BIO_f_cipher(3) OpenSSL BIO_f_cipher(3) NNAAMMEE BIO_f_cipher, BIO_set_cipher, BIO_get_cipher_status, BIO_get_cipher_ctx - cipher BIO filter SSYYNNOOPPSSIISS #include #include BIO_METHOD * BIO_f_cipher(void); void BIO_set_cipher(BIO *b,const EVP_CIPHER *cipher, unsigned char *key, unsigned char *iv, int enc); int BIO_get_cipher_status(BIO *b) int BIO_get_cipher_ctx(BIO *b, EVP_CIPHER_CTX **pctx) DDEESSCCRRIIPPTTIIOONN _B_I_O___f___c_i_p_h_e_r_(_) returns the cipher BIO method. This is a filter BIO that encrypts any data written through it, and decrypts any data read from it. It is a BIO wrapper for the cipher routines _E_V_P___C_i_p_h_e_r_I_n_i_t_(_), _E_V_P___C_i_p_h_e_r_U_p_d_a_t_e_(_) and _E_V_P___C_i_p_h_e_r_F_i_n_a_l_(_). Cipher BIOs do not support _B_I_O___g_e_t_s_(_) or _B_I_O___p_u_t_s_(_). _B_I_O___f_l_u_s_h_(_) on an encryption BIO that is being written through is used to signal that no more data is to be encrypted: this is used to flush and possibly pad the final block through the BIO. _B_I_O___s_e_t___c_i_p_h_e_r_(_) sets the cipher of BIO bb to cciipphheerr using key kkeeyy and IV iivv. eenncc should be set to 1 for encryption and zero for decryption. When reading from an encryption BIO the final block is automatically decrypted and checked when EOF is detected. _B_I_O___g_e_t___c_i_p_h_e_r___s_t_a_t_u_s_(_) is a _B_I_O___c_t_r_l_(_) macro which can be called to determine whether the decryp- tion operation was successful. _B_I_O___g_e_t___c_i_p_h_e_r___c_t_x_(_) is a _B_I_O___c_t_r_l_(_) macro which retrieves the internal BIO cipher context. The retrieved context can be used in conjunction with the standard cipher routines to set it up. This is useful when _B_I_O___s_e_t___c_i_p_h_e_r_(_) is not flexible enough for the applications needs. NNOOTTEESS When encrypting _B_I_O___f_l_u_s_h_(_) mmuusstt be called to flush the final block through the BIO. If it is not then the final block will fail a subse- quent decrypt. When decrypting an error on the final block is signalled by a zero return value from the read operation. A successful decrypt followed by EOF will also return zero for the final read. _B_I_O___g_e_t___c_i_p_h_e_r___s_t_a_t_u_s_(_) should be called to determine if the decrypt was successful. As always, if _B_I_O___g_e_t_s_(_) or _B_I_O___p_u_t_s_(_) support is needed then it can be achieved by preceding the cipher BIO with a buffering BIO. RREETTUURRNN VVAALLUUEESS _B_I_O___f___c_i_p_h_e_r_(_) returns the cipher BIO method. _B_I_O___s_e_t___c_i_p_h_e_r_(_) does not return a value. _B_I_O___g_e_t___c_i_p_h_e_r___s_t_a_t_u_s_(_) returns 1 for a successful decrypt and 0 for failure. _B_I_O___g_e_t___c_i_p_h_e_r___c_t_x_(_) currently always returns 1. EEXXAAMMPPLLEESS TBA SSEEEE AALLSSOO TBA 1.0.2u 2019-12-20 BIO_f_cipher(3)