mirror of
https://github.com/nillerusr/source-engine.git
synced 2024-12-28 09:03:01 +00:00
94 lines
2.6 KiB
Plaintext
94 lines
2.6 KiB
Plaintext
=pod
|
|
|
|
=head1 NAME
|
|
|
|
EVP_PKEY_decrypt_init, EVP_PKEY_decrypt - decrypt using a public key algorithm
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
#include <openssl/evp.h>
|
|
|
|
int EVP_PKEY_decrypt_init(EVP_PKEY_CTX *ctx);
|
|
int EVP_PKEY_decrypt(EVP_PKEY_CTX *ctx,
|
|
unsigned char *out, size_t *outlen,
|
|
const unsigned char *in, size_t inlen);
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
The EVP_PKEY_decrypt_init() function initializes a public key algorithm
|
|
context using key B<pkey> for a decryption operation.
|
|
|
|
The EVP_PKEY_decrypt() function performs a public key decryption operation
|
|
using B<ctx>. The data to be decrypted is specified using the B<in> and
|
|
B<inlen> parameters. If B<out> is B<NULL> then the maximum size of the output
|
|
buffer is written to the B<outlen> parameter. If B<out> is not B<NULL> then
|
|
before the call the B<outlen> parameter should contain the length of the
|
|
B<out> buffer, if the call is successful the decrypted data is written to
|
|
B<out> and the amount of data written to B<outlen>.
|
|
|
|
=head1 NOTES
|
|
|
|
After the call to EVP_PKEY_decrypt_init() algorithm specific control
|
|
operations can be performed to set any appropriate parameters for the
|
|
operation.
|
|
|
|
The function EVP_PKEY_decrypt() can be called more than once on the same
|
|
context if several operations are performed using the same parameters.
|
|
|
|
=head1 RETURN VALUES
|
|
|
|
EVP_PKEY_decrypt_init() and EVP_PKEY_decrypt() return 1 for success and 0
|
|
or a negative value for failure. In particular a return value of -2
|
|
indicates the operation is not supported by the public key algorithm.
|
|
|
|
=head1 EXAMPLE
|
|
|
|
Decrypt data using OAEP (for RSA keys):
|
|
|
|
#include <openssl/evp.h>
|
|
#include <openssl/rsa.h>
|
|
|
|
EVP_PKEY_CTX *ctx;
|
|
unsigned char *out, *in;
|
|
size_t outlen, inlen;
|
|
EVP_PKEY *key;
|
|
/* NB: assumes key in, inlen are already set up
|
|
* and that key is an RSA private key
|
|
*/
|
|
ctx = EVP_PKEY_CTX_new(key);
|
|
if (!ctx)
|
|
/* Error occurred */
|
|
if (EVP_PKEY_decrypt_init(ctx) <= 0)
|
|
/* Error */
|
|
if (EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_OAEP_PADDING) <= 0)
|
|
/* Error */
|
|
|
|
/* Determine buffer length */
|
|
if (EVP_PKEY_decrypt(ctx, NULL, &outlen, in, inlen) <= 0)
|
|
/* Error */
|
|
|
|
out = OPENSSL_malloc(outlen);
|
|
|
|
if (!out)
|
|
/* malloc failure */
|
|
|
|
if (EVP_PKEY_decrypt(ctx, out, &outlen, in, inlen) <= 0)
|
|
/* Error */
|
|
|
|
/* Decrypted data is outlen bytes written to buffer out */
|
|
|
|
=head1 SEE ALSO
|
|
|
|
L<EVP_PKEY_CTX_new(3)|EVP_PKEY_CTX_new(3)>,
|
|
L<EVP_PKEY_encrypt(3)|EVP_PKEY_encrypt(3)>,
|
|
L<EVP_PKEY_sign(3)|EVP_PKEY_sign(3)>,
|
|
L<EVP_PKEY_verify(3)|EVP_PKEY_verify(3)>,
|
|
L<EVP_PKEY_verify_recover(3)|EVP_PKEY_verify_recover(3)>,
|
|
L<EVP_PKEY_derive(3)|EVP_PKEY_derive(3)>
|
|
|
|
=head1 HISTORY
|
|
|
|
These functions were first added to OpenSSL 1.0.0.
|
|
|
|
=cut
|