EVP_OpenInit
Section: OpenSSL (3)
Updated: 2017-05-25
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NAME
EVP_OpenInit, EVP_OpenUpdate, EVP_OpenFinal - EVP envelope decryption
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);
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.
EVP_OpenInit() initializes a cipher context ctx for decryption
with cipher type. It decrypts the encrypted symmetric key of length
ekl bytes passed in the ek parameter using the private key priv.
The IV is supplied in the iv parameter.
EVP_OpenUpdate() and EVP_OpenFinal() have exactly the same properties
as the EVP_DecryptUpdate() and EVP_DecryptFinal() routines, as
documented on the EVP_EncryptInit(3) manual
page.
NOTES
It is possible to call
EVP_OpenInit() twice in the same way as
EVP_DecryptInit(). The first call should have
priv set to
NULL
and (after setting any cipher parameters) it should be called again
with
type set to
NULL.
If the cipher passed in the type 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
EVP_OpenInit() returns 0 on error or a non zero integer (actually the
recovered secret key size) if successful.
EVP_OpenUpdate() returns 1 for success or 0 for failure.
EVP_OpenFinal() returns 0 if the decrypt failed or 1 for success.
SEE ALSO
evp(3),
rand(3),
EVP_EncryptInit(3),
EVP_SealInit(3)
HISTORY
Index
- NAME
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- SYNOPSIS
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- DESCRIPTION
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- NOTES
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- RETURN VALUES
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- SEE ALSO
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- HISTORY
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