move some tools used by the client

Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>

pbs-tools/src/sha.rs

@@ -0,0 +1,29 @@
+//! SHA helpers.
+
+use std::io::Read;
+
+use anyhow::Error;
+
+/// Calculate the sha256sum from a readable object.
+pub fn sha256(file: &mut dyn Read) -> Result<([u8; 32], u64), Error> {
+    let mut hasher = openssl::sha::Sha256::new();
+    let mut buffer = proxmox::tools::vec::undefined(256 * 1024);
+    let mut size: u64 = 0;
+
+    loop {
+        let count = match file.read(&mut buffer) {
+            Ok(0) => break,
+            Ok(count) => count,
+            Err(ref err) if err.kind() == std::io::ErrorKind::Interrupted => {
+                continue;
+            }
+            Err(err) => return Err(err.into()),
+        };
+        size += count as u64;
+        hasher.update(&buffer[..count]);
+    }
+
+    let csum = hasher.finish();
+
+    Ok((csum, size))
+}