6 dgst - perform digest operations
24 [B<-prverify filename>]
25 [B<-signature filename>]
28 [B<-fips-fingerprint>]
34 B<openssl> I<digest> [B<...>]
38 The digest functions output the message digest of a supplied file or files
39 in hexadecimal. The digest functions also generate and verify digital
40 signatures using message digests.
42 The generic name, B<dgst>, may be used with an option specifying the
44 The default digest is I<sha256>.
45 A supported I<digest> name may also be used as the command name.
46 To see the list of supported algorithms, use the I<list --digest-commands>
55 Print out a usage message.
59 Specifies name of a supported digest to be used. To see the list of
60 supported digests, use the command I<list --digest-commands>.
64 Print out the digest in two digit groups separated by colons, only relevant if
65 B<hex> format output is used.
69 Print out BIO debugging information.
73 Prints out a list of supported message digests.
77 Digest is to be output as a hex dump. This is the default case for a "normal"
78 digest as opposed to a digital signature. See NOTES below for digital
79 signatures using B<-hex>.
83 Output the digest or signature in binary form.
87 Output the digest in the "coreutils" format, including newlines.
88 Used by programs like B<sha1sum>.
90 =item B<-out filename>
92 Filename to output to, or standard output by default.
94 =item B<-sign filename>
96 Digitally sign the digest using the private key in "filename". Note this option
97 does not support Ed25519 or Ed448 private keys.
101 Specifies the key format to sign digest with. The DER, PEM, P12,
102 and ENGINE formats are supported.
104 =item B<-sigopt nm:v>
106 Pass options to the signature algorithm during sign or verify operations.
107 Names and values of these options are algorithm-specific.
111 The private key password source. For more information about the format of B<arg>
112 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
114 =item B<-verify filename>
116 Verify the signature using the public key in "filename".
117 The output is either "Verification OK" or "Verification Failure".
119 =item B<-prverify filename>
121 Verify the signature using the private key in "filename".
123 =item B<-signature filename>
125 The actual signature to verify.
129 Create a hashed MAC using "key".
133 Create MAC (keyed Message Authentication Code). The most popular MAC
134 algorithm is HMAC (hash-based MAC), but there are other MAC algorithms
135 which are not based on hash, for instance B<gost-mac> algorithm,
136 supported by B<ccgost> engine. MAC keys and other options should be set
137 via B<-macopt> parameter.
139 =item B<-macopt nm:v>
141 Passes options to MAC algorithm, specified by B<-mac> key.
142 Following options are supported by both by B<HMAC> and B<gost-mac>:
148 Specifies MAC key as alphanumeric string (use if key contain printable
149 characters only). String length must conform to any restrictions of
150 the MAC algorithm for example exactly 32 chars for gost-mac.
152 =item B<hexkey:string>
154 Specifies MAC key in hexadecimal form (two hex digits per byte).
155 Key length must conform to any restrictions of the MAC algorithm
156 for example exactly 32 chars for gost-mac.
160 =item B<-rand file...>
162 A file or files containing random data used to seed the random number
164 Multiple files can be specified separated by an OS-dependent character.
165 The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
168 =item [B<-writerand file>]
170 Writes random data to the specified I<file> upon exit.
171 This can be used with a subsequent B<-rand> flag.
173 =item B<-fips-fingerprint>
175 Compute HMAC using a specific key for certain OpenSSL-FIPS operations.
179 Use engine B<id> for operations (including private key storage).
180 This engine is not used as source for digest algorithms, unless it is
181 also specified in the configuration file or B<-engine_impl> is also
184 =item B<-engine_impl>
186 When used with the B<-engine> option, it specifies to also use
187 engine B<id> for digest operations.
191 File or files to digest. If no files are specified then standard input is
199 To create a hex-encoded message digest of a file:
200 openssl dgst -md5 -hex file.txt
202 To sign a file using SHA-256 with binary file output:
203 openssl dgst -sha256 -sign privatekey.pem -out signature.sign file.txt
205 To verify a signature:
206 openssl dgst -sha256 -verify publickey.pem \
207 -signature signature.sign \
213 The digest mechanisms that are available will depend on the options
214 used when building OpenSSL.
215 The B<list digest-commands> command can be used to list them.
217 New or agile applications should use probably use SHA-256. Other digests,
218 particularly SHA-1 and MD5, are still widely used for interoperating
219 with existing formats and protocols.
221 When signing a file, B<dgst> will automatically determine the algorithm
222 (RSA, ECC, etc) to use for signing based on the private key's ASN.1 info.
223 When verifying signatures, it only handles the RSA, DSA, or ECDSA signature
224 itself, not the related data to identify the signer and algorithm used in
225 formats such as x.509, CMS, and S/MIME.
227 A source of random numbers is required for certain signing algorithms, in
228 particular ECDSA and DSA.
230 The signing and verify options should only be used if a single file is
231 being signed or verified.
233 Hex signatures cannot be verified using B<openssl>. Instead, use "xxd -r"
234 or similar program to transform the hex signature into a binary signature
235 prior to verification.
239 The default digest was changed from MD5 to SHA256 in OpenSSL 1.1.0.
240 The FIPS-related options were removed in OpenSSL 1.1.0.
244 Copyright 2000-2020 The OpenSSL Project Authors. All Rights Reserved.
246 Licensed under the OpenSSL license (the "License"). You may not use
247 this file except in compliance with the License. You can obtain a copy
248 in the file LICENSE in the source distribution or at
249 L<https://www.openssl.org/source/license.html>.