/* $OpenBSD: e_aes.c,v 1.83 2025/07/22 09:31:09 jsing Exp $ */
/* ====================================================================
 * Copyright (c) 2001-2011 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
 *    openssl-core@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 <limits.h>
#include <stdlib.h>
#include <string.h>

#include <openssl/opensslconf.h>

#include "crypto_internal.h"

#ifndef OPENSSL_NO_AES
#include <openssl/aes.h>
#include <openssl/evp.h>

#include "aes_local.h"
#include "err_local.h"
#include "evp_local.h"
#include "modes_local.h"

typedef struct {
        AES_KEY ks;
} EVP_AES_KEY;

typedef struct {
        AES_KEY ks;             /* AES key schedule to use */
        int key_set;            /* Set if key initialised */
        int iv_set;             /* Set if an iv is set */
        GCM128_CONTEXT gcm;
        unsigned char *iv;      /* Temporary IV store */
        int ivlen;              /* IV length */
        int taglen;
        int iv_gen;             /* It is OK to generate IVs */
        int tls_aad_len;        /* TLS AAD length */
} EVP_AES_GCM_CTX;

typedef struct {
        AES_KEY ks1, ks2;       /* AES key schedules to use */
        XTS128_CONTEXT xts;     /* XXX - replace with flags. */
} EVP_AES_XTS_CTX;

typedef struct {
        AES_KEY ks;             /* AES key schedule to use */
        int key_set;            /* Set if key initialised */
        int iv_set;             /* Set if an iv is set */
        int tag_set;            /* Set if tag is valid */
        int len_set;            /* Set if message length set */
        int L, M;               /* L and M parameters from RFC3610 */
        CCM128_CONTEXT ccm;
} EVP_AES_CCM_CTX;

#define MAXBITCHUNK     ((size_t)1<<(sizeof(size_t)*8-4))

static int
aes_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
    const unsigned char *iv, int enc)
{
        EVP_AES_KEY *eak = ctx->cipher_data;

        if (AES_set_encrypt_key(key, ctx->key_len * 8, &eak->ks) < 0) {
                EVPerror(EVP_R_AES_KEY_SETUP_FAILED);
                return 0;
        }

        return 1;
}

static int
aes_cbc_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
    const unsigned char *iv, int encrypt)
{
        EVP_AES_KEY *eak = ctx->cipher_data;

        if (encrypt) {
                if (AES_set_encrypt_key(key, ctx->key_len * 8, &eak->ks) < 0) {
                        EVPerror(EVP_R_AES_KEY_SETUP_FAILED);
                        return 0;
                }
        } else {
                if (AES_set_decrypt_key(key, ctx->key_len * 8, &eak->ks) < 0) {
                        EVPerror(EVP_R_AES_KEY_SETUP_FAILED);
                        return 0;
                }
        }

        return 1;
}

static int
aes_cbc_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
    const unsigned char *in, size_t len)
{
        EVP_AES_KEY *eak = ctx->cipher_data;

        AES_cbc_encrypt(in, out, len, &eak->ks, ctx->iv, ctx->encrypt);

        return 1;
}

static int
aes_ecb_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
    const unsigned char *iv, int encrypt)
{
        EVP_AES_KEY *eak = ctx->cipher_data;

        if (encrypt) {
                if (AES_set_encrypt_key(key, ctx->key_len * 8, &eak->ks) < 0) {
                        EVPerror(EVP_R_AES_KEY_SETUP_FAILED);
                        return 0;
                }
        } else {
                if (AES_set_decrypt_key(key, ctx->key_len * 8, &eak->ks) < 0) {
                        EVPerror(EVP_R_AES_KEY_SETUP_FAILED);
                        return 0;
                }
        }

        return 1;
}

static int
aes_ecb_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
    const unsigned char *in, size_t len)
{
        EVP_AES_KEY *eak = ctx->cipher_data;

        aes_ecb_encrypt_internal(in, out, len, &eak->ks, ctx->encrypt);

        return 1;
}

static int
aes_ofb_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
    const unsigned char *in, size_t len)
{
        EVP_AES_KEY *eak = ctx->cipher_data;

        AES_ofb128_encrypt(in, out, len, &eak->ks, ctx->iv, &ctx->num);

        return 1;
}

static int
aes_cfb_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
    const unsigned char *in, size_t len)
{
        EVP_AES_KEY *eak = ctx->cipher_data;

        AES_cfb128_encrypt(in, out, len, &eak->ks, ctx->iv, &ctx->num,
            ctx->encrypt);

        return 1;
}

static int
aes_cfb8_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
    const unsigned char *in, size_t len)
{
        EVP_AES_KEY *eak = ctx->cipher_data;

        AES_cfb8_encrypt(in, out, len, &eak->ks, ctx->iv, &ctx->num,
            ctx->encrypt);

        return 1;
}

static int
aes_cfb1_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
    const unsigned char *in, size_t len)
{
        EVP_AES_KEY *eak = ctx->cipher_data;

        if ((ctx->flags & EVP_CIPH_FLAG_LENGTH_BITS) != 0) {
                AES_cfb1_encrypt(in, out, len, &eak->ks, ctx->iv, &ctx->num,
                    ctx->encrypt);
                return 1;
        }

        while (len >= MAXBITCHUNK) {
                AES_cfb1_encrypt(in, out, MAXBITCHUNK * 8, &eak->ks, ctx->iv,
                    &ctx->num, ctx->encrypt);
                len -= MAXBITCHUNK;
                in += MAXBITCHUNK;
                out += MAXBITCHUNK;
        }
        if (len > 0) {
                AES_cfb1_encrypt(in, out, len * 8, &eak->ks, ctx->iv, &ctx->num,
                    ctx->encrypt);
        }

        return 1;
}

static int
aes_ctr_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
    const unsigned char *in, size_t len)
{
        EVP_AES_KEY *eak = ctx->cipher_data;
        unsigned int num = ctx->num;

