openssl-dgst, dgst - perform digest operations
openssl dgst [-digest]
[-help] [-c] [-d] [-list] [-hex]
[-binary] [-r] [-out filename] [-sign filename]
[-keyform arg] [-passin arg] [-verify filename]
[-prverify filename] [-signature filename] [-sigopt
nm:v] [-hmac key] [-fips-fingerprint] [-rand
file...] [-engine id] [-engine_impl] [file...]
openssl digest [...]
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 list --digest-commands
- Print out a usage message.
- Specifies name of a supported digest to be used. To see the list of
supported digests, use the command list --digest-commands.
- Print out the digest in two digit groups separated by colons, only
relevant if hex format output is used.
- Print out BIO debugging information.
- Prints out a list of supported message digests.
- 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.
- Output the digest or signature in binary form.
- Output the digest in the "coreutils" format, including newlines.
Used by programs like sha1sum.
- -out filename
- Filename to output to, or standard output by default.
- -sign filename
- Digitally sign the digest using the private key in "filename".
Note this option does not support Ed25519 or Ed448 private keys.
- Specifies the key format to sign digest with. The DER, PEM, P12, and
ENGINE formats are supported.
- Pass options to the signature algorithm during sign or verify operations.
Names and values of these options are algorithm-specific.
- The private key password source. For more information about the format of
arg see "Pass Phrase Options" in openssl(1).
- Verify the signature using the public key in "filename". The
output is either "Verification OK" or "Verification
- Verify the signature using the private key in "filename".
- The actual signature to verify.
- -hmac key
- Create a hashed MAC using "key".
- -mac alg
- 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.
- Passes options to MAC algorithm, specified by -mac key. Following
options are supported by both by HMAC and gost-mac:
- 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.
- 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...
- 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.
- [-writerand file]
- Writes random data to the specified file upon exit. This can be
used with a subsequent -rand flag.
- Compute HMAC using a specific key for certain OpenSSL-FIPS
- -engine id
- 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
- When used with the -engine option, it specifies to also use engine
id for digest operations.
- File or files to digest. If no files are specified then standard input is
To create a hex-encoded message digest of a file:
openssl dgst -md5 -hex file.txt
To sign a file using SHA-256 with binary file output:
openssl dgst -sha256 -sign privatekey.pem -out signature.sign file.txt
To verify a signature:
openssl dgst -sha256 -verify publickey.pem \
-signature signature.sign \
The digest mechanisms that are available will depend on the
options used when building OpenSSL. The list digest-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.
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 2000-2021 The OpenSSL Project Authors. All Rights
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 at