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Diffstat (limited to 'secure/lib/libcrypto/man/man3/EVP_PKEY_encapsulate.3')
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diff --git a/secure/lib/libcrypto/man/man3/EVP_PKEY_encapsulate.3 b/secure/lib/libcrypto/man/man3/EVP_PKEY_encapsulate.3 new file mode 100644 index 000000000000..99630a34c7dc --- /dev/null +++ b/secure/lib/libcrypto/man/man3/EVP_PKEY_encapsulate.3 @@ -0,0 +1,197 @@ +.\" -*- mode: troff; coding: utf-8 -*- +.\" Automatically generated by Pod::Man 5.0102 (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 +.\" ======================================================================== +.\" +.IX Title "EVP_PKEY_ENCAPSULATE 3ossl" +.TH EVP_PKEY_ENCAPSULATE 3ossl 2025-09-30 3.5.4 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_encapsulate_init, EVP_PKEY_auth_encapsulate_init, EVP_PKEY_encapsulate +\&\- Key encapsulation using a KEM algorithm with a public key +.SH SYNOPSIS +.IX Header "SYNOPSIS" +.Vb 1 +\& #include <openssl/evp.h> +\& +\& int EVP_PKEY_encapsulate_init(EVP_PKEY_CTX *ctx, const OSSL_PARAM params[]); +\& int EVP_PKEY_auth_encapsulate_init(EVP_PKEY_CTX *ctx, EVP_PKEY *authpriv, +\& const OSSL_PARAM params[]); +\& int EVP_PKEY_encapsulate(EVP_PKEY_CTX *ctx, +\& unsigned char *wrappedkey, size_t *wrappedkeylen, +\& unsigned char *genkey, size_t *genkeylen); +.Ve +.SH DESCRIPTION +.IX Header "DESCRIPTION" +The \fBEVP_PKEY_encapsulate_init()\fR function initializes a public key algorithm +context \fIctx\fR for an encapsulation operation and then sets the \fIparams\fR +on the context in the same way as calling \fBEVP_PKEY_CTX_set_params\fR\|(3). +Note that \fIctx\fR is usually is produced using \fBEVP_PKEY_CTX_new_from_pkey\fR\|(3), +specifying the public key to use. +.PP +The \fBEVP_PKEY_auth_encapsulate_init()\fR function is similar to +\&\fBEVP_PKEY_encapsulate_init()\fR but also passes an \fIauthpriv\fR authentication private +key that is used during encapsulation. +.PP +The \fBEVP_PKEY_encapsulate()\fR function performs a public key encapsulation +operation using \fIctx\fR. +The shared secret written to \fIgenkey\fR can be used as an input for key +derivation, typically for various symmetric algorithms. +Its size is written to \fIgenkeylen\fR, which must be initialised to the +size of the provided buffer. +.PP +The ciphertext written to \fIwrappedkey\fR is an encapsulated form, which +is expected to be only usable by the holder of the private key corresponding +to the public key associated with \fIctx\fR. +This ciphertext is then communicated to the private-key holder, who can use +\&\fBEVP_PKEY_decapsulate\fR\|(3) to securely recover the same shared secret. +.PP +If \fIwrappedkey\fR is NULL then the maximum size of the output buffer is written +to the \fI*wrappedkeylen\fR parameter unless \fIwrappedkeylen\fR is NULL and the +maximum size of the generated key buffer is written to \fI*genkeylen\fR unless +\&\fIgenkeylen\fR is NULL. +.PP +If \fIwrappedkey\fR is not NULL and the call is successful then the generated +shared secret is written to \fIgenkey\fR