fix(crypto): allow parsing of cost int from env string (#7061)

fic(crypto): allow parsing of cost int from env string

internal/crypto/passwap.go

@@ -145,11 +145,15 @@ func (c *HasherConfig) buildHasher() (hasher passwap.Hasher, prefixes []string,
 	}
 }
 
+// decodeParams uses a mapstructure decoder from the Params map to dst.
+// The decoder fails when there are unused fields in dst.
+// It uses weak input typing, to allow conversion of env strings to ints.
 func (c *HasherConfig) decodeParams(dst any) error {
 	decoder, err := mapstructure.NewDecoder(&mapstructure.DecoderConfig{
-		ErrorUnused: false,
-		ErrorUnset:  true,
-		Result:      dst,
+		ErrorUnused:      false,
+		ErrorUnset:       true,
+		WeaklyTypedInput: true,
+		Result:           dst,
 	})
 	if err != nil {
 		return err

internal/crypto/passwap_test.go

@@ -397,7 +397,11 @@ func TestHasherConfig_decodeParams(t *testing.T) {
 				"a": 1,
 				"b": "2",
 			},
-			wantErr: true,
+			want: dst{
+				A: 1,
+				B: 2,
+			},
+			wantErr: false, // https://github.com/zitadel/zitadel/issues/6913
 		},
 		{
 			name: "ok",