allow additional characters in usernames and passwords (#1580) (#1666)

internal/conf/credential.go

@@ -7,9 +7,9 @@ import (
 	"strings"
 )
 
-var reCredential = regexp.MustCompile(`^[a-zA-Z0-9!\$\(\)\*\+\.;<=>\[\]\^_\-\{\}]+$`)
+var reCredential = regexp.MustCompile(`^[a-zA-Z0-9!\$\(\)\*\+\.;<=>\[\]\^_\-\{\}@#&]+$`)
 
-const credentialSupportedChars = "A-Z,0-9,!,$,(,),*,+,.,;,<,=,>,[,],^,_,-,{,}"
+const credentialSupportedChars = "A-Z,0-9,!,$,(,),*,+,.,;,<,=,>,[,],^,_,-,\",\",@,#,&"
 
 // Credential is a parameter that is used as username or password.
 type Credential string
@@ -29,7 +29,7 @@ func (d *Credential) UnmarshalJSON(b []byte) error {
 	if in != "" &&
 		!strings.HasPrefix(in, "sha256:") &&
 		!reCredential.MatchString(in) {
-		return fmt.Errorf("contains unsupported characters (supported are %s)", credentialSupportedChars)
+		return fmt.Errorf("credential contains unsupported characters. Supported are: %s", credentialSupportedChars)
 	}
 
 	*d = Credential(in)