pymanager/src/_native/verify_trust.cpp at main · python/pymanager · GitHub

Repository navigation

History

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

250

251

252

253

254

255

256

257

258

259

260

261

262

263

264

265

266

267

268

269

270

271

272

273

274

275

276

277

278

279

280

281

282

283

284

285

286

287

288

289

290

291

292

293

294

295

296

297

298

299

300

301

302

303

304

305

306

307

308

309

310

311

312

313

314

315

316

317

318

319

320

321

322

323

324

325

326

327

328

329

330

331

332

333

334

335

336

337

338

339

340

341

342

343

344

345

346

347

348

349

350

351

352

353

354

355

356

357

358

359

360

361

362

363

364

365

366

367

368

369

370

371

372

373

374

375

376

377

378

379

380

381

382

383

384

385

386

387

388

389

390

391

392

393

394

395

396

397

398

399

400

401

402

403

404

405

406

407

408

409

410

411

412

413

414

415

416

417

418

419

420

421

422

423

424

425

426

427

428

429

430

431

432

433

434

435

436

437

438

439

440

441

442

443

444

445

446

447

448

449

450

451

452

453

454

455

456

457

458

459

460

461

462

463

464

465

466

467

468

469

470

471

472

473

474

475

476

477

478

479

480

481

482

483

484

485

486

487

488

489

490

491

492

493

494

495

496

497

498

499

500

501

502

503

504

505

506

507

508

509

510

511

512

513

514

515

516

517

518

519

520

521

522

523

524

525

526

527

528

529

530

531

532

533

534

535

536

537

538

539

540

541

542

543

544

545

546

547

548

549

550

551

552

553

554

555

556

557

558

559

560

561

562

563

564

565

566

#include <Python.h>

#include <windows.h>

#include <mscat.h>

#include <softpub.h>

#include <string>

#include <vector>

#include "helpers.h"

extern "C" {

PyObject *verify_trust(PyObject *, PyObject *args, PyObject *kwargs);

}

static std::vector<BYTE> nameinfo_from_blob(CERT_NAME_BLOB *name)

{

DWORD cb = 0;

if (!CryptDecodeObjectEx(

X509_ASN_ENCODING,

X509_NAME,

name->pbData,

name->cbData,

nullptr,

&cb

) || cb == 0) {

return {};

}

std::vector<BYTE> buf(cb);

if (!CryptDecodeObjectEx(

X509_ASN_ENCODING,

X509_NAME,

name->pbData,

name->cbData,

nullptr,

buf.data(),

&cb

)) {

return {};

}

buf.resize(cb);

return buf;

}

static std::vector<BYTE> nameinfo_from_name(const wchar_t *name)

{

DWORD encoded_size = 0;

if (!CertStrToNameW(X509_ASN_ENCODING, name, CERT_X500_NAME_STR,

nullptr, nullptr, &encoded_size, nullptr)) {

return {};

}

std::vector<BYTE> encoded(encoded_size);

if (!CertStrToNameW(X509_ASN_ENCODING, name, CERT_X500_NAME_STR,

nullptr, encoded.data(), &encoded_size, nullptr)) {

return {};

}

CERT_NAME_BLOB expected_name = {};

expected_name.cbData = encoded_size;

expected_name.pbData = encoded.data();

return nameinfo_from_blob(&expected_name);

}

static std::wstring read_rdn_attr(CERT_RDN_ATTR &attr) {

DWORD cb = CertRDNValueToStrW(attr.dwValueType, &attr.Value, nullptr, 0);

if (cb > 1024) {

return {};

}

std::wstring v(cb, L'\0');

v.resize(CertRDNValueToStrW(attr.dwValueType, &attr.Value, v.data(), cb));

return v;

}

static bool cert_subject_matches(PCCERT_CONTEXT pCert, const wchar_t *expected)

{

if (!pCert || !expected || !*expected) {

return true;

}

auto expected_info_buf = nameinfo_from_name(expected);

auto actual_info_buf = nameinfo_from_blob(&pCert->pCertInfo->Subject);

if (expected_info_buf.empty() || actual_info_buf.empty()) {

return false;

}

const CERT_NAME_INFO *expected_info =

reinterpret_cast<const CERT_NAME_INFO *>(expected_info_buf.data());

const CERT_NAME_INFO *actual_info =

reinterpret_cast<const CERT_NAME_INFO *>(actual_info_buf.data());

// Turn constraints into a vector of (oid, value) pairs.

// Each pair must be present in the actual name.

std::vector<std::pair<std::string, std::wstring>> expected_pairs;

expected_pairs.reserve(8);

for (DWORD i = 0; i < expected_info->cRDN; ++i) {

CERT_RDN &rdn = expected_info->rgRDN[i];

for (DWORD j = 0; j < rdn.cRDNAttr; ++j) {

CERT_RDN_ATTR &attr = rdn.rgRDNAttr[j];

if (!attr.pszObjId) {

return false;

}

auto v = read_rdn_attr(attr);

if (!v.empty()) {

expected_pairs.emplace_back(std::string(attr.pszObjId), std::move(v));

}

// For each expected (OID, value), find an identical (OID, value) in the actual name.

for (const auto &need : expected_pairs) {

const std::string &oid = need.first;

const std::wstring &expect = need.second;

bool found = false;

for (DWORD i = 0; i < actual_info->cRDN && !found; ++i) {

CERT_RDN &rdn = actual_info->rgRDN[i];

for (DWORD j = 0; j < rdn.cRDNAttr; ++j) {

CERT_RDN_ATTR &attr = rdn.rgRDNAttr[j];

if (!attr.pszObjId || oid != attr.pszObjId) {

continue;

