Add x86 intrinsics support for sha1 and sha2 (#167)

Author: newpavlov

Cargo.lock

@@ -18,7 +18,13 @@ name = "sha1"
 digest = "0.9"
 block-buffer = "0.9"
 opaque-debug = "0.3"
+cfg-if = "0.1"
 sha1-asm = { version = "0.4", optional = true }
+
+[target.'cfg(any(target_arch = "x86", target_arch = "x86_64"))'.dependencies]
+cpuid-bool = "0.1"
+
+[target.'cfg(all(target_arch = "aarch64", target_os = "linux"))'.dependencies]
 libc = { version = "0.2.68", optional = true }
 
 [dev-dependencies]
@@ -28,8 +34,7 @@ hex-literal = "0.2"
 [features]
 default = ["std"]
 std = ["digest/std"]
-asm = ["sha1-asm"]
+asm = ["sha1-asm", "libc"]
 
-# TODO: Remove this feature once is_aarch64_feature_detected!() is stabilised.
-# Only used on AArch64 Linux systems, when built without the crypto target_feature.
-asm-aarch64 = ["asm", "libc"]
+# DEPRECATED: use `asm` instead
+asm-aarch64 = ["asm"]

sha1/Cargo.toml

@@ -0,0 +1,32 @@
+use digest::consts::U64;
+use digest::generic_array::GenericArray;
+
+cfg_if::cfg_if! {
+    if #[cfg(all(feature = "asm", target_arch = "aarch64", target_os = "linux"))] {
+        mod soft;
+        mod aarch64;
+        use aarch64::compress as compress_inner;
+    } else if #[cfg(all(feature = "asm", any(target_arch = "x86", target_arch = "x86_64")))] {
+        // TODO: replace after sha1-asm rework
+        fn compress_inner(state: &mut [u32; 5], blocks: &[[u8; 64]]) {
+            for block in blocks {
+                sha1_asm::compress(state, block);
+            }
+        }
+    } else if #[cfg(any(target_arch = "x86", target_arch = "x86_64"))] {
+        mod soft;
+        mod x86;
+        use x86::compress as compress_inner;
+    } else {
+        mod soft;
+        use soft::compress as compress_inner;
+    }
+}
+
+pub fn compress(state: &mut [u32; 5], blocks: &[GenericArray<u8, U64>]) {
+    // SAFETY: GenericArray<u8, U64> and [u8; 64] have
+    // exactly the same memory layout
+    #[allow(unsafe_code)]
+    let blocks: &[[u8; 64]] = unsafe { &*(blocks as *const _ as *const [[u8; 64]]) };
+    compress_inner(state, blocks);
+}

sha1/src/aarch64.rs

@@ -0,0 +1,21 @@
+#![cfg(feature = "asm-aarch64")]
+use libc::{getauxval, AT_HWCAP, HWCAP_SHA1};
+
+fn sha1_supported() -> bool {
+    #[allow(unsafe_code)]
+    let hwcaps: u64 = unsafe { getauxval(AT_HWCAP) };
+    (hwcaps & HWCAP_SHA1) != 0
+}
+
+pub fn compress(state: &mut [u32; 5], blocks: &[u8; 64]) {
+    // TODO: Replace this platform-specific call with is_aarch64_feature_detected!("sha1") once
+    // that macro is stabilised and https://github.com/rust-lang/rfcs/pull/2725 is implemented
+    // to let us use it on no_std.
+    if sha1_supported() {
+        for block in blocks {
+            sha1_asm::compress(state, block);
+        }
+    } else {
+        super::soft::compress(state, blocks);
+    }
+}