Add support for user and groups names

CHANGELOG.md

@@ -13,6 +13,12 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 
+## [Unreleased]
+
+### Added
+- System users and groups can now be specified by name in addition to uid/gid.
+
+
 ## [0.8.0] - 2020-06-12
 
 ### Changed

CONTRIBUTING.md

@@ -13,12 +13,6 @@ Since the author is not a native English speaker, some of the texts used in this
 
 ## Fix issues in dependencies
 
-### nix
-
-The [nix](https://crates.io/crates/nix) crate does not currently allow to retrieve an UID or GID from a user or group name, which prevents ACMEd to do so. A pull request has been made to `nix` in early 2018 but has not been merged yet.
-
-- https://github.com/nix-rust/nix/pull/864
-
 ### rust-openssl
 
 The [openssl](https://crates.io/crates/openssl) crate does not expose the Asn1Time in a usable way, which requires ACMEd to parse certificates using an external library in order to get the `not after` field. This is sub-optimal.

acmed/src/storage.rs

@@ -97,8 +97,8 @@ fn set_owner(cert: &Certificate, path: &PathBuf, file_type: FileType) -> Result<
                 let nix_uid = nix::unistd::Uid::from_raw(raw_uid);
                 Some(nix_uid)
             } else {
-                // TODO: handle username
-                None
+                let user = nix::unistd::User::from_name(&u)?;
+                user.map(|u| u.uid)
             }
         }
         None => None,
@@ -110,8 +110,8 @@ fn set_owner(cert: &Certificate, path: &PathBuf, file_type: FileType) -> Result<
                 let nix_gid = nix::unistd::Gid::from_raw(raw_gid);
                 Some(nix_gid)
             } else {
-                // TODO: handle group name
-                None
+                let grp = nix::unistd::Group::from_name(&g)?;
+                grp.map(|g| g.gid)
             }
         }
         None => None,