prefer errors.As to errors.Is

Signed-off-by: Nicola Murino <nicola.murino@gmail.com>

go.mod

@@ -42,7 +42,7 @@ require (
 	github.com/lestrrat-go/jwx/v2 v2.0.19
 	github.com/lithammer/shortuuid/v3 v3.0.7
 	github.com/mattn/go-sqlite3 v1.14.19
-	github.com/mhale/smtpd v0.8.1
+	github.com/mhale/smtpd v0.8.2
 	github.com/minio/sio v0.3.1
 	github.com/otiai10/copy v1.14.0
 	github.com/pires/go-proxyproto v0.7.0

go.sum

@@ -288,8 +288,8 @@ github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWE
 github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
 github.com/mattn/go-sqlite3 v1.14.19 h1:fhGleo2h1p8tVChob4I9HpmVFIAkKGpiukdrgQbWfGI=
 github.com/mattn/go-sqlite3 v1.14.19/go.mod h1:2eHXhiwb8IkHr+BDWZGa96P6+rkvnG63S2DGjv9HUNg=
-github.com/mhale/smtpd v0.8.1 h1:O02u8O3eYAGxZCGf4E98WjyB+rA3DVFZtchEialjX4s=
-github.com/mhale/smtpd v0.8.1/go.mod h1:MQl+y2hwIEQCXtNhe5+55n0GZOjSmeqORDIXbqUL3x4=
+github.com/mhale/smtpd v0.8.2 h1:rHKOMHeFoDvcq8Na9ErCbNcjlWTSyGtznOmJpWsOzuc=
+github.com/mhale/smtpd v0.8.2/go.mod h1:MQl+y2hwIEQCXtNhe5+55n0GZOjSmeqORDIXbqUL3x4=
 github.com/miekg/dns v1.1.58 h1:ca2Hdkz+cDg/7eNF6V56jjzuZ4aCAE+DbVkILdQWG/4=
 github.com/miekg/dns v1.1.58/go.mod h1:Ypv+3b/KadlvW9vJfXOTf300O4UqaHFzFCuHz+rPkBY=
 github.com/minio/sio v0.3.1 h1:d59r5RTHb1OsQaSl1EaTWurzMMDRLA5fgNmjzD4eVu4=

internal/sftpd/server.go

@@ -283,7 +283,8 @@ func (c *Configuration) getServerConfig() *ssh.ServerConfig {
 		MaxAuthTries: c.MaxAuthTries,
 		PublicKeyCallback: func(conn ssh.ConnMetadata, pubKey ssh.PublicKey) (*ssh.Permissions, error) {
 			sp, err := c.validatePublicKeyCredentials(conn, pubKey)
-			if errors.Is(err, &ssh.PartialSuccessError{}) {
+			var partialSuccess *ssh.PartialSuccessError
+			if errors.As(err, &partialSuccess) {
 				return sp, err
 			}
 			if err != nil {