        AES_ctr128_encrypt(in, out, len, &eak->ks, ctx->iv, ctx->buf, &num);

        ctx->num = (size_t)num;

        return 1;
}

static const EVP_CIPHER aes_128_cbc = {
        .nid = NID_aes_128_cbc,
        .block_size = 16,
        .key_len = 16,
        .iv_len = 16,
        .flags = EVP_CIPH_FLAG_DEFAULT_ASN1 | EVP_CIPH_CBC_MODE,
        .init = aes_cbc_init_key,
        .do_cipher = aes_cbc_cipher,
        .ctx_size = sizeof(EVP_AES_KEY),
};

const EVP_CIPHER *
EVP_aes_128_cbc(void)
{
        return &aes_128_cbc;
}
LCRYPTO_ALIAS(EVP_aes_128_cbc);

static const EVP_CIPHER aes_128_ecb = {
        .nid = NID_aes_128_ecb,
        .block_size = 16,
        .key_len = 16,
        .iv_len = 0,
        .flags = EVP_CIPH_FLAG_DEFAULT_ASN1 | EVP_CIPH_ECB_MODE,
        .init = aes_ecb_init_key,
        .do_cipher = aes_ecb_cipher,
        .ctx_size = sizeof(EVP_AES_KEY),
};

const EVP_CIPHER *
EVP_aes_128_ecb(void)
{
        return &aes_128_ecb;
}
LCRYPTO_ALIAS(EVP_aes_128_ecb);

static const EVP_CIPHER aes_128_ofb = {
        .nid = NID_aes_128_ofb128,
        .block_size = 1,
        .key_len = 16,
        .iv_len = 16,
        .flags = EVP_CIPH_FLAG_DEFAULT_ASN1 | EVP_CIPH_OFB_MODE,
        .init = aes_init_key,
        .do_cipher = aes_ofb_cipher,
        .ctx_size = sizeof(EVP_AES_KEY),
};

const EVP_CIPHER *
EVP_aes_128_ofb(void)
{
        return &aes_128_ofb;
}
LCRYPTO_ALIAS(EVP_aes_128_ofb);

static const EVP_CIPHER aes_128_cfb = {
        .nid = NID_aes_128_cfb128,
        .block_size = 1,
        .key_len = 16,
        .iv_len = 16,
        .flags = EVP_CIPH_FLAG_DEFAULT_ASN1 | EVP_CIPH_CFB_MODE,
        .init = aes_init_key,
        .do_cipher = aes_cfb_cipher,
        .ctx_size = sizeof(EVP_AES_KEY),
};

const EVP_CIPHER *
EVP_aes_128_cfb128(void)
{
        return &aes_128_cfb;
}
LCRYPTO_ALIAS(EVP_aes_128_cfb128);

static const EVP_CIPHER aes_128_cfb1 = {
        .nid = NID_aes_128_cfb1,
        .block_size = 1,
        .key_len = 16,
        .iv_len = 16,
        .flags = EVP_CIPH_CFB_MODE,
        .init = aes_init_key,
        .do_cipher = aes_cfb1_cipher,
        .ctx_size = sizeof(EVP_AES_KEY),
};

const EVP_CIPHER *
EVP_aes_128_cfb1(void)
{
        return &aes_128_cfb1;
}
LCRYPTO_ALIAS(EVP_aes_128_cfb1);

static const EVP_CIPHER aes_128_cfb8 = {
        .nid = NID_aes_128_cfb8,
        .block_size = 1,
        .key_len = 16,
        .iv_len = 16,
        .flags = EVP_CIPH_CFB_MODE,
        .init = aes_init_key,
        .do_cipher = aes_cfb8_cipher,
        .ctx_size = sizeof(EVP_AES_KEY),
};

const EVP_CIPHER *
EVP_aes_128_cfb8(void)
{
        return &aes_128_cfb8;
}
LCRYPTO_ALIAS(EVP_aes_128_cfb8);

static const EVP_CIPHER aes_128_ctr = {
        .nid = NID_aes_128_ctr,
        .block_size = 1,
        .key_len = 16,
        .iv_len = 16,
        .flags = EVP_CIPH_CTR_MODE,
        .init = aes_init_key,
        .do_cipher = aes_ctr_cipher,
        .ctx_size = sizeof(EVP_AES_KEY),
};

const EVP_CIPHER *
EVP_aes_128_ctr(void)
{
        return &aes_128_ctr;
}
LCRYPTO_ALIAS(EVP_aes_128_ctr);

static const EVP_CIPHER aes_192_cbc = {
        .nid = NID_aes_192_cbc,
        .block_size = 16,
        .key_len = 24,
        .iv_len = 16,
        .flags = EVP_CIPH_FLAG_DEFAULT_ASN1 | EVP_CIPH_CBC_MODE,
        .init = aes_cbc_init_key,
        .do_cipher = aes_cbc_cipher,
        .ctx_size = sizeof(EVP_AES_KEY),
};

const EVP_CIPHER *
EVP_aes_192_cbc(void)
{
        return &aes_192_cbc;
}
LCRYPTO_ALIAS(EVP_aes_192_cbc);

static const EVP_CIPHER aes_192_ecb = {
        .nid = NID_aes_192_ecb,
        .block_size = 16,
        .key_len = 24,
        .iv_len = 0,
        .flags = EVP_CIPH_FLAG_DEFAULT_ASN1 | EVP_CIPH_ECB_MODE,
        .init = aes_ecb_init_key,
        .do_cipher = aes_ecb_cipher,
        .ctx_size = sizeof(EVP_AES_KEY),
};

const EVP_CIPHER *
EVP_aes_192_ecb(void)
{
        return &aes_192_ecb;
}
LCRYPTO_ALIAS(EVP_aes_192_ecb);

static const EVP_CIPHER aes_192_ofb = {
        .nid = NID_aes_192_ofb128,
        .block_size = 1,
        .key_len = 24,
        .iv_len = 16,
        .flags = EVP_CIPH_FLAG_DEFAULT_ASN1 | EVP_CIPH_OFB_MODE,
        .init = aes_init_key,
        .do_cipher = aes_ofb_cipher,
        .ctx_size = sizeof(EVP_AES_KEY),
};

const EVP_CIPHER *
EVP_aes_192_ofb(void)
{
        return &aes_192_ofb;
}
LCRYPTO_ALIAS(EVP_aes_192_ofb);

static const EVP_CIPHER aes_192_cfb = {
        .nid = NID_aes_192_cfb128,
        .block_size = 1,
        .key_len = 24,
        .iv_len = 16,
        .flags = EVP_CIPH_FLAG_DEFAULT_ASN1 | EVP_CIPH_CFB_MODE,
        .init = aes_init_key,
        .do_cipher = aes_cfb_cipher,
        .ctx_size = sizeof(EVP_AES_KEY),
};

const EVP_CIPHER *
EVP_aes_192_cfb128(void)
{
        return &aes_192_cfb;
}
LCRYPTO_ALIAS(EVP_aes_192_cfb128);

static const EVP_CIPHER aes_192_cfb1 = {
        .nid = NID_aes_192_cfb1,
        .block_size = 1,
        .key_len = 24,
        .iv_len = 16,
        .flags = EVP_CIPH_CFB_MODE,
        .init = aes_init_key,
        .do_cipher = aes_cfb1_cipher,
        .ctx_size = sizeof(EVP_AES_KEY),
};

const EVP_CIPHER *
EVP_aes_192_cfb1(void)
{
        return &aes_192_cfb1;
}
LCRYPTO_ALIAS(EVP_aes_192_cfb1);

static const EVP_CIPHER aes_192_cfb8 = {
        .nid = NID_aes_192_cfb8,
        .block_size = 1,
        .key_len = 24,
        .iv_len = 16,
        .flags = EVP_CIPH_CFB_MODE,
        .init = aes_init_key,
        .do_cipher = aes_cfb8_cipher,
        .ctx_size = sizeof(EVP_AES_KEY),
};

