HardenedBSD/sys/crypto/openssl/amd64/ossl_aes_gcm.c
Mark Johnston 47d767dab5 ossl: Fix some bugs in the fallback AES-GCM implementation
gcm_*_aesni() are used when the AVX512 implementation is not available.
Fix two bugs which manifest when handling operations spanning multiple
segments:
- Avoid underflow when the length of the input is smaller than the
  residual.
- In gcm_decrypt_aesni(), ensure that we begin the operation at the
  right offset into the input and output buffers.

Reviewed by:	jhb
Fixes:		9b1d87286c ("ossl: Add a fallback AES-GCM implementation using AES-NI")
MFC after:	3 days
Differential Revision:	https://reviews.freebsd.org/D42838
2023-11-30 12:49:47 -05:00

703 lines
16 KiB
C

/*
* Copyright 2010-2022 The OpenSSL Project Authors. All Rights Reserved.
* Copyright (c) 2021, Intel Corporation. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
/*
* This file contains 2 AES-GCM wrapper implementations from OpenSSL, using
* AES-NI and VAES extensions respectively. These were ported from
* cipher_aes_gcm_hw_aesni.inc and cipher_aes_gcm_hw_vaes_avx512.inc. The
* AES-NI implementation makes use of a generic C implementation for partial
* blocks, ported from gcm128.c with OPENSSL_SMALL_FOOTPRINT defined.
*/
#include <sys/endian.h>
#include <sys/systm.h>
#include <crypto/openssl/ossl.h>
#include <crypto/openssl/ossl_aes_gcm.h>
#include <crypto/openssl/ossl_cipher.h>
#include <opencrypto/cryptodev.h>
_Static_assert(
sizeof(struct ossl_gcm_context) <= sizeof(struct ossl_cipher_context),
"ossl_gcm_context too large");
void aesni_set_encrypt_key(const void *key, int bits, void *ctx);
static void
gcm_init(struct ossl_gcm_context *ctx, const void *key, size_t keylen)
{
KASSERT(keylen == 128 || keylen == 192 || keylen == 256,
("%s: invalid key length %zu", __func__, keylen));
memset(&ctx->gcm, 0, sizeof(ctx->gcm));
memset(&ctx->aes_ks, 0, sizeof(ctx->aes_ks));
aesni_set_encrypt_key(key, keylen, &ctx->aes_ks);
ctx->ops->init(ctx, key, keylen);
}
static void
gcm_tag(struct ossl_gcm_context *ctx, unsigned char *tag, size_t len)
{
(void)ctx->ops->finish(ctx, NULL, 0);
memcpy(tag, ctx->gcm.Xi.c, len);
}
void ossl_gcm_gmult_avx512(uint64_t Xi[2], void *gcm128ctx);
void ossl_aes_gcm_init_avx512(const void *ks, void *gcm128ctx);
void ossl_aes_gcm_setiv_avx512(const void *ks, void *gcm128ctx,
const unsigned char *iv, size_t ivlen);
void ossl_aes_gcm_update_aad_avx512(void *gcm128ctx, const unsigned char *aad,
size_t len);
void ossl_aes_gcm_encrypt_avx512(const void *ks, void *gcm128ctx,
unsigned int *pblocklen, const unsigned char *in, size_t len,
unsigned char *out);
void ossl_aes_gcm_decrypt_avx512(const void *ks, void *gcm128ctx,
