xref: /dflybsd-src/crypto/libressl/crypto/evp/e_aes_cbc_hmac_sha1.c (revision 961e30ea7dc61d1112b778ea4981eac68129fb86)

/* $OpenBSD: e_aes_cbc_hmac_sha1.c,v 1.16 2021/12/12 21:30:13 tb Exp $ */
/* ====================================================================
 * Copyright (c) 2011-2013 The OpenSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    licensing@OpenSSL.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 */

#include <stdio.h>
#include <string.h>

#include <openssl/opensslconf.h>

#if !defined(OPENSSL_NO_AES) && !defined(OPENSSL_NO_SHA1)

#include <openssl/evp.h>
#include <openssl/objects.h>
#include <openssl/aes.h>
#include <openssl/sha.h>

#include "constant_time_locl.h"
#include "evp_locl.h"

#define TLS1_1_VERSION 0x0302

typedef struct {
	AES_KEY		ks;
	SHA_CTX		head, tail, md;
	size_t		payload_length;	/* AAD length in decrypt case */
	union {
		unsigned int	tls_ver;
		unsigned char	tls_aad[16];	/* 13 used */
	} aux;
} EVP_AES_HMAC_SHA1;

#define NO_PAYLOAD_LENGTH	((size_t)-1)

#if	defined(AES_ASM) &&	( \
	defined(__x86_64)	|| defined(__x86_64__)	|| \
	defined(_M_AMD64)	|| defined(_M_X64)	|| \
	defined(__INTEL__)	)

#include "x86_arch.h"

#if defined(__GNUC__) && __GNUC__>=2
# define BSWAP(x) ({ unsigned int r=(x); asm ("bswapl %0":"=r"(r):"0"(r)); r; })
#endif

int aesni_set_encrypt_key(const unsigned char *userKey, int bits, AES_KEY *key);
int aesni_set_decrypt_key(const unsigned char *userKey, int bits, AES_KEY *key);

void aesni_cbc_encrypt(const unsigned char *in, unsigned char *out,
    size_t length, const AES_KEY *key, unsigned char *ivec, int enc);

void aesni_cbc_sha1_enc (const void *inp, void *out, size_t blocks,
    const AES_KEY *key, unsigned char iv[16], SHA_CTX *ctx, const void *in0);

#define data(ctx) ((EVP_AES_HMAC_SHA1 *)(ctx)->cipher_data)

static int
aesni_cbc_hmac_sha1_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *inkey,
    const unsigned char *iv, int enc)
{
	EVP_AES_HMAC_SHA1 *key = data(ctx);
	int ret;

	if (enc)
		ret = aesni_set_encrypt_key(inkey, ctx->key_len * 8, &key->ks);
	else
		ret = aesni_set_decrypt_key(inkey, ctx->key_len * 8, &key->ks);

	SHA1_Init(&key->head);	/* handy when benchmarking */
	key->tail = key->head;
	key->md = key->head;

	key->payload_length = NO_PAYLOAD_LENGTH;

	return ret < 0 ? 0 : 1;
}

#define	STITCHED_CALL

#if !defined(STITCHED_CALL)
#define	aes_off 0
#endif

void sha1_block_data_order (void *c, const void *p, size_t len);

static void
sha1_update(SHA_CTX *c, const void *data, size_t len)
{
	const unsigned char *ptr = data;
	size_t res;

	if ((res = c->num)) {
		res = SHA_CBLOCK - res;
		if (len < res)
			res = len;
		SHA1_Update(c, ptr, res);
		ptr += res;
		len -= res;
	}

	res = len % SHA_CBLOCK;
	len -= res;

	if (len) {
		sha1_block_data_order(c, ptr, len / SHA_CBLOCK);

		ptr += len;
		c->Nh += len >> 29;
		c->Nl += len <<= 3;
		if (c->Nl < (unsigned int)len)
			c->Nh++;
	}