const EVP_CIPHER *
EVP_aes_192_cfb8(void)
{
        return &aes_192_cfb8;
}
LCRYPTO_ALIAS(EVP_aes_192_cfb8);

static const EVP_CIPHER aes_192_ctr = {
        .nid = NID_aes_192_ctr,
        .block_size = 1,
        .key_len = 24,
        .iv_len = 16,
        .flags = EVP_CIPH_CTR_MODE,
        .init = aes_init_key,
        .do_cipher = aes_ctr_cipher,
        .ctx_size = sizeof(EVP_AES_KEY),
};

const EVP_CIPHER *
EVP_aes_192_ctr(void)
{
        return &aes_192_ctr;
}
LCRYPTO_ALIAS(EVP_aes_192_ctr);

static const EVP_CIPHER aes_256_cbc = {
        .nid = NID_aes_256_cbc,
        .block_size = 16,
        .key_len = 32,
        .iv_len = 16,
        .flags = EVP_CIPH_FLAG_DEFAULT_ASN1 | EVP_CIPH_CBC_MODE,
        .init = aes_cbc_init_key,
        .do_cipher = aes_cbc_cipher,
        .ctx_size = sizeof(EVP_AES_KEY),
};

const EVP_CIPHER *
EVP_aes_256_cbc(void)
{
        return &aes_256_cbc;
}
LCRYPTO_ALIAS(EVP_aes_256_cbc);

static const EVP_CIPHER aes_256_ecb = {
        .nid = NID_aes_256_ecb,
        .block_size = 16,
        .key_len = 32,
        .iv_len = 0,
        .flags = EVP_CIPH_FLAG_DEFAULT_ASN1 | EVP_CIPH_ECB_MODE,
        .init = aes_ecb_init_key,
        .do_cipher = aes_ecb_cipher,
        .ctx_size = sizeof(EVP_AES_KEY),
};

const EVP_CIPHER *
EVP_aes_256_ecb(void)
{
        return &aes_256_ecb;
}
LCRYPTO_ALIAS(EVP_aes_256_ecb);

static const EVP_CIPHER aes_256_ofb = {
        .nid = NID_aes_256_ofb128,
        .block_size = 1,
        .key_len = 32,
        .iv_len = 16,
        .flags = EVP_CIPH_FLAG_DEFAULT_ASN1 | EVP_CIPH_OFB_MODE,
        .init = aes_init_key,
        .do_cipher = aes_ofb_cipher,
        .ctx_size = sizeof(EVP_AES_KEY),
};

const EVP_CIPHER *
EVP_aes_256_ofb(void)
{
        return &aes_256_ofb;
}
LCRYPTO_ALIAS(EVP_aes_256_ofb);

static const EVP_CIPHER aes_256_cfb = {
        .nid = NID_aes_256_cfb128,
        .block_size = 1,
        .key_len = 32,
        .iv_len = 16,
        .flags = EVP_CIPH_FLAG_DEFAULT_ASN1 | EVP_CIPH_CFB_MODE,
        .init = aes_init_key,
        .do_cipher = aes_cfb_cipher,
        .ctx_size = sizeof(EVP_AES_KEY),
};

const EVP_CIPHER *
EVP_aes_256_cfb128(void)
{
        return &aes_256_cfb;
}
LCRYPTO_ALIAS(EVP_aes_256_cfb128);

static const EVP_CIPHER aes_256_cfb1 = {
        .nid = NID_aes_256_cfb1,
        .block_size = 1,
        .key_len = 32,
        .iv_len = 16,
        .flags = EVP_CIPH_CFB_MODE,
        .init = aes_init_key,
        .do_cipher = aes_cfb1_cipher,
        .ctx_size = sizeof(EVP_AES_KEY),
};

const EVP_CIPHER *
EVP_aes_256_cfb1(void)
{
        return &aes_256_cfb1;
}
LCRYPTO_ALIAS(EVP_aes_256_cfb1);

static const EVP_CIPHER aes_256_cfb8 = {
        .nid = NID_aes_256_cfb8,
        .block_size = 1,
        .key_len = 32,
        .iv_len = 16,
        .flags = EVP_CIPH_CFB_MODE,
        .init = aes_init_key,
        .do_cipher = aes_cfb8_cipher,
        .ctx_size = sizeof(EVP_AES_KEY),
};

const EVP_CIPHER *
EVP_aes_256_cfb8(void)
{
        return &aes_256_cfb8;
}
LCRYPTO_ALIAS(EVP_aes_256_cfb8);

static const EVP_CIPHER aes_256_ctr = {
        .nid = NID_aes_256_ctr,
        .block_size = 1,
        .key_len = 32,
        .iv_len = 16,
        .flags = EVP_CIPH_CTR_MODE,
        .init = aes_init_key,
        .do_cipher = aes_ctr_cipher,
        .ctx_size = sizeof(EVP_AES_KEY),
};

const EVP_CIPHER *
EVP_aes_256_ctr(void)
{
        return &aes_256_ctr;
}
LCRYPTO_ALIAS(EVP_aes_256_ctr);

static int
aes_gcm_cleanup(EVP_CIPHER_CTX *c)
{
        EVP_AES_GCM_CTX *gctx = c->cipher_data;

        if (gctx->iv != c->iv)
                free(gctx->iv);

        explicit_bzero(gctx, sizeof(*gctx));

        return 1;
}

/* increment counter (64-bit int) by 1 */
static void
ctr64_inc(unsigned char *counter)
{
        int n = 8;
        unsigned char  c;

        do {
                --n;
                c = counter[n];
                ++c;
                counter[n] = c;
                if (c)
                        return;
        } while (n);
}

static int
aes_gcm_ctrl(EVP_CIPHER_CTX *c, int type, int arg, void *ptr)
{
        EVP_AES_GCM_CTX *gctx = c->cipher_data;

        switch (type) {
        case EVP_CTRL_INIT:
                gctx->key_set = 0;
                gctx->iv_set = 0;
                if (c->cipher->iv_len == 0) {
                        EVPerror(EVP_R_INVALID_IV_LENGTH);
                        return 0;
                }
                gctx->ivlen = c->cipher->iv_len;
                gctx->iv = c->iv;
                gctx->taglen = -1;
                gctx->iv_gen = 0;
                gctx->tls_aad_len = -1;
                return 1;

        case EVP_CTRL_AEAD_GET_IVLEN:
                *(int *)ptr = gctx->ivlen;
                return 1;

        case EVP_CTRL_AEAD_SET_IVLEN:
                if (arg <= 0)
                        return 0;
                /* Allocate memory for IV if needed */
                if ((arg > EVP_MAX_IV_LENGTH) && (arg > gctx->ivlen)) {
                        if (gctx->iv != c->iv)
                                free(gctx->iv);
                        gctx->iv = malloc(arg);
                        if (!gctx->iv)
                                return 0;
                }
                gctx->ivlen = arg;
                return 1;

