Add support for Event Hub SAS Helper

eventhub/sas_token.go

@@ -0,0 +1,98 @@
+package eventhub
+
+import (
+	"crypto/hmac"
+	"crypto/sha256"
+	"encoding/base64"
+	"fmt"
+	"net/url"
+	"strconv"
+	"strings"
+	"time"
+)
+
+const (
+	connStringSharedAccessKeyKey     = "SharedAccessKey"
+	connStringSharedAccessKeyNameKey = "SharedAccessKeyName"
+)
+
+func ComputeEventHubSASToken(sharedAccessKeyName string,
+	sharedAccessKey string,
+	eventHubUri string,
+	expiry string,
+) (string, error) {
+	uri := url.QueryEscape(eventHubUri)
+
+	expireTime, err := time.Parse(time.RFC3339, expiry)
+	if err != nil {
+		return "", err
+	}
+	expireTimestamp := expireTime.Unix()
+	expireStr := strconv.FormatInt(expireTimestamp, 10)
+
+	stringToSign := uri + "\n" + expireStr
+
+	key := []byte(sharedAccessKey)
+	h := hmac.New(sha256.New, key)
+	h.Write([]byte(stringToSign))
+	signature := base64.StdEncoding.EncodeToString(h.Sum(nil))
+
+	sasToken := "sr=" + uri
+	sasToken += "&sig=" + url.QueryEscape(signature)
+	sasToken += "&se=" + (expireStr)
+	sasToken += "&skn=" + (sharedAccessKeyName)
+
+	return sasToken, nil
+}
+
+func ComputeEventHubSASConnectionString(sasToken string) string {
+	return fmt.Sprintf("SharedAccessSignature %s", sasToken)
+}
+
+func ComputeEventHubSASConnectionUrl(endpoint string, entityPath string) (*string, error) {
+	if endpoint == "" {
+		return nil, fmt.Errorf("endpoint cannot be empty")
+	}
+
+	var url string
+	if entityPath == "" {
+		url = strings.TrimRight(endpoint, "/")
+	} else {
+		url = endpoint + entityPath
+	}
+
+	return &url, nil
+}
+
+func ParseEventHubSASConnectionString(connString string) (map[string]string, error) {
+	// This connection string was for a real Event Hub which has been deleted
+	// so its safe to include here for reference to understand the format.
+	// Endpoint=sb://example-ehn.servicebus.windows.net/;SharedAccessKeyName=example-ehar;SharedAccessKey=DzGpfdyJda9D/xIkME0FLA66wZnheOBID0s1/rrtlHg=;EntityPath=example-eh
+	validKeys := map[string]bool{"Endpoint": true, "SharedAccessKeyName": true, "SharedAccessKey": true, "EntityPath": true}
+	// The k-v pairs are separated with semi-colons
+	tokens := strings.Split(connString, ";")
+
+	kvp := make(map[string]string)
+
+	for _, atoken := range tokens {
+		// The individual k-v are separated by an equals sign.
+		kv := strings.SplitN(atoken, "=", 2)
+		if len(kv) != 2 {
+			return nil, fmt.Errorf("[ERROR] token `%s` is an invalid key=pair (connection string %s)", atoken, connString)
+		}
+
+		key := kv[0]
+		val := kv[1]
+
+		if _, present := validKeys[key]; !present {
+			return nil, fmt.Errorf("[ERROR] Unknown Key `%s` in connection string %s", key, connString)
+		}
+		kvp[key] = val
+	}
+
+	if _, present := kvp[connStringSharedAccessKeyKey]; !present {
+		return nil, fmt.Errorf("[ERROR] Shared Access Key not found in connection string: %s", connString)
+	}
+
+	return kvp, nil
+}

