--- /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_gcm.h"
+#include "aesni_key.h"
+
+#include <crypto/iv/iv_gen_seq.h>
+
+#include <tmmintrin.h>
+
+#define NONCE_SIZE 12
+#define IV_SIZE 8
+#define SALT_SIZE (NONCE_SIZE - IV_SIZE)
+
+typedef struct private_aesni_gcm_t private_aesni_gcm_t;
+
+/**
+ * GCM en/decryption method type
+ */
+typedef void (*aesni_gcm_fn_t)(private_aesni_gcm_t*, size_t, u_char*, u_char*,
+ u_char*, size_t, u_char*, u_char*);
+
+/**
+ * Private data of an aesni_gcm_t object.
+ */
+struct private_aesni_gcm_t {
+
+ /**
+ * Public aesni_gcm_t interface.
+ */
+ aesni_gcm_t public;
+
+ /**
+ * Encryption key schedule
+ */
+ aesni_key_t *key;
+
+ /**
+ * IV generator.
+ */
+ iv_gen_t *iv_gen;
+
+ /**
+ * Length of the integrity check value
+ */
+ size_t icv_size;
+
+ /**
+ * Length of the key in bytes
+ */
+ size_t key_size;
+
+ /**
+ * GCM encryption function
+ */
+ aesni_gcm_fn_t encrypt;
+
+ /**
+ * GCM decryption function
+ */
+ aesni_gcm_fn_t decrypt;
+
+ /**
+ * salt to add to nonce
+ */
+ u_char salt[SALT_SIZE];
+
+ /**
+ * GHASH subkey H, big-endian
+ */
+ __m128i h;
+};
+
+/**
+ * Byte-swap a 128-bit integer
+ */
+static inline __m128i swap128(__m128i x)
+{
+ return _mm_shuffle_epi8(x,
+ _mm_set_epi8(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15));
+}
+
+/**
+ * Multiply two blocks in GF128
+ */
+static inline __m128i mult_block(__m128i h, __m128i y)
+{
+ __m128i t1, t2, t3, t4, t5, t6;
+
+ y = swap128(y);
+
+ t1 = _mm_clmulepi64_si128(h, y, 0x00);
+ t2 = _mm_clmulepi64_si128(h, y, 0x01);
+ t3 = _mm_clmulepi64_si128(h, y, 0x10);
+ t4 = _mm_clmulepi64_si128(h, y, 0x11);
+
+ t2 = _mm_xor_si128(t2, t3);
+ t3 = _mm_slli_si128(t2, 8);
+ t2 = _mm_srli_si128(t2, 8);
+ t1 = _mm_xor_si128(t1, t3);
+ t4 = _mm_xor_si128(t4, t2);
+
+ t5 = _mm_srli_epi32(t1, 31);
+ t1 = _mm_slli_epi32(t1, 1);
+ t6 = _mm_srli_epi32(t4, 31);
+ t4 = _mm_slli_epi32(t4, 1);
+
+ t3 = _mm_srli_si128(t5, 12);
+ t6 = _mm_slli_si128(t6, 4);
+ t5 = _mm_slli_si128(t5, 4);
+ t1 = _mm_or_si128(t1, t5);
+ t4 = _mm_or_si128(t4, t6);
+ t4 = _mm_or_si128(t4, t3);
+
+ t5 = _mm_slli_epi32(t1, 31);
+ t6 = _mm_slli_epi32(t1, 30);
+ t3 = _mm_slli_epi32(t1, 25);
+
+ t5 = _mm_xor_si128(t5, t6);
+ t5 = _mm_xor_si128(t5, t3);
+ t6 = _mm_srli_si128(t5, 4);
+ t4 = _mm_xor_si128(t4, t6);
+ t5 = _mm_slli_si128(t5, 12);
+ t1 = _mm_xor_si128(t1, t5);
+ t4 = _mm_xor_si128(t4, t1);
+
+ t5 = _mm_srli_epi32(t1, 1);
+ t2 = _mm_srli_epi32(t1, 2);
+ t3 = _mm_srli_epi32(t1, 7);
+ t4 = _mm_xor_si128(t4, t2);
+ t4 = _mm_xor_si128(t4, t3);
+ t4 = _mm_xor_si128(t4, t5);
+
+ return swap128(t4);
+}
+
+/**