unsigned int *pblocklen, const unsigned char *in, size_t len,
unsigned char *out);
void ossl_aes_gcm_finalize_avx512(void *gcm128ctx, unsigned int pblocklen);
static void
gcm_init_avx512(struct ossl_gcm_context *ctx, const void *key, size_t keylen)
{
ossl_aes_gcm_init_avx512(&ctx->aes_ks, &ctx->gcm);
}
static void
gcm_setiv_avx512(struct ossl_gcm_context *ctx, const unsigned char *iv,
size_t len)
{
KASSERT(len == AES_GCM_IV_LEN,
("%s: invalid IV length %zu", __func__, len));
ctx->gcm.Yi.u[0] = 0; /* Current counter */
ctx->gcm.Yi.u[1] = 0;
ctx->gcm.Xi.u[0] = 0; /* AAD hash */
ctx->gcm.Xi.u[1] = 0;
ctx->gcm.len.u[0] = 0; /* AAD length */
ctx->gcm.len.u[1] = 0; /* Message length */
ctx->gcm.ares = 0;
ctx->gcm.mres = 0;
ossl_aes_gcm_setiv_avx512(&ctx->aes_ks, ctx, iv, len);
}
static int
gcm_aad_avx512(struct ossl_gcm_context *ctx, const unsigned char *aad,
size_t len)
{
uint64_t alen = ctx->gcm.len.u[0];
size_t lenblks;
unsigned int ares;
/* Bad sequence: call of AAD update after message processing */
if (ctx->gcm.len.u[1])
return -2;
alen += len;
/* AAD is limited by 2^64 bits, thus 2^61 bytes */
if (alen > (1ull << 61) || (sizeof(len) == 8 && alen < len))
return -1;
ctx->gcm.len.u[0] = alen;
ares = ctx->gcm.ares;
/* Partial AAD block left from previous AAD update calls */
if (ares > 0) {
/*
* Fill partial block buffer till full block
* (note, the hash is stored reflected)
*/
while (ares > 0 && len > 0) {
ctx->gcm.Xi.c[15 - ares] ^= *(aad++);
--len;
ares = (ares + 1) % AES_BLOCK_LEN;
}
/* Full block gathered */
if (ares == 0) {
ossl_gcm_gmult_avx512(ctx->gcm.Xi.u, ctx);
} else { /* no more AAD */
ctx->gcm.ares = ares;
return 0;
}
}
/* Bulk AAD processing */
lenblks = len & ((size_t)(-AES_BLOCK_LEN));
if (lenblks > 0) {
ossl_aes_gcm_update_aad_avx512(ctx, aad, lenblks);
aad += lenblks;
len -= lenblks;
}
/* Add remaining AAD to the hash (note, the hash is stored reflected) */
if (len > 0) {
ares = (unsigned int)len;
for (size_t i = 0; i < len; ++i)
ctx->gcm.Xi.c[15 - i] ^= aad[i];
}
ctx->gcm.ares = ares;
return 0;
}
static int
_gcm_encrypt_avx512(struct ossl_gcm_context *ctx, const unsigned char *in,
unsigned char *out, size_t len, bool encrypt)
{
uint64_t mlen = ctx->gcm.len.u[1];
mlen += len;
if (mlen > ((1ull << 36) - 32) || (sizeof(len) == 8 && mlen < len))
return -1;
ctx->gcm.len.u[1] = mlen;
/* Finalize GHASH(AAD) if AAD partial blocks left unprocessed */
if (ctx->gcm.ares > 0) {
ossl_gcm_gmult_avx512(ctx->gcm.Xi.u, ctx);
ctx->gcm.ares = 0;
}
if (encrypt) {
ossl_aes_gcm_encrypt_avx512(&ctx->aes_ks, ctx, &ctx->gcm.mres,
in, len, out);
} else {
ossl_aes_gcm_decrypt_avx512(&ctx->aes_ks, ctx, &ctx->gcm.mres,
in, len, out);
}
return 0;
}
static int
