diff options
Diffstat (limited to 'static/freebsd/man3/EVP_PKEY_verify_recover.3')
| -rw-r--r-- | static/freebsd/man3/EVP_PKEY_verify_recover.3 | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/static/freebsd/man3/EVP_PKEY_verify_recover.3 b/static/freebsd/man3/EVP_PKEY_verify_recover.3 new file mode 100644 index 00000000..f4123550 --- /dev/null +++ b/static/freebsd/man3/EVP_PKEY_verify_recover.3 @@ -0,0 +1,198 @@ +.\" -*- mode: troff; coding: utf-8 -*- +.\" Automatically generated by Pod::Man v6.0.2 (Pod::Simple 3.45) +.\" +.\" 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 +.. +.\" \*(C` and \*(C' are quotes in nroff, nothing in troff, for use with C<>. +.ie n \{\ +. ds C` "" +. ds C' "" +'br\} +.el\{\ +. 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 +.\" +.\" Required to disable full justification in groff 1.23.0. +.if n .ds AD l +.\" ======================================================================== +.\" +.IX Title "EVP_PKEY_VERIFY_RECOVER 3ossl" +.TH EVP_PKEY_VERIFY_RECOVER 3ossl 2026-04-07 3.5.6 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 +EVP_PKEY_verify_recover_init, EVP_PKEY_verify_recover_init_ex, +EVP_PKEY_verify_recover_init_ex2, EVP_PKEY_verify_recover +\&\- recover signature using a public key algorithm +.SH SYNOPSIS +.IX Header "SYNOPSIS" +.Vb 1 +\& #include <openssl/evp.h> +\& +\& int EVP_PKEY_verify_recover_init(EVP_PKEY_CTX *ctx); +\& int EVP_PKEY_verify_recover_init_ex(EVP_PKEY_CTX *ctx, +\& const OSSL_PARAM params[]); +\& int EVP_PKEY_verify_recover_init_ex2(EVP_PKEY_CTX *ctx, EVP_SIGNATURE *algo, +\& const OSSL_PARAM params[]); +\& int EVP_PKEY_verify_recover(EVP_PKEY_CTX *ctx, +\& unsigned char *rout, size_t *routlen, +\& const unsigned char *sig, size_t siglen); +.Ve +.SH DESCRIPTION +.IX Header "DESCRIPTION" +\&\fBEVP_PKEY_verify_recover_init()\fR initializes a public key algorithm context +\&\fIctx\fR for signing using the algorithm given when the context was created +using \fBEVP_PKEY_CTX_new\fR\|(3) or variants thereof. The algorithm is used to +fetch a \fBEVP_SIGNATURE\fR method implicitly, see "Implicit fetch" in \fBprovider\fR\|(7) +for more information about implicit fetches. +.PP +\&\fBEVP_PKEY_verify_recover_init_ex()\fR is the same as +\&\fBEVP_PKEY_verify_recover_init()\fR but additionally sets the passed parameters +\&\fIparams\fR on the context before returning. +.PP +\&\fBEVP_PKEY_verify_recover_init_ex2()\fR is the same as \fBEVP_PKEY_verify_recover_init_ex()\fR, +but works with an explicitly fetched \fBEVP_SIGNATURE\fR \fIalgo\fR. +A context \fIctx\fR without a pre\-loaded key cannot be used with this function. +Depending on what algorithm was fetched, certain details revolving around the +treatment of the input to \fBEVP_PKEY_verify()\fR may be pre\-determined, and in that +case, those details may normally not be changed. +See "NOTES" below for a deeper explanation. +.PP +The \fBEVP_PKEY_verify_recover()\fR function recovers signed data +using \fIctx\fR. The signature is specified using the \fIsig\fR and +\&\fIsiglen\fR parameters. If \fIrout\fR is NULL then the maximum size of the output +buffer is written to the \fIroutlen\fR parameter. If \fIrout\fR is not NULL then +before the call the \fIroutlen\fR parameter should contain the length of the +\&\fIrout\fR buffer, if the