	if (res)
		SHA1_Update(c, ptr, res);
}

#ifdef SHA1_Update
#undef SHA1_Update
#endif
#define SHA1_Update sha1_update

static int
aesni_cbc_hmac_sha1_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
    const unsigned char *in, size_t len)
{
	EVP_AES_HMAC_SHA1 *key = data(ctx);
	unsigned int l;
	size_t plen = key->payload_length,
	    iv = 0,		/* explicit IV in TLS 1.1 and later */
	    sha_off = 0;
#if defined(STITCHED_CALL)
	size_t aes_off = 0, blocks;

	sha_off = SHA_CBLOCK - key->md.num;
#endif

	key->payload_length = NO_PAYLOAD_LENGTH;

	if (len % AES_BLOCK_SIZE)
		return 0;

	if (ctx->encrypt) {
		if (plen == NO_PAYLOAD_LENGTH)
			plen = len;
		else if (len != ((plen + SHA_DIGEST_LENGTH + AES_BLOCK_SIZE) &
		    -AES_BLOCK_SIZE))
			return 0;
		else if (key->aux.tls_ver >= TLS1_1_VERSION)
			iv = AES_BLOCK_SIZE;

#if defined(STITCHED_CALL)
		if (plen > (sha_off + iv) &&
		    (blocks = (plen - (sha_off + iv)) / SHA_CBLOCK)) {
			SHA1_Update(&key->md, in + iv, sha_off);

			aesni_cbc_sha1_enc(in, out, blocks, &key->ks,
			    ctx->iv, &key->md, in + iv + sha_off);
			blocks *= SHA_CBLOCK;
			aes_off += blocks;
			sha_off += blocks;
			key->md.Nh += blocks >> 29;
			key->md.Nl += blocks <<= 3;
			if (key->md.Nl < (unsigned int)blocks)
				key->md.Nh++;
		} else {
			sha_off = 0;
		}
#endif
		sha_off += iv;
		SHA1_Update(&key->md, in + sha_off, plen - sha_off);

		if (plen != len) {	/* "TLS" mode of operation */
			if (in != out)
				memcpy(out + aes_off, in + aes_off,
				    plen - aes_off);

			/* calculate HMAC and append it to payload */
			SHA1_Final(out + plen, &key->md);
			key->md = key->tail;
			SHA1_Update(&key->md, out + plen, SHA_DIGEST_LENGTH);
			SHA1_Final(out + plen, &key->md);

			/* pad the payload|hmac */
			plen += SHA_DIGEST_LENGTH;
			for (l = len - plen - 1; plen < len; plen++)
				out[plen] = l;

			/* encrypt HMAC|padding at once */
			aesni_cbc_encrypt(out + aes_off, out + aes_off,
			    len - aes_off, &key->ks, ctx->iv, 1);
		} else {
			aesni_cbc_encrypt(in + aes_off, out + aes_off,
			    len - aes_off, &key->ks, ctx->iv, 1);
		}
	} else {
		union {
			unsigned int u[SHA_DIGEST_LENGTH/sizeof(unsigned int)];
			unsigned char c[32 + SHA_DIGEST_LENGTH];
		} mac, *pmac;

		/* arrange cache line alignment */
		pmac = (void *)(((size_t)mac.c + 31) & ((size_t)0 - 32));

		/* decrypt HMAC|padding at once */
		aesni_cbc_encrypt(in, out, len, &key->ks, ctx->iv, 0);

		if (plen == 0 || plen == NO_PAYLOAD_LENGTH) {
			SHA1_Update(&key->md, out, len);
		} else if (plen < 4) {
			return 0;
		} else {	/* "TLS" mode of operation */
			size_t inp_len, mask, j, i;
			unsigned int res, maxpad, pad, bitlen;
			int ret = 1;
			union {
				unsigned int u[SHA_LBLOCK];
				unsigned char c[SHA_CBLOCK];
			}
			*data = (void *)key->md.data;

			if ((key->aux.tls_aad[plen - 4] << 8 |
			    key->aux.tls_aad[plen - 3]) >= TLS1_1_VERSION)
				iv = AES_BLOCK_SIZE;

			if (len < (iv + SHA_DIGEST_LENGTH + 1))
				return 0;

			/* omit explicit iv */
			out += iv;
			len -= iv;

