[thirdparty/openssl.git] / doc / man7 / EVP_PKEY-SM2.pod

=pod

=head1 NAME

EVP_PKEY-SM2, EVP_KEYMGMT-SM2, SM2
- EVP_PKEY keytype support for the Chinese SM2 signature and encryption algorithms

=head1 DESCRIPTION

The B<SM2> algorithm was first defined by the Chinese national standard GM/T
0003-2012 and was later standardized by ISO as ISO/IEC 14888. B<SM2> is actually
an elliptic curve based algorithm. The current implementation in OpenSSL supports
both signature and encryption schemes via the EVP interface.

When doing the B<SM2> signature algorithm, it requires a distinguishing identifier
to form the message prefix which is hashed before the real message is hashed.

=head2 Common SM2 parameters

SM2 uses the parameters defined in L<EVP_PKEY-EC(7)/Common EC parameters>.
The following parameters are different:

=over 4

=item "cofactor" (B<OSSL_PKEY_PARAM_EC_COFACTOR>) <unsigned integer>

This parameter is ignored for B<SM2>.

=item (B<OSSL_PKEY_PARAM_DEFAULT_DIGEST>) <UTF8 string>

Getter that returns the default digest name.
(Currently returns "SM3" as of OpenSSL 3.0).

=back

=head1 NOTES

B<SM2> signatures can be generated by using the 'DigestSign' series of APIs, for
instance, EVP_DigestSignInit(), EVP_DigestSignUpdate() and EVP_DigestSignFinal().
Ditto for the verification process by calling the 'DigestVerify' series of APIs.
Note that the SM2 algorithm requires the presence of the public key for signatures,
as such the B<OSSL_PKEY_PARAM_PUB_KEY> option must be set on any key used in signature
generation.

Before computing an B<SM2> signature, an B<EVP_PKEY_CTX> needs to be created,
and an B<SM2> ID must be set for it, like this:

 EVP_PKEY_CTX_set1_id(pctx, id, id_len);

Before calling the EVP_DigestSignInit() or EVP_DigestVerifyInit() functions,
that B<EVP_PKEY_CTX> should be assigned to the B<EVP_MD_CTX>, like this:

 EVP_MD_CTX_set_pkey_ctx(mctx, pctx);

There is normally no need to pass a B<pctx> parameter to EVP_DigestSignInit()
or EVP_DigestVerifyInit() in such a scenario.

SM2 can be tested with the L<openssl-speed(1)> application since version 3.0.
Currently, the only valid algorithm name is B<sm2>.

Since version 3.0, SM2 keys can be generated and loaded only when the domain
parameters specify the SM2 elliptic curve.

=head1 EXAMPLES

This example demonstrates the calling sequence for using an B<EVP_PKEY> to verify
a message with the SM2 signature algorithm and the SM3 hash algorithm:

 #include <openssl/evp.h>

 /* obtain an EVP_PKEY using whatever methods... */
 mctx = EVP_MD_CTX_new();
 pctx = EVP_PKEY_CTX_new(pkey, NULL);
 EVP_PKEY_CTX_set1_id(pctx, id, id_len);
 EVP_MD_CTX_set_pkey_ctx(mctx, pctx);
 EVP_DigestVerifyInit(mctx, NULL, EVP_sm3(), NULL, pkey);
 EVP_DigestVerifyUpdate(mctx, msg, msg_len);
 EVP_DigestVerifyFinal(mctx, sig, sig_len)

=head1 SEE ALSO

L<EVP_PKEY_CTX_new(3)>,
L<EVP_DigestSignInit(3)>,
L<EVP_DigestVerifyInit(3)>,
L<EVP_PKEY_CTX_set1_id(3)>,
L<EVP_MD_CTX_set_pkey_ctx(3)>