        case EVP_CTRL_GCM_SET_TAG:
                if (arg <= 0 || arg > 16 || c->encrypt)
                        return 0;
                memcpy(c->buf, ptr, arg);
                gctx->taglen = arg;
                return 1;

        case EVP_CTRL_GCM_GET_TAG:
                if (arg <= 0 || arg > 16 || !c->encrypt || gctx->taglen < 0)
                        return 0;
                memcpy(ptr, c->buf, arg);
                return 1;

        case EVP_CTRL_GCM_SET_IV_FIXED:
                /* Special case: -1 length restores whole IV */
                if (arg == -1) {
                        memcpy(gctx->iv, ptr, gctx->ivlen);
                        gctx->iv_gen = 1;
                        return 1;
                }
                /* Fixed field must be at least 4 bytes and invocation field
                 * at least 8.
                 */
                if ((arg < 4) || (gctx->ivlen - arg) < 8)
                        return 0;
                if (arg)
                        memcpy(gctx->iv, ptr, arg);
                if (c->encrypt)
                        arc4random_buf(gctx->iv + arg, gctx->ivlen - arg);
                gctx->iv_gen = 1;
                return 1;

        case EVP_CTRL_GCM_IV_GEN:
                if (gctx->iv_gen == 0 || gctx->key_set == 0)
                        return 0;
                CRYPTO_gcm128_setiv(&gctx->gcm, gctx->iv, gctx->ivlen);
                if (arg <= 0 || arg > gctx->ivlen)
                        arg = gctx->ivlen;
                memcpy(ptr, gctx->iv + gctx->ivlen - arg, arg);
                /* Invocation field will be at least 8 bytes in size and
                 * so no need to check wrap around or increment more than
                 * last 8 bytes.
                 */
                ctr64_inc(gctx->iv + gctx->ivlen - 8);
                gctx->iv_set = 1;
                return 1;

        case EVP_CTRL_GCM_SET_IV_INV:
                if (gctx->iv_gen == 0 || gctx->key_set == 0 || c->encrypt)
                        return 0;
                memcpy(gctx->iv + gctx->ivlen - arg, ptr, arg);
                CRYPTO_gcm128_setiv(&gctx->gcm, gctx->iv, gctx->ivlen);
                gctx->iv_set = 1;
                return 1;

        case EVP_CTRL_AEAD_TLS1_AAD:
                /* Save the AAD for later use */
                if (arg != 13)
                        return 0;
                memcpy(c->buf, ptr, arg);
                gctx->tls_aad_len = arg;
                {
                        unsigned int len = c->buf[arg - 2] << 8 |
                            c->buf[arg - 1];

                        /* Correct length for explicit IV */
                        if (len < EVP_GCM_TLS_EXPLICIT_IV_LEN)
                                return 0;
                        len -= EVP_GCM_TLS_EXPLICIT_IV_LEN;

                        /* If decrypting correct for tag too */
                        if (!c->encrypt) {
                                if (len < EVP_GCM_TLS_TAG_LEN)
                                        return 0;
                                len -= EVP_GCM_TLS_TAG_LEN;
                        }
                        c->buf[arg - 2] = len >> 8;
                        c->buf[arg - 1] = len & 0xff;
                }
                /* Extra padding: tag appended to record */
                return EVP_GCM_TLS_TAG_LEN;

        case EVP_CTRL_COPY:
            {
                EVP_CIPHER_CTX *out = ptr;
                EVP_AES_GCM_CTX *gctx_out = out->cipher_data;

                if (gctx->gcm.key) {
                        if (gctx->gcm.key != &gctx->ks)
                                return 0;
                        gctx_out->gcm.key = &gctx_out->ks;
                }

                if (gctx->iv == c->iv) {
                        gctx_out->iv = out->iv;
                } else {
                        if ((gctx_out->iv = calloc(1, gctx->ivlen)) == NULL)
                                return 0;
                        memcpy(gctx_out->iv, gctx->iv, gctx->ivlen);
                }
                return 1;
            }

        default:
                return -1;

        }
}

static int
aes_gcm_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
    const unsigned char *iv, int enc)
{
        EVP_AES_GCM_CTX *gctx = ctx->cipher_data;

        if (!iv && !key)
                return 1;
        if (key) {
                AES_set_encrypt_key(key, ctx->key_len * 8, &gctx->ks);
                CRYPTO_gcm128_init(&gctx->gcm, &gctx->ks, aes_encrypt_block128);

                /* If we have an iv can set it directly, otherwise use
                 * saved IV.
                 */
                if (iv == NULL && gctx->iv_set)
                        iv = gctx->iv;
                if (iv) {
                        CRYPTO_gcm128_setiv(&gctx->gcm, iv, gctx->ivlen);
                        gctx->iv_set = 1;
                }
                gctx->key_set = 1;
        } else {
                /* If key set use IV, otherwise copy */
                if (gctx->key_set)
                        CRYPTO_gcm128_setiv(&gctx->gcm, iv, gctx->ivlen);
                else
                        memcpy(gctx->iv, iv, gctx->ivlen);
                gctx->iv_set = 1;
                gctx->iv_gen = 0;
        }
        return 1;
}

/* Handle TLS GCM packet format. This consists of the last portion of the IV
 * followed by the payload and finally the tag. On encrypt generate IV,
 * encrypt payload and write the tag. On verify retrieve IV, decrypt payload
 * and verify tag.
 */

static int
aes_gcm_tls_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
    const unsigned char *in, size_t len)
{
        EVP_AES_GCM_CTX *gctx = ctx->cipher_data;
        int rv = -1;

        /* Encrypt/decrypt must be performed in place */
        if (out != in ||
            len < (EVP_GCM_TLS_EXPLICIT_IV_LEN + EVP_GCM_TLS_TAG_LEN))
                return -1;

        /* Set IV from start of buffer or generate IV and write to start
         * of buffer.
         */
        if (EVP_CIPHER_CTX_ctrl(ctx, ctx->encrypt ?
            EVP_CTRL_GCM_IV_GEN : EVP_CTRL_GCM_SET_IV_INV,
            EVP_GCM_TLS_EXPLICIT_IV_LEN, out) <= 0)
                goto err;

        /* Use saved AAD */
        if (CRYPTO_gcm128_aad(&gctx->gcm, ctx->buf, gctx->tls_aad_len))
                goto err;

        /* Fix buffer and length to point to payload */
        in += EVP_GCM_TLS_EXPLICIT_IV_LEN;
        out += EVP_GCM_TLS_EXPLICIT_IV_LEN;
        len -= EVP_GCM_TLS_EXPLICIT_IV_LEN + EVP_GCM_TLS_TAG_LEN;
        if (ctx->encrypt) {
                /* Encrypt payload */
                if (CRYPTO_gcm128_encrypt_ctr32(&gctx->gcm, in, out, len,
                    aes_ctr32_encrypt_ctr128f))
                        goto err;
                out += len;