gcm_encrypt_avx512(struct ossl_gcm_context *ctx, const unsigned char *in,
unsigned char *out, size_t len)
{
return _gcm_encrypt_avx512(ctx, in, out, len, true);
}
static int
gcm_decrypt_avx512(struct ossl_gcm_context *ctx, const unsigned char *in,
unsigned char *out, size_t len)
{
return _gcm_encrypt_avx512(ctx, in, out, len, false);
}
static int
gcm_finish_avx512(struct ossl_gcm_context *ctx, const unsigned char *tag,
size_t len)
{
unsigned int *res = &ctx->gcm.mres;
/* Finalize AAD processing */
if (ctx->gcm.ares > 0)
res = &ctx->gcm.ares;
ossl_aes_gcm_finalize_avx512(ctx, *res);
ctx->gcm.ares = ctx->gcm.mres = 0;
if (tag != NULL)
return timingsafe_bcmp(ctx->gcm.Xi.c, tag, len);
return 0;
}
static const struct ossl_aes_gcm_ops gcm_ops_avx512 = {
.init = gcm_init_avx512,
.setiv = gcm_setiv_avx512,
.aad = gcm_aad_avx512,
.encrypt = gcm_encrypt_avx512,
.decrypt = gcm_decrypt_avx512,
.finish = gcm_finish_avx512,
.tag = gcm_tag,
};
size_t aesni_gcm_encrypt(const unsigned char *in, unsigned char *out, size_t len,
const void *key, unsigned char ivec[16], uint64_t *Xi);
size_t aesni_gcm_decrypt(const unsigned char *in, unsigned char *out, size_t len,
const void *key, unsigned char ivec[16], uint64_t *Xi);
void aesni_encrypt(const unsigned char *in, unsigned char *out, void *ks);
void aesni_ctr32_encrypt_blocks(const unsigned char *in, unsigned char *out,
size_t blocks, void *ks, const unsigned char *iv);
void gcm_init_avx(__uint128_t Htable[16], uint64_t Xi[2]);
void gcm_gmult_avx(uint64_t Xi[2], const __uint128_t Htable[16]);
void gcm_ghash_avx(uint64_t Xi[2], const __uint128_t Htable[16], const void *in,
size_t len);
static void
gcm_init_aesni(struct ossl_gcm_context *ctx, const void *key, size_t keylen)
{
aesni_encrypt(ctx->gcm.H.c, ctx->gcm.H.c, &ctx->aes_ks);
#if BYTE_ORDER == LITTLE_ENDIAN
ctx->gcm.H.u[0] = bswap64(ctx->gcm.H.u[0]);
ctx->gcm.H.u[1] = bswap64(ctx->gcm.H.u[1]);
#endif
gcm_init_avx(ctx->gcm.Htable, ctx->gcm.H.u);
}
static void
gcm_setiv_aesni(struct ossl_gcm_context *ctx, const unsigned char *iv,
size_t len)
{
uint32_t ctr;
KASSERT(len == AES_GCM_IV_LEN,
("%s: invalid IV length %zu", __func__, len));
ctx->gcm.len.u[0] = 0;
ctx->gcm.len.u[1] = 0;
ctx->gcm.ares = ctx->gcm.mres = 0;
memcpy(ctx->gcm.Yi.c, iv, len);
ctx->gcm.Yi.c[12] = 0;
ctx->gcm.Yi.c[13] = 0;
ctx->gcm.Yi.c[14] = 0;
ctx->gcm.Yi.c[15] = 1;
ctr = 1;
ctx->gcm.Xi.u[0] = 0;
ctx->gcm.Xi.u[1] = 0;
aesni_encrypt(ctx->gcm.Yi.c, ctx->gcm.EK0.c, &ctx->aes_ks);
ctr++;
#if BYTE_ORDER == LITTLE_ENDIAN
ctx->gcm.Yi.d[3] = bswap32(ctr);
#else
ctx->gcm.Yi.d[3] = ctr;
#endif
}
static int
gcm_aad_aesni(struct ossl_gcm_context *ctx, const unsigned char *aad,
size_t len)
{
size_t i;
unsigned int n;