=head1 COPYRIGHT

Copyright 2018-2021 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
Commit	Line	Data
571286b0 PY	1	=pod
	2
	3	=head1 NAME
	4
a48309cb MC	5	EVP_PKEY-SM2, EVP_KEYMGMT-SM2, SM2
a48309cb MC	6	- EVP_PKEY keytype support for the Chinese SM2 signature and encryption algorithms
571286b0 PY	7
	8	=head1 DESCRIPTION
	9
f922dac8 PY	10	The B<SM2> algorithm was first defined by the Chinese national standard GM/T
	11	0003-2012 and was later standardized by ISO as ISO/IEC 14888. B<SM2> is actually
	12	an elliptic curve based algorithm. The current implementation in OpenSSL supports
	13	both signature and encryption schemes via the EVP interface.
571286b0 PY	14
	15	When doing the B<SM2> signature algorithm, it requires a distinguishing identifier
	16	to form the message prefix which is hashed before the real message is hashed.
	17
5135a9bd SL	18	=head2 Common SM2 parameters
	19
	20	SM2 uses the parameters defined in L<EVP_PKEY-EC(7)/Common EC parameters>.
	21	The following parameters are different:
	22
	23	=over 4
	24
	25	=item "cofactor" (B<OSSL_PKEY_PARAM_EC_COFACTOR>) <unsigned integer>
	26
	27	This parameter is ignored for B<SM2>.
	28
	29	=item (B<OSSL_PKEY_PARAM_DEFAULT_DIGEST>) <UTF8 string>
	30
	31	Getter that returns the default digest name.
	32	(Currently returns "SM3" as of OpenSSL 3.0).
	33
	34	=back
	35
571286b0 PY	36	=head1 NOTES
571286b0 PY	37
f922dac8 PY	38	B<SM2> signatures can be generated by using the 'DigestSign' series of APIs, for
	39	instance, EVP_DigestSignInit(), EVP_DigestSignUpdate() and EVP_DigestSignFinal().
	40	Ditto for the verification process by calling the 'DigestVerify' series of APIs.
4feb4a2b NH	41	Note that the SM2 algorithm requires the presence of the public key for signatures,
	42	as such the B<OSSL_PKEY_PARAM_PUB_KEY> option must be set on any key used in signature
	43	generation.
571286b0	44
f4e4382c RL	45	Before computing an B<SM2> signature, an B<EVP_PKEY_CTX> needs to be created,
f4e4382c RL	46	and an B<SM2> ID must be set for it, like this:
571286b0 PY	47
	48	EVP_PKEY_CTX_set1_id(pctx, id, id_len);
	49
f4e4382c RL	50	Before calling the EVP_DigestSignInit() or EVP_DigestVerifyInit() functions,
f4e4382c RL	51	that B<EVP_PKEY_CTX> should be assigned to the B<EVP_MD_CTX>, like this:
571286b0 PY	52
	53	EVP_MD_CTX_set_pkey_ctx(mctx, pctx);
	54
f4e4382c	55	There is normally no need to pass a B<pctx> parameter to EVP_DigestSignInit()
f922dac8	56	or EVP_DigestVerifyInit() in such a scenario.
571286b0	57
a48309cb	58	SM2 can be tested with the L<openssl-speed(1)> application since version 3.0.
1903a9b7	59	Currently, the only valid algorithm name is B<sm2>.
a56f68ad	60
77072e27 TM	61	Since version 3.0, SM2 keys can be generated and loaded only when the domain
	62	parameters specify the SM2 elliptic curve.
	63
cda77422	64	=head1 EXAMPLES
571286b0	65
f922dac8 PY	66	This example demonstrates the calling sequence for using an B<EVP_PKEY> to verify
f922dac8 PY	67	a message with the SM2 signature algorithm and the SM3 hash algorithm:
571286b0 PY	68
	69	#include <openssl/evp.h>
	70
f922dac8	71	/* obtain an EVP_PKEY using whatever methods... */
571286b0 PY	72	mctx = EVP_MD_CTX_new();
	73	pctx = EVP_PKEY_CTX_new(pkey, NULL);
	74	EVP_PKEY_CTX_set1_id(pctx, id, id_len);
f4e4382c	75	EVP_MD_CTX_set_pkey_ctx(mctx, pctx);
571286b0 PY	76	EVP_DigestVerifyInit(mctx, NULL, EVP_sm3(), NULL, pkey);
	77	EVP_DigestVerifyUpdate(mctx, msg, msg_len);
	78	EVP_DigestVerifyFinal(mctx, sig, sig_len)
	79
	80	=head1 SEE ALSO
	81
	82	L<EVP_PKEY_CTX_new(3)>,
571286b0 PY	83	L<EVP_DigestSignInit(3)>,
	84	L<EVP_DigestVerifyInit(3)>,
	85	L<EVP_PKEY_CTX_set1_id(3)>,
	86	L<EVP_MD_CTX_set_pkey_ctx(3)>
	87
	88	=head1 COPYRIGHT
	89
5135a9bd	90	Copyright 2018-2021 The OpenSSL Project Authors. All Rights Reserved.
571286b0	91
3187791e	92	Licensed under the Apache License 2.0 (the "License"). You may not use
571286b0 PY	93	this file except in compliance with the License. You can obtain a copy
	94	in the file LICENSE in the source distribution or at
	95	L<https://www.openssl.org/source/license.html>.
	96
	97	=cut