ADR-0073: An entry's TOTP parameter fields are read only by Params::from_fields

Status: accepted

Context

They were read three ways in Rust alone, so one entry listed as a 99-digit credential, produced six digits, and handed the app an error instead of a code. Falling back to the otpauth:// default rather than refusing is what keeps one mistyped number from making a whole entry unreadable. Twin: totpParamsOf, pinned by the fixture's params table

Decision

An entry's TOTP parameter fields are read only by Params::from_fields

Evidence

vault-core/src/totp.rs