eventhub/sas_token_test.go

@@ -0,0 +1,144 @@
+package eventhub
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestParseEventHubConnectionString(t *testing.T) {
+	testCases := []struct {
+		input                       string
+		expectedSharedAccessKeyName string
+		expectedSharedAccessKey     string
+		expectedError               bool
+	}{
+		{
+			"Endpoint=sb://acctesteventhubnamespace-test01.servicebus.windows.net/;SharedAccessKeyName=RootManageSharedAccessKey;SharedAccessKey=IUSvXLiPZ3uAQcso/cL7vTiL4zsc/EMtcUzNCC2dhaM=",
+			"RootManageSharedAccessKey",
+			"IUSvXLiPZ3uAQcso/cL7vTiL4zsc/EMtcUzNCC2dhaM=",
+			false,
+		},
+		{
+			"Endpoint=sb://acctesteventhubnamespace-test01.servicebus.windows.net/;SharedAccessKeyName=acctest-test01;SharedAccessKey=R9v9VaHiU/ktFIka8Q4aUbQnZeiSKaevncrsxOTTILw=;EntityPath=acctesteventhub-test01",
+			"acctest-test01",
+			"R9v9VaHiU/ktFIka8Q4aUbQnZeiSKaevncrsxOTTILw=",
+			false,
+		},
+		{
+			"Endpoint=sb://acctesteventhubnamespace-test01.servicebus.windows.net/;SharedAccessKeyName=acctest-test01;SharedAccessKey=R9v9VaHiU/ktFIka8Q4aUbQnZeiSKaevncrsxOTTILw=;EntityPath",
+			"",
+			"",
+			true,
+		},
+	}
+
+	for _, test := range testCases {
+		result, err := ParseEventHubSASConnectionString(test.input)
+
+		if test.expectedError {
+			if err == nil {
+				t.Fatalf("Expected error for %s: %q", test.input, err)
+			}
+			return
+		}
+
+		if !test.expectedError && err != nil {
+			t.Fatalf("Failed to parse resource type string: %s, %q", test.input, result)
+		}
+
+		if val, pres := result[connStringSharedAccessKeyKey]; !pres || val != test.expectedSharedAccessKey {
+			t.Fatalf("Failed to parse Shared Access Key: Expected: %s, Found: %s", test.expectedSharedAccessKey, val)
+		}
+		if val, pres := result[connStringSharedAccessKeyNameKey]; !pres || val != test.expectedSharedAccessKeyName {
+			t.Fatalf("Failed to parse Shared Access Name: Expected: %s, Found: %s", test.expectedSharedAccessKeyName, val)
+		}
+	}
+}
+
+func TestComputeEventHubSASToken(t *testing.T) {
+	testCases := []struct {
+		sharedAccessKeyName string
+		sharedAccessKey     string
+		eventHubUri         string
+		expiry              string
+		knownSasToken       string
+	}{
+		{
+			"RootManageSharedAccessKey",
+			"IUSvXLiPZ3uAQcso/cL7vTiL4zsc/EMtcUzNCC2dhaM=",
+			"sb://acctesteventhubnamespace-test01.servicebus.windows.net",
+			"2022-01-11T08:24:49Z",
+			"sr=sb%3A%2F%2Facctesteventhubnamespace-test01.servicebus.windows.net&sig=8dgxKVwLsOWxX7f4mNtyiez47lxYCJ8h%2FeViD%2BMWY2E%3D&se=1641889489&skn=RootManageSharedAccessKey",
+		},
+		{
+			"acctest-test01",
+			"R9v9VaHiU/ktFIka8Q4aUbQnZeiSKaevncrsxOTTILw=",
+			"sb://acctesteventhubnamespace-test01.servicebus.windows.net/acctesteventhub-test01",
+			"2022-01-11T08:24:49Z",
+			"sr=sb%3A%2F%2Facctesteventhubnamespace-test01.servicebus.windows.net%2Facctesteventhub-test01&sig=%2FaPTDsDZhwpdysw1klgV1fm5a%2Bo3vw2Lb7HsDHyZr4M%3D&se=1641889489&skn=acctest-test01",
+		},
+	}
+
+	for _, test := range testCases {
+		computedToken, err := ComputeEventHubSASToken(test.sharedAccessKeyName,
+			test.sharedAccessKey,
+			test.eventHubUri,
+			test.expiry)
+
+		if err != nil {
+			t.Fatalf("Test Failed: Error computing Event Hub Sas: %q", err)
+		}
+
+		if computedToken != test.knownSasToken {
+			t.Fatalf("Test failed: Expected Azure SAS %s but was %s", test.knownSasToken, computedToken)
+		}
+	}
+}
+
+func TestComputeEventHubSASConnectionString(t *testing.T) {
+	testCases := []struct {
+		sasToken            string
+		sasConnectionString string
+	}{
+		{
+			"sr=sb%3A%2F%2Facctest-ehn-test01.servicebus.windows.net%2Facctest-eh-test01&sig=ozpLwoOHPAWD1s4GE2Khhu508JbcVA4%2FWutXZIV7VfI%3D&se=1672531200&skn=acctest-ehar-test01",
+			"SharedAccessSignature sr=sb%3A%2F%2Facctest-ehn-test01.servicebus.windows.net%2Facctest-eh-test01&sig=ozpLwoOHPAWD1s4GE2Khhu508JbcVA4%2FWutXZIV7VfI%3D&se=1672531200&skn=acctest-ehar-test01",
+		},
+	}
+
+	for _, test := range testCases {
+		computedConnectionString := ComputeEventHubSASConnectionString(test.sasToken)
+
+		if computedConnectionString != test.sasConnectionString {
+			t.Fatalf("Test failed: Expected SAS connection string is %s but was %s", computedConnectionString, test.sasConnectionString)
+		}
+	}
+}
+
+func TestComputeEventHubSASConnectionUrl(t *testing.T) {
+	testCases := []struct {
+		endpoint              string
+		entityPath            string
+		eventHubConnectionUrl string
+	}{
+		{
+			"sb://acctesteventhubnamespace-test01.servicebus.windows.net/",
+			"acctesteventhub-test01",
+			"sb://acctesteventhubnamespace-test01.servicebus.windows.net/acctesteventhub-test01",
+		},
+		{
+			"sb://acctesteventhubnamespace-test01.servicebus.windows.net/",
+			"",
+			"sb://acctesteventhubnamespace-test01.servicebus.windows.net",
+		},
+	}
+
+	for _, test := range testCases {
+		computedEventHubConnectionUrl, err := ComputeEventHubSASConnectionUrl(test.endpoint, test.entityPath)
+		if err != nil {
+			t.Fatalf("Test failed: This call should not have thrown an error")
+		} else if strings.Compare(*computedEventHubConnectionUrl, test.eventHubConnectionUrl) != 0 {
+			t.Fatalf("Test failed: Expected connection url is %s but was %s", *computedEventHubConnectionUrl, test.eventHubConnectionUrl)
+		}
+	}
+}