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Diffstat (limited to 'upstream/debian-unstable/man3/EVP_DigestVerifyInit.3ssl')
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diff --git a/upstream/debian-unstable/man3/EVP_DigestVerifyInit.3ssl b/upstream/debian-unstable/man3/EVP_DigestVerifyInit.3ssl new file mode 100644 index 00000000..d6978c88 --- /dev/null +++ b/upstream/debian-unstable/man3/EVP_DigestVerifyInit.3ssl @@ -0,0 +1,236 @@ +.\" -*- mode: troff; coding: utf-8 -*- +.\" Automatically generated by Pod::Man 5.01 (Pod::Simple 3.43) +.\" +.\" 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_DIGESTVERIFYINIT 3SSL" +.TH EVP_DIGESTVERIFYINIT 3SSL 2024-02-03 3.1.5 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_DigestVerifyInit_ex, EVP_DigestVerifyInit, EVP_DigestVerifyUpdate, +EVP_DigestVerifyFinal, EVP_DigestVerify \- EVP signature verification functions +.SH SYNOPSIS +.IX Header "SYNOPSIS" +.Vb 1 +\& #include <openssl/evp.h> +\& +\& int EVP_DigestVerifyInit_ex(EVP_MD_CTX *ctx, EVP_PKEY_CTX **pctx, +\& const char *mdname, OSSL_LIB_CTX *libctx, +\& const char *props, EVP_PKEY *pkey, +\& const OSSL_PARAM params[]); +\& int EVP_DigestVerifyInit(EVP_MD_CTX *ctx, EVP_PKEY_CTX **pctx, +\& const EVP_MD *type, ENGINE *e, EVP_PKEY *pkey); +\& int EVP_DigestVerifyUpdate(EVP_MD_CTX *ctx, const void *d, size_t cnt); +\& int EVP_DigestVerifyFinal(EVP_MD_CTX *ctx, const unsigned char *sig, +\& size_t siglen); +\& int EVP_DigestVerify(EVP_MD_CTX *ctx, const unsigned char *sig, +\& size_t siglen, const unsigned char *tbs, size_t tbslen); +.Ve +.SH DESCRIPTION +.IX Header "DESCRIPTION" +The EVP signature routines are a high-level interface to digital signatures. +Input data is digested first before the signature verification takes place. +.PP +\&\fBEVP_DigestVerifyInit_ex()\fR sets up verification context \fBctx\fR to use a +digest with the name \fBmdname\fR and public key \fBpkey\fR. The name of the digest to +be used is passed to the provider of the signature algorithm in use. How that +provider interprets the digest name is provider specific. The provider may +implement that digest directly itself or it may (optionally) choose to fetch it +(which could result in a digest from a different provider being selected). If +the provider supports fetching the digest then it may use the \fBprops\fR argument +for the properties to be used during the fetch. Finally, the passed parameters +\&\fIparams\fR, if not NULL, are set on the context before returning. +.PP +The \fIpkey\fR algorithm is used to fetch a \fBEVP_SIGNATURE\fR method implicitly, to +be used for the actual signing. See "Implicit fetch" in \fBprovider\fR\|(7) for +more information about implicit fetches. +.PP +The OpenSSL default and legacy providers support fetching digests and can fetch +those digests from any available provider. The OpenSSL FIPS provider also +supports fetching digests but will only fetch digests that are themselves +implemented inside the FIPS provider. +.PP +\&\fBctx\fR must be created with \fBEVP_MD_CTX_new()\fR before calling this function. If +\&\fBpctx\fR is not NULL, the EVP_PKEY_CTX of the verification operation will be +written to \fB*pctx\fR: this can be used to set alternative verification options. +Note that any existing value in \fB*pctx\fR is overwritten. The EVP_PKEY_CTX value +returned must not be freed directly by the application if \fBctx\fR is not assigned +an EVP_PKEY_CTX value before being passed to \fBEVP_DigestVerifyInit_ex()\fR +(which means the EVP_PKEY_CTX is created inside +\&\fBEVP_DigestVerifyInit_ex()\fR and it will be freed automatically when the +EVP_MD_CTX is freed). If the EVP_PKEY_CTX to be used is created by +EVP_DigestVerifyInit_ex then it will use the \fBOSSL_LIB_CTX\fR specified +in \fIlibctx\fR and the property query string specified in \fIprops\fR. +.PP +No \fBEVP_PKEY_CTX\fR will be created by \fBEVP_DigestVerifyInit_ex()\fR if the +passed \fBctx\fR has already been assigned one via \fBEVP_MD_CTX_set_pkey_ctx\fR\|(3). +See also \fBSM2\fR\|(7). +.PP +Not all digests can be used for all key types. The following combinations apply. +.IP DSA 4 +.IX Item "DSA" +Supports SHA1, SHA224, SHA256, SHA384 and SHA512 +.IP ECDSA 4 +.IX Item "ECDSA" +Supports SHA1, SHA224, SHA256, SHA384, SHA512 and SM3 +.IP "RSA with no padding" 4 +.IX Item "RSA with no padding" +Supports no digests (the digest \fBtype\fR must be NULL) +.IP "RSA with X931 padding" 4 +.IX Item "RSA with X931 padding" +Supports SHA1, SHA256, SHA384 and SHA512 +.IP "All other RSA padding types" 4 +.IX Item "All