2 * Copyright 2008-2021 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
10 #include <openssl/asn1t.h>
11 #include <openssl/pem.h>
12 #include <openssl/x509v3.h>
13 #include <openssl/err.h>
14 #include <openssl/cms.h>
15 #include "cms_local.h"
16 #include "internal/nelem.h"
20 * CMS attribute restrictions are discussed in
21 * - RFC 5652 Section 11.
22 * ESS attribute restrictions are discussed in
23 * - RFC 2634 Section 1.3.4 AND
24 * - RFC 5035 Section 5.4
26 /* This is a signed attribute */
27 #define CMS_ATTR_F_SIGNED 0x01
28 /* This is an unsigned attribute */
29 #define CMS_ATTR_F_UNSIGNED 0x02
30 /* Must be present if there are any other attributes of the same type */
31 #define CMS_ATTR_F_REQUIRED_COND 0x10
32 /* There can only be one instance of this attribute */
33 #define CMS_ATTR_F_ONLY_ONE 0x20
34 /* The Attribute's value must have exactly one entry */
35 #define CMS_ATTR_F_ONE_ATTR_VALUE 0x40
37 /* Attributes rules for different attributes */
39 int nid; /* The attribute id */
41 } cms_attribute_properties[] = {
42 /* See RFC Section 11 */
43 { NID_pkcs9_contentType, CMS_ATTR_F_SIGNED
45 | CMS_ATTR_F_ONE_ATTR_VALUE
46 | CMS_ATTR_F_REQUIRED_COND },
47 { NID_pkcs9_messageDigest, CMS_ATTR_F_SIGNED
49 | CMS_ATTR_F_ONE_ATTR_VALUE
50 | CMS_ATTR_F_REQUIRED_COND },
51 { NID_pkcs9_signingTime, CMS_ATTR_F_SIGNED
53 | CMS_ATTR_F_ONE_ATTR_VALUE },
54 { NID_pkcs9_countersignature, CMS_ATTR_F_UNSIGNED },
56 { NID_id_smime_aa_signingCertificate, CMS_ATTR_F_SIGNED
58 | CMS_ATTR_F_ONE_ATTR_VALUE },
59 { NID_id_smime_aa_signingCertificateV2, CMS_ATTR_F_SIGNED
61 | CMS_ATTR_F_ONE_ATTR_VALUE },
62 { NID_id_smime_aa_receiptRequest, CMS_ATTR_F_SIGNED
64 | CMS_ATTR_F_ONE_ATTR_VALUE }
67 /* CMS SignedData Attribute utilities */
69 int CMS_signed_get_attr_count(const CMS_SignerInfo *si)
71 return X509at_get_attr_count(si->signedAttrs);
74 int CMS_signed_get_attr_by_NID(const CMS_SignerInfo *si, int nid, int lastpos)
76 return X509at_get_attr_by_NID(si->signedAttrs, nid, lastpos);
79 int CMS_signed_get_attr_by_OBJ(const CMS_SignerInfo *si, const ASN1_OBJECT *obj,
82 return X509at_get_attr_by_OBJ(si->signedAttrs, obj, lastpos);
85 X509_ATTRIBUTE *CMS_signed_get_attr(const CMS_SignerInfo *si, int loc)
87 return X509at_get_attr(si->signedAttrs, loc);
90 X509_ATTRIBUTE *CMS_signed_delete_attr(CMS_SignerInfo *si, int loc)
92 return X509at_delete_attr(si->signedAttrs, loc);
95 int CMS_signed_add1_attr(CMS_SignerInfo *si, X509_ATTRIBUTE *attr)
97 if (X509at_add1_attr(&si->signedAttrs, attr))
102 int CMS_signed_add1_attr_by_OBJ(CMS_SignerInfo *si,
103 const ASN1_OBJECT *obj, int type,
104 const void *bytes, int len)
106 if (X509at_add1_attr_by_OBJ(&si->signedAttrs, obj, type, bytes, len))
111 int CMS_signed_add1_attr_by_NID(CMS_SignerInfo *si,
112 int nid, int type, const void *bytes, int len)
114 if (X509at_add1_attr_by_NID(&si->signedAttrs, nid, type, bytes, len))
119 int CMS_signed_add1_attr_by_txt(CMS_SignerInfo *si,
120 const char *attrname, int type,
121 const void *bytes, int len)
123 if (X509at_add1_attr_by_txt(&si->signedAttrs, attrname, type, bytes, len))
128 void *CMS_signed_get0_data_by_OBJ(const CMS_SignerInfo *si,
129 const ASN1_OBJECT *oid,
130 int lastpos, int type)
132 return X509at_get0_data_by_OBJ(si->signedAttrs, oid, lastpos, type);
135 int CMS_unsigned_get_attr_count(const CMS_SignerInfo *si)
137 return X509at_get_attr_count(si->unsignedAttrs);
140 int CMS_unsigned_get_attr_by_NID(const CMS_SignerInfo *si, int nid,
143 return X509at_get_attr_by_NID(si->unsignedAttrs, nid, lastpos);
