aesni: Implement a AES-NI based CTR crypter using the key schedule
authorMartin Willi <martin@revosec.ch>
Thu, 26 Mar 2015 09:37:03 +0000 (10:37 +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_ctr.c [new file with mode: 0644]
src/libstrongswan/plugins/aesni/aesni_ctr.h [new file with mode: 0644]
src/libstrongswan/plugins/aesni/aesni_plugin.c

index c7c8e69..0defa0b 100644 (file)
@@ -3,6 +3,7 @@ AM_CPPFLAGS = \
 
 AM_CFLAGS = \
        -maes \
+       -mssse3 \
        $(PLUGIN_CFLAGS)
 
 if MONOLITHIC
@@ -14,6 +15,7 @@ endif
 libstrongswan_aesni_la_SOURCES = \
        aesni_key.h aesni_key.c \
        aesni_cbc.h aesni_cbc.c \
+       aesni_ctr.h aesni_ctr.c \
        aesni_plugin.h aesni_plugin.c
 
 libstrongswan_aesni_la_LDFLAGS = -module -avoid-version
diff --git a/src/libstrongswan/plugins/aesni/aesni_ctr.c b/src/libstrongswan/plugins/aesni/aesni_ctr.c
new file mode 100644 (file)
index 0000000..fd17945
--- /dev/null
@@ -0,0 +1,223 @@
+/*
+ * 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_ctr.h"
+#include "aesni_key.h"
+
+#include <tmmintrin.h>
+
+typedef struct private_aesni_ctr_t private_aesni_ctr_t;
+
+/**
+ * CTR en/decryption method type
+ */
+typedef void (*aesni_ctr_fn_t)(private_aesni_ctr_t*, size_t, u_char*, u_char*);
+
+/**
+ * Private data of an aesni_ctr_t object.
+ */
+struct private_aesni_ctr_t {
+
+       /**
+        * Public aesni_ctr_t interface.
+        */
+       aesni_ctr_t public;
+
+       /**
+        * Key size
+        */
+       u_int key_size;
+
+       /**
+        * Key schedule
+        */
+       aesni_key_t *key;
+
+       /**
+        * Encryption method
+        */
+       aesni_ctr_fn_t crypt;
+
+       /**
+        * Counter state
+        */
+       struct {
+               char nonce[4];
+               char iv[8];
+               u_int32_t counter;
+       } __attribute__((packed, aligned(sizeof(__m128i)))) state;
+};
+
+/**
+ * Generic CTR encryption
+ */
+static void encrypt_ctr(private_aesni_ctr_t *this,
+                                               size_t len, u_char *in, u_char *out)
+{
+       __m128i state, t, d, b, swap, one, *bi, *bo;
+       u_int i, round, blocks, rem;
+
+       one = _mm_set_epi32(0, 0, 0, 1);
+       swap = _mm_setr_epi8(15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0);
+       state = _mm_load_si128((__m128i*)&this->state);
+       blocks = len / AES_BLOCK_SIZE;
+       rem = len % AES_BLOCK_SIZE;
+       bi = (__m128i*)in;
+       bo = (__m128i*)out;
+
+       for (i = 0; i < blocks; i++)
+       {
+               d = _mm_loadu_si128(bi + i);
+               t = _mm_xor_si128(state, this->key->schedule[0]);
+               for (round = 1; round < this->key->rounds; round++)
+               {
+                       t = _mm_aesenc_si128(t, this->key->schedule[round]);
+               }
+               t = _mm_aesenclast_si128(t, this->key->schedule[this->key->rounds]);
+               t = _mm_xor_si128(t, d);
+               _mm_storeu_si128(bo + i, t);
+
+               /* big endian increment */
+               t = _mm_shuffle_epi8(state, swap);
+               t = _mm_add_epi64(t, one);
+               state = _mm_shuffle_epi8(t, swap);
+       }
+
+       if (rem)
+       {
+               memset(&b, 0, sizeof(b));
+               memcpy(&b, bi + blocks, rem);
+
+               d = _mm_loadu_si128(&b);
+               t = _mm_xor_si128(state, this->key->schedule[0]);
+               for (round = 1; round < this->key->rounds; round++)
+               {
+                       t = _mm_aesenc_si128(t, this->key->schedule[round]);
+               }
+               t = _mm_aesenclast_si128(t, this->key->schedule[this->key->rounds]);
+               t = _mm_xor_si128(t, d);