other RSA padding types" +Support SHA1, SHA224, SHA256, SHA384, SHA512, MD5, MD5_SHA1, MD2, MD4, MDC2, +SHA3\-224, SHA3\-256, SHA3\-384, SHA3\-512 +.IP "Ed25519 and Ed448" 4 +.IX Item "Ed25519 and Ed448" +Support no digests (the digest \fBtype\fR must be NULL) +.IP HMAC 4 +.IX Item "HMAC" +Supports any digest +.IP "CMAC, Poly1305 and Siphash" 4 +.IX Item "CMAC, Poly1305 and Siphash" +Will ignore any digest provided. +.PP +If RSA-PSS is used and restrictions apply then the digest must match. +.PP +\&\fBEVP_DigestVerifyInit()\fR works in the same way as +\&\fBEVP_DigestVerifyInit_ex()\fR except that the \fBmdname\fR parameter will be +inferred from the supplied digest \fBtype\fR, and \fBprops\fR will be NULL. Where +supplied the ENGINE \fBe\fR will be used for the signature verification and digest +algorithm implementations. \fBe\fR may be NULL. +.PP +\&\fBEVP_DigestVerifyUpdate()\fR hashes \fBcnt\fR bytes of data at \fBd\fR into the +verification context \fBctx\fR. This function can be called several times on the +same \fBctx\fR to include additional data. +.PP +\&\fBEVP_DigestVerifyFinal()\fR verifies the data in \fBctx\fR against the signature in +\&\fBsig\fR of length \fBsiglen\fR. +.PP +\&\fBEVP_DigestVerify()\fR verifies \fBtbslen\fR bytes at \fBtbs\fR against the signature +in \fBsig\fR of length \fBsiglen\fR. +.SH "RETURN VALUES" +.IX Header "RETURN VALUES" +\&\fBEVP_DigestVerifyInit()\fR and \fBEVP_DigestVerifyUpdate()\fR return 1 for success and 0 +for failure. +.PP +\&\fBEVP_DigestVerifyFinal()\fR and \fBEVP_DigestVerify()\fR return 1 for success; any other +value indicates failure. A return value of zero indicates that the signature +did not verify successfully (that is, \fBtbs\fR did not match the original data or +the signature had an invalid form), while other values indicate a more serious +error (and sometimes also indicate an invalid signature form). +.PP +The error codes can be obtained from \fBERR_get_error\fR\|(3). +.SH NOTES +.IX Header "NOTES" +The \fBEVP\fR interface to digital signatures should almost always be used in +preference to the low-level interfaces. This is because the code then becomes +transparent to the algorithm used and much more flexible. +.PP +\&\fBEVP_DigestVerify()\fR is a one shot operation which verifies a single block of +data in one function. For algorithms that support streaming it is equivalent +to calling \fBEVP_DigestVerifyUpdate()\fR and \fBEVP_DigestVerifyFinal()\fR. For +algorithms which do not support streaming (e.g. PureEdDSA) it is the only way +to verify data. +.PP +In previous versions of OpenSSL there was a link between message digest types +and public key algorithms. This meant that "clone" digests such as \fBEVP_dss1()\fR +needed to be used to sign using SHA1 and DSA. This is no longer necessary and +the use of clone digest is now discouraged. +.PP +For some key types and parameters the random number generator must be seeded. +If the automatic seeding or reseeding of the OpenSSL CSPRNG fails due to +external circumstances (see \fBRAND\fR\|(7)), the operation will fail. +.PP +The call to \fBEVP_DigestVerifyFinal()\fR internally finalizes a copy of the digest +context. This means that \fBEVP_VerifyUpdate()\fR and \fBEVP_VerifyFinal()\fR can +be called later to digest and verify additional data. +.PP +\&\fBEVP_DigestVerifyInit()\fR and \fBEVP_DigestVerifyInit_ex()\fR functions can be called +multiple times on a context and the parameters set by previous calls should be +preserved if the \fIpkey\fR parameter is NULL. The call then just resets the state +of the \fIctx\fR. +.PP +Ignoring failure returns of \fBEVP_DigestVerifyInit()\fR and \fBEVP_DigestVerifyInit_ex()\fR +functions can lead to subsequent undefined behavior when calling +\&\fBEVP_DigestVerifyUpdate()\fR, \fBEVP_DigestVerifyFinal()\fR, or \fBEVP_DigestVerify()\fR. +.SH "SEE ALSO" +.IX Header "SEE ALSO" +\&\fBEVP_DigestSignInit\fR\|(3), +\&\fBEVP_DigestInit\fR\|(3), +\&\fBevp\fR\|(7), \fBHMAC\fR\|(3), \fBMD2\fR\|(3), +\&\fBMD5\fR\|(3), \fBMDC2\fR\|(3), \fBRIPEMD160\fR\|(3), +\&\fBSHA1\fR\|(3), \fBopenssl\-dgst\fR\|(1), +\&\fBRAND\fR\|(7) +.SH HISTORY +.IX Header "HISTORY" +\&\fBEVP_DigestVerifyInit()\fR, \fBEVP_DigestVerifyUpdate()\fR and \fBEVP_DigestVerifyFinal()\fR +were added in OpenSSL 1.0.0. +.PP +\&\fBEVP_DigestVerifyInit_ex()\fR was added in OpenSSL 3.0. +.PP +\&\fBEVP_DigestVerifyUpdate()\fR was converted from a macro to a function in OpenSSL +3.0. +.SH COPYRIGHT +.IX Header "COPYRIGHT" +Copyright 2006\-2023 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>. |