+ * GHASH on a single block
+ */
+static __m128i ghash(__m128i h, __m128i y, __m128i x)
+{
+ return mult_block(h, _mm_xor_si128(y, x));
+}
+
+/**
+ * Start constructing the ICV for the associated data
+ */
+static __m128i icv_header(private_aesni_gcm_t *this, void *assoc, size_t alen)
+{
+ u_int blocks, rem, i;
+ __m128i y, last, *ab;
+
+ y = _mm_setzero_si128();
+ ab = assoc;
+ blocks = alen / AES_BLOCK_SIZE;
+ rem = alen % AES_BLOCK_SIZE;
+ for (i = 0; i < blocks; i++)
+ {
+ y = ghash(this->h, y, _mm_loadu_si128(ab + i));
+ }
+ if (rem)
+ {
+ last = _mm_setzero_si128();
+ memcpy(&last, ab + blocks, rem);
+
+ y = ghash(this->h, y, last);
+ }
+
+ return y;
+}
+
+/**
+ * Complete the ICV by hashing a assoc/data length block
+ */
+static __m128i icv_tailer(private_aesni_gcm_t *this, __m128i y,
+ size_t alen, size_t dlen)
+{
+ __m128i b;
+
+ htoun64(&b, alen * 8);
+ htoun64((u_char*)&b + sizeof(u_int64_t), dlen * 8);
+
+ return ghash(this->h, y, b);
+}
+
+/**
+ * En-/Decrypt the ICV, trim and store it
+ */
+static void icv_crypt(private_aesni_gcm_t *this, __m128i y, __m128i j,
+ u_char *icv)
+{
+ __m128i t, b;
+ u_int round;
+
+ t = _mm_xor_si128(j, 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(y, t);
+
+ _mm_storeu_si128(&b, t);
+ memcpy(icv, &b, this->icv_size);
+}
+
+/**
+ * Do big-endian increment on x
+ */
+static inline __m128i increment_be(__m128i x)
+{
+ x = swap128(x);
+ x = _mm_add_epi64(x, _mm_set_epi32(0, 0, 0, 1));
+ x = swap128(x);
+
+ return x;
+}
+
+/**
+ * Generate the block J0
+ */
+static inline __m128i create_j(private_aesni_gcm_t *this, u_char *iv)
+{
+ u_char j[AES_BLOCK_SIZE];
+
+ memcpy(j, this->salt, SALT_SIZE);
+ memcpy(j + SALT_SIZE, iv, IV_SIZE);
+ htoun32(j + SALT_SIZE + IV_SIZE, 1);
+
+ return _mm_loadu_si128((__m128i*)j);
+}
+
+/**
+ * Encrypt a remaining incomplete block, return updated Y
+ */
+static __m128i encrypt_gcm_rem(private_aesni_gcm_t *this, u_int rem,
+ void *in, void *out, __m128i cb, __m128i y)
+{
+ __m128i t, b;
+ u_int round;
+
+ memset(&b, 0, sizeof(b));
+ memcpy(&b, in, rem);
+
+ t = _mm_xor_si128(cb, 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]);
+ b = _mm_xor_si128(t, b);
+
+ memcpy(out, &b, rem);
+
+ memset((u_char*)&b + rem, 0, AES_BLOCK_SIZE - rem);
+ return ghash(this->h, y, b);
+}
+
+/**
+ * Decrypt a remaining incomplete block, return updated Y
+ */
+static __m128i decrypt_gcm_rem(private_aesni_gcm_t *this, u_int rem,
+ void *in, void *out, __m128i cb, __m128i y)
+{
+ __m128i t, b;
+ u_int round;
+
+ memset(&b, 0, sizeof(b));
+ memcpy(&b, in, rem);
+
+ y = ghash(this->h, y, b);
+
+ t = _mm_xor_si128(cb, 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]);
