--- /dev/null
+/*
+ * 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;
+}
--- /dev/null
+/*
+ * 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_ @}*/
projects / people / ms / strongswan.git / commitdiff