                /* Finally write tag */
                CRYPTO_gcm128_tag(&gctx->gcm, out, EVP_GCM_TLS_TAG_LEN);
                rv = len + EVP_GCM_TLS_EXPLICIT_IV_LEN + EVP_GCM_TLS_TAG_LEN;
        } else {
                /* Decrypt */
                if (CRYPTO_gcm128_decrypt_ctr32(&gctx->gcm, in, out, len,
                    aes_ctr32_encrypt_ctr128f))
                        goto err;

                /* Retrieve tag */
                CRYPTO_gcm128_tag(&gctx->gcm, ctx->buf, EVP_GCM_TLS_TAG_LEN);

                /* If tag mismatch wipe buffer */
                if (timingsafe_memcmp(ctx->buf, in + len, EVP_GCM_TLS_TAG_LEN) != 0) {
                        explicit_bzero(out, len);
                        goto err;
                }
                rv = len;
        }

err:
        gctx->iv_set = 0;
        gctx->tls_aad_len = -1;
        return rv;
}

static int
aes_gcm_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
    const unsigned char *in, size_t len)
{
        EVP_AES_GCM_CTX *gctx = ctx->cipher_data;

        /* If not set up, return error */
        if (!gctx->key_set)
                return -1;

        if (gctx->tls_aad_len >= 0)
                return aes_gcm_tls_cipher(ctx, out, in, len);

        if (!gctx->iv_set)
                return -1;

        if (in) {
                if (out == NULL) {
                        if (CRYPTO_gcm128_aad(&gctx->gcm, in, len))
                                return -1;
                } else if (ctx->encrypt) {
                        if (CRYPTO_gcm128_encrypt_ctr32(&gctx->gcm,
                            in, out, len, aes_ctr32_encrypt_ctr128f))
                                return -1;
                } else {
                        if (CRYPTO_gcm128_decrypt_ctr32(&gctx->gcm,
                            in, out, len, aes_ctr32_encrypt_ctr128f))
                                return -1;
                }
                return len;
        } else {
                if (!ctx->encrypt) {
                        if (gctx->taglen < 0)
                                return -1;
                        if (CRYPTO_gcm128_finish(&gctx->gcm, ctx->buf,
                            gctx->taglen) != 0)
                                return -1;
                        gctx->iv_set = 0;
                        return 0;
                }
                CRYPTO_gcm128_tag(&gctx->gcm, ctx->buf, 16);
                gctx->taglen = 16;

                /* Don't reuse the IV */
                gctx->iv_set = 0;
                return 0;
        }

}

#define CUSTOM_FLAGS \
    ( EVP_CIPH_FLAG_DEFAULT_ASN1 | EVP_CIPH_CUSTOM_IV | \
      EVP_CIPH_FLAG_CUSTOM_IV_LENGTH | \
      EVP_CIPH_FLAG_CUSTOM_CIPHER | EVP_CIPH_ALWAYS_CALL_INIT | \
      EVP_CIPH_CTRL_INIT | EVP_CIPH_CUSTOM_COPY )

static const EVP_CIPHER aes_128_gcm = {
        .nid = NID_aes_128_gcm,
        .block_size = 1,
        .key_len = 16,
        .iv_len = 12,
        .flags = EVP_CIPH_FLAG_AEAD_CIPHER|CUSTOM_FLAGS | EVP_CIPH_GCM_MODE,
        .init = aes_gcm_init_key,
        .do_cipher = aes_gcm_cipher,
        .cleanup = aes_gcm_cleanup,
        .ctx_size = sizeof(EVP_AES_GCM_CTX),
        .ctrl = aes_gcm_ctrl,
};

const EVP_CIPHER *
EVP_aes_128_gcm(void)
{
        return &aes_128_gcm;
}
LCRYPTO_ALIAS(EVP_aes_128_gcm);

static const EVP_CIPHER aes_192_gcm = {
        .nid = NID_aes_192_gcm,
        .block_size = 1,
        .key_len = 24,
        .iv_len = 12,
        .flags = EVP_CIPH_FLAG_AEAD_CIPHER|CUSTOM_FLAGS | EVP_CIPH_GCM_MODE,
        .init = aes_gcm_init_key,
        .do_cipher = aes_gcm_cipher,
        .cleanup = aes_gcm_cleanup,
        .ctx_size = sizeof(EVP_AES_GCM_CTX),
        .ctrl = aes_gcm_ctrl,
};

const EVP_CIPHER *
EVP_aes_192_gcm(void)
{
        return &aes_192_gcm;
}
LCRYPTO_ALIAS(EVP_aes_192_gcm);

static const EVP_CIPHER aes_256_gcm = {
        .nid = NID_aes_256_gcm,
        .block_size = 1,
        .key_len = 32,
        .iv_len = 12,
        .flags = EVP_CIPH_FLAG_AEAD_CIPHER|CUSTOM_FLAGS | EVP_CIPH_GCM_MODE,
        .init = aes_gcm_init_key,
        .do_cipher = aes_gcm_cipher,
        .cleanup = aes_gcm_cleanup,
        .ctx_size = sizeof(EVP_AES_GCM_CTX),
        .ctrl = aes_gcm_ctrl,
};

const EVP_CIPHER *
EVP_aes_256_gcm(void)
{
        return &aes_256_gcm;
}
LCRYPTO_ALIAS(EVP_aes_256_gcm);

static int
aes_xts_ctrl(EVP_CIPHER_CTX *c, int type, int arg, void *ptr)
{
        EVP_AES_XTS_CTX *xctx = c->cipher_data;

        switch (type) {
        case EVP_CTRL_INIT:
                /*
                 * key1 and key2 are used as an indicator both key and IV
                 * are set
                 */
                xctx->xts.key1 = NULL;
                xctx->xts.key2 = NULL;
                return 1;

        case EVP_CTRL_COPY:
            {
                EVP_CIPHER_CTX *out = ptr;
                EVP_AES_XTS_CTX *xctx_out = out->cipher_data;

                if (xctx->xts.key1) {
                        if (xctx->xts.key1 != &xctx->ks1)
                                return 0;
                        xctx_out->xts.key1 = &xctx_out->ks1;
                }
                if (xctx->xts.key2) {
                        if (xctx->xts.key2 != &xctx->ks2)
                                return 0;
                        xctx_out->xts.key2 = &xctx_out->ks2;
                }
                return 1;
            }
        }
        return -1;
}

static int
aes_xts_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
    const unsigned char *iv, int encrypt)
{
        EVP_AES_XTS_CTX *xctx = ctx->cipher_data;

        if (key != NULL) {
                /* key_len is two AES keys */
                if (encrypt)
                        AES_set_encrypt_key(key, ctx->key_len * 4, &xctx->ks1);
                else
                        AES_set_decrypt_key(key, ctx->key_len * 4, &xctx->ks1);

