1/*
2 * Copyright (c) 2000-2006,2011,2014 Apple Inc. All Rights Reserved.
3 *
4 * @APPLE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. Please obtain a copy of the License at
10 * http://www.opensource.apple.com/apsl/ and read it before using this
11 * file.
12 *
13 * The Original Code and all software distributed under the License are
14 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
15 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
16 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
18 * Please see the License for the specific language governing rights and
19 * limitations under the License.
20 *
21 * @APPLE_LICENSE_HEADER_END@
22 */
23
24
25//
26// acl_codesigning - ACL subject for signature of calling application
27//
28#include <security_cdsa_utilities/acl_codesigning.h>
29#include <security_cdsa_utilities/cssmdata.h>
30#include <security_utilities/endian.h>
31#include <algorithm>
32
33
34//
35// Code signature credentials are validated globally - they are entirely
36// a feature of "the" process (defined by the environment), and take no
37// samples whatsoever.
38//
39bool CodeSignatureAclSubject::validate(const AclValidationContext &context) const
40{
41	// a suitable environment is required for a match
42    if (Environment *env = context.environment<Environment>())
43			return env->verifyCodeSignature(*this, context);
44	else
45		return false;
46}
47
48
49//
50// Make a copy of this subject in CSSM_LIST form.
51// The format is (head), (type code: Wordid), (signature data: datum), (comment: datum)
52//
53CssmList CodeSignatureAclSubject::toList(Allocator &alloc) const
54{
55	assert(path().find('\0') == string::npos);	// no embedded nulls in path
56	uint32_t type = CSSM_ACL_CODE_SIGNATURE_OSX;
57	TypedList list(alloc, CSSM_ACL_SUBJECT_TYPE_CODE_SIGNATURE,
58		new(alloc) ListElement(type),
59		new(alloc) ListElement(alloc, CssmData::wrap(legacyHash(), SHA1::digestLength)),
60		new(alloc) ListElement(alloc, CssmData::wrap(path().c_str(), path().size() + 1)));
61	if (requirement()) {
62		CFRef<CFDataRef> reqData;
63		MacOSError::check(SecRequirementCopyData(requirement(), kSecCSDefaultFlags, &reqData.aref()));
64		list += new(alloc) ListElement(alloc,
65			CssmData::wrap(CFDataGetBytePtr(reqData), CFDataGetLength(reqData)));
66	}
67	for (AuxMap::const_iterator it = beginAux(); it != endAux(); it++)
68		list += new(alloc) ListElement(alloc, CssmData(*it->second));
69	return list;
70}
71
72
73//
74// Create a CodeSignatureAclSubject
75//
76CodeSignatureAclSubject *CodeSignatureAclSubject::Maker::make(const TypedList &list) const
77{
78	// there once was a format with only a hash (length 2+1). It is no longer supported
79	unsigned total = list.length();		// includes subject type header
80	if (total >= 3 + 1
81		&& list[1].is(CSSM_LIST_ELEMENT_WORDID)		// [1] == signature type
82		&& list[1] == CSSM_ACL_CODE_SIGNATURE_OSX
83		&& list[2].is(CSSM_LIST_ELEMENT_DATUM)		// [2] == legacy hash
84		&& list[2].data().length() == SHA1::digestLength
85		&& list[3].is(CSSM_LIST_ELEMENT_DATUM)) {
86		// structurally okay
87		CodeSignatureAclSubject *subj =
88			new CodeSignatureAclSubject(list[2].data().interpretedAs<const SHA1::Byte>(),
89				list[3].data().interpretedAs<const char>());
90		for (unsigned n = 3 + 1; n < total; n++) {
91			if (list[n].is(CSSM_LIST_ELEMENT_DATUM)) {
92				const BlobCore *blob = list[n].data().interpretedAs<const BlobCore>();
93				if (blob->length() < sizeof(BlobCore)) {
94					secdebug("csblob", "runt blob (0x%x/%zd) slot %d in CSSM_LIST",
95						blob->magic(), blob->length(), n);
96					CssmError::throwMe(CSSM_ERRCODE_INVALID_ACL_SUBJECT_VALUE);
97				} else if (blob->length() != list[n].data().length()) {
98					secdebug("csblob", "badly sized blob (0x%x/%zd) slot %d in CSSM_LIST",
99						blob->magic(), blob->length(), n);
100					CssmError::throwMe(CSSM_ERRCODE_INVALID_ACL_SUBJECT_VALUE);
