1=pod 2 3=head1 NAME 4 5dgst, sha, sha1, mdc2, ripemd160, sha224, sha256, sha384, sha512, md2, md4, md5, dss1 - message digests 6 7=head1 SYNOPSIS 8 9B<openssl> B<dgst> 10[B<-sha|-sha1|-mdc2|-ripemd160|-sha224|-sha256|-sha384|-sha512|-md2|-md4|-md5|-dss1>] 11[B<-c>] 12[B<-d>] 13[B<-hex>] 14[B<-binary>] 15[B<-r>] 16[B<-non-fips-allow>] 17[B<-out filename>] 18[B<-sign filename>] 19[B<-keyform arg>] 20[B<-passin arg>] 21[B<-verify filename>] 22[B<-prverify filename>] 23[B<-signature filename>] 24[B<-hmac key>] 25[B<-non-fips-allow>] 26[B<-fips-fingerprint>] 27[B<file...>] 28 29B<openssl> 30[I<digest>] 31[B<...>] 32 33=head1 DESCRIPTION 34 35The digest functions output the message digest of a supplied file or files 36in hexadecimal. The digest functions also generate and verify digital 37signatures using message digests. 38 39=head1 OPTIONS 40 41=over 4 42 43=item B<-c> 44 45print out the digest in two digit groups separated by colons, only relevant if 46B<hex> format output is used. 47 48=item B<-d> 49 50print out BIO debugging information. 51 52=item B<-hex> 53 54digest is to be output as a hex dump. This is the default case for a "normal" 55digest as opposed to a digital signature. See NOTES below for digital 56signatures using B<-hex>. 57 58=item B<-binary> 59 60output the digest or signature in binary form. 61 62=item B<-r> 63 64output the digest in the "coreutils" format used by programs like B<sha1sum>. 65 66=item B<-non-fips-allow> 67 68Allow use of non FIPS digest when in FIPS mode. This has no effect when not in 69FIPS mode. 70 71=item B<-out filename> 72 73filename to output to, or standard output by default. 74 75=item B<-sign filename> 76 77digitally sign the digest using the private key in "filename". 78 79=item B<-keyform arg> 80 81Specifies the key format to sign digest with. The DER, PEM, P12, 82and ENGINE formats are supported. 83 84=item B<-engine id> 85 86Use engine B<id> for operations (including private key storage). 87This engine is not used as source for digest algorithms, unless it is 88also specified in the configuration file. 89 90=item B<-sigopt nm:v> 91 92Pass options to the signature algorithm during sign or verify operations. 93Names and values of these options are algorithm-specific. 94 95 96=item B<-passin arg> 97 98the private key password source. For more information about the format of B<arg> 99see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>. 100 101=item B<-verify filename> 102 103verify the signature using the the public key in "filename". 104The output is either "Verification OK" or "Verification Failure". 105 106=item B<-prverify filename> 107 108verify the signature using the the private key in "filename". 109 110=item B<-signature filename> 111 112the actual signature to verify. 113 114=item B<-hmac key> 115 116create a hashed MAC using "key". 117 118=item B<-mac alg> 119 120create MAC (keyed Message Authentication Code). The most popular MAC 121algorithm is HMAC (hash-based MAC), but there are other MAC algorithms 122which are not based on hash, for instance B<gost-mac> algorithm, 123supported by B<ccgost> engine. MAC keys and other options should be set 124via B<-macopt> parameter. 125 126=item B<-macopt nm:v> 127 128Passes options to MAC algorithm, specified by B<-mac> key. 129Following options are supported by both by B<HMAC> and B<gost-mac>: 130 131=over 8 132 133=item B<key:string> 134 135Specifies MAC key as alphnumeric string (use if key contain printable 136characters only). String length must conform to any restrictions of 137the MAC algorithm for example exactly 32 chars for gost-mac. 138 139=item B<hexkey:string> 140 141Specifies MAC key in hexadecimal form (two hex digits per byte). 142Key length must conform to any restrictions of the MAC algorithm 143for example exactly 32 chars for gost-mac. 144 145=back 146 147=item B<-rand file(s)> 148 149a file or files containing random data used to seed the random number 150generator, or an EGD socket (see L<RAND_egd(3)|RAND_egd(3)>). 151Multiple files can be specified separated by a OS-dependent character. 152The separator is B<;> for MS-Windows, B<,> for OpenVMS, and B<:> for 153all others. 154 155=item B<-non-fips-allow> 156 157enable use of non-FIPS algorithms such as MD5 even in FIPS mode. 158 159=item B<-fips-fingerprint> 160 161compute HMAC using a specific key 162for certain OpenSSL-FIPS operations. 163 164=item B<file...> 165 166file or files to digest. If no files are specified then standard input is 167used. 168 169=back 170 171 172=head1 EXAMPLES 173 174To create a hex-encoded message digest of a file: 175 openssl dgst -md5 -hex file.txt 176 177To sign a file using SHA-256 with binary file output: 178 openssl dgst -sha256 -sign privatekey.pem -out signature.sign file.txt 179 180To verify a signature: 181 openssl dgst -sha256 -verify publickey.pem \ 182 -signature signature.sign \ 183 file.txt 184 185 186=head1 NOTES 187 188The digest of choice for all new applications is SHA1. Other digests are 189however still widely used. 190 191When signing a file, B<dgst> will automatically determine the algorithm 192(RSA, ECC, etc) to use for signing based on the private key's ASN.1 info. 193When verifying signatures, it only handles the RSA, DSA, or ECDSA signature 194itself, not the related data to identify the signer and algorithm used in 195formats such as x.509, CMS, and S/MIME. 196 197A source of random numbers is required for certain signing algorithms, in 198particular ECDSA and DSA. 199 200The signing and verify options should only be used if a single file is 201being signed or verified. 202 203Hex signatures cannot be verified using B<openssl>. Instead, use "xxd -r" 204or similar program to transform the hex signature into a binary signature 205prior to verification. 206 207 208=cut 209