                AES_set_encrypt_key(key + ctx->key_len / 2, ctx->key_len * 4,
                    &xctx->ks2);

                xctx->xts.key1 = &xctx->ks1;
        }

        if (iv != NULL) {
                xctx->xts.key2 = &xctx->ks2;
                memcpy(ctx->iv, iv, 16);
        }

        return 1;
}

static int
aes_xts_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
    const unsigned char *in, size_t len)
{
        EVP_AES_XTS_CTX *xctx = ctx->cipher_data;

        if (xctx->xts.key1 == NULL || xctx->xts.key2 == NULL)
                return 0;

        if (out == NULL || in == NULL || len < AES_BLOCK_SIZE)
                return 0;

        aes_xts_encrypt_internal(in, out, len, xctx->xts.key1, xctx->xts.key2,
            ctx->iv, ctx->encrypt);

        return 1;
}

#define XTS_FLAGS \
    ( EVP_CIPH_FLAG_DEFAULT_ASN1 | EVP_CIPH_CUSTOM_IV | \
      EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CTRL_INIT | EVP_CIPH_CUSTOM_COPY )

static const EVP_CIPHER aes_128_xts = {
        .nid = NID_aes_128_xts,
        .block_size = 1,
        .key_len = 2 * 16,
        .iv_len = 16,
        .flags = XTS_FLAGS | EVP_CIPH_XTS_MODE,
        .init = aes_xts_init_key,
        .do_cipher = aes_xts_cipher,
        .cleanup = NULL,
        .ctx_size = sizeof(EVP_AES_XTS_CTX),
        .ctrl = aes_xts_ctrl,
};

const EVP_CIPHER *
EVP_aes_128_xts(void)
{
        return &aes_128_xts;
}
LCRYPTO_ALIAS(EVP_aes_128_xts);

static const EVP_CIPHER aes_256_xts = {
        .nid = NID_aes_256_xts,
        .block_size = 1,
        .key_len = 2 * 32,
        .iv_len = 16,
        .flags = XTS_FLAGS | EVP_CIPH_XTS_MODE,
        .init = aes_xts_init_key,
        .do_cipher = aes_xts_cipher,
        .cleanup = NULL,
        .ctx_size = sizeof(EVP_AES_XTS_CTX),
        .ctrl = aes_xts_ctrl,
};

const EVP_CIPHER *
EVP_aes_256_xts(void)
{
        return &aes_256_xts;
}
LCRYPTO_ALIAS(EVP_aes_256_xts);

static int
aes_ccm_ctrl(EVP_CIPHER_CTX *c, int type, int arg, void *ptr)
{
        EVP_AES_CCM_CTX *cctx = c->cipher_data;

        switch (type) {
        case EVP_CTRL_INIT:
                cctx->key_set = 0;
                cctx->iv_set = 0;
                cctx->L = 8;
                cctx->M = 12;
                cctx->tag_set = 0;
                cctx->len_set = 0;
                return 1;

        case EVP_CTRL_AEAD_GET_IVLEN:
                *(int *)ptr = 15 - cctx->L;
                return 1;

        case EVP_CTRL_AEAD_SET_IVLEN:
                arg = 15 - arg;

        case EVP_CTRL_CCM_SET_L:
                if (arg < 2 || arg > 8)
                        return 0;
                cctx->L = arg;
                return 1;

        case EVP_CTRL_CCM_SET_TAG:
                if ((arg & 1) || arg < 4 || arg > 16)
                        return 0;
                if ((c->encrypt && ptr) || (!c->encrypt && !ptr))
                        return 0;
                if (ptr) {
                        cctx->tag_set = 1;
                        memcpy(c->buf, ptr, arg);
                }
                cctx->M = arg;
                return 1;

        case EVP_CTRL_CCM_GET_TAG:
                if (!c->encrypt || !cctx->tag_set)
                        return 0;
                if (!CRYPTO_ccm128_tag(&cctx->ccm, ptr, (size_t)arg))
                        return 0;
                cctx->tag_set = 0;
                cctx->iv_set = 0;
                cctx->len_set = 0;
                return 1;

        case EVP_CTRL_COPY:
            {
                EVP_CIPHER_CTX *out = ptr;
                EVP_AES_CCM_CTX *cctx_out = out->cipher_data;

                if (cctx->ccm.key) {
                        if (cctx->ccm.key != &cctx->ks)
                                return 0;
                        cctx_out->ccm.key = &cctx_out->ks;
                }
                return 1;
            }

        default:
                return -1;
        }
}

static int
aes_ccm_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
    const unsigned char *iv, int enc)
{
        EVP_AES_CCM_CTX *cctx = ctx->cipher_data;

        if (!iv && !key)
                return 1;
        if (key) {
                AES_set_encrypt_key(key, ctx->key_len * 8, &cctx->ks);
                CRYPTO_ccm128_init(&cctx->ccm, cctx->M, cctx->L,
                    &cctx->ks, aes_encrypt_block128);
                cctx->key_set = 1;
        }
        if (iv) {
                memcpy(ctx->iv, iv, 15 - cctx->L);
                cctx->iv_set = 1;
        }
        return 1;
}

static int
aes_ccm_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
    const unsigned char *in, size_t len)
{
        EVP_AES_CCM_CTX *cctx = ctx->cipher_data;
        CCM128_CONTEXT *ccm = &cctx->ccm;

        /* If not set up, return error */
        if (!cctx->key_set)
                return -1;

        /* EVP_*Final() doesn't return any data */
        if (in == NULL && out != NULL)
                return 0;

        if (!cctx->iv_set)
                return -1;
        if (!ctx->encrypt && !cctx->tag_set)
                return -1;

        if (!out) {
                if (!in) {
                        if (CRYPTO_ccm128_setiv(ccm, ctx->iv, 15 - cctx->L,
                            len))
                                return -1;
                        cctx->len_set = 1;
                        return len;
                }
                /* If have AAD need message length */
                if (!cctx->len_set && len)
                        return -1;
                CRYPTO_ccm128_aad(ccm, in, len);
                return len;
        }

