91da5e7710
Function-like macros are replaced with prototypes and a note that they are implemented as macros. Constants are just referenced in-line in the text. Tweak BIO_TYPE_... documentation. Also fix RT4592. Reviewed-by: Matt Caswell <matt@openssl.org>
108 lines
3.5 KiB
Text
108 lines
3.5 KiB
Text
=pod
|
|
|
|
=head1 NAME
|
|
|
|
EVP_PKEY_CTX_set_tls1_prf_md,
|
|
EVP_PKEY_CTX_set1_tls1_prf_secret, EVP_PKEY_CTX_add1_tls1_prf_seed -
|
|
TLS PRF key derivation algorithm
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
#include <openssl/kdf.h>
|
|
|
|
int EVP_PKEY_CTX_set_tls1_prf_md(EVP_PKEY_CTX *pctx, const EVP_MD *md);
|
|
int EVP_PKEY_CTX_set1_tls1_prf_secret(EVP_PKEY_CTX *pctx,
|
|
unsigned char *sec, int seclen);
|
|
int EVP_PKEY_CTX_add1_tls1_prf_seed(EVP_PKEY_CTX *pctx, seed, seedlen)
|
|
unsigned char *seed, int seedlen);
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
The B<EVP_PKEY_TLS1_PRF> algorithm implements the PRF key derivation function for
|
|
TLS. It has no associated private key and only implements key derivation
|
|
using EVP_PKEY_derive().
|
|
|
|
EVP_PKEY_set_tls1_prf_md() sets the message digest associated with the
|
|
TLS PRF. EVP_md5_sha1() is treated as a special case which uses the PRF
|
|
algorithm using both B<MD5> and B<SHA1> as used in TLS 1.0 and 1.1.
|
|
|
|
EVP_PKEY_CTX_set_tls1_prf_secret() sets the secret value of the TLS PRF
|
|
to B<seclen> bytes of the buffer B<sec>. Any existing secret value is replaced
|
|
and any seed is reset.
|
|
|
|
EVP_PKEY_CTX_add1_tls1_prf_seed() sets the seed to B<seedlen> bytes of B<seed>.
|
|
If a seed is already set it is appended to the existing value.
|
|
|
|
=head1 STRING CTRLS
|
|
|
|
The TLS PRF also supports string based control operations using
|
|
L<EVP_PKEY_CTX_ctrl_str(3)>.
|
|
The B<type> parameter "md" uses the supplied B<value> as the name of the digest
|
|
algorithm to use.
|
|
The B<type> parameters "secret" and "seed" use the supplied B<value> parameter
|
|
as a secret or seed value.
|
|
The names "hexsecret" and "hexseed" are similar except they take a hex string
|
|
which is converted to binary.
|
|
|
|
=head1 NOTES
|
|
|
|
All these functions are implemented as macros.
|
|
|
|
A context for the TLS PRF can be obtained by calling:
|
|
|
|
EVP_PKEY_CTX *pctx = EVP_PKEY_new_id(EVP_PKEY_TLS1_PRF, NULL);
|
|
|
|
The digest, secret value and seed must be set before a key is derived or an
|
|
error occurs.
|
|
|
|
The total length of all seeds cannot exceed 1024 bytes in length: this should
|
|
be more than enough for any normal use of the TLS PRF.
|
|
|
|
The output length of the PRF is specified by the length parameter in the
|
|
EVP_PKEY_derive() function. Since the output length is variable, setting
|
|
the buffer to B<NULL> is not meaningful for the TLS PRF.
|
|
|
|
Optimised versions of the TLS PRF can be implemented in an ENGINE.
|
|
|
|
=head1 RETURN VALUES
|
|
|
|
All these functions 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
|
|
|
|
This example derives 10 bytes using SHA-256 with the secret key "secret"
|
|
and seed value "seed":
|
|
|
|
EVP_PKEY_CTX *pctx;
|
|
unsigned char out[10];
|
|
size_t outlen = sizeof(out);
|
|
pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_TLS1_PRF, NULL);
|
|
if (EVP_PKEY_derive_init(pctx) <= 0)
|
|
/* Error */
|
|
if (EVP_PKEY_CTX_set_tls1_prf_md(pctx, EVP_sha256()) <= 0)
|
|
/* Error */
|
|
if (EVP_PKEY_CTX_set1_tls1_prf_secret(pctx, "secret", 6) <= 0)
|
|
/* Error */
|
|
if (EVP_PKEY_CTX_add1_tls1_prf_seed(pctx, "seed", 4) <= 0)
|
|
/* Error */
|
|
if (EVP_PKEY_derive(pctx, out, &outlen) <= 0)
|
|
/* Error */
|
|
|
|
=head1 SEE ALSO
|
|
|
|
L<EVP_PKEY_CTX_new(3)>,
|
|
L<EVP_PKEY_CTX_ctrl_str(3)>,
|
|
L<EVP_PKEY_derive(3)>
|
|
|
|
=head1 COPYRIGHT
|
|
|
|
Copyright 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
|