Updated ChunkedDecryptor to use Write trait, and created criterion be…

…nchmarks

crates/bitwarden/Cargo.toml

@@ -59,5 +59,10 @@ bitwarden-api-identity = { path = "../bitwarden-api-identity", version = "=0.2.1
 bitwarden-api-api = { path = "../bitwarden-api-api", version = "=0.2.1" }
 
 [dev-dependencies]
+criterion = { version = "0.5.1", features = ["html_reports"] }
 tokio = { version = "1.28.2", features = ["rt", "macros"] }
 wiremock = "0.5.18"
+
+[[bench]]
+name = "chunked_decryption"
+harness = false

crates/bitwarden/benches/chunked_decryption.rs

@@ -0,0 +1,67 @@
+use std::io::Write;
+
+use bitwarden::crypto::{encrypt_aes256, ChunkedDecryptor, SymmetricCryptoKey};
+use criterion::{black_box, criterion_group, criterion_main, BenchmarkId, Criterion};
+use rand::RngCore;
+
+struct SizeFmt(usize);
+impl std::fmt::Display for SizeFmt {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        const SUFFIXES: [&str; 5] = ["B", "KB", "MB", "GB", "TB"];
+        let mut size = self.0 as f64;
+        for suffix in SUFFIXES {
+            if size < 1024.0 {
+                return write!(f, "{:.1}{}", size, suffix);
+            }
+            size /= 1024.0;
+        }
+        write!(f, "{}", self.0)
+    }
+}
+
+pub fn criterion_benchmark(c: &mut Criterion) {
+    let mut group = c.benchmark_group("decryption");
+
+    for size in [100 * 1024, 15 * 1024 * 1024, 200 * 1024 * 1024] {
+        group.throughput(criterion::Throughput::Bytes(size as u64));
+        if size > 1024 * 1024 {
+            group.sample_size(20);
+        }
+
+        let mut initial_buf = Vec::with_capacity(size);
+        initial_buf.resize(size, 0);
+        rand::thread_rng().fill_bytes(&mut initial_buf[..size]);
+        let key: SymmetricCryptoKey = SymmetricCryptoKey::generate("test");
+        let enc_str = encrypt_aes256(&initial_buf, key.mac_key, key.key).unwrap();
+        let enc_buf = enc_str.to_buffer().unwrap();
+
+        group.bench_with_input(
+            BenchmarkId::new("decrypt_with_key", SizeFmt(size)),
+            &size,
+            |b, _size| b.iter(|| black_box(enc_str.decrypt_with_key(&key).unwrap())),
+        );
+
+        for chunk_size in [64, 2048, 8192] {
+            group.bench_with_input(
+                BenchmarkId::new(format!("ChunkedDecryptor[{chunk_size}]"), SizeFmt(size)),
+                &size,
+                |b, _size| {
+                    b.iter(|| {
+                        let mut decrypted_buf = Vec::with_capacity(size);
+                        let mut cd = ChunkedDecryptor::new(&key, &mut decrypted_buf);
+
+                        for chunk in enc_buf.chunks(chunk_size) {
+                            cd.write_all(chunk).unwrap();
+                        }
+                        cd.finalize().unwrap();
+
+                        //
+                    })
+                },
+            );
+        }
+    }
+}
+
+criterion_group!(benches, criterion_benchmark);
+criterion_main!(benches);