uint64_t alen = ctx->gcm.len.u[0];
if (ctx->gcm.len.u[1])
return -2;
alen += len;
if (alen > (1ull << 61) || (sizeof(len) == 8 && alen < len))
return -1;
ctx->gcm.len.u[0] = alen;
n = ctx->gcm.ares;
if (n) {
while (n && len) {
ctx->gcm.Xi.c[n] ^= *(aad++);
--len;
n = (n + 1) % 16;
}
if (n == 0)
gcm_gmult_avx(ctx->gcm.Xi.u, ctx->gcm.Htable);
else {
ctx->gcm.ares = n;
return 0;
}
}
if ((i = (len & (size_t)-AES_BLOCK_LEN))) {
gcm_ghash_avx(ctx->gcm.Xi.u, ctx->gcm.Htable, aad, i);
aad += i;
len -= i;
}
if (len) {
n = (unsigned int)len;
for (i = 0; i < len; ++i)
ctx->gcm.Xi.c[i] ^= aad[i];
}
ctx->gcm.ares = n;
return 0;
}
static int
gcm_encrypt(struct ossl_gcm_context *ctx, const unsigned char *in,
unsigned char *out, size_t len)
{
unsigned int n, ctr, mres;
size_t i;
uint64_t mlen = ctx->gcm.len.u[1];
mlen += len;
if (mlen > ((1ull << 36) - 32) || (sizeof(len) == 8 && mlen < len))
return -1;
ctx->gcm.len.u[1] = mlen;
mres = ctx->gcm.mres;
if (ctx->gcm.ares) {
/* First call to encrypt finalizes GHASH(AAD) */
gcm_gmult_avx(ctx->gcm.Xi.u, ctx->gcm.Htable);
ctx->gcm.ares = 0;
}
#if BYTE_ORDER == LITTLE_ENDIAN
ctr = bswap32(ctx->gcm.Yi.d[3]);
#else
ctr = ctx->gcm.Yi.d[3];
#endif
n = mres % 16;
for (i = 0; i < len; ++i) {
if (n == 0) {
aesni_encrypt(ctx->gcm.Yi.c, ctx->gcm.EKi.c,
&ctx->aes_ks);
++ctr;
#if BYTE_ORDER == LITTLE_ENDIAN
ctx->gcm.Yi.d[3] = bswap32(ctr);
#else
ctx->gcm.Yi.d[3] = ctr;
#endif
}
ctx->gcm.Xi.c[n] ^= out[i] = in[i] ^ ctx->gcm.EKi.c[n];
mres = n = (n + 1) % 16;
if (n == 0)
gcm_gmult_avx(ctx->gcm.Xi.u, ctx->gcm.Htable);
}
ctx->gcm.mres = mres;
return 0;
}
static int
gcm_encrypt_ctr32(struct ossl_gcm_context *ctx, const unsigned char *in,
unsigned char *out, size_t len)
{
unsigned int n, ctr, mres;
size_t i;
uint64_t mlen = ctx->gcm.len.u[1];
mlen += len;
if (mlen > ((1ull << 36) - 32) || (sizeof(len) == 8 && mlen < len))
return -1;
ctx->gcm.len.u[1] = mlen;
mres = ctx->gcm.mres;
if (ctx->gcm.ares) {
/* First call to encrypt finalizes GHASH(AAD) */
gcm_gmult_avx(ctx->gcm.Xi.u, ctx->gcm.Htable);
ctx->gcm.ares = 0;
}
#if BYTE_ORDER == LITTLE_ENDIAN
ctr = bswap32(ctx->gcm.Yi.d[3]);
#else
ctr = ctx->gcm.Yi.d[3];
#endif
n = mres % 16;
if (n) {
while (n && len) {
ctx->gcm.Xi.c[n] ^= *(out++) = *(in++) ^ ctx->gcm.EKi.c[n];
--len;
n = (n + 1) % 16;
}
if (n == 0) {
gcm_gmult_avx(ctx->gcm.Xi.u, ctx->gcm.Htable);
mres = 0;
} else {
ctx->gcm.mres = n;
return 0;
}
}
if ((i = (len & (size_t)-16))) {
size_t j = i / 16;
aesni_ctr32_encrypt_blocks(in, out, j, &ctx->aes_ks, ctx->gcm.Yi.c);
ctr += (unsigned int)j;
#if BYTE_ORDER == LITTLE_ENDIAN
ctx->gcm.Yi.d[3] = bswap32(ctr);
#else
ctx->gcm.Yi.d[3] = ctr;
#endif
in += i;
len -= i;
while (j--) {
for (i = 0; i < 16; ++i)
