OPENSSL-DHPARAM(1ssl) OpenSSL OPENSSL-DHPARAM(1ssl) (NAME) openssl-dhparam - DH (SYNOPSIS) openssl dhparam [-help] [-inform DER|PEM] [-outform DER|PEM] [-in filename] [-out filename] [-dsaparam] [-check] [-noout] [-text] [-verbose] [-quiet] [-2] [-3] [-5] [-engine id] [-rand files] [-writerand file] [-provider name] [-provider-path path] [-provparam [name:]key=value] [-propquery propq] [numbits] (DESCRIPTION) DH . <> openssl-genpkey(1) . (OPTIONS) -help . -inform DER|PEM, -outform DER|PEM PEM . DHparameter PKCS#3 . openssl-format-options(1) . -in filename . -out filename . . . / (Atomic) (Truncate) . -dsaparam DSA DH DH . ( (p-1)/2 ) DH . DH -dsaparam . DH DSA DH (small-subgroup attacks) . -check . -2, -3, -5 (Generator) . . numbits . numbits numbits . . . (-2 -3 -5) . . -noout . -text DH . -engine id <> openssl(1) . . -rand files, -writerand file <> openssl(1) . -provider name -provider-path path -provparam [name:]key=value -propquery propq <> openssl(1) provider(7) property(7) . -verbose . -quiet () . (NOTES) dh gendh . (SEE ALSO) openssl(1), openssl-pkeyparam(1), openssl-dsaparam(1), openssl-genpkey(1). (HISTORY) -engine OpenSSL 3.0 . -C OpenSSL 3.0 . (COPYRIGHT) - OpenSSL. . . (<<>>) . . LICENSE : 3.6.4 2026-08-25 OPENSSL-DHPARAM(1ssl)