Momentum-Apps/lib/wolfssl/wolfcrypt/src/wc_encrypt.c

/* wc_encrypt.c
 *
 * Copyright (C) 2006-2023 wolfSSL Inc.
 *
 * This file is part of wolfSSL.
 *
 * wolfSSL is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * wolfSSL is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA
 */


#ifdef HAVE_CONFIG_H
    #include <config.h>
#endif

#include <wolfssl/wolfcrypt/settings.h>
#include <wolfssl/wolfcrypt/aes.h>
#include <wolfssl/wolfcrypt/des3.h>
#include <wolfssl/wolfcrypt/hash.h>
#include <wolfssl/wolfcrypt/rc2.h>
#include <wolfssl/wolfcrypt/arc4.h>
#include <wolfssl/wolfcrypt/wc_encrypt.h>
#include <wolfssl/wolfcrypt/error-crypt.h>
#include <wolfssl/wolfcrypt/asn.h>
#include <wolfssl/wolfcrypt/coding.h>
#include <wolfssl/wolfcrypt/pwdbased.h>
#include <wolfssl/wolfcrypt/logging.h>

#ifdef NO_INLINE
    #include <wolfssl/wolfcrypt/misc.h>
#else
    #define WOLFSSL_MISC_INCLUDED
    #include <wolfcrypt/src/misc.c>
#endif

#if !defined(NO_AES) && defined(HAVE_AES_CBC)
#ifdef HAVE_AES_DECRYPT
int wc_AesCbcDecryptWithKey(byte* out, const byte* in, word32 inSz,
                                  const byte* key, word32 keySz, const byte* iv)
{
    int  ret = 0;
#ifdef WOLFSSL_SMALL_STACK
    Aes* aes = NULL;
#else
    Aes  aes[1];
#endif

    if (out == NULL || in == NULL || key == NULL || iv == NULL) {
        return BAD_FUNC_ARG;
    }

#ifdef WOLFSSL_SMALL_STACK
    aes = (Aes*)XMALLOC(sizeof(Aes), NULL, DYNAMIC_TYPE_TMP_BUFFER);
    if (aes == NULL)
        return MEMORY_E;
#endif

    ret = wc_AesInit(aes, NULL, INVALID_DEVID);
    if (ret == 0) {
        ret = wc_AesSetKey(aes, key, keySz, iv, AES_DECRYPTION);
        if (ret == 0)
            ret = wc_AesCbcDecrypt(aes, out, in, inSz);

        wc_AesFree(aes);
    }

#ifdef WOLFSSL_SMALL_STACK
    XFREE(aes, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif

    return ret;
}
#endif /* HAVE_AES_DECRYPT */

int wc_AesCbcEncryptWithKey(byte* out, const byte* in, word32 inSz,
                            const byte* key, word32 keySz, const byte* iv)
{
    int  ret = 0;
#ifdef WOLFSSL_SMALL_STACK
    Aes* aes;
#else
    Aes  aes[1];
#endif

#ifdef WOLFSSL_SMALL_STACK
    aes = (Aes*)XMALLOC(sizeof(Aes), NULL, DYNAMIC_TYPE_TMP_BUFFER);
    if (aes == NULL)
        return MEMORY_E;
#endif

    ret = wc_AesInit(aes, NULL, INVALID_DEVID);
    if (ret == 0) {
        ret = wc_AesSetKey(aes, key, keySz, iv, AES_ENCRYPTION);
        if (ret == 0)
            ret = wc_AesCbcEncrypt(aes, out, in, inSz);

        wc_AesFree(aes);
    }

#ifdef WOLFSSL_SMALL_STACK
    XFREE(aes, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif

    return ret;
}
#endif /* !NO_AES && HAVE_AES_CBC */


#if !defined(NO_DES3) && !defined(WOLFSSL_TI_CRYPT)
int wc_Des_CbcEncryptWithKey(byte* out, const byte* in, word32 sz,
                             const byte* key, const byte* iv)
{
    int ret  = 0;
#ifdef WOLFSSL_SMALL_STACK
    Des* des;
#else
    Des  des[1];
#endif

