6 dgst - perform digest operations
23 [B<-prverify filename>]
24 [B<-signature filename>]
27 [B<-fips-fingerprint>]
33 B<openssl> I<digest> [B<...>]
37 The digest functions output the message digest of a supplied file or files
38 in hexadecimal. The digest functions also generate and verify digital
39 signatures using message digests.
41 The generic name, B<dgst>, may be used with an option specifying the
43 The default digest is I<sha256>.
44 A supported I<digest> name may also be used as the command name.
45 To see the list of supported algorithms, use the I<list --digest-commands>
54 Print out a usage message.
58 Specifies name of a supported digest to be used. To see the list of
59 supported digests, use the command I<list --digest-commands>.
63 Print out the digest in two digit groups separated by colons, only relevant if
64 B<hex> format output is used.
68 Print out BIO debugging information.
72 Digest is to be output as a hex dump. This is the default case for a "normal"
73 digest as opposed to a digital signature. See NOTES below for digital
74 signatures using B<-hex>.
78 Output the digest or signature in binary form.
82 Output the digest in the "coreutils" format used by programs like B<sha1sum>.
84 =item B<-out filename>
86 Filename to output to, or standard output by default.
88 =item B<-sign filename>
90 Digitally sign the digest using the private key in "filename". Note this option
91 does not support Ed25519 or Ed448 private keys. Use the B<pkeyutl> command
96 Specifies the key format to sign digest with. The DER, PEM, P12,
97 and ENGINE formats are supported.
101 Pass options to the signature algorithm during sign or verify operations.
102 Names and values of these options are algorithm-specific.
106 The private key password source. For more information about the format of B<arg>
107 see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
109 =item B<-verify filename>
111 Verify the signature using the public key in "filename".
112 The output is either "Verification OK" or "Verification Failure".
114 =item B<-prverify filename>
116 Verify the signature using the private key in "filename".
118 =item B<-signature filename>
120 The actual signature to verify.
124 Create a hashed MAC using "key".
128 Create MAC (keyed Message Authentication Code). The most popular MAC
129 algorithm is HMAC (hash-based MAC), but there are other MAC algorithms
130 which are not based on hash, for instance B<gost-mac> algorithm,
131 supported by B<ccgost> engine. MAC keys and other options should be set
132 via B<-macopt> parameter.
134 =item B<-macopt nm:v>
136 Passes options to MAC algorithm, specified by B<-mac> key.
137 Following options are supported by both by B<HMAC> and B<gost-mac>:
143 Specifies MAC key as alphanumeric string (use if key contain printable
144 characters only). String length must conform to any restrictions of
145 the MAC algorithm for example exactly 32 chars for gost-mac.
147 =item B<hexkey:string>
149 Specifies MAC key in hexadecimal form (two hex digits per byte).
150 Key length must conform to any restrictions of the MAC algorithm
151 for example exactly 32 chars for gost-mac.
155 =item B<-rand file...>
157 A file or files containing random data used to seed the random number
159 Multiple files can be specified separated by an OS-dependent character.
160 The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
163 =item [B<-writerand file>]
165 Writes random data to the specified I<file> upon exit.
166 This can be used with a subsequent B<-rand> flag.
168 =item B<-fips-fingerprint>
170 Compute HMAC using a specific key for certain OpenSSL-FIPS operations.
174 Use engine B<id> for operations (including private key storage).
175 This engine is not used as source for digest algorithms, unless it is
176 also specified in the configuration file or B<-engine_impl> is also
179 =item B<-engine_impl>
181 When used with the B<-engine> option, it specifies to also use
182 engine B<id> for digest operations.
186 File or files to digest. If no files are specified then standard input is
194 To create a hex-encoded message digest of a file:
195 openssl dgst -md5 -hex file.txt
197 To sign a file using SHA-256 with binary file output:
198 openssl dgst -sha256 -sign privatekey.pem -out signature.sign file.txt
200 To verify a signature:
201 openssl dgst -sha256 -verify publickey.pem \
202 -signature signature.sign \
208 The digest mechanisms that are available will depend on the options
209 used when building OpenSSL.
210 The B<list digest-commands> command can be used to list them.
212 New or agile applications should use probably use SHA-256. Other digests,
213 particularly SHA-1 and MD5, are still widely used for interoperating
214 with existing formats and protocols.
216 When signing a file, B<dgst> will automatically determine the algorithm
217 (RSA, ECC, etc) to use for signing based on the private key's ASN.1 info.
218 When verifying signatures, it only handles the RSA, DSA, or ECDSA signature
219 itself, not the related data to identify the signer and algorithm used in
220 formats such as x.509, CMS, and S/MIME.
222 A source of random numbers is required for certain signing algorithms, in
223 particular ECDSA and DSA.
225 The signing and verify options should only be used if a single file is
226 being signed or verified.
228 Hex signatures cannot be verified using B<openssl>. Instead, use "xxd -r"
229 or similar program to transform the hex signature into a binary signature
230 prior to verification.
234 The default digest was changed from MD5 to SHA256 in OpenSSL 1.1.0.
235 The FIPS-related options were removed in OpenSSL 1.1.0.
239 Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.
241 Licensed under the Apache License 2.0 (the "License"). You may not use
242 this file except in compliance with the License. You can obtain a copy
243 in the file LICENSE in the source distribution or at
244 L<https://www.openssl.org/source/license.html>.