CMS_SIGNED_GET_ATTR(3ossl) OpenSSL CMS_SIGNED_GET_ATTR(3ossl)
NAME
CMS_signed_get_attr_count, CMS_signed_get_attr_by_NID,
CMS_signed_get_attr_by_OBJ, CMS_signed_get_attr,
CMS_signed_delete_attr, CMS_signed_add1_attr,
CMS_signed_add1_attr_by_OBJ, CMS_signed_add1_attr_by_NID,
CMS_signed_add1_attr_by_txt, CMS_signed_get0_data_by_OBJ,
CMS_unsigned_get_attr_count, CMS_unsigned_get_attr_by_NID,
CMS_unsigned_get_attr_by_OBJ, CMS_unsigned_get_attr,
CMS_unsigned_delete_attr, CMS_unsigned_add1_attr,
CMS_unsigned_add1_attr_by_OBJ, CMS_unsigned_add1_attr_by_NID,
CMS_unsigned_add1_attr_by_txt, CMS_unsigned_get0_data_by_OBJ - CMS
signed and unsigned attribute functions
SYNOPSIS
#include <openssl/cms.h>
int CMS_signed_get_attr_count(const CMS_SignerInfo *si);
int CMS_signed_get_attr_by_NID(const CMS_SignerInfo *si, int nid,
int lastpos);
int CMS_signed_get_attr_by_OBJ(const CMS_SignerInfo *si, const ASN1_OBJECT *obj,
int lastpos);
X509_ATTRIBUTE *CMS_signed_get_attr(const CMS_SignerInfo *si, int loc);
X509_ATTRIBUTE *CMS_signed_delete_attr(CMS_SignerInfo *si, int loc);
int CMS_signed_add1_attr(CMS_SignerInfo *si, X509_ATTRIBUTE *attr);
int CMS_signed_add1_attr_by_OBJ(CMS_SignerInfo *si,
const ASN1_OBJECT *obj, int type,
const void *bytes, int len);
int CMS_signed_add1_attr_by_NID(CMS_SignerInfo *si,
int nid, int type,
const void *bytes, int len);
int CMS_signed_add1_attr_by_txt(CMS_SignerInfo *si,
const char *attrname, int type,
const void *bytes, int len);
void *CMS_signed_get0_data_by_OBJ(const CMS_SignerInfo *si,
const ASN1_OBJECT *oid,
int lastpos, int type);
int CMS_unsigned_get_attr_count(const CMS_SignerInfo *si);
int CMS_unsigned_get_attr_by_NID(const CMS_SignerInfo *si, int nid,
int lastpos);
int CMS_unsigned_get_attr_by_OBJ(const CMS_SignerInfo *si,
const ASN1_OBJECT *obj, int lastpos);
X509_ATTRIBUTE *CMS_unsigned_get_attr(const CMS_SignerInfo *si, int loc);
X509_ATTRIBUTE *CMS_unsigned_delete_attr(CMS_SignerInfo *si, int loc);
int CMS_unsigned_add1_attr(CMS_SignerInfo *si, X509_ATTRIBUTE *attr);
int CMS_unsigned_add1_attr_by_OBJ(CMS_SignerInfo *si,
const ASN1_OBJECT *obj, int type,
const void *bytes, int len);
int CMS_unsigned_add1_attr_by_NID(CMS_SignerInfo *si,
int nid, int type,
const void *bytes, int len);
int CMS_unsigned_add1_attr_by_txt(CMS_SignerInfo *si,
const char *attrname, int type,
const void *bytes, int len);
void *CMS_unsigned_get0_data_by_OBJ(CMS_SignerInfo *si, ASN1_OBJECT *oid,
int lastpos, int type);
DESCRIPTION
CMS_signerInfo contains separate attribute lists for signed and
unsigned attributes. Each CMS_signed_XXX() function is used for signed
attributes, and each CMS_unsigned_XXX() function is used for unsigned
attributes. Since the CMS_unsigned_XXX() functions work in the same
way as the CMS_signed_XXX() equivalents, only the CMS_signed_XXX()
functions are described below.
CMS_signed_get_attr_by_OBJ() finds the location of the first matching
object obj in the SignerInfo's si signed attribute list. The search
starts at the position after lastpos. If the returned value is positive
then it can be used on the next call to CMS_signed_get_attr_by_OBJ() as
the value of lastpos in order to iterate through the remaining
attributes. lastpos can be set to any negative value on the first call,
in order to start searching from the start of the signed attribute
list.
CMS_signed_get_attr_by_NID() is similar to CMS_signed_get_attr_by_OBJ()
except that it passes the numerical identifier (NID) nid associated
with the object. See <openssl/obj_mac.h> for a list of NID_*.
CMS_signed_get_attr(3) returns the X509_ATTRIBUTE object at index loc in
the si signed attribute list. loc should be in the range from 0 to
CMS_signed_get_attr_count() - 1.
CMS_signed_delete_attr() removes the X509_ATTRIBUTE object at index loc
in the si signed attribute list. An error occurs if the si attribute
list is NULL.
