aesni: Implement XCBC mode to provide a signer/prf

Compared to the xcbc plugin using AESNI-CBC as backend, this improves
performance of AES-XCBC by ~45%.

src/libstrongswan/plugins/aesni/Makefile.am

@@ -17,6 +17,7 @@ libstrongswan_aesni_la_SOURCES = \
 	aesni_cbc.h aesni_cbc.c \
 	aesni_ctr.h aesni_ctr.c \
 	aesni_ccm.h aesni_ccm.c \
+	aesni_xcbc.h aesni_xcbc.c \
 	aesni_plugin.h aesni_plugin.c
 
 libstrongswan_aesni_la_LDFLAGS = -module -avoid-version

src/libstrongswan/plugins/aesni/aesni_plugin.c

@@ -17,6 +17,7 @@
 #include "aesni_cbc.h"
 #include "aesni_ctr.h"
 #include "aesni_ccm.h"
+#include "aesni_xcbc.h"
 
 #include <stdio.h>
 
@@ -66,6 +67,10 @@ METHOD(plugin_t, get_features, int,
 			PLUGIN_PROVIDE(AEAD, ENCR_AES_CCM_ICV8,  32),
 			PLUGIN_PROVIDE(AEAD, ENCR_AES_CCM_ICV12, 32),
 			PLUGIN_PROVIDE(AEAD, ENCR_AES_CCM_ICV16, 32),
+		PLUGIN_REGISTER(PRF, aesni_xcbc_prf_create),
+			PLUGIN_PROVIDE(PRF, PRF_AES128_XCBC),
+		PLUGIN_REGISTER(SIGNER, aesni_xcbc_signer_create),
+			PLUGIN_PROVIDE(SIGNER, AUTH_AES_XCBC_96),
 	};
 
 	*features = f;

