Merge pull request #558 from sfackler/ige

Support AES IGE

2 files changed, 116 insertions, 0 deletions

diff --git a/openssl/src/aes.rs b/openssl/src/aes.rs
new file mode 100644
index 00000000..d226c515
--- /dev/null
+++ b/openssl/src/aes.rs
@@ -0,0 +1,115 @@
+//! Low level AES functionality
+//!
+//! The `symm` module should be used in preference to this module in most cases.
+use ffi;
+use std::mem;
+use libc::c_int;
+
+use symm::Mode;
+
+#[derive(Debug)]
+pub struct KeyError(());
+
+pub struct AesKey(ffi::AES_KEY);
+
+impl AesKey {
+    /// Prepares a key for encryption.
+    ///
+    /// # Failure
+    ///
+    /// Returns an error if the key is not 128, 192, or 256 bits.
+    pub fn new_encrypt(key: &[u8]) -> Result<AesKey, KeyError> {
+        unsafe {
+            assert!(key.len() <= c_int::max_value() as usize / 8);
+
+            let mut aes_key = mem::uninitialized();
+            let r = ffi::AES_set_encrypt_key(key.as_ptr() as *const _,
+                                             key.len() as c_int * 8,
+                                             &mut aes_key);
+            if r == 0 {
+                Ok(AesKey(aes_key))
+            } else {
+                Err(KeyError(()))
+            }
+        }
+    }
+
+    /// Prepares a key for decryption.
+    ///
+    /// # Failure
+    ///
+    /// Returns an error if the key is not 128, 192, or 256 bits.
+    pub fn new_decrypt(key: &[u8]) -> Result<AesKey, KeyError> {
+        unsafe {
+            assert!(key.len() <= c_int::max_value() as usize / 8);
+
+            let mut aes_key = mem::uninitialized();
+            let r = ffi::AES_set_decrypt_key(key.as_ptr() as *const _,
+                                             key.len() as c_int * 8,
+                                             &mut aes_key);
+
+            if r == 0 {
+                Ok(AesKey(aes_key))
+            } else {
+                Err(KeyError(()))
+            }
+        }
+    }
+}
+
+/// Performs AES IGE encryption or decryption
+///
+/// # Panics
+///
+/// Panics if `in_` is not the same length as `out`, if that length is not a multiple of 16, or if
+/// `iv` is not at least 32 bytes.
+pub fn aes_ige(in_: &[u8], out: &mut [u8], key: &AesKey, iv: &mut [u8], mode: Mode) {
+    unsafe {
+        assert!(in_.len() == out.len());
+        assert!(in_.len() % ffi::AES_BLOCK_SIZE as usize == 0);
+        assert!(iv.len() >= ffi::AES_BLOCK_SIZE as usize * 2);
+
+        let mode = match mode {
+            Mode::Encrypt => ffi::AES_ENCRYPT,
+            Mode::Decrypt => ffi::AES_DECRYPT,
+        };
+        ffi::AES_ige_encrypt(in_.as_ptr() as *const _,
+                             out.as_mut_ptr() as *mut _,
+                             in_.len(),
+                             &key.0,
+                             iv.as_mut_ptr() as *mut _,
+                             mode);
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use hex::FromHex;
+
+    use symm::Mode;
+    use super::*;
+
+    // From https://www.mgp25.com/AESIGE/
+    #[test]
+    fn ige_vector_1() {
+        let raw_key = "000102030405060708090A0B0C0D0E0F";
+        let raw_iv = "000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F";
+        let raw_pt = "0000000000000000000000000000000000000000000000000000000000000000";
+        let raw_ct = "1A8519A6557BE652E9DA8E43DA4EF4453CF456B4CA488AA383C79C98B34797CB";
+
+        let key = AesKey::new_encrypt(&Vec::from_hex(raw_key).unwrap()).unwrap();
+        let mut iv = Vec::from_hex(raw_iv).unwrap();
+        let pt = Vec::from_hex(raw_pt).unwrap();
+        let ct = Vec::from_hex(raw_ct).unwrap();
+
+        let mut ct_actual = vec![0; ct.len()];
+        aes_ige(&pt, &mut ct_actual, &key, &mut iv, Mode::Encrypt);
+        assert_eq!(ct_actual, ct);
+
+        let key = AesKey::new_decrypt(&Vec::from_hex(raw_key).unwrap()).unwrap();
+        let mut iv = Vec::from_hex(raw_iv).unwrap();
+        let mut pt_actual = vec![0; pt.len()];
+        aes_ige(&ct, &mut pt_actual, &key, &mut iv, Mode::Decrypt);
+        assert_eq!(pt_actual, pt);
+    }
+}
diff --git a/openssl/src/lib.rs b/openssl/src/lib.rs
index 9138896b..ea71a269 100644
--- a/openssl/src/lib.rs
+++ b/openssl/src/lib.rs
@@ -24,6 +24,7 @@ mod macros;
 
 mod bio;
 mod util;
+pub mod aes;
 pub mod asn1;
 pub mod bn;
 pub mod crypto;