Section: OpenSSL (1)
openssl-dgst, dgst - perform digest operations
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. Use the pkeyutl command
instead for this.
- -keyform arg
Specifies the key format to sign digest with. The DER, PEM, P12,
and ENGINE formats are supported.
- -sigopt nm:v
Pass options to the signature algorithm during sign or verify operations.
Names and values of these options are algorithm-specific.
- -passin arg
The private key password source. For more information about the format of arg
see the PASS PHRASE ARGUMENTS section in openssl(1).
- -verify filename
Verify the signature using the public key in ``filename''.
The output is either ``Verification OK'' or ``Verification Failure''.
- -prverify filename
Verify the signature using the private key in ``filename''.
- -signature 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.
- -macopt nm:v
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
Multiple files can be specified separated by an OS-dependent character.
The separator is ; for MS-Windows, , for OpenVMS, and : for
- [-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 operations.
- -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
in OpenSSL 1.1.0.
The FIPS-related options were removed in OpenSSL 1.1.0.
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 at