Current Path : /usr/opt/openssl11/share/doc/openssl/html/man3/ |
FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
Current File : //usr/opt/openssl11/share/doc/openssl/html/man3/EVP_PKEY_CTX_set1_tls1_prf_secret.html |
<?xml version="1.0" ?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>EVP_PKEY_CTX_set_tls1_prf_md</title> <meta http-equiv="content-type" content="text/html; charset=utf-8" /> <link rev="made" href="mailto:root@hsxx.drive.ne.jp" /> </head> <body style="background-color: white"> <!-- INDEX BEGIN --> <div name="index"> <p><a name="__index__"></a></p> <ul> <li><a href="#name">NAME</a></li> <li><a href="#synopsis">SYNOPSIS</a></li> <li><a href="#description">DESCRIPTION</a></li> <li><a href="#string_ctrls">STRING CTRLS</a></li> <li><a href="#notes">NOTES</a></li> <li><a href="#return_values">RETURN VALUES</a></li> <li><a href="#examples">EXAMPLES</a></li> <li><a href="#see_also">SEE ALSO</a></li> <li><a href="#copyright">COPYRIGHT</a></li> </ul> <hr name="index" /> </div> <!-- INDEX END --> <p> </p> <hr /> <h1><a name="name">NAME</a></h1> <p>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</p> <p> </p> <hr /> <h1><a name="synopsis">SYNOPSIS</a></h1> <pre> #include <openssl/kdf.h></pre> <pre> 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, unsigned char *seed, int seedlen);</pre> <p> </p> <hr /> <h1><a name="description">DESCRIPTION</a></h1> <p>The <strong>EVP_PKEY_TLS1_PRF</strong> algorithm implements the PRF key derivation function for TLS. It has no associated private key and only implements key derivation using <em>EVP_PKEY_derive(3)</em>.</p> <p>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 <strong>MD5</strong> and <strong>SHA1</strong> as used in TLS 1.0 and 1.1.</p> <p>EVP_PKEY_CTX_set_tls1_prf_secret() sets the secret value of the TLS PRF to <strong>seclen</strong> bytes of the buffer <strong>sec</strong>. Any existing secret value is replaced and any seed is reset.</p> <p>EVP_PKEY_CTX_add1_tls1_prf_seed() sets the seed to <strong>seedlen</strong> bytes of <strong>seed</strong>. If a seed is already set it is appended to the existing value.</p> <p> </p> <hr /> <h1><a name="string_ctrls">STRING CTRLS</a></h1> <p>The TLS PRF also supports string based control operations using <em>EVP_PKEY_CTX_ctrl_str(3)</em>. The <strong>type</strong> parameter "md" uses the supplied <strong>value</strong> as the name of the digest algorithm to use. The <strong>type</strong> parameters "secret" and "seed" use the supplied <strong>value</strong> 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.</p> <p> </p> <hr /> <h1><a name="notes">NOTES</a></h1> <p>All these functions are implemented as macros.</p> <p>A context for the TLS PRF can be obtained by calling:</p> <pre> EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_TLS1_PRF, NULL);</pre> <p>The digest, secret value and seed must be set before a key is derived or an error occurs.</p> <p>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.</p> <p>The output length of the PRF is specified by the length parameter in the <code>EVP_PKEY_derive()</code> function. Since the output length is variable, setting the buffer to <strong>NULL</strong> is not meaningful for the TLS PRF.</p> <p>Optimised versions of the TLS PRF can be implemented in an ENGINE.</p> <p> </p> <hr /> <h1><a name="return_values">RETURN VALUES</a></h1> <p>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.</p> <p> </p> <hr /> <h1><a name="examples">EXAMPLES</a></h1> <p>This example derives 10 bytes using SHA-256 with the secret key "secret" and seed value "seed":</p> <pre> EVP_PKEY_CTX *pctx; unsigned char out[10]; size_t outlen = sizeof(out);</pre> <pre> 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 */</pre> <p> </p> <hr /> <h1><a name="see_also">SEE ALSO</a></h1> <p><em>EVP_PKEY_CTX_new(3)</em>, <em>EVP_PKEY_CTX_ctrl_str(3)</em>, <em>EVP_PKEY_derive(3)</em></p> <p> </p> <hr /> <h1><a name="copyright">COPYRIGHT</a></h1> <p>Copyright 2016-2019 The OpenSSL Project Authors. All Rights Reserved.</p> <p>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 <a href="https://www.openssl.org/source/license.html">https://www.openssl.org/source/license.html</a>.</p> </body> </html>