diff options
Diffstat (limited to 'doc')
-rw-r--r-- | doc/man3/EVP_KDF_CTX.pod | 1 | ||||
-rw-r--r-- | doc/man7/EVP_KDF_X963.pod | 136 |
2 files changed, 137 insertions, 0 deletions
diff --git a/doc/man3/EVP_KDF_CTX.pod b/doc/man3/EVP_KDF_CTX.pod index 2bdefc668a..342807fa14 100644 --- a/doc/man3/EVP_KDF_CTX.pod +++ b/doc/man3/EVP_KDF_CTX.pod @@ -277,6 +277,7 @@ L<EVP_KDF_PBKDF2(7)> L<EVP_KDF_HKDF(7)> L<EVP_KDF_SS(7)> L<EVP_KDF_SSHKDF(7)> +L<EVP_KDF_X963(7)> =head1 HISTORY diff --git a/doc/man7/EVP_KDF_X963.pod b/doc/man7/EVP_KDF_X963.pod new file mode 100644 index 0000000000..11789ae5aa --- /dev/null +++ b/doc/man7/EVP_KDF_X963.pod @@ -0,0 +1,136 @@ +=pod + +=head1 NAME + +EVP_KDF_X963 - The X9.63-2001 EVP_KDF implementation + +=head1 DESCRIPTION + +The EVP_KDF_X963 algorithm implements the key derivation function (X963KDF). +X963KDF is used by Cryptographic Message Syntax (CMS) for EC KeyAgreement, to +derive a key using input such as a shared secret key and shared info. + +=head2 Numeric identity + +B<EVP_KDF_X963> is the numeric identity for this implementation; it +can be used with the EVP_KDF_CTX_new_id() function. + +=head2 Supported controls + +The supported controls are: + +=over 4 + +=item B<EVP_KDF_CTRL_SET_MD> + +This control works as described in L<EVP_KDF_CTX(3)/CONTROLS>. + +=item B<EVP_KDF_CTRL_SET_KEY> + +This control expects two arguments: C<unsigned char *secret>, C<size_t secretlen> + +The shared secret used for key derivation. This control sets the secret. + +EVP_KDF_ctrl_str() takes two type strings for this control: + +=over 4 + +=item "secret" + +The value string is used as is. + +=item "hexsecret" + +The value string is expected to be a hexadecimal number, which will be +decoded before being passed on as the control value. + +=back + +=item B<EVP_KDF_CTRL_SET_SHARED_INFO> + +This control expects two arguments: C<unsigned char *info>, C<size_t infolen> + +An optional value for shared info. This control sets the shared info. + +EVP_KDF_ctrl_str() takes two type strings for this control: + +=over 4 + +=item "info" + +The value string is used as is. + +=item "hexinfo" + +The value string is expected to be a hexadecimal number, which will be +decoded before being passed on as the control value. + +=back + +=back + +=head1 NOTES + +X963KDF is very similar to the SSKDF that uses a digest as the auxilary function, +X963KDF appends the counter to the secret, whereas SSKDF prepends the counter. + +A context for X963KDF can be obtained by calling: + +EVP_KDF_CTX *kctx = EVP_KDF_CTX_new_id(EVP_KDF_X963); + +The output length of an X963KDF is specified via the C<keylen> +parameter to the L<EVP_KDF_derive(3)> function. + +=head1 EXAMPLE + +This example derives 10 bytes, with the secret key "secret" and sharedinfo +value "label": + + EVP_KDF_CTX *kctx; + unsigned char out[10]; + + kctx = EVP_KDF_CTX_new_id(EVP_KDF_X963); + + if (EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_MD, EVP_sha256()) <= 0) { + error("EVP_KDF_CTRL_SET_MD"); + } + if (EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_KEY, "secret", (size_t)6) <= 0) { + error("EVP_KDF_CTRL_SET_KEY"); + } + if (EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_SHARED_INFO, "label", (size_t)5) <= 0) { + error("EVP_KDF_CTRL_SET_SHARED_INFO"); + } + if (EVP_KDF_derive(kctx, out, sizeof(out)) <= 0) { + error("EVP_KDF_derive"); + } + + EVP_KDF_CTX_free(kctx); + +=head1 CONFORMING TO + +"SEC 1: Elliptic Curve Cryptography" + +=head1 SEE ALSO + +L<EVP_KDF_CTX>, +L<EVP_KDF_CTX_new_id(3)>, +L<EVP_KDF_CTX_free(3)>, +L<EVP_KDF_ctrl(3)>, +L<EVP_KDF_size(3)>, +L<EVP_KDF_derive(3)>, +L<EVP_KDF_CTX(3)/CONTROLS> + +=head1 HISTORY + +This functionality was added to OpenSSL 3.0.0. + +=head1 COPYRIGHT + +Copyright 2019 The OpenSSL Project Authors. All Rights Reserved. + +Licensed under the Apache License 2.0 (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 |