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 and documented 130in L<provider-signature(7)/Signature parameters>. 131 132=item B<-passin> I<arg> 133 134The private key password source. For more information about the format of I<arg> 135see L<openssl-passphrase-options(1)>. 136 137=item B<-verify> I<filename> 138 139Verify the signature using the public key in "filename". 140The output is either "Verified OK" or "Verification Failure". 141 142=item B<-prverify> I<filename> 143 144Verify the signature using the private key in "filename". 145 146=item B<-signature> I<filename> 147 148The actual signature to verify. 149 150=item B<-hmac> I<key> 151 152Create a hashed MAC using "key". 153 154The L<openssl-mac(1)> command should be preferred to using this command line 155option. 156 157=item B<-mac> I<alg> 158 159Create MAC (keyed Message Authentication Code). The most popular MAC 160algorithm is HMAC (hash-based MAC), but there are other MAC algorithms 161which are not based on hash, for instance B<gost-mac> algorithm, 162supported by the B<gost> engine. MAC keys and other options should be set 163via B<-macopt> parameter. 164 165The L<openssl-mac(1)> command should be preferred to using this command line 166option. 167 168=item B<-macopt> I<nm>:I<v> 169 170Passes options to MAC algorithm, specified by B<-mac> key. 171Following options are supported by both by B<HMAC> and B<gost-mac>: 172 173=over 4 174 175=item B<key>:I<string> 176 177Specifies MAC key as alphanumeric string (use if key contain printable 178characters only). String length must conform to any restrictions of 179the MAC algorithm for example exactly 32 chars for gost-mac. 180 181=item B<hexkey>:I<string> 182 183Specifies MAC key in hexadecimal form (two hex digits per byte). 184Key length must conform to any restrictions of the MAC algorithm 185for example exactly 32 chars for gost-mac. 186 187=back 188 189The L<openssl-mac(1)> command should be preferred to using this command line 190option. 191 192=item B<-fips-fingerprint> 193 194Compute HMAC using a specific key for certain OpenSSL-FIPS operations. 195 196{- $OpenSSL::safe::opt_r_item -} 197 198{- $OpenSSL::safe::opt_engine_item -} 199{- output_off() if $disabled{"deprecated-3.0"}; "" -} 200The engine is not used for digests unless the B<-engine_impl> option is 201used or it is configured to do so, see L<config(5)/Engine Configuration Module>. 202 203=item B<-engine_impl> I<id> 204 205When used with the B<-engine> option, it specifies to also use 206engine I<id> for digest operations. 207 208{- output_on() if $disabled{"deprecated-3.0"}; "" -} 209{- $OpenSSL::safe::opt_provider_item -} 210 211=item I<file> ... 212 213File or files to digest. If no files are specified then standard input is 214used. 215 216=back 217 218 219=head1 EXAMPLES 220 221To create a hex-encoded message digest of a file: 222 223 openssl dgst -md5 -hex file.txt 224 or 225 openssl md5 file.txt 226 227To sign a file using SHA-256 with binary file output: 228 229 openssl dgst -sha256 -sign privatekey.pem -out signature.sign file.txt 230 or 231 openssl sha256 -sign privatekey.pem -out signature.sign file.txt 232 233To verify a signature: 234 235 openssl dgst -sha256 -verify publickey.pem \ 236 -signature signature.sign \ 237 file.txt 238 239 240=head1 NOTES 241 242The digest mechanisms that are available will depend on the options 243used when building OpenSSL. 244The C<openssl list -digest-algorithms> command can be used to list them. 245 246New or agile applications should use probably use SHA-256. Other digests, 247particularly SHA-1 and MD5, are still widely used for interoperating 248with existing formats and protocols. 249 250When signing a file, this command will automatically determine the algorithm 251(RSA, ECC, etc) to use for signing based on the private key's ASN.1 info. 252When verifying signatures, it only handles the RSA, DSA, or ECDSA signature 253itself, not the related data to identify the signer and algorithm used in 254formats such as x.509, CMS, and S/MIME. 255 256A source of random numbers is required for certain signing algorithms, in 257particular ECDSA and DSA. 258 259The signing and verify options should only be used if a single file is 260being signed or verified. 261 262Hex signatures cannot be verified using B<openssl>. Instead, use "xxd -r" 263or similar program to transform the hex signature into a binary signature 264prior to verification. 265 266The L<openssl-mac(1)> command is preferred over the B<-hmac>, B<-mac> and 267B<-macopt> command line options. 268 269=head1 SEE ALSO 270 271L<openssl-mac(1)> 272 273=head1 HISTORY 274 275The default digest was changed from MD5 to SHA256 in OpenSSL 1.1.0. 276The FIPS-related options were removed in OpenSSL 1.1.0. 277 278The B<-engine> and B<-engine_impl> options were deprecated in OpenSSL 3.0. 279 280=head1 COPYRIGHT 281 282Copyright 2000-2024 The OpenSSL Project Authors. All Rights Reserved. 283 284Licensed under the Apache License 2.0 (the "License"). You may not use 285this file except in compliance with the License. You can obtain a copy 286in the file LICENSE in the source distribution or at 287L<https://www.openssl.org/source/license.html>. 288 289=cut 290
