/usr/man/cat.3/EVP_OpenInit.3(/usr/man/cat.3/EVP_OpenInit.3)

EVP_OpenInit(3)              OpenSSL              EVP_OpenInit(3)

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.

1.0.2t               Last change: 2019-09-10                    1

EVP_OpenInit(3)              OpenSSL              EVP_OpenInit(3)

SEE ALSO

     evp(3), rand(3), EVP_EncryptInit(3), EVP_SealInit(3)

HISTORY

1.0.2t               Last change: 2019-09-10                    2

See also EVP_OpenFinal(3)
See also EVP_OpenUpdate(3)