doc/man3/ASN1_item_sign.pod - third_party/openssl - Git at Google

 =pod

 =head1 NAME

 ASN1_item_sign, ASN1_item_sign_ex, ASN1_item_sign_ctx,
 ASN1_item_verify, ASN1_item_verify_ex, ASN1_item_verify_ctx -
 ASN1 sign and verify

 =head1 SYNOPSIS

  #include <openssl/x509.h>

  int ASN1_item_sign_ex(const ASN1_ITEM *it, X509_ALGOR *algor1,
                        X509_ALGOR *algor2, ASN1_BIT_STRING *signature,
                        const void *data, const ASN1_OCTET_STRING *id,
                        EVP_PKEY *pkey, const EVP_MD *md, OSSL_LIB_CTX *libctx,
                        const char *propq);

  int ASN1_item_sign(const ASN1_ITEM *it, X509_ALGOR *algor1, X509_ALGOR *algor2,
                     ASN1_BIT_STRING *signature, const void *data,
                     EVP_PKEY *pkey, const EVP_MD *md);

  int ASN1_item_sign_ctx(const ASN1_ITEM *it, X509_ALGOR *algor1,
                         X509_ALGOR *algor2, ASN1_BIT_STRING *signature,
                         const void *data, EVP_MD_CTX *ctx);

  int ASN1_item_verify_ex(const ASN1_ITEM *it, const X509_ALGOR *alg,
                          const ASN1_BIT_STRING *signature, const void *data,
                          const ASN1_OCTET_STRING *id, EVP_PKEY *pkey,
                          OSSL_LIB_CTX *libctx, const char *propq);

  int ASN1_item_verify(const ASN1_ITEM *it, const X509_ALGOR *alg,
                       const ASN1_BIT_STRING *signature, const void *data,
                       EVP_PKEY *pkey);

  int ASN1_item_verify_ctx(const ASN1_ITEM *it, const X509_ALGOR *alg,
                           const ASN1_BIT_STRING *signature, const void *data,
                           EVP_MD_CTX *ctx);

 =head1 DESCRIPTION

 ASN1_item_sign_ex() is used to sign arbitrary ASN1 data using a data object
 I<data>, the ASN.1 structure I<it>, private key I<pkey> and message digest I<md>.
 The data that is signed is formed by taking the data object in I<data> and
 converting it to der format using the ASN.1 structure I<it>.
 The I<data> that will be signed, and a structure containing the signature may
 both have a copy of the B<X509_ALGOR>. The ASN1_item_sign_ex() function will
 write the correct B<X509_ALGOR> to the structs based on the algorithms and
 parameters that have been set up. If one of I<algor1> or I<algor2> points to the
 B<X509_ALGOR> of the I<data> to be signed, then that B<X509_ALGOR> will first be
 written before the signature is generated.
 Examples of valid values that can be used by the ASN.1 structure I<it> are
 ASN1_ITEM_rptr(X509_CINF), ASN1_ITEM_rptr(X509_REQ_INFO) and
 ASN1_ITEM_rptr(X509_CRL_INFO).
 The B<OSSL_LIB_CTX> specified in I<libctx> and the property query string
 specified in I<props> are used when searching for algorithms in providers.
 The generated signature is set into I<signature>.
 The optional parameter I<id> can be NULL, but can be set for special key types.
 See EVP_PKEY_CTX_set1_id() for further info. The output parameters <algor1> and
 I<algor2> are ignored if they are NULL.

 ASN1_item_sign() is similar to ASN1_item_sign_ex() but uses default values of
 NULL for the I<id>, I<libctx> and I<propq>.

 ASN1_item_sign_ctx() is similar to ASN1_item_sign() but uses the parameters
 contained in digest context I<ctx>.

