doc/man1/openssl-dgst.pod.in

   1 =pod
   2 {- OpenSSL::safe::output_do_not_edit_headers(); -}
   3
   4 =head1 NAME
   5
   6 openssl-dgst - perform digest operations
   7
   8 =head1 SYNOPSIS
   9
  10 B<openssl> B<dgst>|I<digest>
  11 [B<-I<digest>>]
  12 [B<-help>]
  13 [B<-c>]
  14 [B<-d>]
  15 [B<-debug>]
  16 [B<-list>]
  17 [B<-hex>]
  18 [B<-binary>]
  19 [B<-xoflen> I<length>]
  20 [B<-r>]
  21 [B<-out> I<filename>]
  22 [B<-sign> I<filename>|I<uri>]
  23 [B<-keyform> B<DER>|B<PEM>|B<P12>|B<ENGINE>]
  24 [B<-passin> I<arg>]
  25 [B<-verify> I<filename>]
  26 [B<-prverify> I<filename>]
  27 [B<-signature> I<filename>]
  28 [B<-sigopt> I<nm>:I<v>]
  29 [B<-hmac> I<key>]
  30 [B<-mac> I<alg>]
  31 [B<-macopt> I<nm>:I<v>]
  32 [B<-fips-fingerprint>]
  33 {- $OpenSSL::safe::opt_engine_synopsis -}{- output_off() if $disabled{"deprecated-3.0"}; ""
  34 -}[B<-engine_impl> I<id>]{-
  35   output_on() if $disabled{"deprecated-3.0"}; "" -}
  36 {- $OpenSSL::safe::opt_r_synopsis -}
  37 {- $OpenSSL::safe::opt_provider_synopsis -}
  38 [I<file> ...]
  39
  40 =head1 DESCRIPTION
  41
  42 This command output the message digest of a supplied file or files
  43 in hexadecimal, and also generates and verifies digital
  44 signatures using message digests.
  45
  46 The generic name, B<openssl dgst>, may be used with an option specifying the
  47 algorithm to be used.
  48 The default digest is B<sha256>.
  49 A supported I<digest> name may also be used as the sub-command name.
  50 To see the list of supported algorithms, use C<openssl list -digest-commands>
  51
  52 =head1 OPTIONS
  53
  54 =over 4
  55
  56 =item B<-help>
  57
  58 Print out a usage message.
  59
  60 =item B<-I<digest>>
  61
  62 Specifies name of a supported digest to be used. To see the list of
  63 supported digests, use the command C<list --digest-commands>.
  64
  65 =item B<-c>
  66
  67 Print out the digest in two digit groups separated by colons, only relevant if
  68 the B<-hex> option is given as well.
  69
  70 =item B<-d>, B<-debug>
  71
  72 Print out BIO debugging information.
  73
  74 =item B<-list>
  75
  76 Prints out a list of supported message digests.
  77
  78 =item B<-hex>
  79
  80 Digest is to be output as a hex dump. This is the default case for a "normal"
  81 digest as opposed to a digital signature.  See NOTES below for digital
  82 signatures using B<-hex>.
  83
  84 =item B<-binary>
  85
  86 Output the digest or signature in binary form.
  87
  88 =item B<-xoflen> I<length>
  89
  90 Set the output length for XOF algorithms, such as B<shake128>.
  91
  92 =item B<-r>
  93
  94 =for openssl foreign manual sha1sum(1)
  95
  96 Output the digest in the "coreutils" format, including newlines.
  97 Used by programs like L<sha1sum(1)>.
  98
  99 =item B<-out> I<filename>
 100
 101 Filename to output to, or standard output by default.
 102
 103 =item B<-sign> I<filename>|I<uri>
 104
 105 Digitally sign the digest using the given private key. Note this option
 106 does not support Ed25519 or Ed448 private keys. Use the L<openssl-pkeyutl(1)>
 107 command instead for this.
 108
 109 =item B<-keyform> B<DER>|B<PEM>|B<P12>|B<ENGINE>
 110
 111 The format of the key to sign with; the default is B<PEM>.
 112 The only value with effect is B<ENGINE>; all others have become obsolete.
 113 See L<openssl-format-options(1)> for details.
 114
 115 =item B<-sigopt> I<nm>:I<v>
 116
 117 Pass options to the signature algorithm during sign or verify operations.
 118 Names and values of these options are algorithm-specific.
 119
 120 =item B<-passin> I<arg>
 121
 122 The private key password source. For more information about the format of I<arg>
 123 see L<openssl-passphrase-options(1)>.
 124
 125 =item B<-verify> I<filename>
 126
 127 Verify the signature using the public key in "filename".
 128 The output is either "Verified OK" or "Verification Failure".
 129
 130 =item B<-prverify> I<filename>
 131
 132 Verify the signature using the private key in "filename".
 133
 134 =item B<-signature> I<filename>
 135
 136 The actual signature to verify.
 137
 138 =item B<-hmac> I<key>
 139
 140 Create a hashed MAC using "key".
 141
 142 The L<openssl-mac(1)> command should be preferred to using this command line
 143 option.
