EVP_OpenInit 3 2001-04-12 0.9.9-dev OpenSSL

NAME

EVP_OpenInit, EVP_OpenUpdate, EVP_OpenFinal - EVP envelope decryption

LIBRARY

libcrypto, -lcrypto

SYNOPSIS


 #include 







 int EVP_OpenInit(EVP_CIPHER_CTX *ctx,EVP_CIPHER *type,unsigned char *ek,
                int ekl,unsigned char *iv,EVP_PKEY *priv);
 int EVP_OpenUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out,
         int *outl, unsigned char *in, int inl);
 int EVP_OpenFinal(EVP_CIPHER_CTX *ctx, unsigned char *out,
         int *outl);

DESCRIPTION

The EVP envelope routines are a high level interface to envelope decryption. They decrypt a public key encrypted symmetric key and then decrypt data using it.

_E_V_P___O_p_e_n_I_n_i_t_(_) initializes a cipher context ccttxx for decryption with cipher ttyyppee. It decrypts the encrypted symmetric key of length eekkll bytes passed in the eekk parameter using the private key pprriivv. The IV is supplied in the iivv parameter.

_E_V_P___O_p_e_n_U_p_d_a_t_e_(_) and _E_V_P___O_p_e_n_F_i_n_a_l_(_) have exactly the same properties as the _E_V_P___D_e_c_r_y_p_t_U_p_d_a_t_e_(_) and _E_V_P___D_e_c_r_y_p_t_F_i_n_a_l_(_) routines, as documented on the _E_V_P___E_n_c_r_y_p_t_I_n_i_t(3) manual page.

NOTES

It is possible to call _E_V_P___O_p_e_n_I_n_i_t_(_) twice in the same way as _E_V_P___D_e_c_r_y_p_t_I_n_i_t_(_). The first call should have pprriivv set to NULL and (after setting any cipher parameters) it should be called again with ttyyppee set to NULL.

If the cipher passed in the ttyyppee parameter is a variable length cipher then the key length will be set to the value of the recovered key length. If the cipher is a fixed length cipher then the recovered key length must match the fixed cipher length.

RETURN VALUES

_E_V_P___O_p_e_n_I_n_i_t_(_) returns 0 on error or a non zero integer (actually the recovered secret key size) if successful.

_E_V_P___O_p_e_n_U_p_d_a_t_e_(_) returns 1 for success or 0 for failure.

_E_V_P___O_p_e_n_F_i_n_a_l_(_) returns 0 if the decrypt failed or 1 for success.

SEE ALSO

_o_p_e_n_s_s_l___e_v_p(3), _o_p_e_n_s_s_l___r_a_n_d(3), _E_V_P___E_n_c_r_y_p_t_I_n_i_t(3), _E_V_P___S_e_a_l_I_n_i_t(3)

HISTORY