/*!
    \ingroup openSSL
    
    \brief Getter functions for the respective WOLFSSL_EVP_CIPHER pointers. 
    wolfSSL_EVP_init() must be called once in the program first to populate 
    these cipher strings. WOLFSSL_DES_ECB macro must be defined for 
    wolfSSL_EVP_des_ede3_ecb().
    
    \return pointer Returns a WOLFSSL_EVP_CIPHER pointer for DES EDE3 operations.
    
    \param none No parameters.
    
    _Example_
    \code
    printf("block size des ede3 cbc = %d\n", 
    wolfSSL_EVP_CIPHER_block_size(wolfSSL_EVP_des_ede3_cbc()));
    printf("block size des ede3 ecb = %d\n", 
    wolfSSL_EVP_CIPHER_block_size(wolfSSL_EVP_des_ede3_ecb()));
    \endcode
    
    \sa wolfSSL_EVP_CIPHER_CTX_init
*/
WOLFSSL_API const WOLFSSL_EVP_CIPHER* wolfSSL_EVP_des_ede3_ecb(void);
/*!
    \ingroup openSSL
    
    \brief Getter functions for the respective WOLFSSL_EVP_CIPHER pointers. 
    wolfSSL_EVP_init() must be called once in the program first to populate 
    these cipher strings. WOLFSSL_DES_ECB macro must be defined for 
    wolfSSL_EVP_des_ecb().
    
    \return pointer Returns a WOLFSSL_EVP_CIPHER pointer for DES operations.
    
    \param none No parameters.
    
    _Example_
    \code
    WOLFSSL_EVP_CIPHER* cipher;
    cipher = wolfSSL_EVP_des_ecb();
    …
    \endcode
    
    \sa wolfSSL_EVP_CIPHER_CTX_init
*/
WOLFSSL_API const WOLFSSL_EVP_CIPHER* wolfSSL_EVP_des_cbc(void);
/*!
    \ingroup openSSL
    
    \brief Function for initializing WOLFSSL_EVP_MD_CTX. This function is a 
    wrapper for wolfSSL_EVP_DigestInit() because wolfSSL does not 
    use WOLFSSL_ENGINE.
    
    \return SSL_SUCCESS If successfully set.
    \return SSL_FAILURE If not successful.
    
    \param ctx structure to initialize.
    \param type type of hash to do, for example SHA.
    \param impl engine to use. N/A for wolfSSL, can be NULL.
    
    _Example_
    \code
    WOLFSSL_EVP_MD_CTX* md = NULL;
    wolfCrypt_Init();
    md = wolfSSL_EVP_MD_CTX_new();
    if (md == NULL) {
        printf("error setting md\n");
        return -1;
    }
    printf("cipher md init ret = %d\n", wolfSSL_EVP_DigestInit_ex(md, 
    wolfSSL_EVP_sha1(), e));  
    //free resources
    \endcode
    
    \sa wolfSSL_EVP_MD_CTX_new
    \sa wolfCrypt_Init
    \sa wolfSSL_EVP_MD_CTX_free
*/
WOLFSSL_API int wolfSSL_EVP_DigestInit_ex(WOLFSSL_EVP_MD_CTX* ctx,
                                     const WOLFSSL_EVP_MD* type,
                                     WOLFSSL_ENGINE *impl);
/*!
    \ingroup openSSL
    
    \brief Function for initializing WOLFSSL_EVP_CIPHER_CTX. This function is a 
    wrapper for wolfSSL_CipherInit() because wolfSSL does not 
    use WOLFSSL_ENGINE.
    
    \return SSL_SUCCESS If successfully set.
    \return SSL_FAILURE If not successful.
    
    \param ctx structure to initialize.
    \param type type of encryption/decryption to do, for example AES.
    \param impl engine to use. N/A for wolfSSL, can be NULL.
    \param key key to set .
    \param iv iv if needed by algorithm.
    \param enc encryption (1) or decryption (0) flag.
    
    _Example_
    \code
    WOLFSSL_EVP_CIPHER_CTX* ctx = NULL;
    WOLFSSL_ENGINE* e = NULL;
    unsigned char key[16];
    unsigned char iv[12];
    wolfCrypt_Init();
    ctx = wolfSSL_EVP_CIPHER_CTX_new();
    if (ctx == NULL) {
        printf("issue creating ctx\n");
        return -1;
    }
    
    printf("cipher init ex error ret = %d\n", wolfSSL_EVP_CipherInit_ex(NULL, 
    EVP_aes_128_    cbc(), e, key, iv, 1));
    printf("cipher init ex success ret = %d\n", wolfSSL_EVP_CipherInit_ex(ctx, 
    EVP_aes_128_c    bc(), e, key, iv, 1));
    // free resources
    \endcode
    
    \sa wolfSSL_EVP_CIPHER_CTX_new
    \sa wolfCrypt_Init
    \sa wolfSSL_EVP_CIPHER_CTX_free
*/
WOLFSSL_API int  wolfSSL_EVP_CipherInit_ex(WOLFSSL_EVP_CIPHER_CTX* ctx,
                                    const WOLFSSL_EVP_CIPHER* type,
                                    WOLFSSL_ENGINE *impl,
                                    const unsigned char* key,
                                    const unsigned char* iv,
                                    int enc);
/*!
    \ingroup openSSL
    
    \brief Function for initializing WOLFSSL_EVP_CIPHER_CTX. This function is a 
    wrapper for wolfSSL_EVP_CipherInit() because wolfSSL does not use 
    WOLFSSL_ENGINE. Sets encrypt flag to be encrypt.
    