 144
 145 =item B<-mac> I<alg>
 146
 147 Create MAC (keyed Message Authentication Code). The most popular MAC
 148 algorithm is HMAC (hash-based MAC), but there are other MAC algorithms
 149 which are not based on hash, for instance B<gost-mac> algorithm,
 150 supported by the B<gost> engine. MAC keys and other options should be set
 151 via B<-macopt> parameter.
 152
 153 The L<openssl-mac(1)> command should be preferred to using this command line
 154 option.
 155
 156 =item B<-macopt> I<nm>:I<v>
 157
 158 Passes options to MAC algorithm, specified by B<-mac> key.
 159 Following options are supported by both by B<HMAC> and B<gost-mac>:
 160
 161 =over 4
 162
 163 =item B<key>:I<string>
 164
 165 Specifies MAC key as alphanumeric string (use if key contain printable
 166 characters only). String length must conform to any restrictions of
 167 the MAC algorithm for example exactly 32 chars for gost-mac.
 168
 169 =item B<hexkey>:I<string>
 170
 171 Specifies MAC key in hexadecimal form (two hex digits per byte).
 172 Key length must conform to any restrictions of the MAC algorithm
 173 for example exactly 32 chars for gost-mac.
 174
 175 =back
 176
 177 The L<openssl-mac(1)> command should be preferred to using this command line
 178 option.
 179
 180 =item B<-fips-fingerprint>
 181
 182 Compute HMAC using a specific key for certain OpenSSL-FIPS operations.
 183
 184 {- $OpenSSL::safe::opt_r_item -}
 185
 186 {- $OpenSSL::safe::opt_engine_item -}
 187 {- output_off() if $disabled{"deprecated-3.0"}; "" -}
 188 The engine is not used for digests unless the B<-engine_impl> option is
 189 used or it is configured to do so, see L<config(5)/Engine Configuration Module>.
 190
 191 =item B<-engine_impl> I<id>
 192
 193 When used with the B<-engine> option, it specifies to also use
 194 engine I<id> for digest operations.
 195
 196 {- output_on() if $disabled{"deprecated-3.0"}; "" -}
 197 {- $OpenSSL::safe::opt_provider_item -}
 198
 199 =item I<file> ...
 200
 201 File or files to digest. If no files are specified then standard input is
 202 used.
 203
 204 =back
 205
 206
 207 =head1 EXAMPLES
 208
 209 To create a hex-encoded message digest of a file:
 210  openssl dgst -md5 -hex file.txt
 211
 212 To sign a file using SHA-256 with binary file output:
 213  openssl dgst -sha256 -sign privatekey.pem -out signature.sign file.txt
 214
 215 To verify a signature:
 216  openssl dgst -sha256 -verify publickey.pem \
 217  -signature signature.sign \
 218  file.txt
 219
 220
 221 =head1 NOTES
 222
 223 The digest mechanisms that are available will depend on the options
 224 used when building OpenSSL.
 225 The C<openssl list -digest-commands> command can be used to list them.
 226
 227 New or agile applications should use probably use SHA-256. Other digests,
 228 particularly SHA-1 and MD5, are still widely used for interoperating
 229 with existing formats and protocols.
 230
 231 When signing a file, this command will automatically determine the algorithm
 232 (RSA, ECC, etc) to use for signing based on the private key's ASN.1 info.
 233 When verifying signatures, it only handles the RSA, DSA, or ECDSA signature
 234 itself, not the related data to identify the signer and algorithm used in
 235 formats such as x.509, CMS, and S/MIME.
 236
 237 A source of random numbers is required for certain signing algorithms, in
 238 particular ECDSA and DSA.
 239
 240 The signing and verify options should only be used if a single file is
 241 being signed or verified.
 242
 243 Hex signatures cannot be verified using B<openssl>.  Instead, use "xxd -r"
 244 or similar program to transform the hex signature into a binary signature
 245 prior to verification.
 246
 247 The L<openssl-mac(1)> command is preferred over the B<-hmac>, B<-mac> and
 248 B<-macopt> command line options.
 249
 250 =head1 SEE ALSO
 251
 252 L<openssl-mac(1)>
 253
 254 =head1 HISTORY
 255
 256 The default digest was changed from MD5 to SHA256 in OpenSSL 1.1.0.
 257 The FIPS-related options were removed in OpenSSL 1.1.0.
 258
 259 All B<-keyform> values except B<ENGINE> have become obsolete in OpenSSL 3.0.0
 260 and have no effect.
 261
 262 The B<-engine> and B<-engine_impl> options were deprecated in OpenSSL 3.0.
 263
 264 =head1 COPYRIGHT
 265
 266 Copyright 2000-2021 The OpenSSL Project Authors. All Rights Reserved.
 267
 268 Licensed under the Apache License 2.0 (the "License").  You may not use
 269 this file except in compliance with the License.  You can obtain a copy
 270 in the file LICENSE in the source distribution or at
 271 L<https://www.openssl.org/source/license.html>.
 272
 273 =cut