Merge #252: Reproduce Bitcoin Core's handling of cookie files

b16f7ef Reproduce Bitcoin Core's handling of cookie files (Casey Rodarmor)

Pull request description:

  I was running into an confusing issue where a cookie file that worked with `bitcoin-cli` wasn't working with rust-bitcoincore-rpc. It turned out that the cookie file contained a newline, which Bitcoin Core ignored but `rust-bitcoincore-rpc` included as part of the password.

  This PR reproduces the behavior of Bitcoin Core, so that all cookie files that with Bitcoin Core should work with `rust-bitcoincore-rpc`.

  The commit message:

  Bitcoin Core uses a single call to std::getline to read the contents of cookie files, making it ignore newlines in the file, as well as ignore any lines after the first. This reproduces that behavior, so that all cookie files that work with Bitcoin Core should work with this library.

ACKs for top commit:
  RCasatta:
    utACK b16f7ef

Tree-SHA512: d3d2a0d6d526bbeb905e4dec5ebd2c03a2ca20bd8a06f7336aacc149d6c44c41dee908e702951d21806a33c84c227f37bdce524677b432963b0266950faf467c

client/Cargo.toml

@@ -28,3 +28,6 @@ jsonrpc = "0.14.0"
 serde = "1"
 serde_json = "1"
 bitcoin-private = "0.1.0"
+
+[dev-dependencies]
+tempfile = "3.3.0"

client/src/client.rs

@@ -10,6 +10,7 @@
 
 use std::collections::HashMap;
 use std::fs::File;
+use std::io::{BufRead, BufReader};
 use std::iter::FromIterator;
 use std::path::PathBuf;
 use std::{fmt, result};
@@ -201,19 +202,16 @@ pub enum Auth {
 impl Auth {
     /// Convert into the arguments that jsonrpc::Client needs.
     pub fn get_user_pass(self) -> Result<(Option<String>, Option<String>)> {
-        use std::io::Read;
         match self {
             Auth::None => Ok((None, None)),
             Auth::UserPass(u, p) => Ok((Some(u), Some(p))),
             Auth::CookieFile(path) => {
-                let mut file = File::open(path)?;
-                let mut contents = String::new();
-                file.read_to_string(&mut contents)?;
-                let mut split = contents.splitn(2, ":");
-                Ok((
-                    Some(split.next().ok_or(Error::InvalidCookieFile)?.into()),
-                    Some(split.next().ok_or(Error::InvalidCookieFile)?.into()),
-                ))
+                let line = BufReader::new(File::open(path)?)
+                    .lines()
+                    .next()
+                    .ok_or(Error::InvalidCookieFile)??;
+                let colon = line.find(':').ok_or(Error::InvalidCookieFile)?;
+                Ok((Some(line[..colon].into()), Some(line[colon + 1..].into())))
             }
         }
     }
@@ -1429,4 +1427,34 @@ mod tests {
     fn test_handle_defaults() {
         test_handle_defaults_inner().unwrap();
     }
+
+    #[test]
+    fn auth_cookie_file_ignores_newline() {
+        let tempdir = tempfile::tempdir().unwrap();
+        let path = tempdir.path().join("cookie");
+        std::fs::write(&path, "foo:bar\n").unwrap();
+        assert_eq!(
+            Auth::CookieFile(path).get_user_pass().unwrap(),
+            (Some("foo".into()), Some("bar".into())),
+        );
+    }
+
+    #[test]
+    fn auth_cookie_file_ignores_additional_lines() {
+        let tempdir = tempfile::tempdir().unwrap();
+        let path = tempdir.path().join("cookie");
+        std::fs::write(&path, "foo:bar\nbaz").unwrap();
+        assert_eq!(
+            Auth::CookieFile(path).get_user_pass().unwrap(),
+            (Some("foo".into()), Some("bar".into())),
+        );
+    }
+
+    #[test]
+    fn auth_cookie_file_fails_if_colon_isnt_present() {
+        let tempdir = tempfile::tempdir().unwrap();
+        let path = tempdir.path().join("cookie");
+        std::fs::write(&path, "foobar").unwrap();
+        assert!(matches!(Auth::CookieFile(path).get_user_pass(), Err(Error::InvalidCookieFile)));
+    }
 }

contrib/test.sh

@@ -15,6 +15,7 @@ fi
 
 # Test pinned versions (these are from rust-bitcoin pinning for 1.48).
 if cargo --version | grep ${MSRV}; then
+    cargo update -p tempfile --precise 3.3.0
     cargo update -p log --precise 0.4.18
     cargo update -p serde_json --precise 1.0.99
     cargo update -p serde --precise 1.0.156
@@ -36,4 +37,3 @@ else
   cargo test --verbose
   cargo build --verbose --examples
 fi
-