1 .\" Automatically generated by Pod::Man 4.14 (Pod::Simple 3.43)
4 .\" ========================================================================
5 .de Sp \" Vertical space (when we can't use .PP)
9 .de Vb \" Begin verbatim text
14 .de Ve \" End verbatim text
18 .\" Set up some character translations and predefined strings. \*(-- will
19 .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
20 .\" double quote, and \*(R" will give a right double quote. \*(C+ will
21 .\" give a nicer C++. Capital omega is used to do unbreakable dashes and
22 .\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff,
23 .\" nothing in troff, for use with C<>.
25 .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
29 . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
30 . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch
45 .\" Escape single quotes in literal strings from groff's Unicode transform.
49 .\" If the F register is >0, we'll generate index entries on stderr for
50 .\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
51 .\" entries marked with X<> in POD. Of course, you'll have to process the
52 .\" output yourself in some meaningful fashion.
54 .\" Avoid warning from groff about undefined register 'F'.
58 .if \n(.g .if rF .nr rF 1
59 .if (\n(rF:(\n(.g==0)) \{\
62 . tm Index:\\$1\t\\n%\t"\\$2"
72 .\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
73 .\" Fear. Run. Save yourself. No user-serviceable parts.
74 . \" fudge factors for nroff and troff
83 . ds #H ((1u-(\\\\n(.fu%2u))*.13m)
89 . \" simple accents for nroff and troff
99 . ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
100 . ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
101 . ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
102 . ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
103 . ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
104 . ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
106 . \" troff and (daisy-wheel) nroff accents
107 .ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
108 .ds 8 \h'\*(#H'\(*b\h'-\*(#H'
109 .ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
110 .ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
111 .ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
112 .ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
113 .ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
114 .ds ae a\h'-(\w'a'u*4/10)'e
115 .ds Ae A\h'-(\w'A'u*4/10)'E
116 . \" corrections for vroff
117 .if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
118 .if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
119 . \" for low resolution devices (crt and lpr)
120 .if \n(.H>23 .if \n(.V>19 \
133 .\" ========================================================================
136 .TH EVP 7 "2021-08-24" "1.1.1l" "OpenSSL"
137 .\" For nroff, turn off justification. Always turn off hyphenation; it makes
138 .\" way too many mistakes in technical documents.
142 evp \- high\-level cryptographic functions
144 .IX Header "SYNOPSIS"
146 \& #include <openssl/evp.h>
149 .IX Header "DESCRIPTION"
150 The \s-1EVP\s0 library provides a high-level interface to cryptographic
153 The \fBEVP_Seal\fR\fI\s-1XXX\s0\fR and \fBEVP_Open\fR\fI\s-1XXX\s0\fR
154 functions provide public key encryption and decryption to implement digital \*(L"envelopes\*(R".
156 The \fBEVP_DigestSign\fR\fI\s-1XXX\s0\fR and
157 \&\fBEVP_DigestVerify\fR\fI\s-1XXX\s0\fR functions implement
158 digital signatures and Message Authentication Codes (MACs). Also see the older
159 \&\fBEVP_Sign\fR\fI\s-1XXX\s0\fR and \fBEVP_Verify\fR\fI\s-1XXX\s0\fR
162 Symmetric encryption is available with the \fBEVP_Encrypt\fR\fI\s-1XXX\s0\fR
163 functions. The \fBEVP_Digest\fR\fI\s-1XXX\s0\fR functions provide message digests.
165 The \fB\s-1EVP_PKEY\s0\fR\fI\s-1XXX\s0\fR functions provide a high-level interface to
166 asymmetric algorithms. To create a new \s-1EVP_PKEY\s0 see
167 \&\fBEVP_PKEY_new\fR\|(3). EVP_PKEYs can be associated
168 with a private key of a particular algorithm by using the functions
169 described on the \fBEVP_PKEY_set1_RSA\fR\|(3) page, or
170 new keys can be generated using \fBEVP_PKEY_keygen\fR\|(3).
171 EVP_PKEYs can be compared using \fBEVP_PKEY_cmp\fR\|(3), or printed using
172 \&\fBEVP_PKEY_print_private\fR\|(3).
174 The \s-1EVP_PKEY\s0 functions support the full range of asymmetric algorithm operations:
175 .IP "For key agreement see \fBEVP_PKEY_derive\fR\|(3)" 4
176 .IX Item "For key agreement see EVP_PKEY_derive"
178 .IP "For signing and verifying see \fBEVP_PKEY_sign\fR\|(3), \fBEVP_PKEY_verify\fR\|(3) and \fBEVP_PKEY_verify_recover\fR\|(3). However, note that these functions do not perform a digest of the data to be signed. Therefore, normally you would use the \fBEVP_DigestSignInit\fR\|(3) functions for this purpose." 4
179 .IX Item "For signing and verifying see EVP_PKEY_sign, EVP_PKEY_verify and EVP_PKEY_verify_recover. However, note that these functions do not perform a digest of the data to be signed. Therefore, normally you would use the EVP_DigestSignInit functions for this purpose."
