1DGST(1)                             OpenSSL                            DGST(1)
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NAME

6       openssl-dgst, dgst - perform digest operations
7

SYNOPSIS

9       openssl dgst [-digest] [-help] [-c] [-d] [-hex] [-binary] [-r] [-out
10       filename] [-sign filename] [-keyform arg] [-passin arg] [-verify
11       filename] [-prverify filename] [-signature filename] [-hmac key]
12       [-fips-fingerprint] [-rand file...]  [-engine id] [-engine_impl]
13       [file...]
14
15       openssl digest [...]
16

DESCRIPTION

18       The digest functions output the message digest of a supplied file or
19       files in hexadecimal.  The digest functions also generate and verify
20       digital signatures using message digests.
21
22       The generic name, dgst, may be used with an option specifying the
23       algorithm to be used.  The default digest is sha256.  A supported
24       digest name may also be used as the command name.  To see the list of
25       supported algorithms, use the list --digest-commands command.
26

OPTIONS

28       -help
29           Print out a usage message.
30
31       -digest
32           Specifies name of a supported digest to be used. To see the list of
33           supported digests, use the command list --digest-commands.
34
35       -c  Print out the digest in two digit groups separated by colons, only
36           relevant if hex format output is used.
37
38       -d  Print out BIO debugging information.
39
40       -hex
41           Digest is to be output as a hex dump. This is the default case for
42           a "normal" digest as opposed to a digital signature.  See NOTES
43           below for digital signatures using -hex.
44
45       -binary
46           Output the digest or signature in binary form.
47
48       -r  Output the digest in the "coreutils" format used by programs like
49           sha1sum.
50
51       -out filename
52           Filename to output to, or standard output by default.
53
54       -sign filename
55           Digitally sign the digest using the private key in "filename". Note
56           this option does not support Ed25519 or Ed448 private keys. Use the
57           pkeyutl command instead for this.
58
59       -keyform arg
60           Specifies the key format to sign digest with. The DER, PEM, P12,
61           and ENGINE formats are supported.
62
63       -sigopt nm:v
64           Pass options to the signature algorithm during sign or verify
65           operations.  Names and values of these options are algorithm-
66           specific.
67
68       -passin arg
69           The private key password source. For more information about the
70           format of arg see the PASS PHRASE ARGUMENTS section in openssl(1).
71
72       -verify filename
73           Verify the signature using the public key in "filename".  The
74           output is either "Verification OK" or "Verification Failure".
75
76       -prverify filename
77           Verify the signature using the private key in "filename".
78
79       -signature filename
80           The actual signature to verify.
81
82       -hmac key
83           Create a hashed MAC using "key".
84
85       -mac alg
86           Create MAC (keyed Message Authentication Code). The most popular
87           MAC algorithm is HMAC (hash-based MAC), but there are other MAC
88           algorithms which are not based on hash, for instance gost-mac
89           algorithm, supported by ccgost engine. MAC keys and other options
90           should be set via -macopt parameter.
91
92       -macopt nm:v
93           Passes options to MAC algorithm, specified by -mac key.  Following
94           options are supported by both by HMAC and gost-mac:
95
96           key:string
97               Specifies MAC key as alphanumeric string (use if key contain
98               printable characters only). String length must conform to any
99               restrictions of the MAC algorithm for example exactly 32 chars
100               for gost-mac.
101
102           hexkey:string
103               Specifies MAC key in hexadecimal form (two hex digits per
104               byte).  Key length must conform to any restrictions of the MAC
105               algorithm for example exactly 32 chars for gost-mac.
106
107       -rand file...
108           A file or files containing random data used to seed the random
109           number generator.  Multiple files can be specified separated by an
110           OS-dependent character.  The separator is ; for MS-Windows, , for
111           OpenVMS, and : for all others.
112
113       [-writerand file]
114           Writes random data to the specified file upon exit.  This can be
115           used with a subsequent -rand flag.
116
117       -fips-fingerprint
118           Compute HMAC using a specific key for certain OpenSSL-FIPS
119           operations.
120
121       -engine id
122           Use engine id for operations (including private key storage).  This
123           engine is not used as source for digest algorithms, unless it is
124           also specified in the configuration file or -engine_impl is also
125           specified.
126
127       -engine_impl
128           When used with the -engine option, it specifies to also use engine
129           id for digest operations.
130
131       file...
132           File or files to digest. If no files are specified then standard
133           input is used.
134

EXAMPLES

136       To create a hex-encoded message digest of a file:
137        openssl dgst -md5 -hex file.txt
138
139       To sign a file using SHA-256 with binary file output:
140        openssl dgst -sha256 -sign privatekey.pem -out signature.sign file.txt
141
142       To verify a signature:
143        openssl dgst -sha256 -verify publickey.pem \
144        -signature signature.sign \
145        file.txt
146

NOTES

148       The digest mechanisms that are available will depend on the options
149       used when building OpenSSL.  The list digest-commands command can be
150       used to list them.
151
152       New or agile applications should use probably use SHA-256. Other
153       digests, particularly SHA-1 and MD5, are still widely used for
154       interoperating with existing formats and protocols.
155
156       When signing a file, dgst will automatically determine the algorithm
157       (RSA, ECC, etc) to use for signing based on the private key's ASN.1
158       info.  When verifying signatures, it only handles the RSA, DSA, or
159       ECDSA signature itself, not the related data to identify the signer and
160       algorithm used in formats such as x.509, CMS, and S/MIME.
161
162       A source of random numbers is required for certain signing algorithms,
163       in particular ECDSA and DSA.
164
165       The signing and verify options should only be used if a single file is
166       being signed or verified.
167
168       Hex signatures cannot be verified using openssl.  Instead, use "xxd -r"
169       or similar program to transform the hex signature into a binary
170       signature prior to verification.
171

HISTORY

173       The default digest was changed from MD5 to SHA256 in OpenSSL 1.1.0.
174       The FIPS-related options were removed in OpenSSL 1.1.0.
175
177       Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.
178
179       Licensed under the OpenSSL license (the "License").  You may not use
180       this file except in compliance with the License.  You can obtain a copy
181       in the file LICENSE in the source distribution or at
182       <https://www.openssl.org/source/license.html>.
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1861.1.1d                            2019-10-03                           DGST(1)
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