call is successful recovered data is written to +\&\fIrout\fR and the amount of data written to \fIroutlen\fR. +.SH NOTES +.IX Header "NOTES" +Normally an application is only interested in whether a signature verification +operation is successful in those cases the \fBEVP_verify()\fR function should be +used. +.PP +Sometimes however it is useful to obtain the data originally signed using a +signing operation. Only certain public key algorithms can recover a signature +in this way (for example RSA in PKCS padding mode). +.PP +After the call to \fBEVP_PKEY_verify_recover_init()\fR algorithm specific control +operations can be performed to set any appropriate parameters for the +operation. +.PP +After the call to \fBEVP_PKEY_verify_recover_init_ex2()\fR, algorithm specific control +operations may not be needed if the chosen algorithm implies that those controls +pre\-set (and immutable). +.PP +The function \fBEVP_PKEY_verify_recover()\fR can be called more than once on the same +context if several operations are performed using the same parameters. +.SH "RETURN VALUES" +.IX Header "RETURN VALUES" +\&\fBEVP_PKEY_verify_recover_init()\fR and \fBEVP_PKEY_verify_recover()\fR return 1 for success +and 0 or a negative value for failure. In particular a return value of \-2 +indicates the operation is not supported by the public key algorithm. +.SH EXAMPLES +.IX Header "EXAMPLES" +Recover digest originally signed using PKCS#1 and SHA256 digest: +.PP +.Vb 2 +\& #include <openssl/evp.h> +\& #include <openssl/rsa.h> +\& +\& EVP_PKEY_CTX *ctx; +\& unsigned char *rout, *sig; +\& size_t routlen, siglen; +\& EVP_PKEY *verify_key; +\& +\& /* +\& * NB: assumes verify_key, sig and siglen are already set up +\& * and that verify_key is an RSA public key +\& */ +\& ctx = EVP_PKEY_CTX_new(verify_key, NULL /* no engine */); +\& if (!ctx) +\& /* Error occurred */ +\& if (EVP_PKEY_verify_recover_init(ctx) <= 0) +\& /* Error */ +\& if (EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_PKCS1_PADDING) <= 0) +\& /* Error */ +\& if (EVP_PKEY_CTX_set_signature_md(ctx, EVP_sha256()) <= 0) +\& /* Error */ +\& +\& /* Determine buffer length */ +\& if (EVP_PKEY_verify_recover(ctx, NULL, &routlen, sig, siglen) <= 0) +\& /* Error */ +\& +\& rout = OPENSSL_malloc(routlen); +\& +\& if (!rout) +\& /* malloc failure */ +\& +\& if (EVP_PKEY_verify_recover(ctx, rout, &routlen, sig, siglen) <= 0) +\& /* Error */ +\& +\& /* Recovered data is routlen bytes written to buffer rout */ +.Ve +.SH "SEE ALSO" +.IX Header "SEE ALSO" +\&\fBEVP_PKEY_CTX_new\fR\|(3), +\&\fBEVP_PKEY_encrypt\fR\|(3), +\&\fBEVP_PKEY_decrypt\fR\|(3), +\&\fBEVP_PKEY_sign\fR\|(3), +\&\fBEVP_PKEY_verify\fR\|(3), +\&\fBEVP_PKEY_derive\fR\|(3) +.SH HISTORY +.IX Header "HISTORY" +The \fBEVP_PKEY_verify_recover_init()\fR and \fBEVP_PKEY_verify_recover()\fR +functions were added in OpenSSL 1.0.0. +.PP +The \fBEVP_PKEY_verify_recover_init_ex()\fR function was added in OpenSSL 3.0. +.SH COPYRIGHT +.IX Header "COPYRIGHT" +Copyright 2013\-2024 The OpenSSL Project Authors. All Rights Reserved. +.PP +Licensed under the Apache License 2.0 (the "License"). You may not use +this file except in compliance with the License. You can obtain a copy +in the file LICENSE in the source distribution or at +<https://www.openssl.org/source/license.html>. |