+	params url.Values,
+	body string,
+) string {
+	canon := canonicalizeV5(method, host, uri, params, body, date)
+	mac := hmac.New(sha512.New, []byte(skey))
+	mac.Write([]byte(canon))
+	sig := hex.EncodeToString(mac.Sum(nil))
+	auth := ikey + ":" + sig
+	return "Basic " + base64.StdEncoding.EncodeToString([]byte(auth))
+}
+
 type DuoApi struct {
 	ikey       string
 	skey       string
@@ -133,10 +188,10 @@ func SetTransport(transport func(*http.Transport)) func(*apiOptions) {
 // skey is your Duo integration secret key
 // host is your Duo host
 // userAgent allows you to specify the user agent string used when making
-//           the web request to Duo.  Information about the client will be
-//           appended to the userAgent.
+// the web request to Duo.  Information about the client will be
+// appended to the userAgent.
 // options are optional parameters.  Use SetTimeout() to specify a timeout value
-//         for Rest API calls.  Use SetProxy() to specify proxy settings for Duo API calls.
+// for Rest API calls.  Use SetProxy() to specify proxy settings for Duo API calls.
 //
 // Example: duoapi.NewDuoApi(ikey,skey,host,userAgent,duoapi.SetTimeout(10*time.Second))
 func NewDuoApi(ikey string,
@@ -227,7 +282,7 @@ func (duoapi *DuoApi) SetCustomHTTPClient(c *http.Client) {
 // uri is the URI of the Duo Rest call
 // params HTTP query parameters to include in the call.
 // options Optional parameters.  Use UseTimeout to toggle whether the
-//         Duo Rest API call should timeout or not.
+// Duo Rest API call should timeout or not.
 //
 // Example: duo.Call("GET", "/auth/v2/ping", nil, duoapi.UseTimeout)
 func (duoapi *DuoApi) Call(method string,
@@ -253,7 +308,7 @@ func (duoapi *DuoApi) Call(method string,
 // uri is the URI of the Duo Rest call
 // params HTTP query parameters to include in the call.
 // options Optional parameters.  Use UseTimeout to toggle whether the
-//         Duo Rest API call should timeout or not.
+// Duo Rest API call should timeout or not.
 //
 // Example: duo.SignedCall("GET", "/auth/v2/check", nil, duoapi.UseTimeout)
 func (duoapi *DuoApi) SignedCall(method string,
@@ -288,6 +343,74 @@ func (duoapi *DuoApi) SignedCall(method string,
 	return duoapi.makeRetryableHttpCall(method, url, headers, requestBody, options...)
 }
 
+type JSONParams map[string]interface{}
+
+// Make a signed Duo Rest API call that takes JSON as an argument.
+// See Duo's online documentation for the available REST API's.
+// method is one of GET, POST, PATCH, PUT, DELETE
+// uri is the URI of the Duo Rest call
+// json is the JSON parameters to include in the call.
+// options Optional parameters.  Use UseTimeout to toggle whether the
+// Duo Rest API call should timeout or not.
+//
+//	Example:
+//	params := duoapi.JSONParams{
+//		"user_id":         userid,
+//		"activation_code": activationCode,
+//	}
+//	JSONSignedCall("POST", "/auth/v2/enroll_status", params, duoapi.UseTimeout)
+func (duoapi *DuoApi) JSONSignedCall(method string,
+	uri string,
+	params JSONParams,
+	options ...DuoApiOption) (*http.Response, []byte, error) {
+
+	body_methods := make(map[string]struct{})
+	body_methods["POST"] = struct{}{}
+	body_methods["PUT"] = struct{}{}
+	body_methods["PATCH"] = struct{}{}
+	_, params_go_in_body := body_methods[method]
+
+	now := time.Now().UTC().Format(time.RFC1123Z)
+	var body string
+	api_url := url.URL{
+		Scheme: "https",
+		Host:   duoapi.host,
+		Path:   uri,
+	}
+
+	url_values := url.Values{}
+	if params_go_in_body {
+		body_bytes, err := json.Marshal(params)
+		if err != nil {
+			return nil, nil, err
+		}
+		body = string(body_bytes[:])
+	} else {
+		body = ""
+		var err error
+		url_values, err = jsonToValues(params)
+		if err != nil {
+			return nil, nil, err
+		}
+		api_url.RawQuery = url_values.Encode()
+	}
+
+	auth_sig := signV5(duoapi.ikey, duoapi.skey, method, duoapi.host, uri, now, url_values, body)
+
+	method = strings.ToUpper(method)
+	headers := make(map[string]string)
+	headers["User-Agent"] = duoapi.userAgent
+	headers["Authorization"] = auth_sig
+	headers["Date"] = now
+	var requestBody io.ReadCloser = nil
+	if params_go_in_body {
+		headers["Content-Type"] = "application/json"
+		requestBody = ioutil.NopCloser(strings.NewReader(body))
+	}
+
+	return duoapi.makeRetryableHttpCall(method, api_url, headers, requestBody, options...)
+}
+
 func (duoapi *DuoApi) makeRetryableHttpCall(
 	method string,
 	url url.URL,
diff --git a/go.mod b/go.mod
index c42635e..41e09dc 100644
--- a/go.mod
+++ b/go.mod
@@ -1,3 +1,3 @@
 module github.com/duosecurity/duo_api_golang
 
-go 1.15
+go 1.15
\ No newline at end of file