crypto: lazy_static removed, light parser for address URI added (#2250)

The `lazy_static` package does not work well in `no-std`: it requires
`spin_no_std` feature, which also will propagate into `std` if enabled.
This is not what we want.

This PR provides simple address uri parser which allows to get rid of
_regex_ which was used to parse the address uri, what in turns allows to
remove lazy_static.

Three regular expressions
(`SS58_REGEX`,`SECRET_PHRASE_REGEX`,`JUNCTION_REGEX`) were replaced with
the parser which unifies all of them.

The new parser does not support Unicode, it is ASCII only.

Related to: #2044

---------

Co-authored-by: Bastian Köcher <git@kchr.de>
Co-authored-by: Koute <koute@users.noreply.github.com>
Co-authored-by: command-bot <>

substrate/primitives/core/fuzz/Cargo.toml

@@ -0,0 +1,20 @@
+[package]
+name = "sp-core-fuzz"
+version = "0.0.0"
+publish = false
+
+[package.metadata]
+cargo-fuzz = true
+
+[dependencies]
+lazy_static = "1.4.0"
+libfuzzer-sys = "0.4"
+regex = "1.10.2"
+
+sp-core = { path = ".." }
+
+[[bin]]
+name = "fuzz_address_uri"
+path = "fuzz_targets/fuzz_address_uri.rs"
+test = false
+doc = false

substrate/primitives/core/fuzz/fuzz_targets/fuzz_address_uri.rs

@@ -0,0 +1,53 @@
+// This file is part of Substrate.
+
+// Copyright (C) Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#![no_main]
+
+extern crate libfuzzer_sys;
+extern crate regex;
+extern crate sp_core;
+
+use libfuzzer_sys::fuzz_target;
+use regex::Regex;
+use sp_core::crypto::AddressUri;
+
+lazy_static::lazy_static! {
+	static ref SECRET_PHRASE_REGEX: Regex = Regex::new(r"^(?P<phrase>[a-zA-Z0-9 ]+)?(?P<path>(//?[^/]+)*)(///(?P<password>.*))?$")
+		.expect("constructed from known-good static value; qed");
+}
+
+fuzz_target!(|input: &str| {
+	let regex_result = SECRET_PHRASE_REGEX.captures(input);
+	let manual_result = AddressUri::parse(input);
+	assert_eq!(regex_result.is_some(), manual_result.is_ok());
+	if manual_result.is_err() {
+		let _ = format!("{}", manual_result.as_ref().err().unwrap());
+	}
+	if let (Some(regex_result), Ok(manual_result)) = (regex_result, manual_result) {
+		assert_eq!(regex_result.name("phrase").map(|p| p.as_str()), manual_result.phrase);
+
+		let manual_paths = manual_result
+			.paths
+			.iter()
+			.map(|s| "/".to_string() + s)
+			.collect::<Vec<_>>()
+			.join("");
+
+		assert_eq!(regex_result.name("path").unwrap().as_str().to_string(), manual_paths);
+		assert_eq!(regex_result.name("password").map(|pass| pass.as_str()), manual_result.pass);
+	}
+});