ctx->gcm.Xi.c[i] ^= out[i];
gcm_gmult_avx(ctx->gcm.Xi.u, ctx->gcm.Htable);
out += 16;
}
}
if (len) {
aesni_encrypt(ctx->gcm.Yi.c, ctx->gcm.EKi.c, &ctx->aes_ks);
++ctr;
#if BYTE_ORDER == LITTLE_ENDIAN
ctx->gcm.Yi.d[3] = bswap32(ctr);
#else
ctx->gcm.Yi.d[3] = ctr;
#endif
while (len--) {
ctx->gcm.Xi.c[mres++] ^= out[n] = in[n] ^ ctx->gcm.EKi.c[n];
++n;
}
}
ctx->gcm.mres = mres;
return 0;
}
static int
gcm_encrypt_aesni(struct ossl_gcm_context *ctx, const unsigned char *in,
unsigned char *out, size_t len)
{
size_t bulk = 0, res;
int error;
res = MIN(len, (AES_BLOCK_LEN - ctx->gcm.mres) % AES_BLOCK_LEN);
if ((error = gcm_encrypt(ctx, in, out, res)) != 0)
return error;
bulk = aesni_gcm_encrypt(in + res, out + res, len - res,
&ctx->aes_ks, ctx->gcm.Yi.c, ctx->gcm.Xi.u);
ctx->gcm.len.u[1] += bulk;
bulk += res;
if ((error = gcm_encrypt_ctr32(ctx, in + bulk, out + bulk,
len - bulk)) != 0)
return error;
return 0;
}
static int
gcm_decrypt(struct ossl_gcm_context *ctx, const unsigned char *in,
unsigned char *out, size_t len)
{
unsigned int n, ctr, mres;
size_t i;
uint64_t mlen = ctx->gcm.len.u[1];
mlen += len;
if (mlen > ((1ull << 36) - 32) || (sizeof(len) == 8 && mlen < len))
return -1;
ctx->gcm.len.u[1] = mlen;
mres = ctx->gcm.mres;
if (ctx->gcm.ares) {
/* First call to encrypt finalizes GHASH(AAD) */
gcm_gmult_avx(ctx->gcm.Xi.u, ctx->gcm.Htable);
ctx->gcm.ares = 0;
}
#if BYTE_ORDER == LITTLE_ENDIAN
ctr = bswap32(ctx->gcm.Yi.d[3]);
#else
ctr = ctx->gcm.Yi.d[3];
#endif
n = mres % 16;
for (i = 0; i < len; ++i) {
uint8_t c;
if (n == 0) {
aesni_encrypt(ctx->gcm.Yi.c, ctx->gcm.EKi.c,
&ctx->aes_ks);
++ctr;
#if BYTE_ORDER == LITTLE_ENDIAN
ctx->gcm.Yi.d[3] = bswap32(ctr);
#else
ctx->gcm.Yi.d[3] = ctr;
#endif
}
c = in[i];
out[i] = c ^ ctx->gcm.EKi.c[n];
ctx->gcm.Xi.c[n] ^= c;
mres = n = (n + 1) % 16;
if (n == 0)
gcm_gmult_avx(ctx->gcm.Xi.u, ctx->gcm.Htable);
}
ctx->gcm.mres = mres;
return 0;
}
static int
gcm_decrypt_ctr32(struct ossl_gcm_context *ctx, const unsigned char *in,
unsigned char *out, size_t len)
{
unsigned int n, ctr, mres;
size_t i;
uint64_t mlen = ctx->gcm.len.u[1];
mlen += len;
if (mlen > ((1ull << 36) - 32) || (sizeof(len) == 8 && mlen < len))
return -1;
ctx->gcm.len.u[1] = mlen;
mres = ctx->gcm.mres;
if (ctx->gcm.ares) {
/* First call to decrypt finalizes GHASH(AAD) */
gcm_gmult_avx(ctx->gcm.Xi.u, ctx->gcm.Htable);
ctx->gcm.ares = 0;
}
#if BYTE_ORDER == LITTLE_ENDIAN
ctr = bswap32(ctx->gcm.Yi.d[3]);
#else
ctr = ctx->gcm.Yi.d[3];
#endif
n = mres % 16;
if (n) {
while (n && len) {
uint8_t c = *(in++);
*(out++) = c ^ ctx->gcm.EKi.c[n];
ctx->gcm.Xi.c[n] ^= c;
--len;
n = (n + 1) % 16;
}
if (n == 0) {
gcm_gmult_avx(ctx->gcm.Xi.u, ctx->gcm.Htable);
mres = 0;