src/libstrongswan/plugins/aesni/aesni_xcbc.c

@@ -0,0 +1,378 @@
+/*
+ * Copyright (C) 2008-2015 Martin Willi
+ * Copyright (C) 2012 Tobias Brunner
+ * Hochschule fuer Technik Rapperswil
+ * 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_xcbc.h"
+#include "aesni_key.h"
+
+#include <crypto/prfs/mac_prf.h>
+#include <crypto/signers/mac_signer.h>
+
+typedef struct private_aesni_mac_t private_aesni_mac_t;
+
+/**
+ * Private data of a mac_t object.
+ */
+struct private_aesni_mac_t {
+
+	/**
+	 * Public mac_t interface.
+	 */
+	mac_t public;
+
+	/**
+	 * Key schedule for K1
+	 */
+	aesni_key_t *k1;
+
+	/**
+	 * k2
+	 */
+	__m128i k2;
+
+	/**
+	 * k3
+	 */
+	__m128i k3;
+
+	/**
+	 * E
+	 */
+	__m128i e;
+
+	/**
+	 * remaining, unprocessed bytes in append mode
+	 */
+	u_char rem[AES_BLOCK_SIZE];
+
+	/**
+	 * number of bytes used in remaining
+	 */
+	int rem_size;
+
+	/**
+	 * TRUE if we have zero bytes to xcbc in final()
+	 */
+	bool zero;
+};
+
+METHOD(mac_t, get_mac, bool,
+	private_aesni_mac_t *this, chunk_t data, u_int8_t *out)
+{
+	__m128i k0, k1, k2, k3, k4, k5, k6, k7, k8, k9, k10;
+	__m128i e, *bi;
+	u_int blocks, rem, i;
+
+	if (!this->k1)
+	{
+		return FALSE;
+	}
+
+	k0 = this->k1->schedule[0];
+	k1 = this->k1->schedule[1];
+	k2 = this->k1->schedule[2];
+	k3 = this->k1->schedule[3];
+	k4 = this->k1->schedule[4];
+	k5 = this->k1->schedule[5];
+	k6 = this->k1->schedule[6];
+	k7 = this->k1->schedule[7];
+	k8 = this->k1->schedule[8];
+	k9 = this->k1->schedule[9];
+	k10 = this->k1->schedule[10];
+
+	e = this->e;
+
+	if (data.len)
+	{
+		this->zero = FALSE;
+	}
+
+	if (this->rem_size + data.len > AES_BLOCK_SIZE)
+	{
+		/* (3) For each block M[i], where i = 1 ... n-1:
+		 *     XOR M[i] with E[i-1], then encrypt the result with Key K1,
+		 *     yielding E[i].
+		 */
+
+		/* append data to remaining bytes, process block M[1] */
+		memcpy(this->rem + this->rem_size, data.ptr,
+			   AES_BLOCK_SIZE - this->rem_size);
+		data = chunk_skip(data, AES_BLOCK_SIZE - this->rem_size);
+
+		e = _mm_xor_si128(e, _mm_loadu_si128((__m128i*)this->rem));
+
+		e = _mm_xor_si128(e, k0);
+		e = _mm_aesenc_si128(e, k1);
+		e = _mm_aesenc_si128(e, k2);
+		e = _mm_aesenc_si128(e, k3);
+		e = _mm_aesenc_si128(e, k4);
+		e = _mm_aesenc_si128(e, k5);
+		e = _mm_aesenc_si128(e, k6);
+		e = _mm_aesenc_si128(e, k7);
+		e = _mm_aesenc_si128(e, k8);
+		e = _mm_aesenc_si128(e, k9);
+		e = _mm_aesenclast_si128(e, k10);
+
+		bi = (__m128i*)data.ptr;
+		rem = data.len % AES_BLOCK_SIZE;
+		blocks = data.len / AES_BLOCK_SIZE;
+		if (!rem && blocks)
+		{	/* don't do last block */
+			rem = AES_BLOCK_SIZE;
+			blocks--;
+		}
+
+		/* process blocks M[2] ... M[n-1] */
+		for (i = 0; i < blocks; i++)
+		{
+			e = _mm_xor_si128(e, _mm_loadu_si128(bi + i));
+
+			e = _mm_xor_si128(e, k0);
+			e = _mm_aesenc_si128(e, k1);
+			e = _mm_aesenc_si128(e, k2);
+			e = _mm_aesenc_si128(e, k3);
+			e = _mm_aesenc_si128(e, k4);
+			e = _mm_aesenc_si128(e, k5);
+			e = _mm_aesenc_si128(e, k6);
+			e = _mm_aesenc_si128(e, k7);
+			e = _mm_aesenc_si128(e, k8);
+			e = _mm_aesenc_si128(e, k9);
+			e = _mm_aesenclast_si128(e, k10);
+		}
+
+		/* store remaining bytes of block M[n] */
+		memcpy(this->rem, data.ptr + data.len - rem, rem);
+		this->rem_size = rem;
+	}
+	else
+	{
+		/* no complete block, just copy into remaining */
+		memcpy(this->rem + this->rem_size, data.ptr, data.len);
+		this->rem_size += data.len;
+	}
+
+	if (out)
+	{
+		/* (4) For block M[n]: */
+		if (this->rem_size == AES_BLOCK_SIZE && !this->zero)
+		{
+			/* a) If the blocksize of M[n] is 128 bits:
+			 *    XOR M[n] with E[n-1] and Key K2, then encrypt the result with
+			 *    Key K1, yielding E[n].
+			 */
+			e = _mm_xor_si128(e, this->k2);
+		}
+		else
+		{
+			/* b) If the blocksize of M[n] is less than 128 bits:
+			 *
+			 *  i) Pad M[n] with a single "1" bit, followed by the number of
+			 *     "0" bits (possibly none) required to increase M[n]'s
+			 *     blocksize to 128 bits.
+			 */
+			if (this->rem_size < AES_BLOCK_SIZE)
+			{
+				memset(this->rem + this->rem_size, 0,
+					   AES_BLOCK_SIZE - this->rem_size);
+				this->rem[this->rem_size] = 0x80;
