OPENSSL-EC(1ossl)

📦
version 3.5.9 · 8 versions
, in alpine 3.23, alpine 3.24

🌸 NAME 🌸

okay so bestie, this is openssl-ec — the OpenSSL manual page for EC key processing 💅✨ (that's elliptic curve keys, iykyk). It lives in the openssl-ec(1ossl) manpage family and it's literally your go-to for wrangling EC keys.

🎀 SYNOPSIS 🎀

openssl ec [-help] [-inform DER|PEM|P12|ENGINE] [-outform DER|PEM] [-in
filename|uri] [-passin arg] [-out filename] [-passout arg] [-des]
[-des3] [-idea] [-text] [-noout] [-param_out] [-pubin] [-pubout]
[-conv_form arg] [-param_enc arg] [-no_public] [-check] [-engine id]
[-provider name] [-provider-path path] [-provparam [name:]key=value]
[-propquery propq]

✨ DESCRIPTION ✨

So the openssl-ec(1) command processes EC keys, fr fr. You can convert them between various forms and print out their components — it's giving key glow-up 💖.

Note: OpenSSL uses the private key format specified in 'SEC 1: Elliptic Curve Cryptography' (http://www.secg.org/). So if you ever need to convert an OpenSSL EC private key into the PKCS#8 private key format, that's a whole different slay — use the openssl-pkcs8(1) command for that one 🫶.

💅 OPTIONS 💅

  • -help — prints out a usage message. classic helpful icon behavior ✨
  • -inform DER|PEM|P12|ENGINE — the key input format, and it's unspecified by default. peek openssl-format-options(1) for the deets 🦋
  • -outform DER|PEM — the key output format, default is PEM. again, openssl-format-options(1) has the full tea.

Private keys are an SEC1 private key or PKCS#8 format. Public keys are a SubjectPublicKeyInfo as specified in IETF RFC 3280 👑

  • -in filename|uri — specifies the input to read a key from, or standard input if you don't specify this option. if the key is encrypted, a pass phrase will be prompted for 🔐
  • -out filename — specifies the output filename to write a key to, or standard output if it's not specified. if any encryption options are set then a pass phrase will be prompted for. and bestie, listen: the output filename should not be the same as the input filename 🙈
  • -passin arg, -passout arg — the password source for the input and output file. for more info about the format of arg, see openssl-passphrase-options(1) 💜
  • -des|-des3|-idea — these options encrypt the private key with the DES, triple DES, IDEA or any other cipher supported by OpenSSL before outputting it. a pass phrase is prompted for. if none of these options is specified the key is written in plain text. meaning: using this command to read in an encrypted key with no encryption option can be used to remove the pass phrase from a key, or by setting the encryption options it can be used to add or change the pass phrase 👀✨ these options can only be used with PEM format output files.
  • -text — prints out the public, private key components and parameters. the full anatomy reveal 💅
  • -noout — prevents output of the encoded version of the key.
  • -param_out — prints the elliptic curve parameters 🌈
  • -pubin — by default a private key is read from the input. with this option a public key is read instead. if the input contains no public key but a private key, its public part is used 🫶
  • -pubout — by default a private key is output. with this option a public key will be output instead. this option is automatically set if the input is a public key ⭐
  • -conv_form arg — specifies how the points on the elliptic curve are converted into octet strings. possible values are: compressed, uncompressed (the default value) and hybrid. for more info regarding the point conversion forms please read the X9.62 standard. note: due to patent issues the compressed option is disabled by default for binary curves and can be enabled by defining the preprocessor macro OPENSSL_EC_BIN_PT_COMP at compile time 🧚
  • -param_enc arg — specifies how the elliptic curve parameters are encoded. possible values are: named_curve, i.e. the ec parameters are specified by an OID, or explicit where the ec parameters are explicitly given (see RFC 3279 for the definition of the EC parameters structures). the default value is named_curve. note: the implicitlyCA alternative, as specified in RFC 3279, is currently not implemented in OpenSSL 💀
  • -no_public — omits the public key components from the private key output 🙈
  • -check — checks the consistency of an EC private or public key ✅
  • -engine id — see "Engine Options" in openssl(1). this option is deprecated ⚠️
  • -provider name
  • -provider-path path
  • -provparam [name:]key=value
  • -propquery propq

see "Provider Options" in openssl(1), provider(7), and property(7) 💖

Also just so you know: the openssl-pkey(1) command is capable of performing all the operations this command can, as well as supporting other public key types. main character energy tbh 👑

🌸 EXAMPLES 🌸

The documentation for the openssl-pkey(1) command contains examples equivalent to the ones listed here 🫶

To encrypt a private key using triple DES:

 openssl ec -in key.pem -des3 -out keyout.pem

To convert a private key from PEM to DER format:

 openssl ec -in key.pem -outform DER -out keyout.der

To print out the components of a private key to standard output:

 openssl ec -in key.pem -text -noout

To just output the public part of a private key:

 openssl ec -in key.pem -pubout -out pubkey.pem

To change the parameters encoding to explicit:

 openssl ec -in key.pem -param_enc explicit -out keyout.pem

To change the point conversion form to compressed:

 openssl ec -in key.pem -conv_form compressed -out keyout.pem

🦋 SEE ALSO 🦋

openssl(1), openssl-pkey(1), openssl-ecparam(1), openssl-dsa(1), openssl-rsa(1) — go read these next bestie, they're all linked up 💜

👑 HISTORY 👑

  • The -engine option was deprecated in OpenSSL 3.0.
  • The -conv_form and -no_public options are no longer supported with keys loaded from an engine in OpenSSL 3.0.

Copyright 2003-2023 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>.

and that's the whole page, bestie 🎀 ngl this one's from the OpenSSL 3.5.9 era, dated 2026-09-29 — so go forth and process those EC keys, you've got this 💅✨

📦 where this page comes from