#ifdef WOLFSSL_SMALL_STACK
    des = (Des*)XMALLOC(sizeof(Des), NULL, DYNAMIC_TYPE_TMP_BUFFER);
    if (des == NULL)
        return MEMORY_E;
#endif

    ret = wc_Des_SetKey(des, key, iv, DES_ENCRYPTION);
    if (ret == 0)
        ret = wc_Des_CbcEncrypt(des, out, in, sz);

#ifdef WOLFSSL_SMALL_STACK
    XFREE(des, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif

    return ret;
}

int wc_Des_CbcDecryptWithKey(byte* out, const byte* in, word32 sz,
                             const byte* key, const byte* iv)
{
    int ret  = 0;
#ifdef WOLFSSL_SMALL_STACK
    Des* des;
#else
    Des  des[1];
#endif

#ifdef WOLFSSL_SMALL_STACK
    des = (Des*)XMALLOC(sizeof(Des), NULL, DYNAMIC_TYPE_TMP_BUFFER);
    if (des == NULL)
        return MEMORY_E;
#endif

    ret = wc_Des_SetKey(des, key, iv, DES_DECRYPTION);
    if (ret == 0)
        ret = wc_Des_CbcDecrypt(des, out, in, sz);

#ifdef WOLFSSL_SMALL_STACK
    XFREE(des, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif

    return ret;
}


int wc_Des3_CbcEncryptWithKey(byte* out, const byte* in, word32 sz,
                              const byte* key, const byte* iv)
{
    int ret    = 0;
#ifdef WOLFSSL_SMALL_STACK
    Des3* des3;
#else
    Des3  des3[1];
#endif

#ifdef WOLFSSL_SMALL_STACK
    des3 = (Des3*)XMALLOC(sizeof(Des3), NULL, DYNAMIC_TYPE_TMP_BUFFER);
    if (des3 == NULL)
        return MEMORY_E;
#endif

    ret = wc_Des3Init(des3, NULL, INVALID_DEVID);
    if (ret == 0) {
        ret = wc_Des3_SetKey(des3, key, iv, DES_ENCRYPTION);
        if (ret == 0)
            ret = wc_Des3_CbcEncrypt(des3, out, in, sz);
        wc_Des3Free(des3);
    }

#ifdef WOLFSSL_SMALL_STACK
    XFREE(des3, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif

    return ret;
}


int wc_Des3_CbcDecryptWithKey(byte* out, const byte* in, word32 sz,
                              const byte* key, const byte* iv)
{
    int ret    = 0;
#ifdef WOLFSSL_SMALL_STACK
    Des3* des3;
#else
    Des3  des3[1];
#endif

#ifdef WOLFSSL_SMALL_STACK
    des3 = (Des3*)XMALLOC(sizeof(Des3), NULL, DYNAMIC_TYPE_TMP_BUFFER);
    if (des3 == NULL)
        return MEMORY_E;
#endif

    ret = wc_Des3Init(des3, NULL, INVALID_DEVID);
    if (ret == 0) {
        ret = wc_Des3_SetKey(des3, key, iv, DES_DECRYPTION);
        if (ret == 0)
            ret = wc_Des3_CbcDecrypt(des3, out, in, sz);
        wc_Des3Free(des3);
    }

#ifdef WOLFSSL_SMALL_STACK
    XFREE(des3, NULL, DYNAMIC_TYPE_TMP_BUFFER);
#endif

    return ret;
}

#endif /* !NO_DES3 */


#if !defined(NO_ASN) && defined(WOLFSSL_ENCRYPTED_KEYS)

int wc_BufferKeyDecrypt(EncryptedInfo* info, byte* der, word32 derSz,
    const byte* password, int passwordSz, int hashType)
{
    int ret = NOT_COMPILED_IN;
#ifdef WOLFSSL_SMALL_STACK
    byte* key      = NULL;
#else
    byte  key[WC_MAX_SYM_KEY_SIZE];
#endif

    (void)derSz;
    (void)passwordSz;
    (void)hashType;

    if (der == NULL || password == NULL || info == NULL || info->keySz == 0) {
        return BAD_FUNC_ARG;
    }

    /* use file's salt for key derivation, hex decode first */
    if (Base16_Decode(info->iv, info->ivSz, info->iv, &info->ivSz) != 0) {
        WOLFSSL_ERROR_VERBOSE(BUFFER_E);
        return BUFFER_E;
    }
    if (info->ivSz < PKCS5_SALT_SZ) {
        WOLFSSL_ERROR_VERBOSE(BUFFER_E);
        return BUFFER_E;
    }

