Add hash as CLI function (#1995)

* Add hash as CLI function

* Use streaming SHA3.

parity/cli/mod.rs

@@ -32,6 +32,8 @@ usage! {
 		cmd_snapshot: bool,
 		cmd_restore: bool,
 		cmd_ui: bool,
+		cmd_tools: bool,
+		cmd_hash: bool,
 
 		// Arguments
 		arg_pid_file: String,
@@ -441,6 +443,8 @@ mod tests {
 			cmd_snapshot: false,
 			cmd_restore: false,
 			cmd_ui: false,
+			cmd_tools: false,
+			cmd_hash: false,
 
 			// Arguments
 			arg_pid_file: "".into(),

parity/cli/usage.txt

@@ -14,6 +14,7 @@ Usage:
   parity signer new-token [options]
   parity snapshot <file> [options]
   parity restore [ <file> ] [options]
+  parity tools hash <file>
 
 Operating Options:
   --mode MODE              Set the operating mode. MODE can be one of:
@@ -283,4 +284,3 @@ Miscellaneous Options:
   --no-color               Don't use terminal color codes in output. (default: {flag_no_color})
   -v --version             Show information about version.
   -h --help                Show this screen.
-

parity/configuration.rs

@@ -51,6 +51,7 @@ pub enum Cmd {
 	Blockchain(BlockchainCmd),
 	SignerToken(String),
 	Snapshot(SnapshotCommand),
+	Hash(Option<String>),
 }
 
 #[derive(Debug, PartialEq)]
@@ -94,8 +95,10 @@ impl Configuration {
 
 		let cmd = if self.args.flag_version {
 			Cmd::Version
-		} else if self.args.cmd_signer {
+		} else if self.args.cmd_signer && self.args.cmd_new_token {
 			Cmd::SignerToken(dirs.signer)
+		} else if self.args.cmd_tools && self.args.cmd_hash {
+			Cmd::Hash(self.args.arg_file)
 		} else if self.args.cmd_account {
 			let account_cmd = if self.args.cmd_new {
 				let new_acc = NewAccount {

parity/main.rs

@@ -111,10 +111,23 @@ mod boot;
 mod stratum;
 
 use std::{process, env};
+use std::io::BufReader;
+use std::fs::File;
+use util::sha3::sha3;
 use cli::Args;
 use configuration::{Cmd, Configuration};
 use deprecated::find_deprecated;
 
+fn print_hash_of(maybe_file: Option<String>) -> Result<String, String> {
+	if let Some(file) = maybe_file {
+		let mut f = BufReader::new(try!(File::open(&file).map_err(|_| "Unable to open file".to_owned())));
+		let hash = try!(sha3(&mut f).map_err(|_| "Unable to read from file".to_owned()));
+		Ok(hash.hex())
+	} else {
+		Err("Streaming from standard input not yet supported. Specify a file.".to_owned())
+	}
+}
+
 fn execute(command: Cmd) -> Result<String, String> {
 	match command {
 		Cmd::Run(run_cmd) => {
@@ -122,6 +135,7 @@ fn execute(command: Cmd) -> Result<String, String> {
 			Ok("".into())
 		},
 		Cmd::Version => Ok(Args::print_version()),
+		Cmd::Hash(maybe_file) => print_hash_of(maybe_file),
 		Cmd::Account(account_cmd) => account::execute(account_cmd),
 		Cmd::ImportPresaleWallet(presale_cmd) => presale::execute(presale_cmd),
 		Cmd::Blockchain(blockchain_cmd) => blockchain::execute(blockchain_cmd),