+ b = _mm_xor_si128(t, b);
+
+ memcpy(out, &b, rem);
+
+ return y;
+}
+
+/**
+ * Generic GCM encryption/ICV generation
+ */
+static void encrypt_gcm(private_aesni_gcm_t *this,
+ size_t len, u_char *in, u_char *out, u_char *iv,
+ size_t alen, u_char *assoc, u_char *icv)
+{
+ __m128i d, t, y, j, cb, *bi, *bo;
+ u_int round, blocks, rem, i;
+
+ j = create_j(this, iv);
+ y = icv_header(this, assoc, alen);
+ blocks = len / AES_BLOCK_SIZE;
+ rem = len % AES_BLOCK_SIZE;
+ bi = (__m128i*)in;
+ bo = (__m128i*)out;
+
+ cb = increment_be(j);
+ for (i = 0; i < blocks; i++)
+ {
+ d = _mm_loadu_si128(bi + i);
+ t = _mm_xor_si128(cb, 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);
+
+ y = ghash(this->h, y, t);
+
+ cb = increment_be(cb);
+ }
+
+ if (rem)
+ {
+ y = encrypt_gcm_rem(this, rem, bi + blocks, bo + blocks, cb, y);
+ }
+ y = icv_tailer(this, y, alen, len);
+ icv_crypt(this, y, j, icv);
+}
+
+/**
+ * Generic GCM decryption/ICV generation
+ */
+static void decrypt_gcm(private_aesni_gcm_t *this,
+ size_t len, u_char *in, u_char *out, u_char *iv,
+ size_t alen, u_char *assoc, u_char *icv)
+{
+ __m128i d, t, y, j, cb, *bi, *bo;
+ u_int round, blocks, rem, i;
+
+ j = create_j(this, iv);
+ y = icv_header(this, assoc, alen);
+ blocks = len / AES_BLOCK_SIZE;
+ rem = len % AES_BLOCK_SIZE;
+ bi = (__m128i*)in;
+ bo = (__m128i*)out;
+
+ cb = increment_be(j);
+ for (i = 0; i < blocks; i++)
+ {
+ d = _mm_loadu_si128(bi + i);
+
+ y = ghash(this->h, y, d);
+
+ t = _mm_xor_si128(cb, 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);
+
+ cb = increment_be(cb);
+ }
+
+ if (rem)
+ {
+ y = decrypt_gcm_rem(this, rem, bi + blocks, bo + blocks, cb, y);
+ }
+ y = icv_tailer(this, y, alen, len);
+ icv_crypt(this, y, j, icv);
+}
+
+METHOD(aead_t, encrypt, bool,
+ private_aesni_gcm_t *this, chunk_t plain, chunk_t assoc, chunk_t iv,
+ chunk_t *encr)
+{
+ u_char *out;
+
+ if (!this->key || iv.len != IV_SIZE)
+ {
+ return FALSE;
+ }
+ out = plain.ptr;
+ if (encr)
+ {
+ *encr = chunk_alloc(plain.len + this->icv_size);
+ out = encr->ptr;
+ }
+ this->encrypt(this, plain.len, plain.ptr, out, iv.ptr,
+ assoc.len, assoc.ptr, out + plain.len);
+ return TRUE;
+}
+
+METHOD(aead_t, decrypt, bool,
+ private_aesni_gcm_t *this, chunk_t encr, chunk_t assoc, chunk_t iv,
+ chunk_t *plain)
+{
+ u_char *out, icv[this->icv_size];
+
+ if (!this->key || iv.len != IV_SIZE || encr.len < this->icv_size)
+ {
+ return FALSE;
+ }
+ encr.len -= this->icv_size;
+ out = encr.ptr;
+ if (plain)
+ {
+ *plain = chunk_alloc(encr.len);
+ out = plain->ptr;
+ }
+ this->decrypt(this, encr.len, encr.ptr, out, iv.ptr,
