/* * Copyright 2008-2019 The OpenSSL Project Authors. All Rights Reserved. * * Licensed under the OpenSSL license (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 */ #include <openssl/asn1t.h> #include <openssl/pem.h> #include <openssl/x509v3.h> #include <openssl/err.h> #include <openssl/cms.h> #include "cms_local.h" #include "internal/nelem.h" /*- * Attribute flags. * CMS attribute restrictions are discussed in * - RFC 5652 Section 11. * ESS attribute restrictions are discussed in * - RFC 2634 Section 1.3.4 AND * - RFC 5035 Section 5.4 */ /* This is a signed attribute */ #define CMS_ATTR_F_SIGNED 0x01 /* This is an unsigned attribute */ #define CMS_ATTR_F_UNSIGNED 0x02 /* Must be present if there are any other attributes of the same type */ #define CMS_ATTR_F_REQUIRED_COND 0x10 /* There can only be one instance of this attribute */ #define CMS_ATTR_F_ONLY_ONE 0x20 /* The Attribute's value must have exactly one entry */ #define CMS_ATTR_F_ONE_ATTR_VALUE 0x40 /* Attributes rules for different attributes */ static const struct { int nid; /* The attribute id */ int flags; } cms_attribute_properties[] = { /* See RFC Section 11 */ { NID_pkcs9_contentType, CMS_ATTR_F_SIGNED | CMS_ATTR_F_ONLY_ONE | CMS_ATTR_F_ONE_ATTR_VALUE | CMS_ATTR_F_REQUIRED_COND }, { NID_pkcs9_messageDigest, CMS_ATTR_F_SIGNED | CMS_ATTR_F_ONLY_ONE | CMS_ATTR_F_ONE_ATTR_VALUE | CMS_ATTR_F_REQUIRED_COND }, { NID_pkcs9_signingTime, CMS_ATTR_F_SIGNED | CMS_ATTR_F_ONLY_ONE | CMS_ATTR_F_ONE_ATTR_VALUE }, { NID_pkcs9_countersignature, CMS_ATTR_F_UNSIGNED }, /* ESS */ { NID_id_smime_aa_signingCertificate, CMS_ATTR_F_SIGNED | CMS_ATTR_F_ONLY_ONE | CMS_ATTR_F_ONE_ATTR_VALUE }, { NID_id_smime_aa_signingCertificateV2, CMS_ATTR_F_SIGNED | CMS_ATTR_F_ONLY_ONE | CMS_ATTR_F_ONE_ATTR_VALUE }, { NID_id_smime_aa_receiptRequest, CMS_ATTR_F_SIGNED | CMS_ATTR_F_ONLY_ONE | CMS_ATTR_F_ONE_ATTR_VALUE } }; /* CMS SignedData Attribute utilities */ int CMS_signed_get_attr_count(const CMS_SignerInfo *si) { return X509at_get_attr_count(si->signedAttrs); } int CMS_signed_get_attr_by_NID(const CMS_SignerInfo *si, int nid, int lastpos) { return X509at_get_attr_by_NID(si->signedAttrs, nid, lastpos); } int CMS_signed_get_attr_by_OBJ(const CMS_SignerInfo *si, const ASN1_OBJECT *obj, int lastpos) { return X509at_get_attr_by_OBJ(si->signedAttrs, obj, lastpos); } X509_ATTRIBUTE *CMS_signed_get_attr(const CMS_SignerInfo *si, int loc) { return X509at_get_attr(si->signedAttrs, loc); } X509_ATTRIBUTE *CMS_signed_delete_attr(CMS_SignerInfo *si, int loc) { return X509at_delete_attr(si->signedAttrs, loc); } int CMS_signed_add1_attr(CMS_SignerInfo *si, X509_ATTRIBUTE *attr) { if (X509at_add1_attr(&si->signedAttrs, attr)) return 1; return 0; } int CMS_signed_add1_attr_by_OBJ(CMS_SignerInfo *si, const ASN1_OBJECT *obj, int type, const void *bytes, int len) { if (X509at_add1_attr_by_OBJ(&si->signedAttrs, obj, type, bytes, len)) return 1; return 0; } int CMS_signed_add1_attr_by_NID(CMS_SignerInfo *si, int nid, int type, const void *bytes, int len) { if (X509at_add1_attr_by_NID(&si->signedAttrs, nid, type, bytes, len)) return 1; return 0; } int CMS_signed_add1_attr_by_txt(CMS_SignerInfo *si, const char *attrname, int type, const void *bytes, int len) { if (X509at_add1_attr_by_txt(&si->signedAttrs, attrname, type, bytes, len)) return 1; return 0; } void *CMS_signed_get0_data_by_OBJ(CMS_SignerInfo *si, const ASN1_OBJECT *oid, int lastpos, int type) { return X509at_get0_data_by_OBJ(si->signedAttrs, oid, lastpos, type); } int CMS_unsigned_get_attr_count(const CMS_SignerInfo *si) { return X509at_get_attr_count(si->unsignedAttrs); } int CMS_unsigned_get_attr_by_NID(const CMS_SignerInfo *si, int nid, int lastpos) { return X509at_get_attr_by_NID(si->unsignedAttrs, nid, lastpos); } int CMS_unsigned_get_attr_by_OBJ(const