mirror of
https://github.com/QuasarApp/openssl.git
synced 2025-04-29 03:04:37 +00:00
a45694a356
EVP_DigestSignInit_ex and EVP_DigestVerifyInit_ex did not provide the capability to specify an explicit OPENSSL_CTX parameter. It is still possible by explicitly setting an EVP_PKEY_CTX - but in most cases it would be much simpler to just specify it in the Init call. We add the capability to do that. Reviewed-by: Tomas Mraz <tmraz@fedoraproject.org> (Merged from https://github.com/openssl/openssl/pull/11353)
199 lines
7.7 KiB
Plaintext
199 lines
7.7 KiB
Plaintext
=pod
|
|
|
|
=head1 NAME
|
|
|
|
EVP_DigestSignInit_ex, EVP_DigestSignInit, EVP_DigestSignUpdate,
|
|
EVP_DigestSignFinal, EVP_DigestSign - EVP signing functions
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
#include <openssl/evp.h>
|
|
|
|
int EVP_DigestSignInit_ex(EVP_MD_CTX *ctx, EVP_PKEY_CTX **pctx,
|
|
const char *mdname, const char *props,
|
|
EVP_PKEY *pkey, OPENSSL_CTX *libctx);
|
|
int EVP_DigestSignInit(EVP_MD_CTX *ctx, EVP_PKEY_CTX **pctx,
|
|
const EVP_MD *type, ENGINE *e, EVP_PKEY *pkey);
|
|
int EVP_DigestSignUpdate(EVP_MD_CTX *ctx, const void *d, size_t cnt);
|
|
int EVP_DigestSignFinal(EVP_MD_CTX *ctx, unsigned char *sig, size_t *siglen);
|
|
|
|
int EVP_DigestSign(EVP_MD_CTX *ctx, unsigned char *sigret,
|
|
size_t *siglen, const unsigned char *tbs,
|
|
size_t tbslen);
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
The EVP signature routines are a high level interface to digital signatures.
|
|
Input data is digested first before the signing takes place.
|
|
|
|
EVP_DigestSignInit_ex() sets up signing context I<ctx> to use a digest with the
|
|
name I<mdname> and private key I<pkey>. 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 I<props> argument for
|
|
the properties to be used during the fetch.
|
|
|
|
The I<pkey> algorithm is used to fetch a B<EVP_SIGNATURE> method implicitly, to
|
|
be used for the actual signing. See L<provider(7)/Implicit fetch> for
|
|
more information about implict fetches.
|
|
|
|
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.
|
|
|
|
I<ctx> must be created with EVP_MD_CTX_new() before calling this function. If
|
|
I<pctx> is not NULL, the EVP_PKEY_CTX of the signing operation will be written
|
|
to I<*pctx>: this can be used to set alternative signing options. Note that any
|
|
existing value in I<*pctx> is overwritten. The EVP_PKEY_CTX value returned must
|
|
not be freed directly by the application if I<ctx> is not assigned an
|
|
EVP_PKEY_CTX value before being passed to EVP_DigestSignInit_ex() (which means
|
|
the EVP_PKEY_CTX is created inside EVP_DigestSignInit_ex() 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_DigestSignInit_ex then it will use the B<OPENSSL_CTX> specified
|
|
in I<libctx> and the property query string specified in I<props>.
|
|
|
|
The digest I<mdname> may be NULL if the signing algorithm supports it. The
|
|
I<props> argument can always be NULL.
|
|
|
|
No B<EVP_PKEY_CTX> will be created by EVP_DigestSignInit_ex() if the passed
|
|
I<ctx> has already been assigned one via L<EVP_MD_CTX_set_pkey_ctx(3)>. See also
|
|
L<SM2(7)>.
|
|
|
|
Only EVP_PKEY types that support signing can be used with these functions. This
|
|
includes MAC algorithms where the MAC generation is considered as a form of
|
|
"signing". Built-in EVP_PKEY types supported by these functions are CMAC,
|
|
Poly1305, DSA, ECDSA, HMAC, RSA, SipHash, Ed25519 and Ed448.
|
|
|
|
Not all digests can be used for all key types. The following combinations apply.
|
|
|
|
=over 4
|
|
|
|
=item DSA
|
|
|
|
Supports SHA1, SHA224, SHA256, SHA384 and SHA512
|
|
|
|
=item ECDSA
|
|
|
|
Supports SHA1, SHA224, SHA256, SHA384, SHA512 and SM3
|
|
|
|
=item RSA with no padding
|
|
|
|
Supports no digests (the digest I<type> must be NULL)
|
|
|
|
=item RSA with X931 padding
|
|
|
|
Supports SHA1, SHA256, SHA384 and SHA512
|
|
|
|
=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
|
|
|
|
=item Ed25519 and Ed448
|
|
|
|
Support no digests (the digest I<type> must be NULL)
|
|
|
|
=item HMAC
|
|
|
|
Supports any digest
|
|
|
|
=item CMAC, Poly1305 and SipHash
|
|
|
|
Will ignore any digest provided.
