aesni: Implement a AES-NI based CBC crypter using the key schedule
authorMartin Willi <martin@revosec.ch>
Wed, 25 Mar 2015 16:30:58 +0000 (17:30 +0100)
committerMartin Willi <martin@revosec.ch>
Wed, 15 Apr 2015 09:35:27 +0000 (11:35 +0200)
src/libstrongswan/plugins/aesni/Makefile.am
src/libstrongswan/plugins/aesni/aesni_cbc.c [new file with mode: 0644]
src/libstrongswan/plugins/aesni/aesni_cbc.h [new file with mode: 0644]
src/libstrongswan/plugins/aesni/aesni_plugin.c

index 817afa4..c7c8e69 100644 (file)
@@ -13,6 +13,7 @@ endif
 
 libstrongswan_aesni_la_SOURCES = \
        aesni_key.h aesni_key.c \
+       aesni_cbc.h aesni_cbc.c \
        aesni_plugin.h aesni_plugin.c
 
 libstrongswan_aesni_la_LDFLAGS = -module -avoid-version
diff --git a/src/libstrongswan/plugins/aesni/aesni_cbc.c b/src/libstrongswan/plugins/aesni/aesni_cbc.c
new file mode 100644 (file)
index 0000000..ca35d27
--- /dev/null
@@ -0,0 +1,239 @@
+/*
+ * Copyright (C) 2015 Martin Willi
+ * Copyright (C) 2015 revosec AG
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ */
+
+#include "aesni_cbc.h"
+#include "aesni_key.h"
+
+typedef struct private_aesni_cbc_t private_aesni_cbc_t;
+
+/**
+ * CBC en/decryption method type
+ */
+typedef void (*aesni_cbc_fn_t)(aesni_key_t*, u_int, u_char*, u_char*, u_char*);
+
+/**
+ * Private data of an aesni_cbc_t object.
+ */
+struct private_aesni_cbc_t {
+
+       /**
+        * Public aesni_cbc_t interface.
+        */
+       aesni_cbc_t public;
+
+       /**
+        * Key size
+        */
+       u_int key_size;
+
+       /**
+        * Encryption key schedule
+        */
+       aesni_key_t *ekey;
+
+       /**
+        * Decryption key schedule
+        */
+       aesni_key_t *dkey;
+
+       /**
+        * Encryption method
+        */
+       aesni_cbc_fn_t encrypt;
+
+       /**
+        * Decryption method
+        */
+       aesni_cbc_fn_t decrypt;
+};
+
+/**
+ * Generic CBC encryption
+ */
+static void encrypt_cbc(aesni_key_t *key, u_int blocks, u_char *in,
+                                               u_char *iv, u_char *out)
+{
+       __m128i t, fb, *bi, *bo;
+       int i, round;
+
+       bi = (__m128i*)in;
+       bo = (__m128i*)out;
+
+       fb = _mm_loadu_si128((__m128i*)iv);
+       for (i = 0; i < blocks; i++)
+       {
+               t = _mm_loadu_si128(bi + i);
+               fb = _mm_xor_si128(t, fb);
+               fb = _mm_xor_si128(fb, key->schedule[0]);
+               for (round = 1; round < key->rounds; round++)
+               {
+                       fb = _mm_aesenc_si128(fb, key->schedule[round]);
+               }
+               fb = _mm_aesenclast_si128(fb, key->schedule[key->rounds]);
+               _mm_storeu_si128(bo + i, fb);
+       }
+}
+
+/**
+ * Generic CBC decryption
+ */
+static void decrypt_cbc(aesni_key_t *key, u_int blocks, u_char *in,
+                                               u_char *iv, u_char *out)
+{
+       __m128i t, fb, last, *bi, *bo;
+       int i, round;
+
+       bi = (__m128i*)in;
+       bo = (__m128i*)out;
+
+       fb = _mm_loadu_si128((__m128i*)iv);
+       for (i = 0; i < blocks; i++)
+       {
+               last = _mm_loadu_si128(bi + i);
+               t = _mm_xor_si128(last, key->schedule[0]);
+               for (round = 1; round  < key->rounds; round++)
+               {
+                       t = _mm_aesdec_si128(t, key->schedule[round]);
+               }
+               t = _mm_aesdeclast_si128(t, key->schedule[key->rounds]);
+               t = _mm_xor_si128(t, fb);
+               _mm_storeu_si128(bo + i, t);
+               fb = last;
+       }
+}
+
+/**
+ * Do inline or allocated de/encryption using key schedule
+ */
+static bool crypt(aesni_cbc_fn_t fn, aesni_key_t *key,
+                                 chunk_t data, chunk_t iv, chunk_t *out)
+{
+       u_char *buf;
+
+       if (!key || iv.len != AES_BLOCK_SIZE || data.len % AES_BLOCK_SIZE)
+       {
+               return FALSE;
+       }
+       if (out)
+       {
+               *out = chunk_alloc(data.len);
+               buf = out->ptr;
+       }
+       else
+       {
+               buf = data.ptr;
+       }
+       fn(key, data.len / AES_BLOCK_SIZE, data.ptr, iv.ptr, buf);
