name : DH_check_params.3 .\" Automatically generated by Pod::Man 4.11 (Pod::Simple 3.35) .\" .\" Standard preamble: .\" ======================================================================== .de Sp \" Vertical space (when we can't use .PP) .if t .sp .5v .if n .sp .. .de Vb \" Begin verbatim text .ft CW .nf .ne \\$1 .. .de Ve \" End verbatim text .ft R .fi .. .\" Set up some character translations and predefined strings. \*(-- will .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left .\" double quote, and \*(R" will give a right double quote. \*(C+ will .\" give a nicer C++. Capital omega is used to do unbreakable dashes and .\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff, .\" nothing in troff, for use with C<>. .tr \(*W- .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p' .ie n \{\ . ds -- \(*W- . ds PI pi . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch . ds L" "" . ds R" "" . ds C` "" . ds C' "" 'br\} .el\{\ . ds -- \|\(em\| . ds PI \(*p . ds L" `` . ds R" '' . ds C` . ds C' 'br\} .\" .\" Escape single quotes in literal strings from groff's Unicode transform. .ie \n(.g .ds Aq \(aq .el .ds Aq ' .\" .\" If the F register is >0, we'll generate index entries on stderr for .\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index .\" entries marked with X<> in POD. Of course, you'll have to process the .\" output yourself in some meaningful fashion. .\" .\" Avoid warning from groff about undefined register 'F'. .de IX .. .nr rF 0 .if \n(.g .if rF .nr rF 1 .if (\n(rF:(\n(.g==0)) \{\ . if \nF \{\ . de IX . tm Index:\\$1\t\\n%\t"\\$2" .. . if !\nF==2 \{\ . nr % 0 . nr F 2 . \} . \} .\} .rr rF .\" .\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2). .\" Fear. Run. Save yourself. No user-serviceable parts. . \" fudge factors for nroff and troff .if n \{\ . ds #H 0 . ds #V .8m . ds #F .3m . ds #[ \f1 . ds #] \fP .\} .if t \{\ . ds #H ((1u-(\\\\n(.fu%2u))*.13m) . ds #V .6m . ds #F 0 . ds #[ \& . ds #] \& .\} . \" simple accents for nroff and troff .if n \{\ . ds ' \& . ds ` \& . ds ^ \& . ds , \& . ds ~ ~ . ds / .\} .if t \{\ . ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u" . ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u' . ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u' . ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u' . ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u' . ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u' .\} . \" troff and (daisy-wheel) nroff accents .ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V' .ds 8 \h'\*(#H'\(*b\h'-\*(#H' .ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#] .ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H' .ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u' .ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#] .ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#] .ds ae a\h'-(\w'a'u*4/10)'e .ds Ae A\h'-(\w'A'u*4/10)'E . \" corrections for vroff .if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u' .if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u' . \" for low resolution devices (crt and lpr) .if \n(.H>23 .if \n(.V>19 \ \{\ . ds : e . ds 8 ss . ds o a . ds d- d\h'-1'\(ga . ds D- D\h'-1'\(hy . ds th \o'bp' . ds Th \o'LP' . ds ae ae . ds Ae AE .\} .rm #[ #] #H #V #F C .\" ======================================================================== .\" .IX Title "DH_GENERATE_PARAMETERS 3" .TH DH_GENERATE_PARAMETERS 3 "2023-12-04" "1.1.1w" "OpenSSL" .\" For nroff, turn off justification. Always turn off hyphenation; it makes .\" way too many mistakes in technical documents. .if n .ad l .nh .SH "NAME" DH_generate_parameters_ex, DH_generate_parameters, DH_check, DH_check_params, DH_check_ex, DH_check_params_ex, DH_check_pub_key_ex \&\- generate and check Diffie\-Hellman parameters .SH "SYNOPSIS" .IX Header "SYNOPSIS" .Vb 1 \& #include <openssl/dh.h> \& \& int DH_generate_parameters_ex(DH *dh, int prime_len, int generator, BN_GENCB *cb); \& \& int DH_check(DH *dh, int *codes); \& int DH_check_params(DH *dh, int *codes); \& \& int DH_check_ex(const DH *dh); \& int DH_check_params_ex(const DH *dh); \& int DH_check_pub_key_ex(const DH *dh, const BIGNUM *pub_key); .Ve .PP Deprecated: .PP .Vb 4 \& #if OPENSSL_API_COMPAT < 0x00908000L \& DH *DH_generate_parameters(int prime_len, int generator, \& void (*callback)(int, int, void *), void *cb_arg); \& #endif .Ve .SH "DESCRIPTION" .IX Header "DESCRIPTION" \&\fBDH_generate_parameters_ex()\fR