+               _mm_storeu_si128(&b, t);
+
+               memcpy(bo + blocks, &b, rem);
+       }
+}
+
+METHOD(crypter_t, crypt, bool,
+       private_aesni_ctr_t *this, chunk_t in, chunk_t iv, chunk_t *out)
+{
+       u_char *buf;
+
+       if (!this->key || iv.len != sizeof(this->state.iv))
+       {
+               return FALSE;
+       }
+       memcpy(this->state.iv, iv.ptr, sizeof(this->state.iv));
+       this->state.counter = htonl(1);
+
+       buf = in.ptr;
+       if (out)
+       {
+               *out = chunk_alloc(in.len);
+               buf = out->ptr;
+       }
+       this->crypt(this, in.len, in.ptr, buf);
+       return TRUE;
+}
+
+METHOD(crypter_t, get_block_size, size_t,
+       private_aesni_ctr_t *this)
+{
+       return 1;
+}
+
+METHOD(crypter_t, get_iv_size, size_t,
+       private_aesni_ctr_t *this)
+{
+       return sizeof(this->state.iv);
+}
+
+METHOD(crypter_t, get_key_size, size_t,
+       private_aesni_ctr_t *this)
+{
+       return this->key_size + sizeof(this->state.nonce);
+}
+
+METHOD(crypter_t, set_key, bool,
+       private_aesni_ctr_t *this, chunk_t key)
+{
+       if (key.len != get_key_size(this))
+       {
+               return FALSE;
+       }
+
+       memcpy(this->state.nonce, key.ptr + key.len - sizeof(this->state.nonce),
+                  sizeof(this->state.nonce));
+       key.len -= sizeof(this->state.nonce);
+
+       DESTROY_IF(this->key);
+       this->key = aesni_key_create(TRUE, key);
+
+       return this->key;
+}
+
+METHOD(crypter_t, destroy, void,
+       private_aesni_ctr_t *this)
+{
+       DESTROY_IF(this->key);
+       free(this);
+}
+
+/**
+ * See header
+ */
+aesni_ctr_t *aesni_ctr_create(encryption_algorithm_t algo, size_t key_size)
+{
+       private_aesni_ctr_t *this;
+
+       if (algo != ENCR_AES_CTR)
+       {
+               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 = _crypt,
+                               .decrypt = _crypt,
+                               .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,
+               .crypt = encrypt_ctr,
+       );
+
+       return &this->public;
+}
diff --git a/src/libstrongswan/plugins/aesni/aesni_ctr.h b/src/libstrongswan/plugins/aesni/aesni_ctr.h
new file mode 100644 (file)
index 0000000..6126a2c
--- /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_ctr aesni_ctr
+ * @{ @ingroup aesni
+ */
+
+#ifndef AESNI_CTR_H_
+#define AESNI_CTR_H_
+
+#include <library.h>
+
+typedef struct aesni_ctr_t aesni_ctr_t;
+
+/**
+ * CTR mode crypter using AES-NI
+ */
+struct aesni_ctr_t {
+
+       /**
+        * Implements crypter interface
+        */
+       crypter_t crypter;
+};
+
+/**
+ * Create a aesni_ctr instance.
+ *
+ * @param algo                 encryption algorithm, AES_ENCR_CTR
+ * @param key_size             AES key size, in bytes
+ * @return                             AES-CTR crypter, NULL if not supported
+ */
+aesni_ctr_t *aesni_ctr_create(encryption_algorithm_t algo, size_t key_size);
+
+#endif /** AESNI_CTR_H_ @}*/
index 7464598..697392d 100644 (file)
@@ -15,6 +15,7 @@
 
 #include "aesni_plugin.h"
 #include "aesni_cbc.h"
+#include "aesni_ctr.h"
 
 #include <stdio.h>
 
@@ -50,6 +51,10 @@ METHOD(plugin_t, get_features, int,
                        PLUGIN_PROVIDE(CRYPTER, ENCR_AES_CBC, 16),
                        PLUGIN_PROVIDE(CRYPTER, ENCR_AES_CBC, 24),
                        PLUGIN_PROVIDE(CRYPTER, ENCR_AES_CBC, 32),
+               PLUGIN_REGISTER(CRYPTER, aesni_ctr_create),
+                       PLUGIN_PROVIDE(CRYPTER, ENCR_AES_CTR, 16),
+                       PLUGIN_PROVIDE(CRYPTER, ENCR_AES_CTR, 24),
+                       PLUGIN_PROVIDE(CRYPTER, ENCR_AES_CTR, 32),
        };
 
        *features = f;