OPENSSL-DGST(1) | OpenSSL | OPENSSL-DGST(1) |
openssl-dgst - perform digest operations
openssl dgst|digest [-digest] [-list] [-help] [-c] [-d] [-debug] [-hex] [-binary] [-xoflen length] [-r] [-out filename] [-sign filename|uri] [-keyform DER|PEM|P12|ENGINE] [-passin arg] [-verify filename] [-prverify filename] [-signature filename] [-sigopt nm:v] [-hmac key] [-mac alg] [-macopt nm:v] [-fips-fingerprint] [-engine id] [-engine_impl id] [-rand files] [-writerand file] [-provider name] [-provider-path path] [-provparam [name:]key=value] [-propquery propq] [file ...]
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, openssl 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 sub-command name. To see the list of supported algorithms, use "openssl list -digest-algorithms"
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.
Note that for algorithms that only support one-shot signing (such as Ed25519, ED448, ML-DSA-44, ML-DSA-65 andML-DSA-87) the digest must not be set. For these algorithms the input is buffered (and not digested) before signing. For these algorithms, if the input is larger than 16MB an error will occur.
The openssl-mac(1) command should be preferred to using this command line option.
The openssl-mac(1) command should be preferred to using this command line option.
The openssl-mac(1) command should be preferred to using this command line option.
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).
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
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.
openssl-mac(1)
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.
Copyright 2000-2025 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>.
2025-07-18 | 3.5.1 |