180 .ie n .IP "For encryption and decryption see \fBEVP_PKEY_encrypt\fR\|(3) and \fBEVP_PKEY_decrypt\fR\|(3) respectively. However, note that these functions perform encryption and decryption only. As public key encryption is an expensive operation, normally you would wrap an encrypted message in a ""digital envelope"" using the \fBEVP_SealInit\fR\|(3) and \fBEVP_OpenInit\fR\|(3) functions." 4
181 .el .IP "For encryption and decryption see \fBEVP_PKEY_encrypt\fR\|(3) and \fBEVP_PKEY_decrypt\fR\|(3) respectively. However, note that these functions perform encryption and decryption only. As public key encryption is an expensive operation, normally you would wrap an encrypted message in a ``digital envelope'' using the \fBEVP_SealInit\fR\|(3) and \fBEVP_OpenInit\fR\|(3) functions." 4
182 .IX Item "For encryption and decryption see EVP_PKEY_encrypt and EVP_PKEY_decrypt respectively. However, note that these functions perform encryption and decryption only. As public key encryption is an expensive operation, normally you would wrap an encrypted message in a digital envelope using the EVP_SealInit and EVP_OpenInit functions."
185 The \fBEVP_BytesToKey\fR\|(3) function provides some limited support for password
186 based encryption. Careful selection of the parameters will provide a PKCS#5 \s-1PBKDF1\s0 compatible
187 implementation. However, new applications should not typically use this (preferring, for example,
188 \&\s-1PBKDF2\s0 from PCKS#5).
190 The \fBEVP_Encode\fR\fI\s-1XXX\s0\fR and
191 \&\fBEVP_Decode\fR\fI\s-1XXX\s0\fR functions implement base 64 encoding
194 All the symmetric algorithms (ciphers), digests and asymmetric algorithms
195 (public key algorithms) can be replaced by \s-1ENGINE\s0 modules providing alternative
196 implementations. If \s-1ENGINE\s0 implementations of ciphers or digests are registered
197 as defaults, then the various \s-1EVP\s0 functions will automatically use those
198 implementations automatically in preference to built in software
199 implementations. For more information, consult the \fBengine\fR\|(3) man page.
201 Although low-level algorithm specific functions exist for many algorithms
202 their use is discouraged. They cannot be used with an \s-1ENGINE\s0 and \s-1ENGINE\s0
203 versions of new algorithms cannot be accessed using the low-level functions.
204 Also makes code harder to adapt to new algorithms and some options are not
205 cleanly supported at the low-level and some operations are more efficient
206 using the high-level interface.
208 .IX Header "SEE ALSO"
209 \&\fBEVP_DigestInit\fR\|(3),
210 \&\fBEVP_EncryptInit\fR\|(3),
211 \&\fBEVP_OpenInit\fR\|(3),
212 \&\fBEVP_SealInit\fR\|(3),
213 \&\fBEVP_DigestSignInit\fR\|(3),
214 \&\fBEVP_SignInit\fR\|(3),
215 \&\fBEVP_VerifyInit\fR\|(3),
216 \&\fBEVP_EncodeInit\fR\|(3),
217 \&\fBEVP_PKEY_new\fR\|(3),
218 \&\fBEVP_PKEY_set1_RSA\fR\|(3),
219 \&\fBEVP_PKEY_keygen\fR\|(3),
220 \&\fBEVP_PKEY_print_private\fR\|(3),
221 \&\fBEVP_PKEY_decrypt\fR\|(3),
222 \&\fBEVP_PKEY_encrypt\fR\|(3),
223 \&\fBEVP_PKEY_sign\fR\|(3),
224 \&\fBEVP_PKEY_verify\fR\|(3),
225 \&\fBEVP_PKEY_verify_recover\fR\|(3),
226 \&\fBEVP_PKEY_derive\fR\|(3),
227 \&\fBEVP_BytesToKey\fR\|(3),
228 \&\fBENGINE_by_id\fR\|(3)
230 .IX Header "COPYRIGHT"
231 Copyright 2000\-2020 The OpenSSL Project Authors. All Rights Reserved.
233 Licensed under the OpenSSL license (the \*(L"License\*(R"). You may not use
234 this file except in compliance with the License. You can obtain a copy
235 in the file \s-1LICENSE\s0 in the source distribution or at
236 <https://www.openssl.org/source/license.html>.