dgst.pod 6.2 KB
Newer Older
1
=pod
2

3 4
=head1 NAME

B
Bill Cox 已提交
5
dgst, sha, sha1, mdc2, ripemd160, sha224, sha256, sha384, sha512, md4, md5, blake2b, blake2s - message digests
6 7 8

=head1 SYNOPSIS

R
Rich Salz 已提交
9
B<openssl> B<dgst>
10
[B<-help>]
R
Rich Salz 已提交
11
[B<-I<digest>>]
12 13
[B<-c>]
[B<-d>]
14 15
[B<-hex>]
[B<-binary>]
R
Rich Salz 已提交
16
[B<-r>]
17 18
[B<-out filename>]
[B<-sign filename>]
D
Dr. Stephen Henson 已提交
19
[B<-keyform arg>]
20
[B<-passin arg>]
21 22 23
[B<-verify filename>]
[B<-prverify filename>]
[B<-signature filename>]
24
[B<-hmac key>]
R
Rich Salz 已提交
25
[B<-fips-fingerprint>]
R
Rich Salz 已提交
26 27
[B<-engine id>]
[B<-engine_impl>]
28 29
[B<file...>]

R
Rich Salz 已提交
30 31 32
B<openssl>
[I<digest>]
[B<...>]
33 34 35

=head1 DESCRIPTION

36
The digest functions output the message digest of a supplied file or files
R
Rich Salz 已提交
37 38
in hexadecimal.  The digest functions also generate and verify digital
signatures using message digests.
39

R
Rich Salz 已提交
40 41 42
The generic name, B<dgst>, may be used with an option specifying the
algorithm to be used.
The default digest is I<sha256>.
R
Rich Salz 已提交
43 44
A supported I<digest> name may also be used as the command name.
To see the list of supported algorithms, use the I<list --digest-commands>
R
Rich Salz 已提交
45 46
command.

47 48 49 50
=head1 OPTIONS

=over 4

51 52 53 54
=item B<-help>

Print out a usage message.

R
Rich Salz 已提交
55 56 57 58 59
=item B<-I<digest>>

Specifies name of a supported digest to be used. To see the list of
supported digests, use the command I<list --digest-commands>.

60 61
=item B<-c>

62 63
print out the digest in two digit groups separated by colons, only relevant if
B<hex> format output is used.
64 65 66 67 68

=item B<-d>

print out BIO debugging information.

69 70 71
=item B<-hex>

digest is to be output as a hex dump. This is the default case for a "normal"
R
Rich Salz 已提交
72 73
digest as opposed to a digital signature.  See NOTES below for digital
signatures using B<-hex>.
74 75 76 77 78

=item B<-binary>

output the digest or signature in binary form.

R
Rich Salz 已提交
79 80 81 82
=item B<-r>

output the digest in the "coreutils" format used by programs like B<sha1sum>.

83 84 85 86 87 88 89 90
=item B<-out filename>

filename to output to, or standard output by default.

=item B<-sign filename>

digitally sign the digest using the private key in "filename".

D
Dr. Stephen Henson 已提交
91 92
=item B<-keyform arg>

R
Rich Salz 已提交
93 94
Specifies the key format to sign digest with. The DER, PEM, P12,
and ENGINE formats are supported.
D
Dr. Stephen Henson 已提交
95 96 97 98 99 100 101

=item B<-sigopt nm:v>

Pass options to the signature algorithm during sign or verify operations.
Names and values of these options are algorithm-specific.


102 103 104
=item B<-passin arg>

the private key password source. For more information about the format of B<arg>
R
Rich Salz 已提交
105
see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)>.
106

107 108
=item B<-verify filename>

A
Alex Gaynor 已提交
109
verify the signature using the public key in "filename".
110 111 112 113
The output is either "Verification OK" or "Verification Failure".

=item B<-prverify filename>

A
Alex Gaynor 已提交
114
verify the signature using the private key in "filename".
115 116 117 118 119

=item B<-signature filename>

the actual signature to verify.

120 121 122 123
=item B<-hmac key>

create a hashed MAC using "key".

D
Dr. Stephen Henson 已提交
124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139
=item B<-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 B<gost-mac> algorithm,
supported by B<ccgost> engine. MAC keys and other options should be set
via B<-macopt> parameter.

=item B<-macopt nm:v>

Passes options to MAC algorithm, specified by B<-mac> key.
Following options are supported by both by B<HMAC> and B<gost-mac>:

=over 8

=item B<key:string>
R
Rich Salz 已提交
140

A
Alok Menghrajani 已提交
141
Specifies MAC key as alphanumeric string (use if key contain printable
D
Dr. Stephen Henson 已提交
142 143 144 145 146 147 148 149 150 151 152
characters only). String length must conform to any restrictions of
the MAC algorithm for example exactly 32 chars for gost-mac.

=item B<hexkey:string>

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.

=back

153 154 155
=item B<-rand file(s)>

a file or files containing random data used to seed the random number
R
Rich Salz 已提交
156
generator, or an EGD socket (see L<RAND_egd(3)>).
A
Alex Gaynor 已提交
157
Multiple files can be specified separated by an OS-dependent character.
158 159 160
The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for
all others. 

R
Rich Salz 已提交
161 162 163 164 165
=item B<-fips-fingerprint>

compute HMAC using a specific key
for certain OpenSSL-FIPS operations.

R
Rich Salz 已提交
166 167 168 169 170 171 172 173 174 175 176 177
=item B<-engine id>

Use engine B<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 B<-engine_impl> is also
specified.

=item B<-engine_impl>

When used with the B<-engine> option, it specifies to also use
engine B<id> for digest operations.

178 179 180 181 182 183 184
=item B<file...>

file or files to digest. If no files are specified then standard input is
used.

=back

R
Rich Salz 已提交
185 186 187 188 189 190 191 192 193 194 195 196 197 198 199

=head1 EXAMPLES

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 \
 file.txt


200 201
=head1 NOTES

R
Rich Salz 已提交
202 203 204 205
The digest mechanisms that are available will depend on the options
used when building OpenSSL.
The B<list digest-commands> command can be used to list them.

R
Rich Salz 已提交
206 207 208
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.
209

R
Rich Salz 已提交
210 211 212 213 214
When signing a file, B<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.
215 216

A source of random numbers is required for certain signing algorithms, in
R
Rich Salz 已提交
217
particular ECDSA and DSA.
218 219 220 221

The signing and verify options should only be used if a single file is
being signed or verified.

R
Rich Salz 已提交
222 223 224 225
Hex signatures cannot be verified using B<openssl>.  Instead, use "xxd -r"
or similar program to transform the hex signature into a binary signature
prior to verification.

R
Rich Salz 已提交
226 227
=head1 HISTORY

B
Ben Kaduk 已提交
228
The default digest was changed from MD5 to SHA256 in Openssl 1.1.
229
The FIPS-related options were removed in OpenSSL 1.1
R
Rich Salz 已提交
230

231
=cut
R
Rich Salz 已提交
232 233 234 235 236 237 238 239 240 241 242

=head1 COPYRIGHT

Copyright 2000-2016 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
L<https://www.openssl.org/source/license.html>.

=cut