CMS_signed_add1_attr() pushes a copy of the passed in X509_ATTRIBUTE
object to the si signed attribute list. A new signed attribute list is
created if required. An error occurs if attr is NULL.
CMS_signed_add1_attr_by_OBJ() creates a new signed X509_ATTRIBUTE using
X509_ATTRIBUTE_set1_object() and X509_ATTRIBUTE_set1_data() to assign a
new obj with type type and data bytes of length len and then pushes it
to the key object's attribute list.
CMS_signed_add1_attr_by_NID() is similar to
CMS_signed_add1_attr_by_OBJ() except that it passes the numerical
identifier (NID) nid associated with the object. See
<openssl/obj_mac.h> for a list of NID_*.
CMS_signed_add1_attr_by_txt() is similar to
CMS_signed_add1_attr_by_OBJ() except that it passes a name attrname
associated with the object. See <openssl/obj_mac.h> for a list of SN_*
names.
CMS_signed_get0_data_by_OBJ() finds the first attribute in a si signed
attributes list that matches the obj starting at index lastpos and
returns the data retrieved from the found attributes first ASN1_TYPE
object. An error will occur if the attribute type type does not match
the type of the ASN1_TYPE object OR if type is either V_ASN1_BOOLEAN or
V_ASN1_NULL OR the attribute is not found. If lastpos is less than -1
then an error will occur if there are multiple objects in the signed
attribute list that match obj. If lastpos is less than -2 then an
error will occur if there is more than one ASN1_TYPE object in the
found signed attribute.
Refer to X509_ATTRIBUTE(3) for information related to attributes.
RETURN VALUES
The CMS_unsigned_XXX() functions return values are similar to those of
the equivalent CMS_signed_XXX() functions.
CMS_signed_get_attr_count() returns the number of signed attributes in
the SignerInfo si, or -1 if the signed attribute list is NULL.
CMS_signed_get_attr_by_OBJ() returns -1 if either the signed attribute
list of si is empty OR if obj is not found, otherwise it returns the
location of the obj in the SignerInfo's si signed attribute list.
CMS_signed_get_attr_by_NID() is similar to CMS_signed_get_attr_by_OBJ()
except that it returns -2 if the nid is not known by OpenSSL.
CMS_signed_get_attr(3) returns either a signed X509_ATTRIBUTE or NULL on
error.
CMS_signed_delete_attr() returns either the removed signed
X509_ATTRIBUTE or NULL if there is a error.
CMS_signed_add1_attr(), CMS_signed_add1_attr_by_OBJ(),
CMS_signed_add1_attr_by_NID(), CMS_signed_add1_attr_by_txt(), return 1
on success or 0 on error.
CMS_signed_get0_data_by_OBJ() returns the data retrieved from the found
signed attributes first ASN1_TYPE object, or NULL if an error occurs.
NOTES
Some attributes are added automatically during the signing process.
Calling CMS_SignerInfo_sign() adds the NID_pkcs9_signingTime signed
attribute.
Calling CMS_final(), CMS_final_digest() or CMS_dataFinal() adds the
NID_pkcs9_messageDigest signed attribute.
The NID_pkcs9_contentType signed attribute is always added if the
NID_pkcs9_signingTime attribute is added.
Calling CMS_sign_ex(), CMS_sign_receipt() or CMS_add1_signer() may add
attributes depending on the flags parameter. See CMS_add1_signer(3) for
more information.
OpenSSL applies special rules for the following attribute NIDs:
CMS Signed Attributes
NID_pkcs9_contentType NID_pkcs9_messageDigest NID_pkcs9_signingTime
ESS Signed Attributes
NID_id_smime_aa_signingCertificate
NID_id_smime_aa_signingCertificateV2 NID_id_smime_aa_receiptRequest
CMS Unsigned Attributes
NID_pkcs9_countersignature
CMS_signed_add1_attr(), CMS_signed_add1_attr_by_OBJ(),
CMS_signed_add1_attr_by_NID(), CMS_signed_add1_attr_by_txt() and the
equivalent CMS_unsigned_add1_attrXXX() functions allow duplicate
attributes to be added. The attribute rules are not checked during
these function calls, and are deferred until the sign or verify process
(i.e. during calls to any of CMS_sign_ex(), CMS_sign(),
CMS_sign_receipt(), CMS_add1_signer(), CMS_Final(), CMS_dataFinal(),
CMS_final_digest(), CMS_verify(), CMS_verify_receipt() or
CMS_SignedData_verify()).
For CMS attribute rules see RFC 5652 Section 11. For ESS attribute
rules see RFC 2634 Section 1.3.4 and RFC 5035 Section 5.4.
SEE ALSO
X509_ATTRIBUTE(3)
COPYRIGHT
Copyright 2023-2024 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
<https://www.openssl.org/source/license.html>.
3.3.2 2024-09-04 CMS_SIGNED_GET_ATTR(3ossl)
openssl 3.3.2 - Generated Sat Sep 7 14:20:56 CDT 2024