EVP_KDF-TLS13_KDF - Online Linux Manual PageSection : 7ossl
Updated : 2023-03-21
Source : 3.0.8
Note : OpenSSL
NAMEEVP_KDF−TLS13_KDF − The TLS 1.3 EVP_KDF implementation
DESCRIPTIONSupport for computing the TLS 1.3 version of the HKDF KDF through the EVP_KDF API. The EVP_KDF−TLS13_KDF algorithm implements the HKDF key derivation function as used by TLS 1.3.
Identity"TLS13−KDF" is the name for this implementation; it can be used with the EVP_KDF_fetch() function.
Supported parametersThe supported parameters are: .IP """properties"" (OSSL_KDF_PARAM_PROPERTIES) <UTF8 string>" 4 .IP """digest"" (OSSL_KDF_PARAM_DIGEST) <UTF8 string>" 4 .IP """key"" (OSSL_KDF_PARAM_KEY) <octet string>" 4 .IP """salt"" (OSSL_KDF_PARAM_SALT) <octet string>" 4 These parameters work as described in "PARAMETERS" in EVP_KDF (3). .IP """prefix"" (OSSL_KDF_PARAM_PREFIX) <octet string>" 4 This parameter sets the label prefix on the specified TLS 1.3 KDF context. For TLS 1.3 this should be set to the ASCII string "tls13 " without a trailing zero byte. Refer to RFC 8446 section 7.1 "Key Schedule" for details. .IP """label"" (OSSL_KDF_PARAM_LABEL) <octet string>" 4 This parameter sets the label on the specified TLS 1.3 KDF context. Refer to RFC 8446 section 7.1 "Key Schedule" for details. .IP """data"" (OSSL_KDF_PARAM_DATA) <octet string>" 4 This parameter sets the context data on the specified TLS 1.3 KDF context. Refer to RFC 8446 section 7.1 "Key Schedule" for details. .IP """mode"" (OSSL_KDF_PARAM_MODE) <UTF8 string> or <integer>" 4 This parameter sets the mode for the TLS 1.3 KDF operation. There are two modes that are currently defined: .IP """EXTRACT_ONLY"" or EVP_KDF_HKDF_MODE_EXTRACT_ONLY" 4 In this mode calling EVP_KDF_derive (3) will just perform the extract operation. The value returned will be the intermediate fixed-length pseudorandom key K. The keylen parameter must match the size of K, which can be looked up by calling EVP_KDF_CTX_get_kdf_size() after setting the mode and digest. The digest, key and salt values must be set before a key is derived otherwise an error will occur. .IP """EXPAND_ONLY"" or EVP_KDF_HKDF_MODE_EXPAND_ONLY" 4 In this mode calling EVP_KDF_derive (3) will just perform the expand operation. The input key should be set to the intermediate fixed-length pseudorandom key K returned from a previous extract operation. The digest, key and info values must be set before a key is derived otherwise an error will occur.
NOTESThis KDF is intended for use by the TLS 1.3 implementation in libssl. It does not support all the options and capabilities that HKDF does. The OSSL_PARAM array passed to EVP_KDF_derive (3) or ​EVP_KDF_CTX_set_params (3) must specify all of the parameters required. This KDF does not support a piecemeal approach to providing these. A context for a TLS 1.3 KDF can be obtained by calling: ​ EVP_KDF *kdf = EVP_KDF_fetch(NULL, "TLS13−KDF", NULL); ​ EVP_KDF_CTX *kctx = EVP_KDF_CTX_new(kdf); The output length of a TLS 1.3 KDF expand operation is specified via the ​keylen parameter to the EVP_KDF_derive (3) function. When using EVP_KDF_HKDF_MODE_EXTRACT_ONLY the keylen parameter must equal the size of the intermediate fixed-length pseudorandom key otherwise an error will occur. For that mode, the fixed output size can be looked up by calling ​EVP_KDF_CTX_get_kdf_size() after setting the mode and digest on the ​EVP_KDF_CTX.
CONFORMING TORFC 8446
SEE ALSO​EVP_KDF (3), ​EVP_KDF_CTX_new (3), ​EVP_KDF_CTX_free (3), ​EVP_KDF_CTX_get_kdf_size (3), ​EVP_KDF_CTX_set_params (3), ​EVP_KDF_derive (3), "PARAMETERS" in EVP_KDF (3), ​EVP_KDF−HKDF (7)
HISTORYThis functionality was added in OpenSSL 3.0.
