OpenSSL will then omit the value from the certificate. Now, we can use this to generate the keys and certificates with OpenSSL using the configuration file. Using the configuration file to auto-fill the necessary values First, lets generate the certificate for the Certificate Authority using the configuration file. Use the following command to generate the random key: openssl rand -hex 64 -out key.bin Do this every time you encrypt a file. Use a new key every time! The key format is HEX because the base64 format adds newlines. The -pass argument later on only takes the first line of the file, so the full key is not used.

1. Openssl Create Rsa Key
2. Openssl Create Public Key From Private Key
3. Using Openssl To Create Keys For Mac Os
4. Using Openssl To Create Keys For Mac Osx
5. Install Openssl On Mac
6. Openssl Create Key
7. Using Openssl To Create Keys For Mac Catalina

Before adding a new SSH key to the ssh-agent to manage your keys, you should have checked for existing SSH keys and generated a new SSH key. When adding your SSH key to the agent, use the default macOS ssh-add command, and not an application installed by macports, homebrew, or some other external source. OpenSSL (included with Linux/Unix and macOS, and easily installed on Windows with Cygwin) The commands below demonstrate examples of how to create a.pfx/.p12 file in the command line using OpenSSL: PEM (.pem.crt.cer) to PFX openssl pkcs12 -export -out certificate.pfx -inkey privateKey.key -in certificate.crt -certfile more.crt. Generating keys using OpenSSL There are two ways of getting private keys into a YubiKey: You can either generate the keys directly on the YubiKey, or generate them outside of the device, and then importing them into the YubiKey.

SYNOPSIS

openssldgst [-Idigest] [-help] [-c] [-d] [-hex] [-binary] [-r] [-outfilename] [-signfilename] [-keyformarg] [-passinarg] [-verifyfilename] [-prverifyfilename] [-signaturefilename] [-hmackey] [-fips-fingerprint] [-randfile...] [-engineid] [-engine_impl] [file...]

openssl Idigest [...]

DESCRIPTION

The digest functions output the message digest of a supplied file or files in hexadecimal. The digest functions also generate and verify digital signatures using message digests.

The generic name, dgst, may be used with an option specifying the algorithm to be used. The default digest is sha256. A supported digest name may also be used as the command name. To see the list of supported algorithms, use the openssl_list--digest-commands command.

Options

-help

Print out a usage message.

-Idigest

Specifies name of a supported digest to be used. To see the list of supported digests, use the command openssl_list--digest-commands.

-c

prints out the digest in two digit groups separated by colons, only relevant if hex format output is used.

-d

prints out BIO debugging information.

-hex

outputs digest as a hex dump. This is the default case for a 'normal' digest as opposed to a digital signature. See NOTES below for digital signatures using -hex.

-binary

outputs the digest or signature in binary form.

-r

output the digest in the 'coreutils' format used by programs like sha1sum.

-outfilename

specifies the file name to output to, or standard output by default.

-signfilename

. Note this option does not support Ed25519 or Ed448 private keys. Use the openssl_pkeyutl command instead for this.

digitally signs the digest using the private key in filename.

-keyformarg

Specifies the key format to sign digest with. The DER, PEM, P12, and ENGINE formats are supported.

-sigoptnm:v

Pass options to the signature algorithm during sign or verify operations. Names and values of these options are algorithm-specific.

-passinarg

the private key password source. For more information about the format of arg see the PASS PHRASE ARGUMENTS section in openssl.

-verifyfilename

verifies the signature using the public key in filename. The output is either Verification OK or Verification Failure.

-prverifyfilename

verifies the signature using the private key in filename.

-signaturefilename

specifies the actual signature to verify.

-hmackey

create a hashed MAC using 'key'.

-macalg

create MAC (keyed Message Authentication Code). The most popular MAC algorithm is HMAC (hash-based MAC), but there are other MAC algorithms which are not based on hash, for instance gost-mac algorithm, supported by ccgost engine. MAC keys and other options should be set via -macopt parameter.

-macoptnm:v

Passes options to MAC algorithm, specified by -mac key. Following options are supported by both by HMAC and gost-mac

key:string

Specifies MAC key as alphanumeric string (use if key contain printable characters only). String length must conform to any restrictions of the MAC algorithm for example exactly 32 chars for gost-mac.

hexkey:string

Specifies MAC key in hexadecimal form (two hex digits per byte). Key length must conform to any restrictions of the MAC algorithm for example exactly 32 chars for gost-mac.

-rand file...

Openssl Create Rsa Key

specifies a file or files containing random data used to seed the random number generator. Multiple files can be specified separated by an OS-dependent character. The separator is ; for MS-Windows, , for OpenVMS, and : for all others.

[-writerandfile]

Writes random data to the specified file upon exit. This can be used with a subsequent -rand flag.

-fips-fingerprint

compute HMAC using a specific key for certain OpenSSL-FIPS operations.

