#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)
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 decryption 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.
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.
_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.