			/* figure out payload length */
			pad = out[len - 1];
			maxpad = len - (SHA_DIGEST_LENGTH + 1);
			maxpad |= (255 - maxpad) >> (sizeof(maxpad) * 8 - 8);
			maxpad &= 255;

			ret &= constant_time_ge(maxpad, pad);

			inp_len = len - (SHA_DIGEST_LENGTH + pad + 1);
			mask = (0 - ((inp_len - len) >>
			    (sizeof(inp_len) * 8 - 1)));
			inp_len &= mask;
			ret &= (int)mask;

			key->aux.tls_aad[plen - 2] = inp_len >> 8;
			key->aux.tls_aad[plen - 1] = inp_len;

			/* calculate HMAC */
			key->md = key->head;
			SHA1_Update(&key->md, key->aux.tls_aad, plen);

#if 1
			len -= SHA_DIGEST_LENGTH;		/* amend mac */
			if (len >= (256 + SHA_CBLOCK)) {
				j = (len - (256 + SHA_CBLOCK)) &
				    (0 - SHA_CBLOCK);
				j += SHA_CBLOCK - key->md.num;
				SHA1_Update(&key->md, out, j);
				out += j;
				len -= j;
				inp_len -= j;
			}

			/* but pretend as if we hashed padded payload */
			bitlen = key->md.Nl + (inp_len << 3);	/* at most 18 bits */
#ifdef BSWAP
			bitlen = BSWAP(bitlen);
#else
			mac.c[0] = 0;
			mac.c[1] = (unsigned char)(bitlen >> 16);
			mac.c[2] = (unsigned char)(bitlen >> 8);
			mac.c[3] = (unsigned char)bitlen;
			bitlen = mac.u[0];
#endif

			pmac->u[0] = 0;
			pmac->u[1] = 0;
			pmac->u[2] = 0;
			pmac->u[3] = 0;
			pmac->u[4] = 0;

			for (res = key->md.num, j = 0; j < len; j++) {
				size_t c = out[j];
				mask = (j - inp_len) >> (sizeof(j) * 8 - 8);
				c &= mask;
				c |= 0x80 & ~mask &
				    ~((inp_len - j) >> (sizeof(j) * 8 - 8));
				data->c[res++] = (unsigned char)c;

				if (res != SHA_CBLOCK)
					continue;

				/* j is not incremented yet */
				mask = 0 - ((inp_len + 7 - j) >>
				    (sizeof(j) * 8 - 1));
				data->u[SHA_LBLOCK - 1] |= bitlen&mask;
				sha1_block_data_order(&key->md, data, 1);
				mask &= 0 - ((j - inp_len - 72) >>
				    (sizeof(j) * 8 - 1));
				pmac->u[0] |= key->md.h0 & mask;
				pmac->u[1] |= key->md.h1 & mask;
				pmac->u[2] |= key->md.h2 & mask;
				pmac->u[3] |= key->md.h3 & mask;
				pmac->u[4] |= key->md.h4 & mask;
				res = 0;
			}

			for (i = res; i < SHA_CBLOCK; i++, j++)
				data->c[i] = 0;

			if (res > SHA_CBLOCK - 8) {
				mask = 0 - ((inp_len + 8 - j) >>
				    (sizeof(j) * 8 - 1));
				data->u[SHA_LBLOCK - 1] |= bitlen & mask;
				sha1_block_data_order(&key->md, data, 1);
				mask &= 0 - ((j - inp_len - 73) >>
				    (sizeof(j) * 8 - 1));
				pmac->u[0] |= key->md.h0 & mask;
				pmac->u[1] |= key->md.h1 & mask;
				pmac->u[2] |= key->md.h2 & mask;
				pmac->u[3] |= key->md.h3 & mask;
				pmac->u[4] |= key->md.h4 & mask;

				memset(data, 0, SHA_CBLOCK);
				j += 64;
			}
			data->u[SHA_LBLOCK - 1] = bitlen;
			sha1_block_data_order(&key->md, data, 1);
			mask = 0 - ((j - inp_len - 73) >> (sizeof(j) * 8 - 1));
			pmac->u[0] |= key->md.h0 & mask;
			pmac->u[1] |= key->md.h1 & mask;
			pmac->u[2] |= key->md.h2 & mask;
			pmac->u[3] |= key->md.h3 & mask;
			pmac->u[4] |= key->md.h4 & mask;

