如何在sha256中sha256与sha256的哈希输出
问题描述:
我写过一些生存期问题的防火墙代码。如何在sha256中sha256与sha256的哈希输出
let mut sha256 = Sha256::new();
sha256.input_str(input.as_slice());
for i in range(0i,16) {
println!("i == {}, hash == {}", i, sha256.result_str());
let bytes = sha256.result_bytes().as_slice();
sha256.input(bytes);
}
的错误是:
$ cargo build && ./target/hello_world asdfasdf
Compiling hello_world v0.1.0 (file:///home/chris/hello_world)
src/hello_world.rs:41:21: 41:42 error: borrowed value does not live long enough
src/hello_world.rs:41 let bytes = sha256.result_bytes().as_slice();
^~~~~~~~~~~~~~~~~~~~~
src/hello_world.rs:39:27: 43:6 note: reference must be valid for the block at 39:26...
src/hello_world.rs:39 for i in range(0i,16) {
src/hello_world.rs:40 println!("i == {}, hash == {}", i, sha256.result_str());
src/hello_world.rs:41 let bytes = sha256.result_bytes().as_slice();
src/hello_world.rs:42 sha256.input(bytes);
src/hello_world.rs:43 }
src/hello_world.rs:41:9: 41:53 note: ...but borrowed value is only valid for the statement at 41:8; consider using a `let` binding to increase its lifetime
src/hello_world.rs:41 let bytes = sha256.result_bytes().as_slice();
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
error: aborting due to previous error
Could not compile `hello_world`.
To learn more, run the command again with --verbose.
如何我可以改变这一点,还是让它有效地执行?
答
这是因为result_bytes()
的结果在该行后被丢弃,并且as_slice()
正在获取对它的引用。借阅检查员不会让它发生。
对于它的工作,你应该写它想:
let mut sha256 = Sha256::new();
sha256.input_str(input.as_slice());
for i in range(0i,16) {
println!("i == {}, hash == {}", i, sha256.result_str());
let bytes = sha256.result_bytes();
sha256.reset();
sha256.input(bytes.as_slice());
}
希望它帮助。
你从哪里得到sha256?我正在寻找一个很好的实现 – 2017-08-05 06:30:30