diff options
author | Andrea Grandi <andrea.grandi@intel.com> | 2016-10-18 10:26:38 +0100 |
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committer | Matt Caswell <matt@openssl.org> | 2016-10-19 10:30:30 +0100 |
commit | be118c3d574d340031ef3ad1fbffa171fdfee580 (patch) | |
tree | 7a871839d99d55a92dea1781a8108573765e18df /doc/crypto/EVP_PKEY_CTX_set_tls1_prf_md.pod | |
parent | e97afdad659b6523a8f172097bf4f10ca2ce0867 (diff) |
Add missing .pod extension to EVP_PKEY_CTX_set_tls1_prf_md
Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit efba60ca7ab72cae62baad2aaaf2da32d1093c38)
Diffstat (limited to 'doc/crypto/EVP_PKEY_CTX_set_tls1_prf_md.pod')
-rw-r--r-- | doc/crypto/EVP_PKEY_CTX_set_tls1_prf_md.pod | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/doc/crypto/EVP_PKEY_CTX_set_tls1_prf_md.pod b/doc/crypto/EVP_PKEY_CTX_set_tls1_prf_md.pod new file mode 100644 index 0000000000..0d57f9fb6a --- /dev/null +++ b/doc/crypto/EVP_PKEY_CTX_set_tls1_prf_md.pod @@ -0,0 +1,108 @@ +=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 |