xref: /freebsd/secure/lib/libcrypto/man/man3/DH_set_method.3 (revision 174c0ac687ec4ccb0b56ee30d48c0a7b8b9c4e15)
Automatically generated by Pod::Man 4.14 (Pod::Simple 3.42)

Standard preamble:
========================================================================
..
..
.. 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 -- \(*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\} . 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.

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'.
.. .nr rF 0 . if \nF \{\ . de IX . tm Index:\\$1\t\\n%\t"\\$2" .. . if !\nF==2 \{\ . nr % 0 . nr F 2 . \} . \} .\} .rr rF Fear. Run. Save yourself. No user-serviceable parts.
. \" fudge factors for nroff and troff . ds #H 0 . ds #V .8m . ds #F .3m . ds #[ \f1 . ds #] .\} . ds #H ((1u-(\\\\n(.fu%2u))*.13m) . ds #V .6m . ds #F 0 . ds #[ \& . ds #] \& .\} . \" simple accents for nroff and troff . ds ' \& . ds ` \& . ds ^ \& . ds , \& . ds ~ ~ . ds / .\} . 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 . \" corrections for vroff . \" for low resolution devices (crt and lpr) \{\ . 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 .\} ========================================================================

Title "DH_SET_METHOD 3ossl"
DH_SET_METHOD 3ossl "2023-09-19" "3.0.11" "OpenSSL"
For nroff, turn off justification. Always turn off hyphenation; it makes
way too many mistakes in technical documents.
"NAME"
DH_set_default_method, DH_get_default_method, DH_set_method, DH_new_method, DH_OpenSSL - select DH method
"SYNOPSIS"
Header "SYNOPSIS" .Vb 1 #include <openssl/dh.h> .Ve

The following functions have been deprecated since OpenSSL 3.0, and can be hidden entirely by defining \s-1OPENSSL_API_COMPAT\s0 with a suitable version value, see openssl_user_macros\|(7):

.Vb 1 void DH_set_default_method(const DH_METHOD *meth); \& const DH_METHOD *DH_get_default_method(void); \& int DH_set_method(DH *dh, const DH_METHOD *meth); \& DH *DH_new_method(ENGINE *engine); \& const DH_METHOD *DH_OpenSSL(void); .Ve

"DESCRIPTION"
Header "DESCRIPTION" All of the functions described on this page are deprecated. Applications should instead use the provider APIs.

A \s-1DH_METHOD\s0 specifies the functions that OpenSSL uses for Diffie-Hellman operations. By modifying the method, alternative implementations such as hardware accelerators may be used. \s-1IMPORTANT:\s0 See the \s-1NOTES\s0 section for important information about how these \s-1DH API\s0 functions are affected by the use of \s-1ENGINE\s0 \s-1API\s0 calls.

Initially, the default \s-1DH_METHOD\s0 is the OpenSSL internal implementation, as returned by DH_OpenSSL().

\fBDH_set_default_method() makes meth the default method for all \s-1DH\s0 structures created later. \fB\s-1NB\s0: This is true only whilst no \s-1ENGINE\s0 has been set as a default for \s-1DH,\s0 so this function is no longer recommended. This function is not thread-safe and should not be called at the same time as other OpenSSL functions.

\fBDH_get_default_method() returns a pointer to the current default \s-1DH_METHOD.\s0 However, the meaningfulness of this result is dependent on whether the \s-1ENGINE API\s0 is being used, so this function is no longer recommended.

\fBDH_set_method() selects meth to perform all operations using the key dh. This will replace the \s-1DH_METHOD\s0 used by the \s-1DH\s0 key and if the previous method was supplied by an \s-1ENGINE,\s0 the handle to that \s-1ENGINE\s0 will be released during the change. It is possible to have \s-1DH\s0 keys that only work with certain \s-1DH_METHOD\s0 implementations (e.g. from an \s-1ENGINE\s0 module that supports embedded hardware-protected keys), and in such cases attempting to change the \s-1DH_METHOD\s0 for the key can have unexpected results.

\fBDH_new_method() allocates and initializes a \s-1DH\s0 structure so that engine will be used for the \s-1DH\s0 operations. If engine is \s-1NULL,\s0 the default \s-1ENGINE\s0 for \s-1DH\s0 operations is used, and if no default \s-1ENGINE\s0 is set, the \s-1DH_METHOD\s0 controlled by \fBDH_set_default_method() is used.

A new \s-1DH_METHOD\s0 object may be constructed using DH_meth_new() (see \fBDH_meth_new\|(3)).

"RETURN VALUES"
Header "RETURN VALUES" \fBDH_OpenSSL() and DH_get_default_method() return pointers to the respective \fB\s-1DH_METHOD\s0s.

\fBDH_set_default_method() returns no value.

\fBDH_set_method() returns nonzero if the provided meth was successfully set as the method for dh (including unloading the \s-1ENGINE\s0 handle if the previous method was supplied by an \s-1ENGINE\s0).

\fBDH_new_method() returns \s-1NULL\s0 and sets an error code that can be obtained by \fBERR_get_error\|(3) if the allocation fails. Otherwise it returns a pointer to the newly allocated structure.

"SEE ALSO"
Header "SEE ALSO" \fBDH_new\|(3), DH_new\|(3), DH_meth_new\|(3)
"HISTORY"
Header "HISTORY" All of these functions were deprecated in OpenSSL 3.0.
"COPYRIGHT"
Header "COPYRIGHT" Copyright 2000-2021 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (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>.