#ifdef WOLFSSL_SMALL_STACK
    key = (byte*)XMALLOC(WC_MAX_SYM_KEY_SIZE, NULL, DYNAMIC_TYPE_SYMMETRIC_KEY);
    if (key == NULL) {
        return MEMORY_E;
    }
#endif
#ifdef WOLFSSL_CHECK_MEM_ZERO
    wc_MemZero_Add("wc_BufferKeyDecrypt key", key, WC_MAX_SYM_KEY_SIZE);
#endif

    (void)XMEMSET(key, 0, WC_MAX_SYM_KEY_SIZE);

#ifndef NO_PWDBASED
    if ((ret = wc_PBKDF1(key, password, passwordSz, info->iv, PKCS5_SALT_SZ, 1,
                                        (int)info->keySz, hashType)) != 0) {
#ifdef WOLFSSL_SMALL_STACK
        XFREE(key, NULL, DYNAMIC_TYPE_SYMMETRIC_KEY);
#elif defined(WOLFSSL_CHECK_MEM_ZERO)
        wc_MemZero_Check(key, WC_MAX_SYM_KEY_SIZE);
#endif
        return ret;
    }
#endif

#ifndef NO_DES3
    if (info->cipherType == WC_CIPHER_DES)
        ret = wc_Des_CbcDecryptWithKey(der, der, derSz, key, info->iv);
    if (info->cipherType == WC_CIPHER_DES3)
        ret = wc_Des3_CbcDecryptWithKey(der, der, derSz, key, info->iv);
#endif /* NO_DES3 */
#if !defined(NO_AES) && defined(HAVE_AES_CBC) && defined(HAVE_AES_DECRYPT)
    if (info->cipherType == WC_CIPHER_AES_CBC)
        ret = wc_AesCbcDecryptWithKey(der, der, derSz, key, info->keySz,
            info->iv);
#endif /* !NO_AES && HAVE_AES_CBC && HAVE_AES_DECRYPT */

    ForceZero(key, WC_MAX_SYM_KEY_SIZE);
#ifdef WOLFSSL_SMALL_STACK
    XFREE(key, NULL, DYNAMIC_TYPE_SYMMETRIC_KEY);
#elif defined(WOLFSSL_CHECK_MEM_ZERO)
    wc_MemZero_Check(key, WC_MAX_SYM_KEY_SIZE);
#endif

    return ret;
}

int wc_BufferKeyEncrypt(EncryptedInfo* info, byte* der, word32 derSz,
    const byte* password, int passwordSz, int hashType)
{
    int ret = NOT_COMPILED_IN;
#ifdef WOLFSSL_SMALL_STACK
    byte* key      = NULL;
#else
    byte  key[WC_MAX_SYM_KEY_SIZE];
#endif

    (void)derSz;
    (void)passwordSz;
    (void)hashType;

    if (der == NULL || password == NULL || info == NULL || info->keySz == 0 ||
            info->ivSz < PKCS5_SALT_SZ) {
        return BAD_FUNC_ARG;
    }

#ifdef WOLFSSL_SMALL_STACK
    key = (byte*)XMALLOC(WC_MAX_SYM_KEY_SIZE, NULL, DYNAMIC_TYPE_SYMMETRIC_KEY);
    if (key == NULL) {
        return MEMORY_E;
    }
#endif /* WOLFSSL_SMALL_STACK */
#ifdef WOLFSSL_CHECK_MEM_ZERO
    XMEMSET(key, 0xff, WC_MAX_SYM_KEY_SIZE);
    wc_MemZero_Add("wc_BufferKeyDecrypt key", key, WC_MAX_SYM_KEY_SIZE);
#endif

    (void)XMEMSET(key, 0, WC_MAX_SYM_KEY_SIZE);

#ifndef NO_PWDBASED
    if ((ret = wc_PBKDF1(key, password, passwordSz, info->iv, PKCS5_SALT_SZ, 1,
                                        (int)info->keySz, hashType)) != 0) {
#ifdef WOLFSSL_SMALL_STACK
        XFREE(key, NULL, DYNAMIC_TYPE_SYMMETRIC_KEY);
#elif defined(WOLFSSL_CHECK_MEM_ZERO)
        wc_MemZero_Check(key, WC_MAX_SYM_KEY_SIZE);
#endif
        return ret;
    }
#endif