generates Diffie-Hellman parameters that can be shared among a group of users, and stores them in the provided \fB\s-1DH\s0\fR structure. The pseudo-random number generator must be seeded before calling it. The parameters generated by \fBDH_generate_parameters_ex()\fR should not be used in signature schemes. .PP \&\fBprime_len\fR is the length in bits of the safe prime to be generated. \&\fBgenerator\fR is a small number > 1, typically 2 or 5. .PP A callback function may be used to provide feedback about the progress of the key generation. If \fBcb\fR is not \fB\s-1NULL\s0\fR, it will be called as described in \fBBN_generate_prime\fR\|(3) while a random prime number is generated, and when a prime has been found, \fBBN_GENCB_call(cb, 3, 0)\fR is called. See \fBBN_generate_prime_ex\fR\|(3) for information on the \fBBN_GENCB_call()\fR function. .PP \&\fBDH_generate_parameters()\fR is similar to \fBDH_generate_prime_ex()\fR but expects an old-style callback function; see \&\fBBN_generate_prime\fR\|(3) for information on the old-style callback. .PP \&\fBDH_check_params()\fR confirms that the \fBp\fR and \fBg\fR are likely enough to be valid. This is a lightweight check, if a more thorough check is needed, use \&\fBDH_check()\fR. The value of \fB*codes\fR is updated with any problems found. If \fB*codes\fR is zero then no problems were found, otherwise the following bits may be set: .IP "\s-1DH_CHECK_P_NOT_PRIME\s0" 4 .IX Item "DH_CHECK_P_NOT_PRIME" The parameter \fBp\fR has been determined to not being an odd prime. Note that the lack of this bit doesn't guarantee that \fBp\fR is a prime. .IP "\s-1DH_NOT_SUITABLE_GENERATOR\s0" 4 .IX Item "DH_NOT_SUITABLE_GENERATOR" The generator \fBg\fR is not suitable. Note that the lack of this bit doesn't guarantee that \fBg\fR is suitable, unless \fBp\fR is known to be a strong prime. .IP "\s-1DH_MODULUS_TOO_LARGE\s0" 4 .IX Item "DH_MODULUS_TOO_LARGE" The modulus is too large. .PP \&\fBDH_check()\fR confirms that the Diffie-Hellman parameters \fBdh\fR are valid. The value of \fB*codes\fR is updated with any problems found. If \fB*codes\fR is zero then no problems were found, otherwise the following bits may be set: .IP "\s-1DH_CHECK_P_NOT_PRIME\s0" 4 .IX Item "DH_CHECK_P_NOT_PRIME" The parameter \fBp\fR is not prime. .IP "\s-1DH_CHECK_P_NOT_SAFE_PRIME\s0" 4 .IX Item "DH_CHECK_P_NOT_SAFE_PRIME" The parameter \fBp\fR is not a safe prime and no \fBq\fR value is present. .IP "\s-1DH_UNABLE_TO_CHECK_GENERATOR\s0" 4 .IX Item "DH_UNABLE_TO_CHECK_GENERATOR" The generator \fBg\fR cannot be checked for suitability. .IP "\s-1DH_NOT_SUITABLE_GENERATOR\s0" 4 .IX Item "DH_NOT_SUITABLE_GENERATOR" The generator \fBg\fR is not suitable. .IP "\s-1DH_CHECK_Q_NOT_PRIME\s0" 4 .IX Item "DH_CHECK_Q_NOT_PRIME" The parameter \fBq\fR is not prime. .IP "\s-1DH_CHECK_INVALID_Q_VALUE\s0" 4 .IX Item "DH_CHECK_INVALID_Q_VALUE" The parameter \fBq\fR is invalid. .IP "\s-1DH_CHECK_INVALID_J_VALUE\s0" 4 .IX Item "DH_CHECK_INVALID_J_VALUE" The parameter \fBj\fR is invalid. .PP \&\fBDH_check_ex()\fR, \fBDH_check_params()\fR and \fBDH_check_pub_key_ex()\fR are similar to \&\fBDH_check()\fR and \fBDH_check_params()\fR respectively, but the error reasons are added to the thread's error queue instead of provided as return values from the function. .SH "RETURN VALUES" .IX Header "RETURN VALUES" \&\fBDH_generate_parameters_ex()\fR, \fBDH_check()\fR and \fBDH_check_params()\fR return 1 if the check could be performed, 0 otherwise. .PP \&\fBDH_generate_parameters()\fR returns a pointer to the \s-1DH\s0 structure or \s-1NULL\s0 if the parameter generation fails. .PP \&\fBDH_check_ex()\fR, \fBDH_check_params()\fR and \fBDH_check_pub_key_ex()\fR return 1 if the check is successful, 0 for failed. .PP The error codes can be obtained by \fBERR_get_error\fR\|(3). .SH "SEE ALSO" .IX Header "SEE ALSO" \&\fBDH_new\fR\|(3), \fBERR_get_error\fR\|(3), \fBRAND_bytes\fR\|(3), \&\fBDH_free\fR\|(3) .SH "HISTORY" .IX Header "HISTORY" \&\fBDH_generate_parameters()\fR was deprecated in OpenSSL 0.9.8; use \&\fBDH_generate_parameters_ex()\fR instead. .SH "COPYRIGHT" .IX Header "COPYRIGHT" Copyright 2000\-2018 The OpenSSL Project Authors. All Rights Reserved. .PP Licensed under the OpenSSL license (the \*(L"License\*(R"). You may not use this file except in compliance with the License. You can obtain a copy in the file \s-1LICENSE\s0 in the source distribution or at <https://www.openssl.org/source/license.html>.