|
|
|
|
=back
|
|
|
|
If RSA-PSS is used and restrictions apply then the digest must match.
|
|
|
|
EVP_DigestSignInit() works in the same way as EVP_DigestSignInit_ex() except
|
|
that the I<mdname> parameter will be inferred from the supplied digest I<type>,
|
|
and I<props> will be NULL. Where supplied the ENGINE I<e> will be used for the
|
|
signing and digest algorithm implementations. I<e> may be NULL.
|
|
|
|
EVP_DigestSignUpdate() hashes I<cnt> bytes of data at I<d> into the
|
|
signature context I<ctx>. This function can be called several times on the
|
|
same I<ctx> to include additional data.
|
|
|
|
EVP_DigestSignFinal() signs the data in I<ctx> and places the signature in I<sig>.
|
|
If I<sig> is NULL then the maximum size of the output buffer is written to
|
|
the I<siglen> parameter. If I<sig> is not NULL then before the call the
|
|
I<siglen> parameter should contain the length of the I<sig> buffer. If the
|
|
call is successful the signature is written to I<sig> and the amount of data
|
|
written to I<siglen>.
|
|
|
|
EVP_DigestSign() signs I<tbslen> bytes of data at I<tbs> and places the
|
|
signature in I<sig> and its length in I<siglen> in a similar way to
|
|
EVP_DigestSignFinal().
|
|
|
|
=head1 RETURN VALUES
|
|
|
|
EVP_DigestSignInit(), EVP_DigestSignUpdate(), EVP_DigestSignFinal() and
|
|
EVP_DigestSign() return 1 for success and 0 for failure.
|
|
|
|
The error codes can be obtained from L<ERR_get_error(3)>.
|
|
|
|
=head1 NOTES
|
|
|
|
The B<EVP> 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.
|
|
|
|
EVP_DigestSign() is a one shot operation which signs a single block of data
|
|
in one function. For algorithms that support streaming it is equivalent to
|
|
calling EVP_DigestSignUpdate() and EVP_DigestSignFinal(). For algorithms which
|
|
do not support streaming (e.g. PureEdDSA) it is the only way to sign data.
|
|
|
|
In previous versions of OpenSSL there was a link between message digest types
|
|
and public key algorithms. This meant that "clone" digests such as EVP_dss1()
|
|
needed to be used to sign using SHA1 and DSA. This is no longer necessary and
|
|
the use of clone digest is now discouraged.
|
|
|
|
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 L<RAND(7)>), the operation will fail.
|
|
|
|
The call to EVP_DigestSignFinal() internally finalizes a copy of the digest
|
|
context. This means that calls to EVP_DigestSignUpdate() and
|
|
EVP_DigestSignFinal() can be called later to digest and sign additional data.
|
|
|
|
Since only a copy of the digest context is ever finalized, the context must
|
|
be cleaned up after use by calling EVP_MD_CTX_free() or a memory leak
|
|
will occur.
|
|
|
|
The use of EVP_PKEY_size() with these functions is discouraged because some
|
|
signature operations may have a signature length which depends on the
|
|
parameters set. As a result EVP_PKEY_size() would have to return a value
|
|
which indicates the maximum possible signature for any set of parameters.
|
|
|
|
=head1 SEE ALSO
|
|
|
|
L<EVP_DigestVerifyInit(3)>,
|
|
L<EVP_DigestInit(3)>,
|
|
L<evp(7)>, L<HMAC(3)>, L<MD2(3)>,
|
|
L<MD5(3)>, L<MDC2(3)>, L<RIPEMD160(3)>,
|
|
L<SHA1(3)>, L<openssl-dgst(1)>,
|
|
L<RAND(7)>
|
|
|
|
=head1 HISTORY
|
|
|
|
EVP_DigestSignInit(), EVP_DigestSignUpdate() and EVP_DigestSignFinal()
|
|
were added in OpenSSL 1.0.0.
|
|
|
|
EVP_DigestSignInit_ex() was added in OpenSSL 3.0.
|
|
|
|
EVP_DigestSignUpdate() was converted from a macro to a function in OpenSSL 3.0.
|
|
|
|
=head1 COPYRIGHT
|
|
|
|
Copyright 2006-2018 The OpenSSL Project Authors. All Rights Reserved.
|
|
|
|
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
|
|
L<https://www.openssl.org/source/license.html>.
|
|
|
|
=cut
|