headers.rs (2481B)
1 /* 2 This file is part of TALER 3 Copyright (C) 2026 Taler Systems SA 4 5 TALER is free software; you can redistribute it and/or modify it under the 6 terms of the GNU Affero General Public License as published by the Free Software 7 Foundation; either version 3, or (at your option) any later version. 8 9 TALER is distributed in the hope that it will be useful, but WITHOUT ANY 10 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR 11 A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details. 12 13 You should have received a copy of the GNU Affero General Public License along with 14 TALER; see the file COPYING. If not, see <http://www.gnu.org/licenses/> 15 */ 16 17 use hyper::{HeaderMap, header::HeaderName}; 18 use taler_common::encoding::base64; 19 20 #[derive(Debug, thiserror::Error)] 21 pub enum HeaderError { 22 #[error("Missing header {0}")] 23 Missing(HeaderName), 24 #[error("Malformed header {0} expected string got binary")] 25 NotStr(HeaderName), 26 #[error("Malformed header {0} expected {1} got '{2}'")] 27 Malformed(HeaderName, &'static str, Box<str>), 28 } 29 30 pub trait HeaderParser<E> { 31 fn parse<T>( 32 &self, 33 name: impl Into<HeaderName>, 34 kind: &'static str, 35 transform: impl FnOnce(&str) -> Result<T, ()>, 36 ) -> Result<T, E>; 37 fn str_header(&self, name: impl Into<HeaderName>) -> Result<String, E> { 38 self.parse(name, "string", |s| Ok(s.to_owned())) 39 } 40 fn int_header(&self, name: impl Into<HeaderName>) -> Result<u64, E> { 41 self.parse(name, "integer", |s| s.parse().map_err(|_| ())) 42 } 43 fn bool_header(&self, name: impl Into<HeaderName>) -> Result<bool, E> { 44 self.parse(name, "boolean", |s| s.parse().map_err(|_| ())) 45 } 46 fn b64_header(&self, name: impl Into<HeaderName>) -> Result<Vec<u8>, E> { 47 self.parse(name, "b64", |s| base64::decode(s).map_err(|_| ())) 48 } 49 } 50 51 impl HeaderParser<HeaderError> for HeaderMap { 52 fn parse<T>( 53 &self, 54 name: impl Into<HeaderName>, 55 kind: &'static str, 56 transform: impl FnOnce(&str) -> Result<T, ()>, 57 ) -> Result<T, HeaderError> { 58 let name = name.into(); 59 let Some(value) = self.get(&name) else { 60 return Err(HeaderError::Missing(name)); 61 }; 62 let Ok(str) = value.to_str() else { 63 return Err(HeaderError::NotStr(name)); 64 }; 65 transform(str).map_err(|_| HeaderError::Malformed(name, kind, str.into())) 66 } 67 }