+++ /dev/null
-=pod
-
-=head1 NAME
-
-EVP_SealInit, EVP_SealUpdate, EVP_SealFinal - EVP envelope encryption
-
-=head1 SYNOPSIS
-
- #include <openssl/evp.h>
-
- int EVP_SealInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *type,
- unsigned char **ek, int *ekl, unsigned char *iv,
- EVP_PKEY **pubk, int npubk);
- int EVP_SealUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out,
- int *outl, unsigned char *in, int inl);
- int EVP_SealFinal(EVP_CIPHER_CTX *ctx, unsigned char *out,
- int *outl);
-
-=head1 DESCRIPTION
-
-The EVP envelope routines are a high level interface to envelope
-encryption. They generate a random key and IV (if required) then
-"envelope" it by using public key encryption. Data can then be
-encrypted using this key.
-
-EVP_SealInit() initializes a cipher context B<ctx> for encryption
-with cipher B<type> using a random secret key and IV. B<type> is normally
-supplied by a function such as EVP_aes_256_cbc(). The secret key is encrypted
-using one or more public keys, this allows the same encrypted data to be
-decrypted using any of the corresponding private keys. B<ek> is an array of
-buffers where the public key encrypted secret key will be written, each buffer
-must contain enough room for the corresponding encrypted key: that is
-B<ek[i]> must have room for B<EVP_PKEY_size(pubk[i])> bytes. The actual
-size of each encrypted secret key is written to the array B<ekl>. B<pubk> is
-an array of B<npubk> public keys.
-
-The B<iv> parameter is a buffer where the generated IV is written to. It must
-contain enough room for the corresponding cipher's IV, as determined by (for
-example) EVP_CIPHER_iv_length(type).
-
-If the cipher does not require an IV then the B<iv> parameter is ignored
-and can be B<NULL>.
-
-EVP_SealUpdate() and EVP_SealFinal() have exactly the same properties
-as the EVP_EncryptUpdate() and EVP_EncryptFinal() routines, as
-documented on the L<EVP_EncryptInit(3)> manual
-page.
-
-=head1 RETURN VALUES
-
-EVP_SealInit() returns 0 on error or B<npubk> if successful.
-
-EVP_SealUpdate() and EVP_SealFinal() return 1 for success and 0 for
-failure.
-
-=head1 NOTES
-
-Because a random secret key is generated the random number generator
-must be seeded before calling EVP_SealInit().
-
-The public key must be RSA because it is the only OpenSSL public key
-algorithm that supports key transport.
-
-Envelope encryption is the usual method of using public key encryption
-on large amounts of data, this is because public key encryption is slow
-but symmetric encryption is fast. So symmetric encryption is used for
-bulk encryption and the small random symmetric key used is transferred
-using public key encryption.
-
-It is possible to call EVP_SealInit() twice in the same way as
-EVP_EncryptInit(). The first call should have B<npubk> set to 0
-and (after setting any cipher parameters) it should be called again
-with B<type> set to NULL.
-
-=head1 SEE ALSO
-
-L<evp(3)>, L<rand(3)>,
-L<EVP_EncryptInit(3)>,
-L<EVP_OpenInit(3)>
-
-=head1 COPYRIGHT
-
-Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
-
-Licensed under the OpenSSL license (the "License"). You may not use
-this file except in compliance with the License. You can obtain a copy
-in the file LICENSE in the source distribution or at
-L<https://www.openssl.org/source/license.html>.
-
-=cut
projects / openssl.git / blobdiff