+			}
+			/*  ii) XOR M[n] with E[n-1] and Key K3, then encrypt the result
+			 *      with Key K1, yielding E[n].
+			 */
+			e = _mm_xor_si128(e, this->k3);
+		}
+		e = _mm_xor_si128(e, _mm_loadu_si128((__m128i*)this->rem));
+
+		e = _mm_xor_si128(e, k0);
+		e = _mm_aesenc_si128(e, k1);
+		e = _mm_aesenc_si128(e, k2);
+		e = _mm_aesenc_si128(e, k3);
+		e = _mm_aesenc_si128(e, k4);
+		e = _mm_aesenc_si128(e, k5);
+		e = _mm_aesenc_si128(e, k6);
+		e = _mm_aesenc_si128(e, k7);
+		e = _mm_aesenc_si128(e, k8);
+		e = _mm_aesenc_si128(e, k9);
+		e = _mm_aesenclast_si128(e, k10);
+		_mm_storeu_si128((__m128i*)out, e);
+
+		/* (2) Define E[0] = 0x00000000000000000000000000000000 */
+		e = _mm_setzero_si128();
+		this->rem_size = 0;
+		this->zero = TRUE;
+	}
+	this->e = e;
+	return TRUE;
+}
+
+METHOD(mac_t, get_mac_size, size_t,
+	private_aesni_mac_t *this)
+{
+	return AES_BLOCK_SIZE;
+}
+
+METHOD(mac_t, set_key, bool,
+	private_aesni_mac_t *this, chunk_t key)
+{
+	__m128i t1, t2, t3;
+	u_char k1[AES_BLOCK_SIZE];
+	u_int round;
+	chunk_t k;
+
+	/* reset state */
+	this->e = _mm_setzero_si128();
+	this->rem_size = 0;
+	this->zero = TRUE;
+
+	/* Create RFC4434 variable keys if required */
+	if (key.len == AES_BLOCK_SIZE)
+	{
+		k = key;
+	}
+	else if (key.len < AES_BLOCK_SIZE)
+	{	/* pad short keys */
+		k = chunk_alloca(AES_BLOCK_SIZE);
+		memset(k.ptr, 0, k.len);
+		memcpy(k.ptr, key.ptr, key.len);
+	}
+	else
+	{	/* shorten key using XCBC */
+		k = chunk_alloca(AES_BLOCK_SIZE);
+		memset(k.ptr, 0, k.len);
+		if (!set_key(this, k) || !get_mac(this, key, k.ptr))
+		{
+			return FALSE;
+		}
+	}
+
+	/*
+	 * (1) Derive 3 128-bit keys (K1, K2 and K3) from the 128-bit secret
+	 *     key K, as follows:
+	 *     K1 = 0x01010101010101010101010101010101 encrypted with Key K
+	 *     K2 = 0x02020202020202020202020202020202 encrypted with Key K
+	 *     K3 = 0x03030303030303030303030303030303 encrypted with Key K
+	 */
+
+	DESTROY_IF(this->k1);
+	this->k1 = aesni_key_create(TRUE, k);
+	if (!this->k1)
+	{
+		return FALSE;
+	}
+
+	t1 = _mm_set1_epi8(0x01);
+	t2 = _mm_set1_epi8(0x02);
+	t3 = _mm_set1_epi8(0x03);
+
+	t1 = _mm_xor_si128(t1, this->k1->schedule[0]);
+	t2 = _mm_xor_si128(t2, this->k1->schedule[0]);
+	t3 = _mm_xor_si128(t3, this->k1->schedule[0]);
+
+	for (round = 1; round < this->k1->rounds; round++)
+	{
+		t1 = _mm_aesenc_si128(t1, this->k1->schedule[round]);
+		t2 = _mm_aesenc_si128(t2, this->k1->schedule[round]);
+		t3 = _mm_aesenc_si128(t3, this->k1->schedule[round]);
+	}
+
+	t1 = _mm_aesenclast_si128(t1, this->k1->schedule[this->k1->rounds]);
+	t2 = _mm_aesenclast_si128(t2, this->k1->schedule[this->k1->rounds]);
+	t3 = _mm_aesenclast_si128(t3, this->k1->schedule[this->k1->rounds]);
+
+	_mm_storeu_si128((__m128i*)k1, t1);
+	this->k2 = t2;
+	this->k3 = t3;
+
+	this->k1->destroy(this->k1);
+	this->k1 = aesni_key_create(TRUE, chunk_from_thing(k1));
+
+	memwipe(k1, AES_BLOCK_SIZE);
+	return this->k1 != NULL;
+}
+
+METHOD(mac_t, destroy, void,
+	private_aesni_mac_t *this)
+{
+	DESTROY_IF(this->k1);
+	memwipe(&this->k2, sizeof(this->k2));
+	memwipe(&this->k3, sizeof(this->k3));
+	free(this);
+}
+
+/*
+ * Described in header
+ */
+mac_t *aesni_xcbc_create(encryption_algorithm_t algo, size_t key_size)
+{
+	private_aesni_mac_t *this;
+
+	INIT(this,
+		.public = {
+			.get_mac = _get_mac,
+			.get_mac_size = _get_mac_size,
+			.set_key = _set_key,
+			.destroy = _destroy,
+		},
+	);
+
+	return &this->public;
+}
+
+/*
+ * Described in header.
+ */
+prf_t *aesni_xcbc_prf_create(pseudo_random_function_t algo)
+{
+	mac_t *xcbc;
+
+	switch (algo)
+	{
+		case PRF_AES128_XCBC:
+			xcbc = aesni_xcbc_create(ENCR_AES_CBC, 16);
+			break;
+		default:
+			return NULL;
+	}
+	if (xcbc)
+	{
+		return mac_prf_create(xcbc);
+	}
+	return NULL;
+}
+
+/*
+ * Described in header
+ */
+signer_t *aesni_xcbc_signer_create(integrity_algorithm_t algo)
+{
+	size_t trunc;
+	mac_t *xcbc;
+
+	switch (algo)
+	{
+		case AUTH_AES_XCBC_96:
+			xcbc = aesni_xcbc_create(ENCR_AES_CBC, 16);
+			trunc = 12;
+			break;
+		default:
+			return NULL;
+	}
+	if (xcbc)
+	{
+		return mac_signer_create(xcbc, trunc);
+	}
+	return NULL;
+}

