Initial commit

.gitignore

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+/target
+.*.sw*

Cargo.lock

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+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+[[package]]
+name = "testsuid"
+version = "0.1.0"

Cargo.toml

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+[package]
+name = "testsuid"
+version = "0.1.0"
+authors = ["southerntofu <southerntofu@thunix.net>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

README.md

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+# testsuid
+
+This program is a simple git wrapper intended to be used with suid/guid bits set to "impersonate" another user and let them clone a repository (with their consent, of course).
+
+When cloning the repository without initializing the submodules, everything works as expected. However, it appears git fails when cloning submodules when called from a suid program (the program uses `git clone --recursive`).
+
+How to reproduce:
+
+```
+$ git clone https://tildegit.org/southerntofu/testsuid
+$ cd testsuid
+$ cargo build --release
+$ cp target/release/testsuid /tmp/testsuid
+$ chmod u+s,g+s /tmp/testsuid
+$ mkdir /tmp/dest/
+$ /tmp/testsuid "https://tildegit.org/tilde-fr/site" /tmp/dest/1
+Cloning https://tildegit.org/tilde-fr/site to /tmp/dest/1 (recursive: false)
+$ # SUCCESS
+$ /tmp/testsuid --recursive "https://tildegit.org/tilde-fr/site" /tmp/dest/2
+Cloning https://tildegit.org/tilde-fr/site to /tmp/dest/2 (recursive: true)
+$ # SUCCESS
+$ # Now let's try from a different user.
+$ su guest
+$ /tmp/testsuid "https://tildegit.org/tilde-fr/site" /tmp/dest/3
+Cloning https://tildegit.org/tilde-fr/site to /tmp/dest3 (recursive: false)
+$ # SUCCESS
+$ /tmp/testsuid --recursive "https://tildegit.org/tilde-fr/site" /tmp/dest/4
+Cloning https://tildegit.org/tilde-fr/site to /tmp/dest/4 (recursive: true)
+FAILED!
+STDOUT:
+
+STDERR:
+18:24:38.064467 git.c:418               trace: built-in: git clone --recursive https://tildegit.org/tilde-fr/site /tmp/dest/4
+Cloning into '/tmp/dest/4'...
+18:24:38.070170 run-command.c:643       trace: run_command: git-remote-https origin https://tildegit.org/tilde-fr/site
+18:24:38.621635 run-command.c:643       trace: run_command: git fetch-pack --stateless-rpc --stdin --lock-pack --thin --check-self-contained-and-connected --cloning --no-progress https://tildegit.org/tilde-fr/site/
+18:24:38.625704 git.c:418               trace: built-in: git fetch-pack --stateless-rpc --stdin --lock-pack --thin --check-self-contained-and-connected --cloning --no-progress https://tildegit.org/tilde-fr/site/
+18:24:38.820744 run-command.c:643       trace: run_command: git unpack-objects -q --pack_header=2,60
+18:24:38.823934 git.c:418               trace: built-in: git unpack-objects -q --pack_header=2,60
+18:24:38.840025 run-command.c:643       trace: run_command: git rev-list --objects --stdin --not --all --quiet
+18:24:38.841075 git.c:418               trace: built-in: git rev-list --objects --stdin --not --all --quiet
+warning: unable to access '/home/guest/.config/git/attributes': Permission denied
+18:24:38.848734 run-command.c:643       trace: run_command: git submodule update --require-init --recursive
+18:24:38.849745 git.c:669               trace: exec: git-submodule update --require-init --recursive
+18:24:38.849789 run-command.c:643       trace: run_command: git-submodule update --require-init --recursive
+18:24:38.857209 git.c:418               trace: built-in: git rev-parse --git-dir
+18:24:38.858398 git.c:418               trace: built-in: git rev-parse --git-path objects
+18:24:38.859289 git.c:418               trace: built-in: git rev-parse -q --git-dir
+18:24:38.861442 git.c:418               trace: built-in: git rev-parse --show-prefix
+18:24:38.862713 git.c:418               trace: built-in: git rev-parse --show-toplevel
+18:24:38.864570 git.c:418               trace: built-in: git submodule--helper init
+error: could not lock config file /tmp/dest/4/.git/config: Permission denied
+fatal: Failed to register url for submodule path 'themes/water'
+```

src/main.rs

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+use std::process::Command;
+
+fn help() {
+    eprintln!("testsuid [--recursive] REMOTE DESTINATION");
+}
+
+fn main() {
+    let args: Vec<String> = std::env::args().collect();
+
+    let (recurse, source, dest) = match args.len() {
+        0|1|2 => {
+            help();
+            panic!();
+        },
+        3 => {
+            (
+                false,
+                args.get(1).unwrap(),
+                args.get(2).unwrap()
+            )
+        },
+        4 => {
+            let recurse = args.get(1).unwrap();
+            if ! (recurse == "--recursive" || recurse == "-r") {
+                eprintln!("You provided 3 arguments. The first one must be -r or --recursive.");
+                eprintln!("Otherwise, please give me only 2 arguments.");
+                help();
+                panic!();
+            }
+            (
+                true,
+                args.get(2).unwrap(),
+                args.get(3).unwrap()
+            )
+        },
+        _ => {
+            help();
+            panic!();
+        }
+    };
+
+    println!("Cloning {} to {} (recursive: {})", source, dest, recurse);
+
+    let output = if recurse {
+        Command::new("git")
+            .arg("clone")
+            .arg("--recursive")
+            .arg(source)
+            .arg(dest)
+            .env("GIT_TRACE", "1")
+            .output().expect("Failed to run process")
+    } else {
+        Command::new("git")
+            .arg("clone")
+            .arg(source)
+            .arg(dest)
+            .env("GIT_TRACE", "1")
+            .output().expect("Failed to run process")
+    };
+
+    if !output.status.success() {
+        println!("FAILED!");
+        println!("STDOUT:");
+        println!("{}", String::from_utf8_lossy(&output.stdout));
+        println!("STDERR:");
+        println!("{}", String::from_utf8_lossy(&output.stderr));
+    }
+}