/* $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,
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 * 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