-engineid

Use engine id for operations (including private key storage). This engine is not used as source for digest algorithms, unless it is also specified in the configuration file or -engine_impl is also specified.

-engine_impl

When used with the -engine option, it specifies to also use engine id for digest operations.

file...

specifies the file or files to digest. If no files are specified then standard input is used.

EXAMPLES

To create a hex-encoded message digest of a file:

To sign a file using SHA-256 with binary file output:

To verify a signature:

NOTES

The digest mechanisms that are available will depend on the options used when building OpenSSL. The openssl_listdigest-commands command can be used to list them.

New or agile applications should use probably use SHA-256. Other digests, particularly SHA-1 and MD5, are still widely used for interoperating with existing formats and protocols.

When signing a file, dgst will automatically determine the algorithm (RSA, ECC, etc) to use for signing based on the private key's ASN.1 info. When verifying signatures, it only handles the RSA, DSA, or ECDSA signature itself, not the related data to identify the signer and algorithm used in formats such as x.509, CMS, and S/MIME.

A source of random numbers is required for certain signing algorithms, in particular ECDSA and DSA.

The signing and verify options should only be used if a single file is being signed or verified.

Hex signatures cannot be verified using openssl. Instead, use 'xxd -r' or similar program to transform the hex signature into a binary signature prior to verification.

HISTORY

The default digest was changed from MD5 to SHA256 in OpenSSL 1.1.0. The FIPS-related options were removed in OpenSSL 1.1.0.

COPYRIGHT

Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the OpenSSL license (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 here: OpenSSL.

AVAILABILITY

PTC MKS Toolkit for System Administrators
PTC MKS Toolkit for Developers
PTC MKS Toolkit for Interoperability
PTC MKS Toolkit for Professional Developers
PTC MKS Toolkit for Professional Developers 64-Bit Edition
PTC MKS Toolkit for Enterprise Developers
PTC MKS Toolkit for Enterprise Developers 64-Bit Edition

PTC MKS Toolkit 10.3 Documentation Build 39.

Skip to main content

Encrypt and decrypt files to public keys via the OpenSSL Command Line

Published: 25-10-2018 | Author: Remy van Elst | Text only version of this article

Openssl Create Public Key From Private Key

This small tutorial will show you how to use the openssl command line to encryptand decrypt a file using a public key. We will first generate a random key,encrypt that random key against the public key of the other person and use thatrandom key to encrypt the actual file with using symmetric encryption.

Because of how the RSA algorithm works it is not possible to encrypt largefiles. If you create a key of n bits, then the file you want to encrypt mustnot larger than (n minus 11) bits. The most effective use of RSA crypto is toencrypt a random generated password, then encrypt the file with the passwordusing symmetric crypto. If the file is larger then the key size the encryptioncommand will fail:

We generate a random file and use that as the key to encrypt the large file withsymmetric crypto. That random file acts as the password so to say. We encryptthe large file with the small password file as password. Then we send theencrypted file and the encrypted key to the other party and then can decrypt thekey with their public key, the use that key to decrypt the large file.

The following commands are relevant when you work with RSA keys:

• openssl genrsa: Generates an RSA private keys.
• openssl rsa: Manage RSA private keys (includes generating a public key from it).
• openssl rsautl: Encrypt and decrypt files with RSA keys.

The key is just a string of random bytes. We use a base64 encoded string of 128bytes, which is 175 characters. Since 175 characters is 1400 bits, even a smallRSA key will be able to encrypt it.

Get the public key

Let the other party send you a certificate or their public key. If they send toa certificate you can extract the public key using this command:

Generate the random password file

Use the following command to generate the random key:

Do this every time you encrypt a file. Use a new key every time!

Update 25-10-2018

The key format is HEX because the base64 format adds newlines. The -passargument later on only takes the first line of the file, so the full key is notused. (Thanks Ken Larson for pointing this to me)

Encrypt the file with the random key

Use the following command to encrypt the large file with the random key:

The file size doesn't grows that much:

It's encrypted however:

Using Openssl To Create Keys For Mac Os

Encrypt the random key with the public keyfile

Use the following command to encrypt the random keyfile with the other personspublic key:

Using Openssl To Create Keys For Mac Osx

You can safely send the key.bin.enc and the largefile.pdf.enc to the otherparty.

You might want to sign the two files with your public key as well.

Decrypt the random key with our private key file

If you want to decrypt a file encrypted with this setup, use the followingcommand with your privte key (beloning to the pubkey the random key was cryptedto) to decrypt the random key:

This will result in the decrypted random key we encrypted the file in.

Install Openssl On Mac

Decrypt the large file with the random key

Openssl Create Key

Once you have the random key, you can decrypt the encrypted file with thedecrypted key:

This will result in the decrypted large file.

Tags: ca, certificate, decrypt, encrypt, openssl, pki, ssl, tls, tutorials

Using Openssl To Create Keys For Mac Catalina