openssl-dgst - perform digest operations

Copyright

       Copyright 2000-2024 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>.

3.4.1                                              2025-04-03                                 OPENSSL-DGST(1SSL)

Description

       This command output the message digest of a supplied file or files in hexadecimal, and also generates and
       verifies digital signatures using message digests.

       The generic name, openssldgst, 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 sub-command name.  To see the
       list of supported algorithms, use "openssl list -digest-algorithms"

Examples

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

        openssl dgst -md5 -hex file.txt
        or
        openssl md5 file.txt

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

        openssl dgst -sha256 -sign privatekey.pem -out signature.sign file.txt
        or
        openssl sha256 -sign privatekey.pem -out signature.sign file.txt

       To verify a signature:

        openssl dgst -sha256 -verify publickey.pem \
        -signature signature.sign \
        file.txt

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.

       The -engine and -engine_impl options were deprecated in OpenSSL 3.0.

Name

       openssl-dgst - perform digest operations

Notes

       The digest mechanisms that are available will depend on the options  used  when  building  OpenSSL.   The
       "openssl list -digest-algorithms" 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, this command 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.

       The openssl-mac(1) command is preferred over the -hmac, -mac and -macopt command line options.

Options

-help
Print out a usage message.

-digest
Specifies name of a supported digest to be used. See option -list below :

-list
Prints out a list of supported message digests.

-c Print out the digest in two digit groups separated by colons, only relevant if the -hex option is
given as well.

-d, -debug
Print out BIO debugging information.

-hex
Digest is to be output 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
Output the digest or signature in binary form.

-xoflenlength
Set the output length for XOF algorithms, such as shake128 and shake256. This option is not
supported for signing operations.

For OpenSSL providers it is required to set this value for shake algorithms, since the previous
default values were only set to supply half of the maximum security strength.

To ensure the maximum security strength of 128 bits, the xoflen for shake128 should be set to at
least 32 (bytes). For compatibility with previous versions of OpenSSL, it may be set to 16, resulting
in a security strength of only 64 bits.

To ensure the maximum security strength of 256 bits, the xoflen for shake256 should be set to at
least 64 (bytes). For compatibility with previous versions of OpenSSL, it may be set to 32, resulting
in a security strength of only 128 bits.

-r Output the digest in the "coreutils" format, including newlines. Used by programs like sha1sum(1).

-outfilename
Filename to output to, or standard output by default.

-signfilename|uri
Digitally sign the digest using the given private key. Note this option does not support Ed25519 or
Ed448 private keys. Use the openssl-pkeyutl(1) command instead for this.

-keyformDER|PEM|P12|ENGINE
The format of the key to sign with; unspecified by default. See openssl-format-options(1) for
details.

-sigoptnm:v
Pass options to the signature algorithm during sign or verify operations. Names and values of these
options are algorithm-specific and documented in "Signature parameters" in provider-signature(7).

-passinarg
The private key password source. For more information about the format of arg see
openssl-passphrase-options(1).

-verifyfilename
Verify the signature using the public key in "filename". The output is either "Verified OK" or
"Verification Failure".

-prverifyfilename
Verify the signature using the private key in "filename".

-signaturefilename
The actual signature to verify.

-hmackey
Create a hashed MAC using "key".

The openssl-mac(1) command should be preferred to using this command line option.

-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 the gost engine. MAC keys and other options should be set via -macopt
parameter.

The openssl-mac(1) command should be preferred to using this command line option.

-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.

The openssl-mac(1) command should be preferred to using this command line option.

-fips-fingerprint
Compute HMAC using a specific key for certain OpenSSL-FIPS operations.

-randfiles, -writerandfile
See "Random State Options" in openssl(1) for details.

-engineid
See "Engine Options" in openssl(1). This option is deprecated.

The engine is not used for digests unless the -engine_impl option is used or it is configured to do
so, see "Engine Configuration Module" in config(5).

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

-providername-provider-pathpath-propquerypropq
See "Provider Options" in openssl(1), provider(7), and property(7).

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

Synopsis

openssldgst|digest [-digest] [-list] [-help] [-c] [-d] [-debug] [-hex] [-binary] [-xoflenlength] [-r]
       [-outfilename] [-signfilename|uri] [-keyformDER|PEM|P12|ENGINE] [-passinarg] [-verifyfilename]
       [-prverifyfilename] [-signaturefilename] [-sigoptnm:v] [-hmackey] [-macalg] [-macoptnm:v]
       [-fips-fingerprint] [-engineid] [-engine_implid] [-randfiles] [-writerandfile] [-providername]
       [-provider-pathpath] [-propquerypropq] [file ...]