1=pod 2{- OpenSSL::safe::output_do_not_edit_headers(); -} 3 4=head1 NAME 5 6openssl-dgst - perform digest operations 7 8=head1 SYNOPSIS 9 10B<openssl> B<dgst>|I<digest> 11[B<-I<digest>>] 12[B<-list>] 13[B<-help>] 14[B<-c>] 15[B<-d>] 16[B<-debug>] 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 42This command output the message digest of a supplied file or files 43in hexadecimal, and also generates and verifies digital 44signatures using message digests. 45 46The generic name, B<openssl dgst>, may be used with an option specifying the 47algorithm to be used. 48The default digest is B<sha256>. 49A supported I<digest> name may also be used as the sub-command name. 50To see the list of supported algorithms, use C<openssl list -digest-algorithms> 51 52=head1 OPTIONS 53 54=over 4 55 56=item B<-help> 57 58Print out a usage message. 59 60=item B<-I<digest>> 61 62Specifies name of a supported digest to be used. See option B<-list> below : 63 64=item B<-list> 65 66Prints out a list of supported message digests. 67 68=item B<-c> 69 70Print out the digest in two digit groups separated by colons, only relevant if 71the B<-hex> option is given as well. 72 73=item B<-d>, B<-debug> 74 75Print out BIO debugging information. 76 77=item B<-hex> 78 79Digest is to be output as a hex dump. This is the default case for a "normal" 80digest as opposed to a digital signature. See NOTES below for digital 81signatures using B<-hex>. 82 83=item B<-binary> 84 85Output the digest or signature in binary form. 86 87=item B<-xoflen> I<length> 88 89Set the output length for XOF algorithms, such as B<shake128> and B<shake256>. 90This option is not supported for signing operations. 91 92For OpenSSL providers it is recommended to set this value for shake algorithms, 93since the default values are set to only supply half of the maximum security 94strength. 95 96For backwards compatibility reasons the default xoflen length for B<shake128> is 9716 (bytes) which results in a security strength of only 64 bits. To ensure the 98maximum security strength of 128 bits, the xoflen should be set to at least 32. 99 100For backwards compatibility reasons the default xoflen length for B<shake256> is 10132 (bytes) which results in a security strength of only 128 bits. To ensure the 102maximum security strength of 256 bits, the xoflen should be set to at least 64. 103 104=item B<-r> 105 106=for openssl foreign manual sha1sum(1) 107 108Output the digest in the "coreutils" format, including newlines. 109Used by programs like L<sha1sum(1)>. 110 111=item B<-out> I<filename> 112 113Filename to output to, or standard output by default. 114 115=item B<-sign> I<filename>|I<uri> 116 117Digitally sign the digest using the given private key. Note this option 118does not support Ed25519 or Ed448 private keys. Use the L<openssl-pkeyutl(1)> 119command instead for this. 120 121=item B<-keyform> B<DER>|B<PEM>|B<P12>|B<ENGINE> 122 123The format of the key to sign with; unspecified by default. 124See L<openssl-format-options(1)> for details. 125 126=item B<-sigopt> I<nm>:I<v> 127 128Pass options to the signature algorithm during sign or verify operations. 129Names and values of these options are algorithm-specific. 130 131=item B<-passin> I<arg> 132 133The private key password source. For more information about the format of I<arg> 134see L<openssl-passphrase-options(1)>. 135 136=item B<-verify> I<filename> 137 138Verify the signature using the public key in "filename". 139The output is either "Verified OK" or "Verification Failure". 140 141=item B<-prverify> I<filename> 142 143Verify the signature using the private key in "filename". 144 145=item B<-signature> I<filename> 146 147The actual signature to verify. 148 149=item B<-hmac> I<key> 150 151Create a hashed MAC using "key". 152 153The L<openssl-mac(1)> command should be preferred to using this command line 154option. 155 156=item B<-mac> I<alg> 157 158Create MAC (keyed Message Authentication Code). The most popular MAC 159algorithm is HMAC (hash-based MAC), but there are other MAC algorithms 160which are not based on hash, for instance B<gost-mac> algorithm, 161supported by the B<gost> engine. MAC keys and other options should be set 162via B<-macopt> parameter. 