COPYRIGHTCopyright 2021 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 <https://www.openssl.org/source/license.html>. 0
Johanes Gumabo
Data Size   :   14,400 byte
man-EVP_KDF-TLS13_KDF.7osslBuild   :   2024-12-29, 07:25   :  
Visitor Screen   :   x
Visitor Counter ( page / site )   :   5 / 256,312
Visitor ID   :     :  
Visitor IP   :   18.189.186.5   :  
Visitor Provider   :   AMAZON-02   :  
Provider Position ( lat x lon )   :   39.962500 x -83.006100   :   x
Provider Accuracy Radius ( km )   :   1000   :  
Provider City   :   Columbus   :  
Provider Province   :   Ohio ,   :   ,
Provider Country   :   United States   :  
Provider Continent   :   North America   :  
Visitor Recorder   :   Version   :  
Visitor Recorder   :   Library   :  
Online Linux Manual Page   :   Version   :   Online Linux Manual Page - Fedora.40 - march=x86-64 - mtune=generic - 24.12.29
Online Linux Manual Page   :   Library   :   lib_c - 24.10.03 - march=x86-64 - mtune=generic - Fedora.40
Online Linux Manual Page   :   Library   :   lib_m - 24.10.03 - march=x86-64 - mtune=generic - Fedora.40
Data Base   :   Version   :   Online Linux Manual Page Database - 24.04.13 - march=x86-64 - mtune=generic - fedora-38
Data Base   :   Library   :   lib_c - 23.02.07 - march=x86-64 - mtune=generic - fedora.36
Very long time ago, I have the best tutor, Wenzel Svojanovsky . If someone knows the email address of Wenzel Svojanovsky , please send an email to johanes_gumabo@yahoo.co.id .
If error, please print screen and send to johanes_gumabo@yahoo.co.id
Under development. Support me via PayPal.
ERROR : Need New Coding :         (parse_manual_page_|252|EVP_KDF-TLS13_KDF.7ossl|24/25|el══─{─══.|.el══─{─══. ds C` )         (htmlprn|149|EVP_KDF-TLS13_KDF.7ossl|24/25|.el══─{─══. ds C` |.el══─{─══. ds C` )         (parse_manual_page_|252|EVP_KDF-TLS13_KDF.7ossl|27|br══─}─══|'br══─}─══ )         (htmlprn|149|EVP_KDF-TLS13_KDF.7ossl|27|'br══─}─══ |'br══─}─══ )         (rof_IP|5|EVP_KDF-TLS13_KDF.7ossl|79|5|.IP """properties"" (\fBOSSL_KDF_PARAM_PROPERTIES\fR) " 4 )         (rof_IP|5|EVP_KDF-TLS13_KDF.7ossl|82|5|.IP """digest"" (\fBOSSL_KDF_PARAM_DIGEST\fR) " 4 )         (rof_IP|5|EVP_KDF-TLS13_KDF.7ossl|84|5|.IP """key"" (\fBOSSL_KDF_PARAM_KEY\fR) " 4 )         (rof_IP|5|EVP_KDF-TLS13_KDF.7ossl|86|5|.IP """salt"" (\fBOSSL_KDF_PARAM_SALT\fR) " 4 )         (rof_IP|5|EVP_KDF-TLS13_KDF.7ossl|90|5|.IP """prefix"" (\fBOSSL_KDF_PARAM_PREFIX\fR) " 4 )         (rof_IP|5|EVP_KDF-TLS13_KDF.7ossl|95|5|.IP """label"" (\fBOSSL_KDF_PARAM_LABEL\fR) " 4 )         (rof_IP|5|EVP_KDF-TLS13_KDF.7ossl|99|5|.IP """data"" (\fBOSSL_KDF_PARAM_DATA\fR) " 4 )         (rof_IP|5|EVP_KDF-TLS13_KDF.7ossl|103|5|.IP """mode"" (\fBOSSL_KDF_PARAM_MODE\fR) or " 4 )         (rof_IP|5|EVP_KDF-TLS13_KDF.7ossl|108|5|.IP """EXTRACT_ONLY"" or \fBEVP_KDF_HKDF_MODE_EXTRACT_ONLY\fR" 4 )         (rof_IP|5|EVP_KDF-TLS13_KDF.7ossl|117|5|.IP """EXPAND_ONLY"" or \fBEVP_KDF_HKDF_MODE_EXPAND_ONLY\fR" 4 )