        /* If not set length yet do it */
        if (!cctx->len_set) {
                if (CRYPTO_ccm128_setiv(ccm, ctx->iv, 15 - cctx->L, len))
                        return -1;
                cctx->len_set = 1;
        }
        if (ctx->encrypt) {
                if (CRYPTO_ccm128_encrypt_ccm64(ccm, in, out, len,
                    aes_ccm64_encrypt_ccm128f) != 0)
                        return -1;
                cctx->tag_set = 1;
                return len;
        } else {
                int rv = -1;
                if (CRYPTO_ccm128_decrypt_ccm64(ccm, in, out, len,
                    aes_ccm64_decrypt_ccm128f) == 0) {
                        unsigned char tag[16];
                        if (CRYPTO_ccm128_tag(ccm, tag, cctx->M)) {
                                if (timingsafe_memcmp(tag, ctx->buf, cctx->M) == 0)
                                        rv = len;
                        }
                }
                if (rv == -1)
                        explicit_bzero(out, len);
                cctx->iv_set = 0;
                cctx->tag_set = 0;
                cctx->len_set = 0;
                return rv;
        }
}

static const EVP_CIPHER aes_128_ccm = {
        .nid = NID_aes_128_ccm,
        .block_size = 1,
        .key_len = 16,
        .iv_len = 12,
        .flags = CUSTOM_FLAGS | EVP_CIPH_CCM_MODE,
        .init = aes_ccm_init_key,
        .do_cipher = aes_ccm_cipher,
        .cleanup = NULL,
        .ctx_size = sizeof(EVP_AES_CCM_CTX),
        .ctrl = aes_ccm_ctrl,
};

const EVP_CIPHER *
EVP_aes_128_ccm(void)
{
        return &aes_128_ccm;
}
LCRYPTO_ALIAS(EVP_aes_128_ccm);

static const EVP_CIPHER aes_192_ccm = {
        .nid = NID_aes_192_ccm,
        .block_size = 1,
        .key_len = 24,
        .iv_len = 12,
        .flags = CUSTOM_FLAGS | EVP_CIPH_CCM_MODE,
        .init = aes_ccm_init_key,
        .do_cipher = aes_ccm_cipher,
        .cleanup = NULL,
        .ctx_size = sizeof(EVP_AES_CCM_CTX),
        .ctrl = aes_ccm_ctrl,
};

const EVP_CIPHER *
EVP_aes_192_ccm(void)
{
        return &aes_192_ccm;
}
LCRYPTO_ALIAS(EVP_aes_192_ccm);

static const EVP_CIPHER aes_256_ccm = {
        .nid = NID_aes_256_ccm,
        .block_size = 1,
        .key_len = 32,
        .iv_len = 12,
        .flags = CUSTOM_FLAGS | EVP_CIPH_CCM_MODE,
        .init = aes_ccm_init_key,
        .do_cipher = aes_ccm_cipher,
        .cleanup = NULL,
        .ctx_size = sizeof(EVP_AES_CCM_CTX),
        .ctrl = aes_ccm_ctrl,
};

const EVP_CIPHER *
EVP_aes_256_ccm(void)
{
        return &aes_256_ccm;
}
LCRYPTO_ALIAS(EVP_aes_256_ccm);

#define EVP_AEAD_AES_GCM_TAG_LEN 16

struct aead_aes_gcm_ctx {
        union {
                double align;
                AES_KEY ks;
        } ks;
        GCM128_CONTEXT gcm;
        unsigned char tag_len;
};

static int
aead_aes_gcm_init(EVP_AEAD_CTX *ctx, const unsigned char *key, size_t key_len,
    size_t tag_len)
{
        struct aead_aes_gcm_ctx *gcm_ctx;
        const size_t key_bits = key_len * 8;

        /* EVP_AEAD_CTX_init should catch this. */
        if (key_bits != 128 && key_bits != 256) {
                EVPerror(EVP_R_BAD_KEY_LENGTH);
                return 0;
        }

        if (tag_len == EVP_AEAD_DEFAULT_TAG_LENGTH)
                tag_len = EVP_AEAD_AES_GCM_TAG_LEN;

        if (tag_len > EVP_AEAD_AES_GCM_TAG_LEN) {
                EVPerror(EVP_R_TAG_TOO_LARGE);
                return 0;
        }

        if ((gcm_ctx = calloc(1, sizeof(struct aead_aes_gcm_ctx))) == NULL)
                return 0;

        AES_set_encrypt_key(key, key_bits, &gcm_ctx->ks.ks);
        CRYPTO_gcm128_init(&gcm_ctx->gcm, &gcm_ctx->ks.ks, aes_encrypt_block128);
        gcm_ctx->tag_len = tag_len;
        ctx->aead_state = gcm_ctx;

        return 1;
}

static void
aead_aes_gcm_cleanup(EVP_AEAD_CTX *ctx)
{
        struct aead_aes_gcm_ctx *gcm_ctx = ctx->aead_state;

        freezero(gcm_ctx, sizeof(*gcm_ctx));
}

static int
aead_aes_gcm_seal(const EVP_AEAD_CTX *ctx, unsigned char *out, size_t *out_len,
    size_t max_out_len, const unsigned char *nonce, size_t nonce_len,
    const unsigned char *in, size_t in_len, const unsigned char *ad,
    size_t ad_len)
{
        const struct aead_aes_gcm_ctx *gcm_ctx = ctx->aead_state;
        GCM128_CONTEXT gcm;
        size_t bulk = 0;

        if (max_out_len < in_len + gcm_ctx->tag_len) {
                EVPerror(EVP_R_BUFFER_TOO_SMALL);
                return 0;
        }

        memcpy(&gcm, &gcm_ctx->gcm, sizeof(gcm));

        if (nonce_len == 0) {
                EVPerror(EVP_R_INVALID_IV_LENGTH);
                return 0;
        }
        CRYPTO_gcm128_setiv(&gcm, nonce, nonce_len);

        if (ad_len > 0 && CRYPTO_gcm128_aad(&gcm, ad, ad_len))
                return 0;

        if (CRYPTO_gcm128_encrypt_ctr32(&gcm, in + bulk, out + bulk,
            in_len - bulk, aes_ctr32_encrypt_ctr128f))
                return 0;

        CRYPTO_gcm128_tag(&gcm, out + in_len, gcm_ctx->tag_len);
        *out_len = in_len + gcm_ctx->tag_len;

        return 1;
}

static int
aead_aes_gcm_open(const EVP_AEAD_CTX *ctx, unsigned char *out, size_t *out_len,
    size_t max_out_len, const unsigned char *nonce, size_t nonce_len,
    const unsigned char *in, size_t in_len, const unsigned char *ad,
    size_t ad_len)
{
        const struct aead_aes_gcm_ctx *gcm_ctx = ctx->aead_state;
        unsigned char tag[EVP_AEAD_AES_GCM_TAG_LEN];
        GCM128_CONTEXT gcm;
        size_t plaintext_len;
        size_t bulk = 0;

        if (in_len < gcm_ctx->tag_len) {
                EVPerror(EVP_R_BAD_DECRYPT);
                return 0;
        }

        plaintext_len = in_len - gcm_ctx->tag_len;

        if (max_out_len < plaintext_len) {
                EVPerror(EVP_R_BUFFER_TOO_SMALL);
                return 0;
        }

        memcpy(&gcm, &gcm_ctx->gcm, sizeof(gcm));

        if (nonce_len == 0) {
                EVPerror(EVP_R_INVALID_IV_LENGTH);
                return 0;
        }
        CRYPTO_gcm128_setiv(&gcm, nonce, nonce_len);

        if (CRYPTO_gcm128_aad(&gcm, ad, ad_len))
                return 0;

        if (CRYPTO_gcm128_decrypt_ctr32(&gcm, in + bulk, out + bulk,
            in_len - bulk - gcm_ctx->tag_len, aes_ctr32_encrypt_ctr128f))
                return 0;

