Add commoncrypto crate

Cargo.toml

@@ -1,2 +1,2 @@
 [workspace]
-members = ["commoncrypto-sys"]
+members = ["commoncrypto-sys", "commoncrypto"]

ci/script.sh

@@ -14,3 +14,4 @@ run_cargo() {
 }
 
 run_cargo commoncrypto-sys
+run_cargo commoncrypto

commoncrypto-sys/src/lib.rs

@@ -182,7 +182,7 @@ extern "C" {
                     output: *mut u8)
                     -> c_int;
     /// Allocate and initialize a `CCDigestCtx` for a digest.
-    pub fn CCDigestCreate(algorithm: CCDigestAlgorithm) -> &CCDigestCtx;
+    pub fn CCDigestCreate(algorithm: CCDigestAlgorithm) -> *mut CCDigestCtx;
     /// Continue to digest data. Returns `0` on success.
     pub fn CCDigestUpdate(ctx: *mut CCDigestCtx, data: *const u8, length: usize) -> c_int;
     /// Conclude digest operations and produce the digest output. Returns `0` on success.

commoncrypto/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "commoncrypto"
+version = "0.1.0"
+authors = ["Mark Lee"]
+
+[dependencies]
+commoncrypto-sys = { version = "0.1.0", path = "../commoncrypto-sys" }
+hex = "0.2"

commoncrypto/src/lib.rs

@@ -0,0 +1,151 @@
+// Copyright (c) 2016 Mark Lee
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+//! Idiomatic Rust wrappers for `CommonCrypto` structs.
+
+#![warn(missing_docs)]
+
+extern crate commoncrypto_sys;
+extern crate hex;
+
+use commoncrypto_sys::{CCDigestCreate, CCDigestCtx, CCDigestDestroy, CCDigestFinal,
+                       CCDigestGetOutputSizeFromRef, CCDigestReset, CCDigestUpdate};
+use std::io;
+
+pub use commoncrypto_sys::CCDigestAlgorithm;
+
+const MAX_DIGEST_SIZE: usize = 64;
+
+macro_rules! err_from_ccdigest_retval{
+    ($func_name: expr, $val: expr) => {
+        Err(io::Error::new(io::ErrorKind::Other,
+                           format!("{} returned nonzero: {}", $func_name, $val)))
+    }
+}
+
+#[derive(PartialEq, Copy, Clone, Debug)]
+enum State {
+    Reset,
+    Updated,
+    Finalized,
+}
+
+/// Generates cryptographic hashes.
+#[derive(Debug)]
+pub struct Hasher {
+    ctx: *mut CCDigestCtx,
+    state: State,
+}
+
+impl Hasher {
+    /// Creates a new `Hasher` which will use the given cryptographic `algorithm`.
+    pub fn new(algorithm: CCDigestAlgorithm) -> Hasher {
+        let ctx: *mut CCDigestCtx;
+        unsafe {
+            ctx = CCDigestCreate(algorithm);
+        }
+        Hasher {
+            ctx: ctx,
+            state: State::Reset,
+        }
+    }
+
+    fn init(&mut self) {
+        match self.state {
+            State::Reset => return,
+            State::Updated => {
+                let _ = self.finish();
+            }
+            State::Finalized => (),
+        }
+        unsafe { CCDigestReset(self.ctx) };
+        self.state = State::Reset;
+    }
+
+    /// Feeds data into the hasher.
+    pub fn update(&mut self, data: &[u8]) -> io::Result<usize> {
+        if self.state == State::Finalized {
+            self.init();
+        }
+        let result = unsafe { CCDigestUpdate(self.ctx, data.as_ptr() as *mut _, data.len()) };
+        if result == 0 {
+            self.state = State::Updated;
+            Ok(data.len())
+        } else {
+            err_from_ccdigest_retval!("CCDigestCreate", result)
+        }
+    }
+
+    /// Finalizes digest operations and produces the digest output.
+    pub fn finish(&mut self) -> io::Result<Vec<u8>> {
+        if self.state == State::Finalized {
+            self.init();
+        }
+        let expected_len = unsafe { CCDigestGetOutputSizeFromRef(self.ctx) };
+        let mut md = vec![0; MAX_DIGEST_SIZE];
+        let result = unsafe { CCDigestFinal(self.ctx, md.as_mut_ptr()) };
+        if result == 0 {
+            self.state = State::Finalized;
+            md.truncate(expected_len);
+            Ok(md)
+        } else {
+            err_from_ccdigest_retval!("CCDigestFinal", result)
+        }
+    }
+}
+
+impl io::Write for Hasher {
+    #[inline]
+    fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
+        self.update(buf)
+    }
+
+    fn flush(&mut self) -> io::Result<()> {
+        Ok(())
+    }
+}
+
+impl Drop for Hasher {
+    fn drop(&mut self) {
+        if self.state != State::Finalized {
+            let _ = self.finish();
+        }
+        unsafe { CCDigestDestroy(self.ctx) }
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use hex::ToHex;
+    use std::io::Write;
+    use super::*;
+
+    const TO_HASH: &'static str = "The quick brown fox jumps over the lazy dog";
+    const TO_HASH_MD5: &'static str = "9e107d9d372bb6826bd81d3542a419d6";
+
+    #[test]
+    fn md5_hasher() {
+        let mut hasher = Hasher::new(CCDigestAlgorithm::kCCDigestMD5);
+        assert!(hasher.write_all(TO_HASH.as_bytes()).is_ok());
+        let result = hasher.finish();
+        assert!(result.is_ok());
+        assert_eq!(result.expect("Hash failed").to_hex(), TO_HASH_MD5)
+    }
+}