EVP_OpenInit

EVP_OpenInit, EVP_OpenUpdate, EVP_OpenFinal ? EVP envelope decryption

 #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);

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 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.

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.

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