146 int CMS_unsigned_get_attr_by_OBJ(const CMS_SignerInfo *si,
147 const ASN1_OBJECT *obj, int lastpos)
149 return X509at_get_attr_by_OBJ(si->unsignedAttrs, obj, lastpos);
152 X509_ATTRIBUTE *CMS_unsigned_get_attr(const CMS_SignerInfo *si, int loc)
154 return X509at_get_attr(si->unsignedAttrs, loc);
157 X509_ATTRIBUTE *CMS_unsigned_delete_attr(CMS_SignerInfo *si, int loc)
159 return X509at_delete_attr(si->unsignedAttrs, loc);
162 int CMS_unsigned_add1_attr(CMS_SignerInfo *si, X509_ATTRIBUTE *attr)
164 if (X509at_add1_attr(&si->unsignedAttrs, attr))
169 int CMS_unsigned_add1_attr_by_OBJ(CMS_SignerInfo *si,
170 const ASN1_OBJECT *obj, int type,
171 const void *bytes, int len)
173 if (X509at_add1_attr_by_OBJ(&si->unsignedAttrs, obj, type, bytes, len))
178 int CMS_unsigned_add1_attr_by_NID(CMS_SignerInfo *si,
180 const void *bytes, int len)
182 if (X509at_add1_attr_by_NID(&si->unsignedAttrs, nid, type, bytes, len))
187 int CMS_unsigned_add1_attr_by_txt(CMS_SignerInfo *si,
188 const char *attrname, int type,
189 const void *bytes, int len)
191 if (X509at_add1_attr_by_txt(&si->unsignedAttrs, attrname,
197 void *CMS_unsigned_get0_data_by_OBJ(CMS_SignerInfo *si, ASN1_OBJECT *oid,
198 int lastpos, int type)
200 return X509at_get0_data_by_OBJ(si->unsignedAttrs, oid, lastpos, type);
204 * Retrieve an attribute by nid from a stack of attributes starting at index
206 * Returns the attribute or NULL if there is no attribute.
207 * If an attribute was found *lastpos returns the index of the found attribute.
209 static X509_ATTRIBUTE *cms_attrib_get(int nid,
210 const STACK_OF(X509_ATTRIBUTE) *attrs,
216 loc = X509at_get_attr_by_NID(attrs, nid, *lastpos);
220 at = X509at_get_attr(attrs, loc);
225 static int cms_check_attribute(int nid, int flags, int type,
226 const STACK_OF(X509_ATTRIBUTE) *attrs,
230 X509_ATTRIBUTE *at = cms_attrib_get(nid, attrs, &lastpos);
233 int count = X509_ATTRIBUTE_count(at);
235 /* Is this attribute allowed? */
236 if (((flags & type) == 0)
237 /* check if multiple attributes of the same type are allowed */
238 || (((flags & CMS_ATTR_F_ONLY_ONE) != 0)
239 && cms_attrib_get(nid, attrs, &lastpos) != NULL)
240 /* Check if attribute should have exactly one value in its set */
241 || (((flags & CMS_ATTR_F_ONE_ATTR_VALUE) != 0)
243 /* There should be at least one value */
247 /* fail if a required attribute is missing */
249 && ((flags & CMS_ATTR_F_REQUIRED_COND) != 0)
250 && (flags & type) != 0)
257 * Check that the signerinfo attributes obey the attribute rules which includes
258 * the following checks
259 * - If any signed attributes exist then there must be a Content Type
260 * and Message Digest attribute in the signed attributes.
261 * - The countersignature attribute is an optional unsigned attribute only.
262 * - Content Type, Message Digest, and Signing time attributes are signed
263 * attributes. Only one instance of each is allowed, with each of these
264 * attributes containing a single attribute value in its set.
266 int ossl_cms_si_check_attributes(const CMS_SignerInfo *si)
269 int have_signed_attrs = (CMS_signed_get_attr_count(si) > 0);
270 int have_unsigned_attrs = (CMS_unsigned_get_attr_count(si) > 0);
272 for (i = 0; i < (int)OSSL_NELEM(cms_attribute_properties); ++i) {
273 int nid = cms_attribute_properties[i].nid;
274 int flags = cms_attribute_properties[i].flags;
276 if (!cms_check_attribute(nid, flags, CMS_ATTR_F_SIGNED,
277 si->signedAttrs, have_signed_attrs)
278 || !cms_check_attribute(nid, flags, CMS_ATTR_F_UNSIGNED,
279 si->unsignedAttrs, have_unsigned_attrs)) {
280 ERR_raise(ERR_LIB_CMS, CMS_R_ATTRIBUTE_ERROR);