← Back
Editing: RSA_public_decrypt.3
.\" Automatically generated by Pod::Man 4.11 (Pod::Simple 3.35) .\" .\" Standard preamble: .\" ======================================================================== .de Sp \" Vertical space (when we can't use .PP) .if t .sp .5v .if n .sp .. .de Vb \" Begin verbatim text .ft CW .nf .ne \\$1 .. .de Ve \" End verbatim text .ft R .fi .. .\" Set up some character translations and predefined strings. \*(-- will .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left .\" double quote, and \*(R" will give a right double quote. \*(C+ will .\" give a nicer C++. Capital omega is used to do unbreakable dashes and .\" therefore won't be available. \*(C` and \*(C' expand to `' in nroff, .\" nothing in troff, for use with C<>. .tr \(*W- .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p' .ie n \{\ . ds -- \(*W- . ds PI pi . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch . ds L" "" . ds R" "" . ds C` "" . ds C' "" 'br\} .el\{\ . ds -- \|\(em\| . ds PI \(*p . ds L" `` . ds R" '' . ds C` . ds C' 'br\} .\" .\" Escape single quotes in literal strings from groff's Unicode transform. .ie \n(.g .ds Aq \(aq .el .ds Aq ' .\" .\" If the F register is >0, we'll generate index entries on stderr for .\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index .\" entries marked with X<> in POD. Of course, you'll have to process the .\" output yourself in some meaningful fashion. .\" .\" Avoid warning from groff about undefined register 'F'. .de IX .. .nr rF 0 .if \n(.g .if rF .nr rF 1 .if (\n(rF:(\n(.g==0)) \{\ . if \nF \{\ . de IX . tm Index:\\$1\t\\n%\t"\\$2" .. . if !\nF==2 \{\ . nr % 0 . nr F 2 . \} . \} .\} .rr rF .\" .\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2). .\" Fear. Run. Save yourself. No user-serviceable parts. . \" fudge factors for nroff and troff .if n \{\ . ds #H 0 . ds #V .8m . ds #F .3m . ds #[ \f1 . ds #] \fP .\} .if t \{\ . ds #H ((1u-(\\\\n(.fu%2u))*.13m) . ds #V .6m . ds #F 0 . ds #[ \& . ds #] \& .\} . \" simple accents for nroff and troff .if n \{\ . ds ' \& . ds ` \& . ds ^ \& . ds , \& . ds ~ ~ . ds / .\} .if t \{\ . ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u" . ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u' . ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u' . ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u' . ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u' . ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u' .\} . \" troff and (daisy-wheel) nroff accents .ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V' .ds 8 \h'\*(#H'\(*b\h'-\*(#H' .ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#] .ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H' .ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u' .ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#] .ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#] .ds ae a\h'-(\w'a'u*4/10)'e .ds Ae A\h'-(\w'A'u*4/10)'E . \" corrections for vroff .if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u' .if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u' . \" for low resolution devices (crt and lpr) .if \n(.H>23 .if \n(.V>19 \ \{\ . ds : e . ds 8 ss . ds o a . ds d- d\h'-1'\(ga . ds D- D\h'-1'\(hy . ds th \o'bp' . ds Th \o'LP' . ds ae ae . ds Ae AE .\} .rm #[ #] #H #V #F C .\" ======================================================================== .\" .IX Title "RSA_private_encrypt 3" .TH RSA_private_encrypt 3 "2019-12-20" "1.0.2u" "OpenSSL" .\" For nroff, turn off justification. Always turn off hyphenation; it makes .\" way too many mistakes in technical documents. .if n .ad l .nh .SH "NAME" RSA_private_encrypt, RSA_public_decrypt \- low level signature operations .SH "SYNOPSIS" .IX Header "SYNOPSIS" .Vb 1 \& #include <openssl/rsa.h> \& \& int RSA_private_encrypt(int flen, const unsigned char *from, \& unsigned char *to, RSA *rsa, int padding); \& \& int RSA_public_decrypt(int flen, const unsigned char *from, \& unsigned char *to, RSA *rsa, int padding); .Ve .SH "DESCRIPTION" .IX Header "DESCRIPTION" These functions handle \s-1RSA\s0 signatures at a low level. .PP \&\fBRSA_private_encrypt()\fR signs the \fBflen\fR bytes at \fBfrom\fR (usually a message digest with an algorithm identifier) using the private key \&\fBrsa\fR and stores the signature in \fBto\fR. \fBto\fR must point to \&\fBRSA_size(rsa)\fR bytes of memory. .PP \&\fBpadding\fR denotes one of the following modes: .IP "\s-1RSA_PKCS1_PADDING\s0" 4 .IX Item "RSA_PKCS1_PADDING" \&\s-1PKCS\s0 #1 v1.5 padding. This function does not handle the \&\fBalgorithmIdentifier\fR specified in \s-1PKCS\s0 #1. When generating or verifying \s-1PKCS\s0 #1 signatures, \fBRSA_sign\fR\|(3) and \fBRSA_verify\fR\|(3) should be used. .IP "\s-1RSA_NO_PADDING\s0" 4 .IX Item "RSA_NO_PADDING" Raw \s-1RSA\s0 signature. This mode should \fIonly\fR be used to implement cryptographically sound padding modes in the application code. Signing user data directly with \s-1RSA\s0 is insecure. .PP \&\fBRSA_public_decrypt()\fR recovers the message digest from the \fBflen\fR bytes long signature at \fBfrom\fR using the signer's public key \&\fBrsa\fR. \fBto\fR must point to a memory section large enough to hold the message digest (which is smaller than \fBRSA_size(rsa) \- 11\fR). \fBpadding\fR is the padding mode that was used to sign the data. .SH "RETURN VALUES" .IX Header "RETURN VALUES" \&\fBRSA_private_encrypt()\fR returns the size of the signature (i.e., RSA_size(rsa)). \fBRSA_public_decrypt()\fR returns the size of the recovered message digest. .PP On error, \-1 is returned; the error codes can be obtained by \fBERR_get_error\fR\|(3). .SH "SEE ALSO" .IX Header "SEE ALSO" \&\fBERR_get_error\fR\|(3), \fBrsa\fR\|(3), \&\fBRSA_sign\fR\|(3), \fBRSA_verify\fR\|(3) .SH "HISTORY" .IX Header "HISTORY" The \fBpadding\fR argument was added in SSLeay 0.8. \s-1RSA_NO_PADDING\s0 is available since SSLeay 0.9.0.
Save File
Cancel