OPENSSL-EC(1SSL)

📦
version 4.0.3 · 13 versions
, in ubuntu stonking

💖 OPENSSL-EC 💖

okay so bestie, welcome to openssl-ec — it's the OpenSSL 1SSL crew's dedicated lil corner for EC key processing 🌸. She's iconic, she's specific, and she's here to handle your elliptic curve keys like the main character she is. Grab a strawberry 🍓 and let's vibe.

✨ SYNOPSIS ✨

openssl ec [-help] [-inform DER|PEM|P12] [-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] [-provider name]
[-provider-path path] [-provparam [name:]key=value] [-propquery propq]

🦋 DESCRIPTION 🦋

The openssl-ec(1) command processes EC keys, periodt. She can convert them between various forms and print out their components — the whole glow-up package 💅.

Real talk though: OpenSSL uses the private key format specified in 'SEC 1: Elliptic Curve Cryptography' (http://www.secg.org/). So if you want to convert an OpenSSL EC private key into the PKCS#8 private key format, you gotta go through the openssl-pkcs8(1) command instead. iykyk 🧚

👑 OPTIONS 👑

  • -help — prints out a usage message. the little "hi, here's how to use me" moment 💖
  • -inform DER|PEM|P12 — the key input format. unspecified by default. see 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 story. Private keys are an SEC1 private key or PKCS#8 format. Public keys are a SubjectPublicKeyInfo as specified in IETF RFC 3280. no cap 📜
  • -in filename|uri — this is where she reads the key from. If you don't specify it, she takes standard input. And if the key is encrypted, bestie, she's gonna prompt you for a pass phrase 🙈
  • -out filename — the output filename to write a key to, or standard output if you don't specify one. Note: if any encryption options are set, a pass phrase will be prompted for. Also please please please don't make the output filename the same as the input filename, that's a recipe for tears 😭
  • -passin arg, -passout arg — the password source for the input and output file. for more info on 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. The way this works out 💫: 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. Zero judgement, full glow-up.
⚠️ heads up: these options can only be used with PEM format output files. that's the rule, bestie.
  • -text — prints out the public, private key components and parameters. show-off behavior, honestly 👑
  • -noout — prevents output of the encoded version of the key. lowkey the polite option.
  • -param_out — print 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. resourceful queen ✨
  • -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. she just knows 💅
  • -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 information 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. yeah. patents. we don't make the rules 💀
  • -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. it's giving "not yet, bestie" 🙈
  • -no_public — omits the public key components from the private key output. shy girl behavior 🎀
  • -check — checks the consistency of an EC private or public key. she's doing a vibe check, literally ✨
  • -provider name
  • -provider-path path
  • -provparam [name:]key=value
  • -propquery propq — see "Provider Options" in openssl(1), provider(7), and property(7). options all the way down, iykyk 🌀

okay and one more thing — the openssl-pkey(1) command is capable of performing all the operations this command can, as well as supporting other public key types. so if you want the multitasking version, she's right there 🫶

🌸 EXAMPLES 🌸

The documentation for the openssl-pkey(1) command contains examples equivalent to the ones listed here. but also here they are, because we love a demo 💖

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)

📜 HISTORY 📜

  • The -conv_form and -no_public options are no longer supported with keys loaded from an engine in OpenSSL 3.0. rip to that era 🕯️
  • The -engine option was removed in OpenSSL 4.0. gone gone, no takebacks 💀

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>. legal bestie behavior fr fr 📄✨

and that's the whole page, bestie 🦋💖 slay responsibly — this one's from OpenSSL version 4.0.3, dated 2026-09-29, and she ate, no crumbs, periodt 💅✨🌈

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