 ASN1_item_verify_ex() is used to verify the signature I<signature> of internal
 data I<data> using the public key I<pkey> and algorithm identifier I<alg>.
 The data that is verified is formed by taking the data object in I<data> and
 converting it to der format using the ASN.1 structure I<it>.
 The B<OSSL_LIB_CTX> specified in I<libctx> and the property query string
 specified in I<props> are used when searching for algorithms in providers.
 The optional parameter I<id> can be NULL, but can be set for special key types.
 See EVP_PKEY_CTX_set1_id() for further info.

 ASN1_item_verify() is similar to ASN1_item_verify_ex() but uses default values of
 NULL for the I<id>, I<libctx> and I<propq>.

 ASN1_item_verify_ctx() is similar to ASN1_item_verify() but uses the parameters
 contained in digest context I<ctx>.


 =head1 RETURN VALUES

 All sign functions return the size of the signature in bytes for success and
 zero for failure.

 All verify functions return 1 if the signature is valid and 0 if the signature
 check fails. If the signature could not be checked at all because it was
 ill-formed or some other error occurred then -1 is returned.

 =head1 EXAMPLES

 In the following example a 'MyObject' object is signed using the key contained
 in an EVP_MD_CTX. The signature is written to MyObject.signature. The object is
 then output in DER format and then loaded back in and verified.

  #include <openssl/x509.h>
  #include <openssl/asn1t.h>

  /* An object used to store the ASN1 data fields that will be signed */
  typedef struct MySignInfoObject_st
  {
      ASN1_INTEGER *version;
      X509_ALGOR sig_alg;
  } MySignInfoObject;

  DECLARE_ASN1_FUNCTIONS(MySignInfoObject)
  /*
   * A higher level object containing the ASN1 fields, signature alg and
   * output signature.
   */
  typedef struct MyObject_st
  {
      MySignInfoObject info;
      X509_ALGOR sig_alg;
      ASN1_BIT_STRING *signature;
  } MyObject;

  DECLARE_ASN1_FUNCTIONS(MyObject)

  /* The ASN1 definition of MySignInfoObject */
  ASN1_SEQUENCE_cb(MySignInfoObject, NULL) = {
      ASN1_SIMPLE(MySignInfoObject, version, ASN1_INTEGER)
      ASN1_EMBED(MySignInfoObject, sig_alg, X509_ALGOR),
  } ASN1_SEQUENCE_END_cb(MySignInfoObject, MySignInfoObject)

  /* new, free, d2i & i2d functions for MySignInfoObject */
  IMPLEMENT_ASN1_FUNCTIONS(MySignInfoObject)

  /* The ASN1 definition of MyObject */
  ASN1_SEQUENCE_cb(MyObject, NULL) = {
      ASN1_EMBED(MyObject, info, MySignInfoObject),
      ASN1_EMBED(MyObject, sig_alg, X509_ALGOR),
      ASN1_SIMPLE(MyObject, signature, ASN1_BIT_STRING)
  } ASN1_SEQUENCE_END_cb(MyObject, MyObject)

  /* new, free, d2i & i2d functions for MyObject */
  IMPLEMENT_ASN1_FUNCTIONS(MyObject)

  int test_asn1_item_sign_verify(const char *mdname, EVP_PKEY *pkey, long version)
  {
     int ret = 0;
     unsigned char *obj_der = NULL;
     const unsigned char *p = NULL;
     MyObject *obj = NULL, *loaded_obj = NULL;
     const ASN1_ITEM *it = ASN1_ITEM_rptr(MySignInfoObject);
     EVP_MD_CTX *sctx = NULL, *vctx = NULL;
     int len;

     /* Create MyObject and set its version */
     obj = MyObject_new();
     if (obj == NULL)
         goto err;
     if (!ASN1_INTEGER_set(obj->info.version, version))
         goto err;

     /* Set the key and digest used for signing */
     sctx = EVP_MD_CTX_new();
     if (sctx == NULL
         || !EVP_DigestSignInit_ex(sctx, NULL, mdname, NULL, NULL, pkey))
         goto err;