src/libstrongswan/plugins/aesni/aesni_xcbc.h

@@ -0,0 +1,52 @@
+/*
+ * 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_xcbc aesni_xcbc
+ * @{ @ingroup aesni
+ */
+
+#ifndef AESNI_XCBC_H_
+#define AESNI_XCBC_H_
+
+#include <crypto/mac.h>
+#include <crypto/prfs/prf.h>
+#include <crypto/signers/signer.h>
+
+/**
+ * Create a generic mac_t object using AESNI XCBC
+ *
+ * @param algo		underlying encryption algorithm
+ * @param key_size	size of encryption key, in bytes
+ */
+mac_t *aesni_xcbc_create(encryption_algorithm_t algo, size_t key_size);
+
+/**
+ * Creates a new prf_t object based AESNI XCBC.
+ *
+ * @param algo		algorithm to implement
+ * @return			prf_t object, NULL if not supported
+ */
+prf_t *aesni_xcbc_prf_create(pseudo_random_function_t algo);
+
+/**
+ * Creates a new signer_t object based on AESNI XCBC.
+ *
+ * @param algo		algorithm to implement
+ * @return			signer_t, NULL if not supported
+ */
+signer_t *aesni_xcbc_signer_create(integrity_algorithm_t algo);
+
+#endif /** AESNI_XCBC_H_ @}*/