#ifndef NO_DES3
    if (info->cipherType == WC_CIPHER_DES)
        ret = wc_Des_CbcEncryptWithKey(der, der, derSz, key, info->iv);
    if (info->cipherType == WC_CIPHER_DES3)
        ret = wc_Des3_CbcEncryptWithKey(der, der, derSz, key, info->iv);
#endif /* NO_DES3 */
#if !defined(NO_AES) && defined(HAVE_AES_CBC)
    if (info->cipherType == WC_CIPHER_AES_CBC)
        ret = wc_AesCbcEncryptWithKey(der, der, derSz, key, info->keySz,
            info->iv);
#endif /* !NO_AES && HAVE_AES_CBC */

    ForceZero(key, WC_MAX_SYM_KEY_SIZE);
#ifdef WOLFSSL_SMALL_STACK
    XFREE(key, NULL, DYNAMIC_TYPE_SYMMETRIC_KEY);
#elif defined(WOLFSSL_CHECK_MEM_ZERO)
    wc_MemZero_Check(key, WC_MAX_SYM_KEY_SIZE);
#endif

    return ret;
}

#endif /* !NO_ASN && WOLFSSL_ENCRYPTED_KEYS */


#if !defined(NO_PWDBASED) && !defined(NO_ASN)

#if defined(HAVE_PKCS8) || defined(HAVE_PKCS12)
/* Decrypt/Encrypt input in place from parameters based on id
 *
 * returns a negative value on fail case
 */
int wc_CryptKey(const char* password, int passwordSz, byte* salt,
                      int saltSz, int iterations, int id, byte* input,
                      int length, int version, byte* cbcIv, int enc, int shaOid)
{
    int typeH = WC_HASH_TYPE_NONE;
    word32 derivedLen = 0;
    int ret = 0;
#ifdef WOLFSSL_SMALL_STACK
    byte* key = NULL;
#else
    byte key[PKCS_MAX_KEY_SIZE];
#endif

    (void)input;
    (void)length;
    (void)enc;

    WOLFSSL_ENTER("wc_CryptKey");

    if (length < 0)
        return BAD_LENGTH_E;

    switch (id) {
    #ifndef NO_DES3
        #ifndef NO_MD5
        case PBE_MD5_DES:
            typeH = WC_MD5;
            derivedLen = 16;           /* may need iv for v1.5 */
            break;
        #endif
        #ifndef NO_SHA
        case PBE_SHA1_DES:
            typeH = WC_SHA;
            derivedLen = 16;           /* may need iv for v1.5 */
            break;
        #endif /* !NO_SHA */
        #if !defined(NO_SHA) || !defined(NO_SHA256)
        case PBE_SHA1_DES3:
            switch (shaOid) {
            #ifndef NO_SHA256
                case HMAC_SHA256_OID:
                    typeH = WC_SHA256;
                    derivedLen = 32;
                    break;
            #endif
            #ifndef NO_SHA
                default:
                    typeH = WC_SHA;
                    derivedLen = 32;           /* may need iv for v1.5 */
                    break;
            #endif
            }
        break;
        #endif
    #endif /* !NO_DES3 */
    #if !defined(NO_SHA) && !defined(NO_RC4)
        case PBE_SHA1_RC4_128:
            typeH = WC_SHA;
            derivedLen = 16;
            break;
    #endif
    #if defined(WOLFSSL_AES_256)
        case PBE_AES256_CBC:
            switch(shaOid) {
                case HMAC_SHA256_OID:
                    typeH = WC_SHA256;
                    derivedLen = 32;
                    break;
            #ifndef NO_SHA
                default:
                    typeH = WC_SHA;
                    derivedLen = 32;
                    break;
            #endif
            }
            break;
    #endif /* WOLFSSL_AES_256 && !NO_SHA */
    #if defined(WOLFSSL_AES_128)
        case PBE_AES128_CBC:
            switch(shaOid) {
                case HMAC_SHA256_OID:
                    typeH = WC_SHA256;
                    derivedLen = 16;
                    break;
            #ifndef NO_SHA
                default:
                    typeH = WC_SHA;
                    derivedLen = 16;
                    break;
            #endif
            }
            break;
    #endif /* WOLFSSL_AES_128 && !NO_SHA */
    #ifdef WC_RC2
        case PBE_SHA1_40RC2_CBC:
            typeH = WC_SHA;
            derivedLen = 5;
            break;
    #endif
        default:
            WOLFSSL_MSG("Unknown/Unsupported encrypt/decrypt id");
            (void)shaOid;
            ret = ALGO_ID_E;
            WOLFSSL_ERROR_VERBOSE(ret);
    }