+       return TRUE;
+}
+
+METHOD(crypter_t, encrypt, bool,
+       private_aesni_cbc_t *this, chunk_t data, chunk_t iv, chunk_t *encrypted)
+{
+       return crypt(this->encrypt, this->ekey, data, iv, encrypted);
+}
+
+METHOD(crypter_t, decrypt, bool,
+       private_aesni_cbc_t *this, chunk_t data, chunk_t iv, chunk_t *decrypted)
+{
+       return crypt(this->decrypt, this->dkey, data, iv, decrypted);
+}
+
+METHOD(crypter_t, get_block_size, size_t,
+       private_aesni_cbc_t *this)
+{
+       return AES_BLOCK_SIZE;
+}
+
+METHOD(crypter_t, get_iv_size, size_t,
+       private_aesni_cbc_t *this)
+{
+       return AES_BLOCK_SIZE;
+}
+
+METHOD(crypter_t, get_key_size, size_t,
+       private_aesni_cbc_t *this)
+{
+       return this->key_size;
+}
+
+METHOD(crypter_t, set_key, bool,
+       private_aesni_cbc_t *this, chunk_t key)
+{
+       if (key.len != this->key_size)
+       {
+               return FALSE;
+       }
+
+       DESTROY_IF(this->ekey);
+       DESTROY_IF(this->dkey);
+
+       this->ekey = aesni_key_create(TRUE, key);
+       this->dkey = aesni_key_create(FALSE, key);
+
+       return this->ekey && this->dkey;
+}
+
+METHOD(crypter_t, destroy, void,
+       private_aesni_cbc_t *this)
+{
+       DESTROY_IF(this->ekey);
+       DESTROY_IF(this->dkey);
+       free(this);
+}
+
+/**
+ * See header
+ */
+aesni_cbc_t *aesni_cbc_create(encryption_algorithm_t algo, size_t key_size)
+{
+       private_aesni_cbc_t *this;
+
+       if (algo != ENCR_AES_CBC)
+       {
+               return NULL;
+       }
+       switch (key_size)
+       {
+               case 0:
+                       key_size = 16;
+                       break;
+               case 16:
+               case 24:
+               case 32:
+                       break;
+               default:
+                       return NULL;
+       }
+
+       INIT(this,
+               .public = {
+                       .crypter = {
+                               .encrypt = _encrypt,
+                               .decrypt = _decrypt,
+                               .get_block_size = _get_block_size,
+                               .get_iv_size = _get_iv_size,
+                               .get_key_size = _get_key_size,
+                               .set_key = _set_key,
+                               .destroy = _destroy,
+                       },
+               },
+               .key_size = key_size,
+               .encrypt = encrypt_cbc,
+               .decrypt = decrypt_cbc,
+       );
+
+       return &this->public;
+}
diff --git a/src/libstrongswan/plugins/aesni/aesni_cbc.h b/src/libstrongswan/plugins/aesni/aesni_cbc.h
new file mode 100644 (file)
index 0000000..c004ec6
--- /dev/null
@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2015 Martin Willi
+ * Copyright (C) 2015 revosec AG
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ */
+
+/**
+ * @defgroup aesni_cbc aesni_cbc
+ * @{ @ingroup aesni
+ */
+
+#ifndef AESNI_CBC_H_
+#define AESNI_CBC_H_
+
+#include <library.h>
+
+typedef struct aesni_cbc_t aesni_cbc_t;
+
+/**
+ * CBC mode crypter using AES-NI
+ */
+struct aesni_cbc_t {
+
+       /**
+        * Implements crypter interface
+        */
+       crypter_t crypter;
+};
+
+/**
+ * Create a aesni_cbc instance.
+ *
+ * @param algo                 encryption algorithm, AES_ENCR_CBC
+ * @param key_size             AES key size, in bytes
+ * @return                             AES-CBC crypter, NULL if not supported
+ */
+aesni_cbc_t *aesni_cbc_create(encryption_algorithm_t algo, size_t key_size);
+
+#endif /** AESNI_CBC_H_ @}*/
index 2e3ffaf..7464598 100644 (file)
@@ -14,6 +14,7 @@
  */
 
 #include "aesni_plugin.h"
+#include "aesni_cbc.h"
 
 #include <stdio.h>
 
@@ -45,6 +46,10 @@ METHOD(plugin_t, get_features, int,
        private_aesni_plugin_t *this, plugin_feature_t *features[])
 {
        static plugin_feature_t f[] = {
+               PLUGIN_REGISTER(CRYPTER, aesni_cbc_create),
+                       PLUGIN_PROVIDE(CRYPTER, ENCR_AES_CBC, 16),
+                       PLUGIN_PROVIDE(CRYPTER, ENCR_AES_CBC, 24),
+                       PLUGIN_PROVIDE(CRYPTER, ENCR_AES_CBC, 32),
        };
 
        *features = f;