} else {
ctx->gcm.mres = n;
return 0;
}
}
if ((i = (len & (size_t)-16))) {
size_t j = i / 16;
while (j--) {
size_t k;
for (k = 0; k < 16; ++k)
ctx->gcm.Xi.c[k] ^= in[k];
gcm_gmult_avx(ctx->gcm.Xi.u, ctx->gcm.Htable);
in += 16;
}
j = i / 16;
in -= i;
aesni_ctr32_encrypt_blocks(in, out, j, &ctx->aes_ks, ctx->gcm.Yi.c);
ctr += (unsigned int)j;
#if BYTE_ORDER == LITTLE_ENDIAN
ctx->gcm.Yi.d[3] = bswap32(ctr);
#else
ctx->gcm.Yi.d[3] = ctr;
#endif
out += i;
in += i;
len -= i;
}
if (len) {
aesni_encrypt(ctx->gcm.Yi.c, ctx->gcm.EKi.c, &ctx->aes_ks);
++ctr;
#if BYTE_ORDER == LITTLE_ENDIAN
ctx->gcm.Yi.d[3] = bswap32(ctr);
#else
ctx->gcm.Yi.d[3] = ctr;
#endif
while (len--) {
uint8_t c = in[n];
ctx->gcm.Xi.c[mres++] ^= c;
out[n] = c ^ ctx->gcm.EKi.c[n];
++n;
}
}
ctx->gcm.mres = mres;
return 0;
}
static int
gcm_decrypt_aesni(struct ossl_gcm_context *ctx, const unsigned char *in,
unsigned char *out, size_t len)
{
size_t bulk = 0, res;
int error;
res = MIN(len, (AES_BLOCK_LEN - ctx->gcm.mres) % AES_BLOCK_LEN);
if ((error = gcm_decrypt(ctx, in, out, res)) != 0)
return error;
bulk = aesni_gcm_decrypt(in + res, out + res, len - res, &ctx->aes_ks,
ctx->gcm.Yi.c, ctx->gcm.Xi.u);
ctx->gcm.len.u[1] += bulk;
bulk += res;
if ((error = gcm_decrypt_ctr32(ctx, in + bulk, out + bulk, len - bulk)) != 0)
return error;
return 0;
}
static int
gcm_finish_aesni(struct ossl_gcm_context *ctx, const unsigned char *tag,
size_t len)
{
uint64_t alen = ctx->gcm.len.u[0] << 3;
uint64_t clen = ctx->gcm.len.u[1] << 3;
if (ctx->gcm.mres || ctx->gcm.ares)
gcm_gmult_avx(ctx->gcm.Xi.u, ctx->gcm.Htable);
#if BYTE_ORDER == LITTLE_ENDIAN
alen = bswap64(alen);
clen = bswap64(clen);
#endif
ctx->gcm.Xi.u[0] ^= alen;
ctx->gcm.Xi.u[1] ^= clen;
gcm_gmult_avx(ctx->gcm.Xi.u, ctx->gcm.Htable);
ctx->gcm.Xi.u[0] ^= ctx->gcm.EK0.u[0];
ctx->gcm.Xi.u[1] ^= ctx->gcm.EK0.u[1];
if (tag != NULL)
return timingsafe_bcmp(ctx->gcm.Xi.c, tag, len);
return 0;
}
static const struct ossl_aes_gcm_ops gcm_ops_aesni = {
.init = gcm_init_aesni,
.setiv = gcm_setiv_aesni,
.aad = gcm_aad_aesni,
.encrypt = gcm_encrypt_aesni,
.decrypt = gcm_decrypt_aesni,
.finish = gcm_finish_aesni,
.tag = gcm_tag,
};
int ossl_aes_gcm_setkey_aesni(const unsigned char *key, int klen, void *_ctx);
int
ossl_aes_gcm_setkey_aesni(const unsigned char *key, int klen,
void *_ctx)
{
struct ossl_gcm_context *ctx;
ctx = _ctx;
ctx->ops = &gcm_ops_aesni;
gcm_init(ctx, key, klen);
return (0);
}
int ossl_aes_gcm_setkey_avx512(const unsigned char *key, int klen, void *_ctx);
int
ossl_aes_gcm_setkey_avx512(const unsigned char *key, int klen,
void *_ctx)
{
struct ossl_gcm_context *ctx;
ctx = _ctx;
ctx->ops = &gcm_ops_avx512;
gcm_init(ctx, key, klen);
return (0);
}