    #ifdef WOLFSSL_SMALL_STACK
    if (ret == 0) {
        key = (byte*)XMALLOC(PKCS_MAX_KEY_SIZE, NULL, DYNAMIC_TYPE_TMP_BUFFER);
        if (key == NULL)
            ret = MEMORY_E;
    }
    #endif

    if (ret == 0) {
    #ifdef WOLFSSL_CHECK_MEM_ZERO
        XMEMSET(key, 0xff, PKCS_MAX_KEY_SIZE);
        wc_MemZero_Add("wc_CryptKey key", key, PKCS_MAX_KEY_SIZE);
    #endif

        switch (version) {
    #ifndef NO_HMAC
            case PKCS5v2:
                ret = wc_PBKDF2(key, (byte*)password, passwordSz,
                                salt, saltSz, iterations, (int)derivedLen, typeH);
                break;
    #endif
    #ifndef NO_SHA
            case PKCS5:
                ret = wc_PBKDF1(key, (byte*)password, passwordSz,
                                salt, saltSz, iterations, (int)derivedLen, typeH);
                break;
    #endif
    #ifdef HAVE_PKCS12
            case PKCS12v1:
            {
                int  i, idx = 0;
                byte unicodePasswd[MAX_UNICODE_SZ];

                if ( (passwordSz * 2 + 2) > (int)sizeof(unicodePasswd)) {
                    ret = UNICODE_SIZE_E;
                    break;
                }

                for (i = 0; i < passwordSz; i++) {
                    unicodePasswd[idx++] = 0x00;
                    unicodePasswd[idx++] = (byte)password[i];
                }
                /* add trailing NULL */
                unicodePasswd[idx++] = 0x00;
                unicodePasswd[idx++] = 0x00;

                ret =  wc_PKCS12_PBKDF(key, unicodePasswd, idx, salt, saltSz,
                                    iterations, (int)derivedLen, typeH, 1);
                if (id != PBE_SHA1_RC4_128) {
                    ret += wc_PKCS12_PBKDF(cbcIv, unicodePasswd, idx, salt,
                                    saltSz, iterations, 8, typeH, 2);
                }
                break;
            }
    #endif /* HAVE_PKCS12 */
            default:
                WOLFSSL_MSG("Unknown/Unsupported PKCS version");
                ret = ALGO_ID_E;
                WOLFSSL_ERROR_VERBOSE(ret);
        } /* switch (version) */
    }

    if (ret == 0) {
        switch (id) {
    #ifndef NO_DES3
        #if !defined(NO_SHA) || !defined(NO_MD5)
            case PBE_MD5_DES:
            case PBE_SHA1_DES:
            {
                Des    des;
                byte*  desIv = key + 8;

                if (version == PKCS5v2 || version == PKCS12v1)
                    desIv = cbcIv;

                if (enc) {
                    ret = wc_Des_SetKey(&des, key, desIv, DES_ENCRYPTION);
                }
                else {
                    ret = wc_Des_SetKey(&des, key, desIv, DES_DECRYPTION);
                }
                if (ret == 0) {
                    if (enc) {
                        wc_Des_CbcEncrypt(&des, input, input, (word32)length);
                    }
                    else {
                        wc_Des_CbcDecrypt(&des, input, input, (word32)length);
                    }
                }
                break;
            }
        #endif /* !NO_SHA || !NO_MD5 */