#ifdef BSWAP
			pmac->u[0] = BSWAP(pmac->u[0]);
			pmac->u[1] = BSWAP(pmac->u[1]);
			pmac->u[2] = BSWAP(pmac->u[2]);
			pmac->u[3] = BSWAP(pmac->u[3]);
			pmac->u[4] = BSWAP(pmac->u[4]);
#else
			for (i = 0; i < 5; i++) {
				res = pmac->u[i];
				pmac->c[4 * i + 0] = (unsigned char)(res >> 24);
				pmac->c[4 * i + 1] = (unsigned char)(res >> 16);
				pmac->c[4 * i + 2] = (unsigned char)(res >> 8);
				pmac->c[4 * i + 3] = (unsigned char)res;
			}
#endif
			len += SHA_DIGEST_LENGTH;
#else
			SHA1_Update(&key->md, out, inp_len);
			res = key->md.num;
			SHA1_Final(pmac->c, &key->md);

			{
				unsigned int inp_blocks, pad_blocks;

				/* but pretend as if we hashed padded payload */
				inp_blocks = 1 + ((SHA_CBLOCK - 9 - res) >>
				    (sizeof(res) * 8 - 1));
				res += (unsigned int)(len - inp_len);
				pad_blocks = res / SHA_CBLOCK;
				res %= SHA_CBLOCK;
				pad_blocks += 1 + ((SHA_CBLOCK - 9 - res) >>
				    (sizeof(res) * 8 - 1));
				for (; inp_blocks < pad_blocks; inp_blocks++)
					sha1_block_data_order(&key->md,
					    data, 1);
			}
#endif
			key->md = key->tail;
			SHA1_Update(&key->md, pmac->c, SHA_DIGEST_LENGTH);
			SHA1_Final(pmac->c, &key->md);

			/* verify HMAC */
			out += inp_len;
			len -= inp_len;
#if 1
			{
				unsigned char *p =
				    out + len - 1 - maxpad - SHA_DIGEST_LENGTH;
				size_t off = out - p;
				unsigned int c, cmask;

				maxpad += SHA_DIGEST_LENGTH;
				for (res = 0, i = 0, j = 0; j < maxpad; j++) {
					c = p[j];
					cmask = ((int)(j - off -
					    SHA_DIGEST_LENGTH)) >>
					    (sizeof(int) * 8 - 1);
					res |= (c ^ pad) & ~cmask;	/* ... and padding */
					cmask &= ((int)(off - 1 - j)) >>
					    (sizeof(int) * 8 - 1);
					res |= (c ^ pmac->c[i]) & cmask;
					i += 1 & cmask;
				}
				maxpad -= SHA_DIGEST_LENGTH;

				res = 0 - ((0 - res) >> (sizeof(res) * 8 - 1));
				ret &= (int)~res;
			}
#else
			for (res = 0, i = 0; i < SHA_DIGEST_LENGTH; i++)
				res |= out[i] ^ pmac->c[i];
			res = 0 - ((0 - res) >> (sizeof(res) * 8 - 1));
			ret &= (int)~res;

			/* verify padding */
			pad = (pad & ~res) | (maxpad & res);
			out = out + len - 1 - pad;
			for (res = 0, i = 0; i < pad; i++)
				res |= out[i] ^ pad;

			res = (0 - res) >> (sizeof(res) * 8 - 1);
			ret &= (int)~res;
#endif
			return ret;
		}
	}

	return 1;
}

static int
aesni_cbc_hmac_sha1_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg, void *ptr)
{
	EVP_AES_HMAC_SHA1 *key = data(ctx);

	switch (type) {
	case EVP_CTRL_AEAD_SET_MAC_KEY:
		{
			unsigned int  i;
			unsigned char hmac_key[64];

			memset(hmac_key, 0, sizeof(hmac_key));

			if (arg > (int)sizeof(hmac_key)) {
				SHA1_Init(&key->head);
				SHA1_Update(&key->head, ptr, arg);
				SHA1_Final(hmac_key, &key->head);
			} else {
				memcpy(hmac_key, ptr, arg);
			}

