Add haveibeenpwned sample function

Idea from Matthew Holt, using the haveibeenpwned API to query
whether a password has been found in a data-breach.

Signed-off-by: Alex Ellis (VMware) <alexellis2@gmail.com>

sample-functions/haveibeenpwned/handler.go

+// Copyright (c) OpenFaaS Author(s) 2018. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+// API source - https://haveibeenpwned.com/API/v2#SearchingPwnedPasswordsByRange
+// Idea from Matthew Holt (@mholt6)
+
+package function
+
+import (
+	"crypto/sha1"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"strconv"
+	"strings"
+)
+
+// Handle a serverless request
+func Handle(payload []byte) string {
+
+	if len(payload) == 0 {
+		return "Enter a number of characters."
+	}
+
+	hashed := fmt.Sprintf("%X", sha1.Sum(payload))
+	prefix := hashed[:5]
+
+	c := http.Client{}
+
+	req, _ := http.NewRequest(http.MethodGet,
+		fmt.Sprintf("https://api.pwnedpasswords.com/range/%s", prefix), nil)
+
+	res, err := c.Do(req)
+	if err != nil {
+		return err.Error()
+	}
+
+	var bytesOut []byte
+	if res.Body != nil {
+		defer res.Body.Close()
+		bytesOut, _ = ioutil.ReadAll(res.Body)
+	}
+
+	passwords := string(bytesOut)
+	foundTimes, findErr := findPassword(passwords, prefix, hashed)
+	if findErr != nil {
+		return findErr.Error()
+	}
+
+	result := result{Found: foundTimes}
+	output, _ := json.Marshal(result)
+	return string(output)
+}
+
+type result struct {
+	Found int `json:"found"`
+}
+
+func findPassword(passwords string, prefix string, hashed string) (int, error) {
+	foundTimes := 0
+
+	for _, passwordLine := range strings.Split(passwords, "\r\n") {
+		if passwordLine != "" {
+			parts := strings.Split(passwordLine, ":")
+
+			if fmt.Sprintf("%s%s", prefix, parts[0]) == hashed {
+				var convErr error
+				foundTimes, convErr = strconv.Atoi(parts[1])
+				if convErr != nil {
+					return 0, fmt.Errorf(`Cannot convert value: "%s", error: "%s"\n`, parts[1], convErr)
+				}
+				break
+			}
+		}
+	}
+	return foundTimes, nil
+}

sample-functions/haveibeenpwned/handler_test.go

+package function
+
+import (
+	"encoding/json"
+	"testing"
+)
+
+func Test_Handle(t *testing.T) {
+	res := Handle([]byte("test1234"))
+
+	result := result{}
+	err := json.Unmarshal([]byte(res), &result)
+	if err != nil {
+		t.Errorf("unable to unmarshal response, error: %s", err)
+		t.Fail()
+	}
+
+	if result.Found == 0 {
+		t.Errorf("expected test1234 to be found several times")
+		t.Fail()
+	}
+}

sample-functions/stack.yml

 provider:
   name: faas
-  gateway: http://localhost:8080  # can be a remote server
+  gateway: http://localhost:8080
 
 functions:
   alpinefunction:
     lang: dockerfile
-    handler: ./AlpineFunction
+    handler: ./alpinefunction
     image: functions/alpine:latest
-    environment:
-      fprocess: "cat"
-
-  pwgen:
-    lang: dockerfile
-    handler: ./pwgen
-    image: functions/pwgen-sample:latest
-
   apikey-secret:
     lang: go
     handler: ./apikey-secret
     image: functions/apikey-secret:0.1
-
   captainsintent:
     lang: dockerfile
-    handler: ./CaptainsIntent
+    handler: ./captainsintent
     image: functions/captainsintent:latest
-
-  echo:
-    lang: dockerfile
-    handler: ./echo
-    image: functions/faas-echo:latest
-
   changecolorintent:
     lang: dockerfile
-    handler: ./ChangeColorIntent
+    handler: ./changecolorintent
     image: functions/alexa-leds:latest
-
   chelloworld:
     lang: dockerfile
-    handler: ./CHelloWorld/src
+    handler: ./chelloworld
     image: functions/helloc:latest
-
   dockerhubstats:
     lang: dockerfile
-    handler: ./DockerHubStats
+    handler: ./dockerhubstats
     image: functions/hubstats:latest
-
+  echo:
+    lang: dockerfile
+    handler: ./echo
+    image: functions/faas-echo:latest
   gif-maker:
     lang: dockerfile
     handler: ./gif-maker
     image: functions/gif-maker:latest
-    environment:
-      read_timeout:	60
-      write_timeout: 60 
-
+  haveibeenpwned:
+    lang: go
+    handler: ./haveibeenpwned
+    image: haveibeenpwned:latest
   hostnameintent:
     lang: dockerfile
-    handler: ./HostnameIntent
+    handler: ./hostnameintent
     image: functions/hostname-intent:latest
-
   markdownrender:
     lang: dockerfile
-    handler: ./MarkdownRender
+    handler: ./markdownrender
     image: functions/markdown-render:latest
-
+  nmap:
+    lang: dockerfile
+    handler: ./nmap
+    image: functions/nmap:0.1
   nodeinfo:
     lang: dockerfile
-    handler: ./NodeInfo
+    handler: ./nodeinfo
     image: functions/node-info:latest
-
   phantomjs:
     lang: dockerfile
-    handler: ./Phantomjs
+    handler: ./phantomjs
     image: functions/phantomjs:latest
-
+  pwgen:
+    lang: dockerfile
+    handler: ./pwgen
+    image: functions/pwgen-sample:latest
   resizeimagemagick:
     lang: dockerfile
-    handler: ./ResizeImageMagick
+    handler: ./resizeimagemagick
     image: functions/resizer:latest
-
   sentimentanalysis:
     lang: dockerfile
-    handler: ./SentimentAnalysis
+    handler: ./sentimentanalysis
     image: functions/sentimentanalysis:latest
-
   webhookstash:
     lang: dockerfile
-    handler: ./WebhookStash
+    handler: ./webhookstash
     image: functions/webhookstash:latest
-
   wordcountfunction:
     lang: dockerfile
-    handler: ./WordCountFunction
+    handler: ./wordcountfunction
     image: functions/wordcount:latest
-    environment:
-      fprocess: "wc"
-
-  nmap:
-    lang: dockerfile
-    handler: ./Nmap
-    image: functions/nmap:0.1
-