and its size is written to +\&\fI*genkeylen\fR (which must be non-NULL). +The encapsulated ciphertext is written to \fIwrappedkey\fR and +its size is written to \fI*wrappedkeylen\fR (must also be non-NULL), +The value pointed to by \fIwrappedlen\fR initially hold the size of the +\&\fIunwrapped\fR buffer so that its size can be validated by the call, ensuring it +is large enough to hold the result written to \fIwrapped\fR. +.PP +Absent detailed prior knowledge of the internals of the specific KEM +algorithm, callers SHOULD NOT assume that the returned shared secret and +ciphertext are necessarily of the maximum possible length. +The lengths returned via \fI*wrappedkeylen\fR and \fI*genkeylen\fR SHOULD +be used to determine the actual lengths of the outputs. +.SH NOTES +.IX Header "NOTES" +After the call to \fBEVP_PKEY_encapsulate_init()\fR, algorithm-specific parameters +for the operation may be set or modified using \fBEVP_PKEY_CTX_set_params\fR\|(3). +.SH "RETURN VALUES" +.IX Header "RETURN VALUES" +\&\fBEVP_PKEY_encapsulate_init()\fR, \fBEVP_PKEY_auth_encapsulate_init()\fR and +\&\fBEVP_PKEY_encapsulate()\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" +Encapsulate an RSASVE key (for RSA keys). +.PP +.Vb 1 +\& #include <openssl/evp.h> +\& +\& /* +\& * NB: assumes rsa_pub_key is an public key of another party. +\& */ +\& +\& EVP_PKEY_CTX *ctx = NULL; +\& size_t secretlen = 0, outlen = 0; +\& unsigned char *out = NULL, *secret = NULL; +\& +\& ctx = EVP_PKEY_CTX_new_from_pkey(libctx, rsa_pub_key, NULL); +\& if (ctx == NULL) +\& /* Error */ +\& if (EVP_PKEY_encapsulate_init(ctx, NULL) <= 0) +\& /* Error */ +\& +\& /* Set the mode \- only \*(AqRSASVE\*(Aq is currently supported */ +\& if (EVP_PKEY_CTX_set_kem_op(ctx, "RSASVE") <= 0) +\& /* Error */ +\& /* Determine buffer length */ +\& if (EVP_PKEY_encapsulate(ctx, NULL, &outlen, NULL, &secretlen) <= 0) +\& /* Error */ +\& +\& out = OPENSSL_malloc(outlen); +\& secret = OPENSSL_malloc(secretlen); +\& if (out == NULL || secret == NULL) +\& /* malloc failure */ +\& +\& /* +\& * The generated \*(Aqsecret\*(Aq can be used as key material. +\& * The encapsulated \*(Aqout\*(Aq can be sent to another party who can +\& * decapsulate it using their private key to retrieve the \*(Aqsecret\*(Aq. +\& */ +\& if (EVP_PKEY_encapsulate(ctx, out, &outlen, secret, &secretlen) <= 0) +\& /* Error */ +.Ve +.SH "SEE ALSO" +.IX Header "SEE ALSO" +\&\fBEVP_PKEY_CTX_new_from_pkey\fR\|(3), +\&\fBEVP_PKEY_decapsulate\fR\|(3), +\&\fBEVP_KEM\-RSA\fR\|(7), +\&\fBEVP_KEM\-X25519\fR\|(7), +\&\fBEVP_KEM\-EC\fR\|(7), +\&\fBEVP_KEM\-ML\-KEM\-512\fR\|(7), +\&\fBEVP_KEM\-ML\-KEM\-768\fR\|(7), +\&\fBEVP_KEM\-ML\-KEM\-1024\fR\|(7) +.SH HISTORY +.IX Header "HISTORY" +The functions \fBEVP_PKEY_encapsulate_init()\fR and \fBEVP_PKEY_encapsulate()\fR were +added in OpenSSL 3.0. +The function \fBEVP_PKEY_auth_encapsulate_init()\fR was added in OpenSSL 3.2. +.PP +Support for \fBML-KEM\fR was added in OpenSSL 3.5. +.SH COPYRIGHT +.IX Header "COPYRIGHT" +Copyright 2020\-2025 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>. |