1 files changed, 87 insertions, 0 deletions
diff --git a/src/crypto/hmac.rs b/src/crypto/hmac.rs
new file mode 100644
index 00000000..5bc8b359
--- /dev/null
+++ b/src/crypto/hmac.rs
@@ -0,0 +1,87 @@
+/*
+ * Copyright 2013 Jack Lloyd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+use hash::*;
+use std::{libc,ptr,vec};
+
+#[allow(non_camel_case_types)]
+pub struct HMAC_CTX {
+    md: EVP_MD,
+    md_ctx: EVP_MD_CTX,
+    i_ctx: EVP_MD_CTX,
+    o_ctx: EVP_MD_CTX,
+    key_length: libc::c_uint,
+    key: [libc::c_uchar, ..128]
+}
+
+#[link(name = "crypto")]
+extern {
+    fn HMAC_CTX_init(ctx: *mut HMAC_CTX, key: *u8, keylen: libc::c_int, md: EVP_MD);
+
+    fn HMAC_Update(ctx: *mut HMAC_CTX, input: *u8, len: libc::c_uint);
+
+    fn HMAC_Final(ctx: *mut HMAC_CTX, output: *mut u8, len: *mut libc::c_uint);
+}
+
+pub struct HMAC {
+    priv ctx: HMAC_CTX,
+    priv len: uint,
+}
+
+pub fn HMAC(ht: HashType, key: ~[u8]) -> HMAC {
+    unsafe {
+
+        let (evp, mdlen) = evpmd(ht);
+
+        let mut ctx : HMAC_CTX = HMAC_CTX {
+            md: ptr::null(),
+            md_ctx: ptr::null(),
+            i_ctx: ptr::null(),
+            o_ctx: ptr::null(),
+            key_length: 0,
+            key: [0u8, .. 128]
+        };
+
+        HMAC_CTX_init(&mut ctx,
+                                 key.as_ptr(),
+                                 key.len() as libc::c_int,
+                                 evp);
+
+        HMAC { ctx: ctx, len: mdlen }
+    }
+}
+
+impl HMAC {
+    pub fn update(&mut self, data: &[u8]) {
+        unsafe {
+            data.as_imm_buf(|pdata, len| {
+                HMAC_Update(&mut self.ctx, pdata, len as libc::c_uint)
+            });
+        }
+    }
+
+    pub fn final(&mut self) -> ~[u8] {
+        unsafe {
+            let mut res = vec::from_elem(self.len, 0u8);
+            let mut outlen: libc::c_uint = 0;
+            res.as_mut_buf(|pres, _len| {
+                HMAC_Final(&mut self.ctx, pres, &mut outlen);
+                assert!(self.len == outlen as uint)
+            });
+            res
+        }
+    }
+}