Auto merge of #4542 - equal-l2:sha256-crypto-hash, r=alexcrichton

Use crypto-hash to calculate SHA256

`crypto-hash` is an abstraction library for native hash libraries.
It uses CryptoAPI on Windows, CommonCrypto on macOS, and OpenSSL on *nix.

This PR will also remove `openssl` and `advapi32-sys` from dependencies since they are only used for calculating SHA256, which is superseded by `crypto-hash`.
(`crypto-hash` itself uses `openssl` and `advapi32-sys` though)

Cargo.toml

@@ -20,6 +20,7 @@ path = "src/cargo/lib.rs"
 atty = "0.2"
 crates-io = { path = "src/crates-io", version = "0.12" }
 crossbeam = "0.3"
+crypto-hash = "0.3"
 curl = "0.4.6"
 docopt = "0.8.1"
 env_logger = "0.4"
@@ -52,14 +53,10 @@ termcolor = "0.3"
 toml = "0.4"
 url = "1.1"
 
-[target.'cfg(unix)'.dependencies]
-openssl = "0.9"
-
 [target.'cfg(target_os = "macos")'.dependencies]
 core-foundation = { version = "0.4.4", features = ["mac_os_10_7_support"] }
 
 [target.'cfg(windows)'.dependencies]
-advapi32-sys = "0.2"
 kernel32-sys = "0.2"
 miow = "0.2"
 psapi-sys = "0.1"

src/cargo/util/sha256.rs

@@ -1,100 +1,23 @@
-pub use self::imp::Sha256;
+extern crate crypto_hash;
+use self::crypto_hash::{Hasher,Algorithm};
+use std::io::Write;
 
-// Someone upstream will link to OpenSSL, so we don't need to explicitly
-// link to it ourselves. Hence we pick up Sha256 digests from OpenSSL
-#[cfg(not(windows))]
-mod imp {
-    extern crate openssl;
+pub struct Sha256(Hasher);
 
-    use std::io::Write;
-    use self::openssl::hash::{Hasher, MessageDigest};
-
-    pub struct Sha256(Hasher);
-
-    impl Sha256 {
-        pub fn new() -> Sha256 {
-            let hasher = Hasher::new(MessageDigest::sha256()).unwrap();
-            Sha256(hasher)
-        }
-
-        pub fn update(&mut self, bytes: &[u8]) {
-            let _ = self.0.write_all(bytes);
-        }
-
-        pub fn finish(&mut self) -> [u8; 32] {
-            let mut ret = [0u8; 32];
-            let data = self.0.finish2().unwrap();
-            ret.copy_from_slice(&data[..]);
-            ret
-        }
-    }
-}
-
-// Leverage the crypto APIs that windows has built in.
-#[cfg(windows)]
-mod imp {
-    extern crate winapi;
-    extern crate advapi32;
-    use std::io;
-    use std::ptr;
-
-    use self::winapi::{DWORD, HCRYPTPROV, HCRYPTHASH};
-    use self::winapi::{PROV_RSA_AES, CRYPT_SILENT, CRYPT_VERIFYCONTEXT, CALG_SHA_256, HP_HASHVAL};
-    use self::advapi32::{CryptAcquireContextW, CryptCreateHash, CryptDestroyHash};
-    use self::advapi32::{CryptGetHashParam, CryptHashData, CryptReleaseContext};
-
-    macro_rules! call{ ($e:expr) => ({
-        if $e == 0 {
-            panic!("failed {}: {}", stringify!($e), io::Error::last_os_error())
-        }
-    }) }
-
-    pub struct Sha256 {
-        hcryptprov: HCRYPTPROV,
-        hcrypthash: HCRYPTHASH,
+impl Sha256 {
+    pub fn new() -> Sha256 {
+        let hasher = Hasher::new(Algorithm::SHA256);
+        Sha256(hasher)
     }
 
-    impl Sha256 {
-        pub fn new() -> Sha256 {
-            let mut hcp = 0;
-            call!(unsafe {
-                CryptAcquireContextW(&mut hcp, ptr::null(), ptr::null(),
-                                     PROV_RSA_AES,
-                                     CRYPT_VERIFYCONTEXT | CRYPT_SILENT)
-            });
-            let mut ret = Sha256 { hcryptprov: hcp, hcrypthash: 0 };
-            call!(unsafe {
-                CryptCreateHash(ret.hcryptprov, CALG_SHA_256,
-                                0, 0, &mut ret.hcrypthash)
-            });
-            ret
-        }
-
-        pub fn update(&mut self, bytes: &[u8]) {
-            call!(unsafe {
-                CryptHashData(self.hcrypthash, bytes.as_ptr() as *mut _,
-                              bytes.len() as DWORD, 0)
-            })
-        }
-
-        pub fn finish(&mut self) -> [u8; 32] {
-            let mut ret = [0u8; 32];
-            let mut len = ret.len() as DWORD;
-            call!(unsafe {
-                CryptGetHashParam(self.hcrypthash, HP_HASHVAL, ret.as_mut_ptr(),
-                                  &mut len, 0)
-            });
-            assert_eq!(len as usize, ret.len());
-            ret
-        }
+    pub fn update(&mut self, bytes: &[u8]) {
+        let _ = self.0.write_all(bytes);
     }
 
-    impl Drop for Sha256 {
-        fn drop(&mut self) {
-            if self.hcrypthash != 0 {
-                call!(unsafe { CryptDestroyHash(self.hcrypthash) });
-            }
-            call!(unsafe { CryptReleaseContext(self.hcryptprov, 0) });
-        }
+    pub fn finish(&mut self) -> [u8; 32] {
+        let mut ret = [0u8; 32];
+        let data = self.0.finish();
+        ret.copy_from_slice(&data[..]);
+        ret
     }
 }