101				}
102				subj->add(blob);
103			} else
104				CssmError::throwMe(CSSM_ERRCODE_INVALID_ACL_SUBJECT_VALUE);
105		}
106		return subj;
107	} else
108		CssmError::throwMe(CSSM_ERRCODE_INVALID_ACL_SUBJECT_VALUE);
109}
110
111CodeSignatureAclSubject *CodeSignatureAclSubject::Maker::make(Version version,
112	Reader &pub, Reader &priv) const
113{
114	assert(version == 0);
115	Endian<uint32> sigType; pub(sigType);
116	const void *data; size_t length; pub.countedData(data, length);
117	const void *commentData; size_t commentLength; pub.countedData(commentData, commentLength);
118	if (sigType == CSSM_ACL_CODE_SIGNATURE_OSX
119		&& length == SHA1::digestLength) {
120		return make((const SHA1::Byte *)data, CssmData::wrap(commentData, commentLength));
121	}
122	CssmError::throwMe(CSSM_ERRCODE_INVALID_ACL_SUBJECT_VALUE);
123}
124
125CodeSignatureAclSubject *CodeSignatureAclSubject::Maker::make(const SHA1::Byte *hash,
126	const CssmData &commentBag) const
127{
128	using namespace LowLevelMemoryUtilities;
129	const char *path = commentBag.interpretedAs<const char>();
130	CodeSignatureAclSubject *subj = new CodeSignatureAclSubject(hash, path);
131	for (const BlobCore *blob = increment<BlobCore>(commentBag.data(), alignUp(strlen(path) + 1, commentBagAlignment));
132			blob < commentBag.end();
133			blob = increment<const BlobCore>(blob, alignUp(blob->length(), commentBagAlignment))) {
134		size_t leftInBag = difference(commentBag.end(), blob);
135		if (leftInBag < sizeof(BlobCore) || blob->length() < sizeof(BlobCore) || blob->length() > leftInBag) {
136			secdebug("csblob", "invalid blob (0x%x/%zd) [%zd in bag] in code signing ACL for %s - stopping scan",
137				blob->magic(), blob->length(), leftInBag, subj->path().c_str());
138			break;	// can't trust anything beyond this blob
139		}
140		subj->add(blob);
141	}
142	return subj;
143}
144
145
146//
147// Export the subject to a memory blob
148//
149void CodeSignatureAclSubject::exportBlob(Writer::Counter &pub, Writer::Counter &priv)
150{
151	using LowLevelMemoryUtilities::alignUp;
152	assert(path().find('\0') == string::npos);	// no embedded nulls in path
153	Endian<uint32> sigType = CSSM_ACL_CODE_SIGNATURE_OSX; pub(sigType);
154	pub.countedData(legacyHash(), SHA1::digestLength);
155	size_t size = path().size() + 1;
156	if (requirement()) {
157		CFRef<CFDataRef> reqData;
158		MacOSError::check(SecRequirementCopyData(requirement(), kSecCSDefaultFlags, &reqData.aref()));
159		size = alignUp(size, commentBagAlignment) + CFDataGetLength(reqData);
160	}
161	for (AuxMap::const_iterator it = beginAux(); it != endAux(); it++) {
162		size = alignUp(size, commentBagAlignment) + it->second->length();
163	}
164	pub.countedData(NULL, size);
165}
166
167void CodeSignatureAclSubject::exportBlob(Writer &pub, Writer &priv)
168{
169	using LowLevelMemoryUtilities::alignUp;
170	Endian<uint32> sigType = CSSM_ACL_CODE_SIGNATURE_OSX; pub(sigType);
171	pub.countedData(legacyHash(), SHA1::digestLength);
172	CssmAutoData commentBag(Allocator::standard(), path().c_str(), path().size() + 1);
173	static const uint32_t zero = 0;
174	if (requirement()) {
175		CFRef<CFDataRef> reqData;
176		MacOSError::check(SecRequirementCopyData(requirement(), kSecCSDefaultFlags, &reqData.aref()));
177		commentBag.append(&zero,
178			alignUp(commentBag.length(), commentBagAlignment) - commentBag.length());
179		commentBag.append(CFDataGetBytePtr(reqData), CFDataGetLength(reqData));
180	}
181	for (AuxMap::const_iterator it = beginAux(); it != endAux(); it++) {
182		commentBag.append(&zero,
183			alignUp(commentBag.length(), commentBagAlignment) - commentBag.length());
184		commentBag.append(CssmData(*it->second));
185	}
186	pub.countedData(commentBag);
187}
188
189
190#ifdef DEBUGDUMP
191
192void CodeSignatureAclSubject::debugDump() const
193{
194	Debug::dump("CodeSigning ");
195	OSXVerifier::dump();
196}
197
198#endif //DEBUGDUMP
199