CMS_SignerInfo *si, const ASN1_OBJECT *obj, int lastpos) { return X509at_get_attr_by_OBJ(si->unsignedAttrs, obj, lastpos); } X509_ATTRIBUTE *CMS_unsigned_get_attr(const CMS_SignerInfo *si, int loc) { return X509at_get_attr(si->unsignedAttrs, loc); } X509_ATTRIBUTE *CMS_unsigned_delete_attr(CMS_SignerInfo *si, int loc) { return X509at_delete_attr(si->unsignedAttrs, loc); } int CMS_unsigned_add1_attr(CMS_SignerInfo *si, X509_ATTRIBUTE *attr) { if (X509at_add1_attr(&si->unsignedAttrs, attr)) return 1; return 0; } int CMS_unsigned_add1_attr_by_OBJ(CMS_SignerInfo *si, const ASN1_OBJECT *obj, int type, const void *bytes, int len) { if (X509at_add1_attr_by_OBJ(&si->unsignedAttrs, obj, type, bytes, len)) return 1; return 0; } int CMS_unsigned_add1_attr_by_NID(CMS_SignerInfo *si, int nid, int type, const void *bytes, int len) { if (X509at_add1_attr_by_NID(&si->unsignedAttrs, nid, type, bytes, len)) return 1; return 0; } int CMS_unsigned_add1_attr_by_txt(CMS_SignerInfo *si, const char *attrname, int type, const void *bytes, int len) { if (X509at_add1_attr_by_txt(&si->unsignedAttrs, attrname, type, bytes, len)) return 1; return 0; } void *CMS_unsigned_get0_data_by_OBJ(CMS_SignerInfo *si, ASN1_OBJECT *oid, int lastpos, int type) { return X509at_get0_data_by_OBJ(si->unsignedAttrs, oid, lastpos, type); } /* * Retrieve an attribute by nid from a stack of attributes starting at index * *lastpos + 1. * Returns the attribute or NULL if there is no attribute. * If an attribute was found *lastpos returns the index of the found attribute. */ static X509_ATTRIBUTE *cms_attrib_get(int nid, const STACK_OF(X509_ATTRIBUTE) *attrs, int *lastpos) { X509_ATTRIBUTE *at; int loc; loc = X509at_get_attr_by_NID(attrs, nid, *lastpos); if (loc < 0) return NULL; at = X509at_get_attr(attrs, loc); *lastpos = loc; return at; } static int cms_check_attribute(int nid, int flags, int type, const STACK_OF(X509_ATTRIBUTE) *attrs, int have_attrs) { int lastpos = -1; X509_ATTRIBUTE *at = cms_attrib_get(nid, attrs, &lastpos); if (at != NULL) { int count = X509_ATTRIBUTE_count(at); /* Is this attribute allowed? */ if (((flags & type) == 0) /* check if multiple attributes of the same type are allowed */ || (((flags & CMS_ATTR_F_ONLY_ONE) != 0) && cms_attrib_get(nid, attrs, &lastpos) != NULL) /* Check if attribute should have exactly one value in its set */ || (((flags & CMS_ATTR_F_ONE_ATTR_VALUE) != 0) && count != 1) /* There should be at least one value */ || count == 0) return 0; } else { /* fail if a required attribute is missing */ if (have_attrs && ((flags & CMS_ATTR_F_REQUIRED_COND) != 0) && (flags & type) != 0) return 0; } return 1; } /* * Check that the signerinfo attributes obey the attribute rules which includes * the following checks * - If any signed attributes exist then there must be a Content Type * and Message Digest attribute in the signed attributes. * - The countersignature attribute is an optional unsigned attribute only. * - Content Type, Message Digest, and Signing time attributes are signed * attributes. Only one instance of each is allowed, with each of these * attributes containing a single attribute value in its set. */ int CMS_si_check_attributes(const CMS_SignerInfo *si) { int i; int have_signed_attrs = (CMS_signed_get_attr_count(si) > 0); int have_unsigned_attrs = (CMS_unsigned_get_attr_count(si) > 0); for (i = 0; i < (int)OSSL_NELEM(cms_attribute_properties); ++i) { int nid = cms_attribute_properties[i].nid; int flags = cms_attribute_properties[i].flags; if (!cms_check_attribute(nid, flags, CMS_ATTR_F_SIGNED, si->signedAttrs, have_signed_attrs) || !cms_check_attribute(nid, flags, CMS_ATTR_F_UNSIGNED, si->unsignedAttrs, have_unsigned_attrs)) { CMSerr(CMS_F_CMS_SI_CHECK_ATTRIBUTES, CMS_R_ATTRIBUTE_ERROR); return 0; } } return 1; }