			for (i = 0; i < sizeof(hmac_key); i++)
				hmac_key[i] ^= 0x36;		/* ipad */
			SHA1_Init(&key->head);
			SHA1_Update(&key->head, hmac_key, sizeof(hmac_key));

			for (i = 0; i < sizeof(hmac_key); i++)
				hmac_key[i] ^= 0x36 ^ 0x5c;	/* opad */
			SHA1_Init(&key->tail);
			SHA1_Update(&key->tail, hmac_key, sizeof(hmac_key));

			explicit_bzero(hmac_key, sizeof(hmac_key));

			return 1;
		}
	case EVP_CTRL_AEAD_TLS1_AAD:
		{
			unsigned char *p = ptr;
			unsigned int len;

			/* RFC 5246, 6.2.3.3: additional data has length 13 */
			if (arg != 13)
				return -1;

			len = p[arg - 2] << 8 | p[arg - 1];

			if (ctx->encrypt) {
				key->payload_length = len;
				if ((key->aux.tls_ver = p[arg - 4] << 8 |
				    p[arg - 3]) >= TLS1_1_VERSION) {
					len -= AES_BLOCK_SIZE;
					p[arg - 2] = len >> 8;
					p[arg - 1] = len;
				}
				key->md = key->head;
				SHA1_Update(&key->md, p, arg);

				return (int)(((len + SHA_DIGEST_LENGTH +
				    AES_BLOCK_SIZE) & -AES_BLOCK_SIZE) - len);
			} else {
				memcpy(key->aux.tls_aad, ptr, arg);
				key->payload_length = arg;

				return SHA_DIGEST_LENGTH;
			}
		}
	default:
		return -1;
	}
}

static EVP_CIPHER aesni_128_cbc_hmac_sha1_cipher = {
#ifdef NID_aes_128_cbc_hmac_sha1
	.nid = NID_aes_128_cbc_hmac_sha1,
#else
	.nid = NID_undef,
#endif
	.block_size = 16,
	.key_len = 16,
	.iv_len = 16,
	.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_FLAG_DEFAULT_ASN1 |
	    EVP_CIPH_FLAG_AEAD_CIPHER,
	.init = aesni_cbc_hmac_sha1_init_key,
	.do_cipher = aesni_cbc_hmac_sha1_cipher,
	.ctx_size = sizeof(EVP_AES_HMAC_SHA1),
	.ctrl = aesni_cbc_hmac_sha1_ctrl
};

static EVP_CIPHER aesni_256_cbc_hmac_sha1_cipher = {
#ifdef NID_aes_256_cbc_hmac_sha1
	.nid = NID_aes_256_cbc_hmac_sha1,
#else
	.nid = NID_undef,
#endif
	.block_size = 16,
	.key_len = 32,
	.iv_len = 16,
	.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_FLAG_DEFAULT_ASN1 |
	    EVP_CIPH_FLAG_AEAD_CIPHER,
	.init = aesni_cbc_hmac_sha1_init_key,
	.do_cipher = aesni_cbc_hmac_sha1_cipher,
	.ctx_size = sizeof(EVP_AES_HMAC_SHA1),
	.ctrl = aesni_cbc_hmac_sha1_ctrl
};

const EVP_CIPHER *
EVP_aes_128_cbc_hmac_sha1(void)
{
	return (OPENSSL_cpu_caps() & CPUCAP_MASK_AESNI) ?
	    &aesni_128_cbc_hmac_sha1_cipher : NULL;
}

const EVP_CIPHER *
EVP_aes_256_cbc_hmac_sha1(void)
{
	return (OPENSSL_cpu_caps() & CPUCAP_MASK_AESNI) ?
	    &aesni_256_cbc_hmac_sha1_cipher : NULL;
}
#else
const EVP_CIPHER *
EVP_aes_128_cbc_hmac_sha1(void)
{
	return NULL;
}

const EVP_CIPHER *
EVP_aes_256_cbc_hmac_sha1(void)
{
	    return NULL;
}
#endif
#endif