2 files changed, 37 insertions, 2 deletions
diff --git a/modules/password/password.go b/modules/password/password.go
index 1c4b9c514a..e1f1f769ec 100644
--- a/modules/password/password.go
+++ b/modules/password/password.go
@@ -6,6 +6,7 @@ package password
 
 import (
 	"bytes"
+	goContext "context"
 	"crypto/rand"
 	"math/big"
 	"strings"
@@ -88,7 +89,7 @@ func IsComplexEnough(pwd string) bool {
 	return true
 }
 
-// Generate  a random password
+// Generate a random password
 func Generate(n int) (string, error) {
 	NewComplexity()
 	buffer := make([]byte, n)
@@ -101,7 +102,11 @@ func Generate(n int) (string, error) {
 			}
 			buffer[j] = validChars[rnd.Int64()]
 		}
-		if IsComplexEnough(string(buffer)) && string(buffer[0]) != " " && string(buffer[n-1]) != " " {
+		pwned, err := IsPwned(goContext.Background(), string(buffer))
+		if err != nil {
+			return "", err
+		}
+		if IsComplexEnough(string(buffer)) && !pwned && string(buffer[0]) != " " && string(buffer[n-1]) != " " {
 			return string(buffer), nil
 		}
 	}
diff --git a/modules/password/pwn.go b/modules/password/pwn.go
new file mode 100644
index 0000000000..938524e6de
--- /dev/null
+++ b/modules/password/pwn.go
@@ -0,0 +1,30 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package password
+
+import (
+	"context"
+
+	"code.gitea.io/gitea/modules/setting"
+
+	"go.jolheiser.com/pwn"
+)
+
+// IsPwned checks whether a password has been pwned
+// NOTE: This func returns true if it encounters an error under the assumption that you ALWAYS want to check against
+// HIBP, so not getting a response should block a password until it can be verified.
+func IsPwned(ctx context.Context, password string) (bool, error) {
+	if !setting.PasswordCheckPwn {
+		return false, nil
+	}
+
+	client := pwn.New(pwn.WithContext(ctx))
+	count, err := client.CheckPassword(password, true)
+	if err != nil {
+		return true, err
+	}
+
+	return count > 0, nil
+}