        #ifndef NO_SHA
            case PBE_SHA1_DES3:
            {
                Des3   des;
                byte*  desIv = key + 24;

                if (version == PKCS5v2 || version == PKCS12v1)
                    desIv = cbcIv;

                ret = wc_Des3Init(&des, NULL, INVALID_DEVID);
                if (ret != 0) {
                    break;
                }
                if (enc) {
                    ret = wc_Des3_SetKey(&des, key, desIv, DES_ENCRYPTION);
                }
                else {
                    ret = wc_Des3_SetKey(&des, key, desIv, DES_DECRYPTION);
                }
                if (ret == 0) {
                    if (enc) {
                        ret = wc_Des3_CbcEncrypt(&des, input, input, (word32)length);
                    }
                    else {
                        ret = wc_Des3_CbcDecrypt(&des, input, input, (word32)length);
                    }
                }
                wc_Des3Free(&des);
                break;
            }
        #endif /* !NO_SHA */
    #endif
    #if !defined(NO_RC4) && !defined(NO_SHA)
            case PBE_SHA1_RC4_128:
            {
                Arc4    dec;

                wc_Arc4SetKey(&dec, key, derivedLen);
                wc_Arc4Process(&dec, input, input, (word32)length);
                break;
            }
    #endif
    #if !defined(NO_AES) && defined(HAVE_AES_CBC)
        #ifdef WOLFSSL_AES_256
            case PBE_AES256_CBC:
            case PBE_AES128_CBC:
            {
                int free_aes;

            #ifdef WOLFSSL_SMALL_STACK
                Aes *aes;
                aes = (Aes *)XMALLOC(sizeof *aes, NULL, DYNAMIC_TYPE_AES);
                if (aes == NULL) {
                    ret = MEMORY_E;
                    break;
                }
            #else
                Aes aes[1];
            #endif
                free_aes = 0;
                ret = wc_AesInit(aes, NULL, INVALID_DEVID);
                if (ret == 0) {
                    free_aes = 1;
                    if (enc) {
                        ret = wc_AesSetKey(aes, key, derivedLen, cbcIv,
                                                            AES_ENCRYPTION);
                    }
                    else {
                        ret = wc_AesSetKey(aes, key, derivedLen, cbcIv,
                                                            AES_DECRYPTION);
                    }
                }
                if (ret == 0) {
                    if (enc)
                        ret = wc_AesCbcEncrypt(aes, input, input, (word32)length);
                    else
                        ret = wc_AesCbcDecrypt(aes, input, input, (word32)length);
                }
                if (free_aes)
                    wc_AesFree(aes);
                ForceZero(aes, sizeof(Aes));
            #ifdef WOLFSSL_SMALL_STACK
                XFREE(aes, NULL, DYNAMIC_TYPE_AES);
            #endif
                break;
            }
        #endif /* WOLFSSL_AES_256 */
    #endif /* !NO_AES && HAVE_AES_CBC */
    #ifdef WC_RC2
            case PBE_SHA1_40RC2_CBC:
            {
                Rc2 rc2;
                /* effective key size for RC2-40-CBC is 40 bits */
                ret = wc_Rc2SetKey(&rc2, key, derivedLen, cbcIv, 40);
                if (ret == 0) {
                    if (enc)
                        ret = wc_Rc2CbcEncrypt(&rc2, input, input, length);
                    else
                        ret = wc_Rc2CbcDecrypt(&rc2, input, input, length);
                }
                if (ret == 0) {
                    ForceZero(&rc2, sizeof(Rc2));
                }
                break;
            }
    #endif

            default:
                WOLFSSL_MSG("Unknown/Unsupported encrypt/decryption algorithm");
                ret = ALGO_ID_E;
                WOLFSSL_ERROR_VERBOSE(ret);
        }
    }

#ifdef WOLFSSL_SMALL_STACK
    if (key != NULL)
#endif
    {
        ForceZero(key, PKCS_MAX_KEY_SIZE);
    #ifdef WOLFSSL_SMALL_STACK
        XFREE(key, NULL, DYNAMIC_TYPE_TMP_BUFFER);
    #elif defined(WOLFSSL_CHECK_MEM_ZERO)
        wc_MemZero_Check(key, PKCS_MAX_KEY_SIZE);
    #endif
    }

    return ret;
}

#endif /* HAVE_PKCS8 || HAVE_PKCS12 */
#endif /* !NO_PWDBASED && !NO_ASN */