     /*
      * it contains the mapping between ASN.1 data and an object MySignInfoObject
      * obj->info is the 'MySignInfoObject' object that will be
      *   converted into DER data and then signed.
      * obj->signature will contain the output signature.
      * obj->sig_alg is filled with the private key's signing algorithm id.
      * obj->info.sig_alg is another copy of the signing algorithm id that sits
      * within MyObject.
      */
     len = ASN1_item_sign_ctx(it, &obj->sig_alg, &obj->info.sig_alg,
                              obj->signature, &obj->info, sctx);
     if (len <= 0
         || X509_ALGOR_cmp(&obj->sig_alg, &obj->info.sig_alg) != 0)
         goto err;

     /* Output MyObject in der form */
     len = i2d_MyObject(obj, &obj_der);
     if (len <= 0)
         goto err;

     /* Set the key and digest used for verifying */
     vctx = EVP_MD_CTX_new();
     if (vctx == NULL
         || !EVP_DigestVerifyInit_ex(vctx, NULL, mdname, NULL, NULL, pkey))
         goto err;

     /* Load the der data back into an object */
     p = obj_der;
     loaded_obj = d2i_MyObject(NULL, &p, len);
     if (loaded_obj == NULL)
         goto err;
     /* Verify the loaded object */
     ret = ASN1_item_verify_ctx(it, &loaded_obj->sig_alg, loaded_obj->signature,
                                &loaded_obj->info, vctx);
 err:
     OPENSSL_free(obj_der);
     MyObject_free(loaded_obj);
     MyObject_free(obj);
     EVP_MD_CTX_free(sctx);
     EVP_MD_CTX_free(vctx);
     return ret;
  }

 =head1 SEE ALSO

 L<X509_sign(3)>,
 L<X509_verify(3)>

 =head1 HISTORY

 ASN1_item_sign_ex() and ASN1_item_verify_ex() were added in OpenSSL 3.0.

 =head1 COPYRIGHT

 Copyright 2020-2022 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
	=pod

	=head1 NAME

	ASN1_item_sign, ASN1_item_sign_ex, ASN1_item_sign_ctx,
	ASN1_item_verify, ASN1_item_verify_ex, ASN1_item_verify_ctx -
	ASN1 sign and verify

	=head1 SYNOPSIS

	#include <openssl/x509.h>

	int ASN1_item_sign_ex(const ASN1_ITEM it, X509_ALGOR algor1,
	X509_ALGOR algor2, ASN1_BIT_STRING signature,
	const void data, const ASN1_OCTET_STRING id,
	EVP_PKEY pkey, const EVP_MD md, OSSL_LIB_CTX *libctx,
	const char *propq);

	int ASN1_item_sign(const ASN1_ITEM it, X509_ALGOR algor1, X509_ALGOR *algor2,
	ASN1_BIT_STRING signature, const void data,
	EVP_PKEY pkey, const EVP_MD md);

	int ASN1_item_sign_ctx(const ASN1_ITEM it, X509_ALGOR algor1,
	X509_ALGOR algor2, ASN1_BIT_STRING signature,
	const void data, EVP_MD_CTX ctx);

	int ASN1_item_verify_ex(const ASN1_ITEM it, const X509_ALGOR alg,
	const ASN1_BIT_STRING signature, const void data,
	const ASN1_OCTET_STRING id, EVP_PKEY pkey,
	OSSL_LIB_CTX libctx, const char propq);

	int ASN1_item_verify(const ASN1_ITEM it, const X509_ALGOR alg,
	const ASN1_BIT_STRING signature, const void data,
	EVP_PKEY *pkey);

	int ASN1_item_verify_ctx(const ASN1_ITEM it, const X509_ALGOR alg,
	const ASN1_BIT_STRING signature, const void data,
	EVP_MD_CTX *ctx);