        CRYPTO_gcm128_tag(&gcm, tag, gcm_ctx->tag_len);
        if (timingsafe_memcmp(tag, in + plaintext_len, gcm_ctx->tag_len) != 0) {
                EVPerror(EVP_R_BAD_DECRYPT);
                return 0;
        }

        *out_len = plaintext_len;

        return 1;
}

static const EVP_AEAD aead_aes_128_gcm = {
        .key_len = 16,
        .nonce_len = 12,
        .overhead = EVP_AEAD_AES_GCM_TAG_LEN,
        .max_tag_len = EVP_AEAD_AES_GCM_TAG_LEN,

        .init = aead_aes_gcm_init,
        .cleanup = aead_aes_gcm_cleanup,
        .seal = aead_aes_gcm_seal,
        .open = aead_aes_gcm_open,
};

static const EVP_AEAD aead_aes_256_gcm = {
        .key_len = 32,
        .nonce_len = 12,
        .overhead = EVP_AEAD_AES_GCM_TAG_LEN,
        .max_tag_len = EVP_AEAD_AES_GCM_TAG_LEN,

        .init = aead_aes_gcm_init,
        .cleanup = aead_aes_gcm_cleanup,
        .seal = aead_aes_gcm_seal,
        .open = aead_aes_gcm_open,
};

const EVP_AEAD *
EVP_aead_aes_128_gcm(void)
{
        return &aead_aes_128_gcm;
}
LCRYPTO_ALIAS(EVP_aead_aes_128_gcm);

const EVP_AEAD *
EVP_aead_aes_256_gcm(void)
{
        return &aead_aes_256_gcm;
}
LCRYPTO_ALIAS(EVP_aead_aes_256_gcm);

typedef struct {
        union {
                double align;
                AES_KEY ks;
        } ks;
        unsigned char *iv;
} EVP_AES_WRAP_CTX;

static int
aes_wrap_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
    const unsigned char *iv, int enc)
{
        EVP_AES_WRAP_CTX *wctx = (EVP_AES_WRAP_CTX *)ctx->cipher_data;

        if (iv == NULL && key == NULL)
                return 1;

        if (key != NULL) {
                if (ctx->encrypt)
                        AES_set_encrypt_key(key, 8 * ctx->key_len,
                            &wctx->ks.ks);
                else
                        AES_set_decrypt_key(key, 8 * ctx->key_len,
                            &wctx->ks.ks);

                if (iv == NULL)
                        wctx->iv = NULL;
        }

        if (iv != NULL) {
                int iv_len = EVP_CIPHER_CTX_iv_length(ctx);

                if (iv_len < 0 || iv_len > sizeof(ctx->iv))
                        return 0;
                memcpy(ctx->iv, iv, iv_len);
                wctx->iv = ctx->iv;
        }

        return 1;
}

static int
aes_wrap_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
    const unsigned char *in, size_t inlen)
{
        EVP_AES_WRAP_CTX *wctx = ctx->cipher_data;
        int ret;

        if (in == NULL)
                return 0;

        if (inlen % 8 != 0)
                return -1;
        if (ctx->encrypt && inlen < 8)
                return -1;
        if (!ctx->encrypt && inlen < 16)
                return -1;
        if (inlen > INT_MAX)
                return -1;

        if (out == NULL) {
                if (ctx->encrypt)
                        return inlen + 8;
                else
                        return inlen - 8;
        }

        if (ctx->encrypt)
                ret = AES_wrap_key(&wctx->ks.ks, wctx->iv, out, in,
                    (unsigned int)inlen);
        else
                ret = AES_unwrap_key(&wctx->ks.ks, wctx->iv, out, in,
                    (unsigned int)inlen);

        return ret != 0 ? ret : -1;
}

static int
aes_wrap_ctrl(EVP_CIPHER_CTX *c, int type, int arg, void *ptr)
{
        EVP_AES_WRAP_CTX *wctx = c->cipher_data;

        switch (type) {
        case EVP_CTRL_COPY:
            {
                EVP_CIPHER_CTX *out = ptr;
                EVP_AES_WRAP_CTX *wctx_out = out->cipher_data;

                if (wctx->iv != NULL) {
                        if (c->iv != wctx->iv)
                                return 0;

                        wctx_out->iv = out->iv;
                }

                return 1;
            }
        }

        return -1;
}

#define WRAP_FLAGS \
    ( EVP_CIPH_WRAP_MODE | EVP_CIPH_CUSTOM_IV | EVP_CIPH_FLAG_CUSTOM_CIPHER | \
      EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_FLAG_DEFAULT_ASN1 | \
      EVP_CIPH_CUSTOM_COPY )

static const EVP_CIPHER aes_128_wrap = {
        .nid = NID_id_aes128_wrap,
        .block_size = 8,
        .key_len = 16,
        .iv_len = 8,
        .flags = WRAP_FLAGS,
        .init = aes_wrap_init_key,
        .do_cipher = aes_wrap_cipher,
        .cleanup = NULL,
        .ctx_size = sizeof(EVP_AES_WRAP_CTX),
        .set_asn1_parameters = NULL,
        .get_asn1_parameters = NULL,
        .ctrl = aes_wrap_ctrl,
};

const EVP_CIPHER *
EVP_aes_128_wrap(void)
{
        return &aes_128_wrap;
}
LCRYPTO_ALIAS(EVP_aes_128_wrap);

static const EVP_CIPHER aes_192_wrap = {
        .nid = NID_id_aes192_wrap,
        .block_size = 8,
        .key_len = 24,
        .iv_len = 8,
        .flags = WRAP_FLAGS,
        .init = aes_wrap_init_key,
        .do_cipher = aes_wrap_cipher,
        .cleanup = NULL,
        .ctx_size = sizeof(EVP_AES_WRAP_CTX),
        .set_asn1_parameters = NULL,
        .get_asn1_parameters = NULL,
        .ctrl = aes_wrap_ctrl,
};

const EVP_CIPHER *
EVP_aes_192_wrap(void)
{
        return &aes_192_wrap;
}
LCRYPTO_ALIAS(EVP_aes_192_wrap);

static const EVP_CIPHER aes_256_wrap = {
        .nid = NID_id_aes256_wrap,
        .block_size = 8,
        .key_len = 32,
        .iv_len = 8,
        .flags = WRAP_FLAGS,
        .init = aes_wrap_init_key,
        .do_cipher = aes_wrap_cipher,
        .cleanup = NULL,
        .ctx_size = sizeof(EVP_AES_WRAP_CTX),
        .set_asn1_parameters = NULL,
        .get_asn1_parameters = NULL,
        .ctrl = aes_wrap_ctrl,
};

const EVP_CIPHER *
EVP_aes_256_wrap(void)
{
        return &aes_256_wrap;
}
LCRYPTO_ALIAS(EVP_aes_256_wrap);

#endif