openssl-dgst, dgst - perform digest operations
] [ -help
] [ -d
] [ -hex
] [ -binary
] [ -r
] [ -sign filename
] [ -keyform arg
] [ -verify filename
] [ -prverify filename
] [ -hmac key
] [ -fips-fingerprint
] [ -engine id
] [ -engine_impl
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
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
- Print out the digest in two digit groups separated by
colons, only relevant if hex format output is used.
- Print out BIO debugging information.
- 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 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
- -passin arg
- The private key password source. For more information about
the format of arg see the PASS PHRASE ARGUMENTS section in
- -verify filename
- Verify the signature using the public key in
"filename". The output is either "Verification OK" or
- -prverify filename
- Verify the signature using the private key in
- -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
- 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
- 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
- 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 used.
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
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 2000-2019 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