	=head1 DESCRIPTION

	ASN1_item_sign_ex() is used to sign arbitrary ASN1 data using a data object
	I<data>, the ASN.1 structure I<it>, private key I<pkey> and message digest I<md>.
	The data that is signed is formed by taking the data object in I<data> and
	converting it to der format using the ASN.1 structure I<it>.
	The I<data> that will be signed, and a structure containing the signature may
	both have a copy of the B<X509_ALGOR>. The ASN1_item_sign_ex() function will
	write the correct B<X509_ALGOR> to the structs based on the algorithms and
	parameters that have been set up. If one of I<algor1> or I<algor2> points to the
	B<X509_ALGOR> of the I<data> to be signed, then that B<X509_ALGOR> will first be
	written before the signature is generated.
	Examples of valid values that can be used by the ASN.1 structure I<it> are
	ASN1_ITEM_rptr(X509_CINF), ASN1_ITEM_rptr(X509_REQ_INFO) and
	ASN1_ITEM_rptr(X509_CRL_INFO).
	The B<OSSL_LIB_CTX> specified in I<libctx> and the property query string
	specified in I<props> are used when searching for algorithms in providers.
	The generated signature is set into I<signature>.
	The optional parameter I<id> can be NULL, but can be set for special key types.
	See EVP_PKEY_CTX_set1_id() for further info. The output parameters <algor1> and
	I<algor2> are ignored if they are NULL.

	ASN1_item_sign() is similar to ASN1_item_sign_ex() but uses default values of
	NULL for the I<id>, I<libctx> and I<propq>.

	ASN1_item_sign_ctx() is similar to ASN1_item_sign() but uses the parameters
	contained in digest context I<ctx>.

	ASN1_item_verify_ex() is used to verify the signature I<signature> of internal
	data I<data> using the public key I<pkey> and algorithm identifier I<alg>.
	The data that is verified is formed by taking the data object in I<data> and
	converting it to der format using the ASN.1 structure I<it>.
	The B<OSSL_LIB_CTX> specified in I<libctx> and the property query string
	specified in I<props> are used when searching for algorithms in providers.
	The optional parameter I<id> can be NULL, but can be set for special key types.
	See EVP_PKEY_CTX_set1_id() for further info.

	ASN1_item_verify() is similar to ASN1_item_verify_ex() but uses default values of
	NULL for the I<id>, I<libctx> and I<propq>.

	ASN1_item_verify_ctx() is similar to ASN1_item_verify() but uses the parameters
	contained in digest context I<ctx>.


	=head1 RETURN VALUES

	All sign functions return the size of the signature in bytes for success and
	zero for failure.

	All verify functions return 1 if the signature is valid and 0 if the signature
	check fails. If the signature could not be checked at all because it was
	ill-formed or some other error occurred then -1 is returned.

	=head1 EXAMPLES

	In the following example a 'MyObject' object is signed using the key contained
	in an EVP_MD_CTX. The signature is written to MyObject.signature. The object is
	then output in DER format and then loaded back in and verified.

	#include <openssl/x509.h>
	#include <openssl/asn1t.h>

	/* An object used to store the ASN1 data fields that will be signed */
	typedef struct MySignInfoObject_st
	{
	ASN1_INTEGER *version;
	X509_ALGOR sig_alg;
	} MySignInfoObject;

	DECLARE_ASN1_FUNCTIONS(MySignInfoObject)
	/*
	* A higher level object containing the ASN1 fields, signature alg and
	* output signature.
	*/
	typedef struct MyObject_st
	{
	MySignInfoObject info;
	X509_ALGOR sig_alg;
	ASN1_BIT_STRING *signature;
	} MyObject;

	DECLARE_ASN1_FUNCTIONS(MyObject)