    \return SSL_SUCCESS If successfully set.
    \return SSL_FAILURE If not successful.
    
    \param ctx structure to initialize.
    \param type type of encryption to do, for example AES.
    \param impl engine to use. N/A for wolfSSL, can be NULL.
    \param key key to use.
    \param iv iv to use.
    
    _Example_
    \code
    WOLFSSL_EVP_CIPHER_CTX* ctx = NULL;
    wolfCrypt_Init();
    ctx = wolfSSL_EVP_CIPHER_CTX_new();
    if (ctx == NULL) {
        printf("error setting ctx\n");
        return -1;
    }
    printf("cipher ctx init ret = %d\n", wolfSSL_EVP_EncryptInit_ex(ctx, 
    wolfSSL_EVP_aes_128_cbc(), e, key, iv));
    //free resources
    \endcode

    \sa wolfSSL_EVP_CIPHER_CTX_new
    \sa wolfCrypt_Init
    \sa wolfSSL_EVP_CIPHER_CTX_free
*/
WOLFSSL_API int  wolfSSL_EVP_EncryptInit_ex(WOLFSSL_EVP_CIPHER_CTX* ctx,
                                    const WOLFSSL_EVP_CIPHER* type,
                                    WOLFSSL_ENGINE *impl,
                                    const unsigned char* key,
                                    const unsigned char* iv);
/*!
    \ingroup openSSL
    
    \brief Function for initializing WOLFSSL_EVP_CIPHER_CTX. This function is a 
    wrapper for wolfSSL_EVP_CipherInit() because wolfSSL does not use 
    WOLFSSL_ENGINE. Sets encrypt flag to be decrypt.
    
    \return SSL_SUCCESS If successfully set.
    \return SSL_FAILURE If not successful.
    
    \param ctx structure to initialize.
    \param type type of encryption/decryption to do, for example AES.
    \param impl engine to use. N/A for wolfSSL, can be NULL.
    \param key key to set .
    \param iv iv if needed by algorithm.
    \param enc encryption (1) or decryption (0) flag.
    
    _Example_
    \code
    WOLFSSL_EVP_CIPHER_CTX* ctx = NULL;
    WOLFSSL_ENGINE* e = NULL;
    unsigned char key[16];
    unsigned char iv[12];

    wolfCrypt_Init();

    ctx = wolfSSL_EVP_CIPHER_CTX_new();
    if (ctx == NULL) {
        printf("issue creating ctx\n");
        return -1;
    }

    printf("cipher init ex error ret = %d\n", wolfSSL_EVP_DecryptInit_ex(NULL, 
    EVP_aes_128_    cbc(), e, key, iv, 1));
    printf("cipher init ex success ret = %d\n", wolfSSL_EVP_DecryptInit_ex(ctx, 
    EVP_aes_128_c    bc(), e, key, iv, 1));
// free resources
    \endcode
    
    \sa wolfSSL_EVP_CIPHER_CTX_new
    \sa wolfCrypt_Init
    \sa wolfSSL_EVP_CIPHER_CTX_free
*/
WOLFSSL_API int  wolfSSL_EVP_DecryptInit_ex(WOLFSSL_EVP_CIPHER_CTX* ctx,
                                    const WOLFSSL_EVP_CIPHER* type,
                                    WOLFSSL_ENGINE *impl,
                                    const unsigned char* key,
                                    const unsigned char* iv);
/*!
    \ingroup openSSL
    
    \brief Function for encrypting/decrypting data. In buffer is added to be 
    encrypted or decrypted and out buffer holds the results. outl will be the 
    length of encrypted/decrypted information.
    
    \return SSL_SUCCESS If successfull.
    \return SSL_FAILURE If not successful.

    \param ctx structure to get cipher type from.
    \param out buffer to hold output.
    \param outl adjusted to be size of output.
    \param in buffer to perform operation on.
    \param inl length of input buffer.
    