163 164The L<openssl-mac(1)> command should be preferred to using this command line 165option. 166 167=item B<-macopt> I<nm>:I<v> 168 169Passes options to MAC algorithm, specified by B<-mac> key. 170Following options are supported by both by B<HMAC> and B<gost-mac>: 171 172=over 4 173 174=item B<key>:I<string> 175 176Specifies MAC key as alphanumeric string (use if key contain printable 177characters only). String length must conform to any restrictions of 178the MAC algorithm for example exactly 32 chars for gost-mac. 179 180=item B<hexkey>:I<string> 181 182Specifies MAC key in hexadecimal form (two hex digits per byte). 183Key length must conform to any restrictions of the MAC algorithm 184for example exactly 32 chars for gost-mac. 185 186=back 187 188The L<openssl-mac(1)> command should be preferred to using this command line 189option. 190 191=item B<-fips-fingerprint> 192 193Compute HMAC using a specific key for certain OpenSSL-FIPS operations. 194 195{- $OpenSSL::safe::opt_r_item -} 196 197{- $OpenSSL::safe::opt_engine_item -} 198{- output_off() if $disabled{"deprecated-3.0"}; "" -} 199The engine is not used for digests unless the B<-engine_impl> option is 200used or it is configured to do so, see L<config(5)/Engine Configuration Module>. 201 202=item B<-engine_impl> I<id> 203 204When used with the B<-engine> option, it specifies to also use 205engine I<id> for digest operations. 206 207{- output_on() if $disabled{"deprecated-3.0"}; "" -} 208{- $OpenSSL::safe::opt_provider_item -} 209 210=item I<file> ... 211 212File or files to digest. If no files are specified then standard input is 213used. 214 215=back 216 217 218=head1 EXAMPLES 219 220To create a hex-encoded message digest of a file: 221 222 openssl dgst -md5 -hex file.txt 223 or 224 openssl md5 file.txt 225 226To sign a file using SHA-256 with binary file output: 227 228 openssl dgst -sha256 -sign privatekey.pem -out signature.sign file.txt 229 or 230 openssl sha256 -sign privatekey.pem -out signature.sign file.txt 231 232To verify a signature: 233 234 openssl dgst -sha256 -verify publickey.pem \ 235 -signature signature.sign \ 236 file.txt 237 238 239=head1 NOTES 240 241The digest mechanisms that are available will depend on the options 242used when building OpenSSL. 243The C<openssl list -digest-algorithms> command can be used to list them. 244 245New or agile applications should use probably use SHA-256. Other digests, 246particularly SHA-1 and MD5, are still widely used for interoperating 247with existing formats and protocols. 248 249When signing a file, this command will automatically determine the algorithm 250(RSA, ECC, etc) to use for signing based on the private key's ASN.1 info. 251When verifying signatures, it only handles the RSA, DSA, or ECDSA signature 252itself, not the related data to identify the signer and algorithm used in 253formats such as x.509, CMS, and S/MIME. 254 255A source of random numbers is required for certain signing algorithms, in 256particular ECDSA and DSA. 257 258The signing and verify options should only be used if a single file is 259being signed or verified. 260 261Hex signatures cannot be verified using B<openssl>. Instead, use "xxd -r" 262or similar program to transform the hex signature into a binary signature 263prior to verification. 264 265The L<openssl-mac(1)> command is preferred over the B<-hmac>, B<-mac> and 266B<-macopt> command line options. 267 268=head1 SEE ALSO 269 270L<openssl-mac(1)> 271 272=head1 HISTORY 273 274The default digest was changed from MD5 to SHA256 in OpenSSL 1.1.0. 275The FIPS-related options were removed in OpenSSL 1.1.0. 276 277The B<-engine> and B<-engine_impl> options were deprecated in OpenSSL 3.0. 278 279=head1 COPYRIGHT 280 281Copyright 2000-2022 The OpenSSL Project Authors. All Rights Reserved. 282 283Licensed under the Apache License 2.0 (the "License"). You may not use 284this file except in compliance with the License. You can obtain a copy 285in the file LICENSE in the source distribution or at 286L<https://www.openssl.org/source/license.html>. 287 288=cut 289