	/* The ASN1 definition of MySignInfoObject */
	ASN1_SEQUENCE_cb(MySignInfoObject, NULL) = {
	ASN1_SIMPLE(MySignInfoObject, version, ASN1_INTEGER)
	ASN1_EMBED(MySignInfoObject, sig_alg, X509_ALGOR),
	} ASN1_SEQUENCE_END_cb(MySignInfoObject, MySignInfoObject)

	/* new, free, d2i & i2d functions for MySignInfoObject */
	IMPLEMENT_ASN1_FUNCTIONS(MySignInfoObject)

	/* The ASN1 definition of MyObject */
	ASN1_SEQUENCE_cb(MyObject, NULL) = {
	ASN1_EMBED(MyObject, info, MySignInfoObject),
	ASN1_EMBED(MyObject, sig_alg, X509_ALGOR),
	ASN1_SIMPLE(MyObject, signature, ASN1_BIT_STRING)
	} ASN1_SEQUENCE_END_cb(MyObject, MyObject)

	/* new, free, d2i & i2d functions for MyObject */
	IMPLEMENT_ASN1_FUNCTIONS(MyObject)

	int test_asn1_item_sign_verify(const char mdname, EVP_PKEY pkey, long version)
	{
	int ret = 0;
	unsigned char *obj_der = NULL;
	const unsigned char *p = NULL;
	MyObject obj = NULL, loaded_obj = NULL;
	const ASN1_ITEM *it = ASN1_ITEM_rptr(MySignInfoObject);
	EVP_MD_CTX sctx = NULL, vctx = NULL;
	int len;

	/* Create MyObject and set its version */
	obj = MyObject_new();
	if (obj == NULL)
	goto err;
	if (!ASN1_INTEGER_set(obj->info.version, version))
	goto err;

	/* Set the key and digest used for signing */
	sctx = EVP_MD_CTX_new();
	if (sctx == NULL
	\|\| !EVP_DigestSignInit_ex(sctx, NULL, mdname, NULL, NULL, pkey))
	goto err;

	/*
	* it contains the mapping between ASN.1 data and an object MySignInfoObject
	* obj->info is the 'MySignInfoObject' object that will be
	* converted into DER data and then signed.
	* obj->signature will contain the output signature.
	* obj->sig_alg is filled with the private key's signing algorithm id.
	* obj->info.sig_alg is another copy of the signing algorithm id that sits
	* within MyObject.
	*/
	len = ASN1_item_sign_ctx(it, &obj->sig_alg, &obj->info.sig_alg,
	obj->signature, &obj->info, sctx);
	if (len <= 0
	\|\| X509_ALGOR_cmp(&obj->sig_alg, &obj->info.sig_alg) != 0)
	goto err;

	/* Output MyObject in der form */
	len = i2d_MyObject(obj, &obj_der);
	if (len <= 0)
	goto err;

	/* Set the key and digest used for verifying */
	vctx = EVP_MD_CTX_new();
	if (vctx == NULL
	\|\| !EVP_DigestVerifyInit_ex(vctx, NULL, mdname, NULL, NULL, pkey))
	goto err;

	/* Load the der data back into an object */
	p = obj_der;
	loaded_obj = d2i_MyObject(NULL, &p, len);
	if (loaded_obj == NULL)
	goto err;
	/* Verify the loaded object */
	ret = ASN1_item_verify_ctx(it, &loaded_obj->sig_alg, loaded_obj->signature,
	&loaded_obj->info, vctx);
	err:
	OPENSSL_free(obj_der);
	MyObject_free(loaded_obj);
	MyObject_free(obj);
	EVP_MD_CTX_free(sctx);
	EVP_MD_CTX_free(vctx);
	return ret;
	}

	=head1 SEE ALSO

	L<X509_sign(3)>,
	L<X509_verify(3)>

	=head1 HISTORY

	ASN1_item_sign_ex() and ASN1_item_verify_ex() were added in OpenSSL 3.0.

	=head1 COPYRIGHT

	Copyright 2020-2022 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