    _Example_
    \code
    WOLFSSL_EVP_CIPHER_CTX* ctx = NULL;
    unsigned char out[100];
    int outl;
    unsigned char in[100];
    int inl = 100;

    ctx = wolfSSL_EVP_CIPHER_CTX_new();
    // set up ctx
    ret = wolfSSL_EVP_CipherUpdate(ctx, out, outl, in, inl);
    // check ret value
    // buffer out holds outl bytes of data
    // free resources
    \endcode
    
    \sa wolfSSL_EVP_CIPHER_CTX_new
    \sa wolfCrypt_Init
    \sa wolfSSL_EVP_CIPHER_CTX_free
*/
WOLFSSL_API int wolfSSL_EVP_CipherUpdate(WOLFSSL_EVP_CIPHER_CTX *ctx,
                                   unsigned char *out, int *outl,
                                   const unsigned char *in, int inl);
/*!
    \ingroup openSSL
    
    \brief This function performs the final cipher operations adding in 
    padding. If WOLFSSL_EVP_CIPH_NO_PADDING flag is set in 
    WOLFSSL_EVP_CIPHER_CTX structure then 1 is returned and no 
    encryption/decryption is done. If padding flag is seti padding is added and 
    encrypted when ctx is set to encrypt, padding values are checked when set 
    to decrypt.
    
    \return 1 Returned on success.
    \return 0 If encountering a failure.
    
    \param ctx structure to decrypt/encrypt with.
    \param out buffer for final decrypt/encrypt.
    \param out1 size of out buffer when data has been added by function.
    
    _Example_
    \code
    WOLFSSL_EVP_CIPHER_CTX* ctx;
    int out1;
    unsigned char out[64];
    // create ctx
    wolfSSL_EVP_CipherFinal(ctx, out, &out1);
    \endcode
    
    \sa wolfSSL_EVP_CIPHER_CTX_new
*/
WOLFSSL_API int  wolfSSL_EVP_CipherFinal(WOLFSSL_EVP_CIPHER_CTX *ctx,
                                   unsigned char *out, int *outl);
/*!
    \ingroup openSSL
    
    \brief Setter function for WOLFSSL_EVP_CIPHER_CTX structure key length.
    
    \return SSL_SUCCESS If successfully set.
    \return SSL_FAILURE If failed to set key length.
    
    \param ctx structure to set key length.
    \param keylen key length.
    
    _Example_
    \code
    WOLFSSL_EVP_CIPHER_CTX* ctx;
    int keylen;
    // create ctx
    wolfSSL_EVP_CIPHER_CTX_set_key_length(ctx, keylen);
    \endcode
    
    \sa wolfSSL_EVP_CIPHER_flags
*/
WOLFSSL_API int  wolfSSL_EVP_CIPHER_CTX_set_key_length(WOLFSSL_EVP_CIPHER_CTX* ctx,
                                                     int keylen);
/*!
    \ingroup openSSL
    
    \brief This is a getter function for the ctx block size.
    
    \return size Returns ctx->block_size.
    
    \param ctx the cipher ctx to get block size of.
    
    _Example_
    \code
    const WOLFSSL_CVP_CIPHER_CTX* ctx;
    //set up ctx
    printf(“block size = %d\n”, wolfSSL_EVP_CIPHER_CTX_block_size(ctx));
    \endcode
    
    \sa wolfSSL_EVP_CIPHER_block_size
*/
WOLFSSL_API int wolfSSL_EVP_CIPHER_CTX_block_size(const WOLFSSL_EVP_CIPHER_CTX *ctx);
/*!
    \ingroup openSSL
    
    \brief This is a getter function for the block size of cipher.
    
    \return size returns the block size.
    
    \param cipher cipher to get block size of.
    
    _Example_
    \code
    printf(“block size = %d\n”, 
    wolfSSL_EVP_CIPHER_block_size(wolfSSL_EVP_aes_256_ecb()));
    \endcode
    
    \sa wolfSSL_EVP_aes_256_ctr
*/
WOLFSSL_API int wolfSSL_EVP_CIPHER_block_size(const WOLFSSL_EVP_CIPHER *cipher);
/*!
    \ingroup openSSL
    
    \brief Setter function for WOLFSSL_EVP_CIPHER_CTX structure.
    
    \return none No returns.
    
    \param ctx structure to set flag.
    \param flag flag to set in structure.
    
    _Example_
    \code
    WOLFSSL_EVP_CIPHER_CTX* ctx;
    int flag;
    // create ctx
    wolfSSL_EVP_CIPHER_CTX_set_flags(ctx, flag);
    \endcode
    
    \sa wolfSSL_EVP_CIPHER_flags
*/
WOLFSSL_API void wolfSSL_EVP_CIPHER_CTX_set_flags(WOLFSSL_EVP_CIPHER_CTX *ctx, int flags);
/*!
    \ingroup openSSL
    
    \brief Setter function for WOLFSSL_EVP_CIPHER_CTX structure to use padding.
    
    \return SSL_SUCCESS If successfully set.
    \return BAD_FUNC_ARG If null argument passed in.
    
    \param ctx structure to set padding flag.
    \param padding 0 for not setting padding, 1 for setting padding.
    
    _Example_
    \code
    WOLFSSL_EVP_CIPHER_CTX* ctx;
    // create ctx
    wolfSSL_EVP_CIPHER_CTX_set_padding(ctx, 1);
    \endcode
    
    \sa wolfSSL_EVP_CIPHER_flags
*/
WOLFSSL_API int  wolfSSL_EVP_CIPHER_CTX_set_padding(WOLFSSL_EVP_CIPHER_CTX *c, int pad);
