openssl/doc/crypto/EVP_OpenInit.pod
2000-03-08 01:48:12 +00:00

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=pod
=head1 NAME
EVP_OpenInit, EVP_OpenUpdate, EVP_OpenFinal - EVP envelope decryption
=head1 SYNOPSIS
#include <openssl/evp.h>
int EVP_OpenInit(EVP_CIPHER_CTX *ctx,EVP_CIPHER *type,unsigned char *ek,
int ekl,unsigned char *iv,EVP_PKEY *priv);
void EVP_OpenUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out,
int *outl, unsigned char *in, int inl);
void EVP_OpenFinal(EVP_CIPHER_CTX *ctx, unsigned char *out,
int *outl);
=head1 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.
EVP_OpenInit() initialises a cipher context B<ctx> for decryption
with cipher B<type>. It decrypts the encrypted symmetric key of length
B<ekl> bytes passed in the B<ek> parameter using the private key B<priv>.
The IV is supplied in the B<iv> parameter.
EVP_OpenUpdate() and EVP_OpenFinal() have exactly the same properties
as the EVP_DecryptUpdate() and EVP_DecryptFinal() routines, as
documented on the L<EVP_EncryptInit(3)|EVP_EncryptInit(3)> manual
page.
=head1 RETURN VALUES
EVP_OpenInit() returns -1 on error or an non zero integer (actually the
recovered secret key size) if successful.
EVP_SealUpdate() does not return a value.
EVP_SealFinal() returns 0 if the decrypt failed or 1 for success.
=head1 SEE ALSO
L<evp(3)|evp(3)>,L<rand(3)|rand(3)>
L<EVP_EncryptInit(3)|EVP_EncryptInit(3)>,
L<EVP_SealInit(3)|EVP_SealInit(3)>
=head1 HISTORY
=cut