+ assoc.len, assoc.ptr, icv);
+ return memeq_const(icv, encr.ptr + encr.len, this->icv_size);
+}
+
+METHOD(aead_t, get_block_size, size_t,
+ private_aesni_gcm_t *this)
+{
+ return 1;
+}
+
+METHOD(aead_t, get_icv_size, size_t,
+ private_aesni_gcm_t *this)
+{
+ return this->icv_size;
+}
+
+METHOD(aead_t, get_iv_size, size_t,
+ private_aesni_gcm_t *this)
+{
+ return IV_SIZE;
+}
+
+METHOD(aead_t, get_iv_gen, iv_gen_t*,
+ private_aesni_gcm_t *this)
+{
+ return this->iv_gen;
+}
+
+METHOD(aead_t, get_key_size, size_t,
+ private_aesni_gcm_t *this)
+{
+ return this->key_size + SALT_SIZE;
+}
+
+METHOD(aead_t, set_key, bool,
+ private_aesni_gcm_t *this, chunk_t key)
+{
+ u_int round;
+ __m128i h;
+
+ if (key.len != this->key_size + SALT_SIZE)
+ {
+ return FALSE;
+ }
+
+ memcpy(this->salt, key.ptr + key.len - SALT_SIZE, SALT_SIZE);
+ key.len -= SALT_SIZE;
+
+ DESTROY_IF(this->key);
+ this->key = aesni_key_create(TRUE, key);
+
+ h = _mm_xor_si128(_mm_setzero_si128(), this->key->schedule[0]);
+ for (round = 1; round < this->key->rounds; round++)
+ {
+ h = _mm_aesenc_si128(h, this->key->schedule[round]);
+ }
+ h = _mm_aesenclast_si128(h, this->key->schedule[this->key->rounds]);
+
+ this->h = swap128(h);
+
+ return TRUE;
+}
+
+METHOD(aead_t, destroy, void,
+ private_aesni_gcm_t *this)
+{
+ DESTROY_IF(this->key);
+ memwipe(&this->h, sizeof(this->h));
+ this->iv_gen->destroy(this->iv_gen);
+ free(this);
+}
+
+/**
+ * See header
+ */
+aesni_gcm_t *aesni_gcm_create(encryption_algorithm_t algo,
+ size_t key_size, size_t salt_size)
+{
+ private_aesni_gcm_t *this;
+ size_t icv_size;
+
+ switch (key_size)
+ {
+ case 0:
+ key_size = 16;
+ break;
+ case 16:
+ case 24:
+ case 32:
+ break;
+ default:
+ return NULL;
+ }
+ if (salt_size && salt_size != SALT_SIZE)
+ {
+ /* currently not supported */
+ return NULL;
+ }
+ switch (algo)
+ {
+ case ENCR_AES_GCM_ICV8:
+ algo = ENCR_AES_CBC;
+ icv_size = 8;
+ break;
+ case ENCR_AES_GCM_ICV12:
+ algo = ENCR_AES_CBC;
+ icv_size = 12;
+ break;
+ case ENCR_AES_GCM_ICV16:
+ algo = ENCR_AES_CBC;
+ icv_size = 16;
+ break;
+ default:
+ return NULL;
+ }
+
+ INIT(this,
+ .public = {
+ .aead = {
+ .encrypt = _encrypt,
+ .decrypt = _decrypt,
+ .get_block_size = _get_block_size,
+ .get_icv_size = _get_icv_size,
+ .get_iv_size = _get_iv_size,
+ .get_iv_gen = _get_iv_gen,
+ .get_key_size = _get_key_size,
+ .set_key = _set_key,
+ .destroy = _destroy,
+ },
+ },
+ .key_size = key_size,
+ .iv_gen = iv_gen_seq_create(),
+ .icv_size = icv_size,
+ .encrypt = encrypt_gcm,
+ .decrypt = decrypt_gcm,
+ );
+
+ return &this->public;
+}
projects / people / ms / strongswan.git / commitdiff