}

auto v = read_rdn_attr(attr);

if (CompareStringOrdinal(v.c_str(), -1, expect.c_str(), -1, TRUE) == CSTR_EQUAL) {

found = true;

break;

}

if (!found) {

return false;

}

return true;

}

static bool cert_has_explicit_eku(PCCERT_CONTEXT pCert, const wchar_t *eku_in) {

// No cert or no EKU passes this check

if (!pCert || !eku_in || !*eku_in) {

return true;

}

std::string expect_oid;

int n = WideCharToMultiByte(CP_UTF8, 0, eku_in, -1, NULL, 0, NULL, NULL);

if (n <= 0) {

return false;

}

expect_oid.resize((size_t)n - 1);

WideCharToMultiByte(CP_UTF8, 0, eku_in, -1, expect_oid.data(), n, NULL, NULL);

DWORD cbUsage = 0;

SetLastError(0);

if (!CertGetEnhancedKeyUsage(pCert, 0, NULL, &cbUsage) || !cbUsage) {

// CRYPT_E_NOT_FOUND => "all uses" => NOT acceptable when checking for a specific EKU

return false;

}

std::vector<BYTE> buf(cbUsage);

PCERT_ENHKEY_USAGE pUsage = (PCERT_ENHKEY_USAGE)buf.data();

SetLastError(0);

if (!CertGetEnhancedKeyUsage(pCert, 0, pUsage, &cbUsage)) {

// Failed to get the info means we fail the match

return false;

}

for (DWORD i = 0; i < pUsage->cUsageIdentifier; ++i) {

const char *oid = pUsage->rgpszUsageIdentifier[i];

if (oid && _stricmp(oid, expect_oid.c_str()) == 0) return true;

}

return false;

}

static void bytes_to_member_tag_hex(const BYTE *pb, DWORD cb, std::wstring &out) {

out.clear();

out.resize((size_t)cb * 2);

for (DWORD i = 0; i < cb; ++i) {

wchar_t tmp[3] = {0};

swprintf(tmp, 3, L"%02X", (unsigned)pb[i]);

out[(size_t)i * 2 + 0] = tmp[0];

out[(size_t)i * 2 + 1] = tmp[1];

}

static DWORD file_hash_in_catalog(const wchar_t *file_path, const wchar_t *cat_path) {

DWORD err = ERROR_NOT_FOUND;

HANDLE hFile = INVALID_HANDLE_VALUE;

HMODULE hWintrust = NULL;

HCATADMIN hCatAdmin = NULL;

HANDLE hCat = NULL;

BYTE *pbHash = NULL;

DWORD cbHash = 0;

typedef BOOL (WINAPI *pfnCalcHash2)(HCATADMIN, HANDLE, DWORD*, BYTE*, DWORD);

pfnCalcHash2 CalcHash2 = NULL;

hFile = CreateFileW(file_path, GENERIC_READ,

FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,

NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);

if (hFile == INVALID_HANDLE_VALUE) {

goto error;

}

hWintrust = LoadLibraryExW(L"wintrust.dll", NULL, LOAD_LIBRARY_SEARCH_SYSTEM32);

if (!hWintrust) {

goto error;

}

CalcHash2 = (pfnCalcHash2)GetProcAddress(hWintrust, "CryptCATAdminCalcHashFromFileHandle2");

if (!CalcHash2) {

goto error;

}

// Try SHA256 then SHA1 (common cases). If both fail, treat as not found.

static const wchar_t *algs[] = { L"SHA256", L"SHA1" };

for (auto alg : algs) {

if (hCatAdmin) {

CryptCATAdminReleaseContext(hCatAdmin, 0);

hCatAdmin = NULL;

}

cbHash = 0;

// alg name needs to be mutable for silly reasons. Fine, we'll play along

std::wstring alg_str = alg;

alg_str.push_back(L'\0');

if (!CryptCATAdminAcquireContext2(&hCatAdmin, NULL, alg_str.data(), NULL, 0) || !hCatAdmin) {

continue;

}

// Rewind file (previous hash has read it)

(void)SetFilePointer(hFile, 0, NULL, FILE_BEGIN);

DWORD tmp = 0;

SetLastError(0);

if (!CalcHash2(hCatAdmin, hFile, &tmp, NULL, 0)) {

DWORD gle = GetLastError();

if (gle != ERROR_INSUFFICIENT_BUFFER) {

// Try next algorithm

continue;

}

cbHash = tmp;

if (cbHash == 0) {

continue;

}

if (pbHash) {

LocalFree(pbHash);

pbHash = NULL;

}

pbHash = (BYTE*)LocalAlloc(LPTR, cbHash);

if (!pbHash) {

err = ERROR_OUTOFMEMORY;

goto cleanup;

}

DWORD cbOut = cbHash;

SetLastError(0);

if (!CalcHash2(hCatAdmin, hFile, &cbOut, pbHash, 0) || cbOut == 0) {

// Try next algorithm

continue;

}

cbHash = cbOut;

std::wstring memberTag;

bytes_to_member_tag_hex(pbHash, cbHash, memberTag);

if (hCat) {

CryptCATClose(hCat);

hCat = NULL;

}

// Catalog path also needs to be writable...

std::wstring cat_path_str = cat_path;

cat_path_str.push_back(L'\0');

hCat = CryptCATOpen(cat_path_str.data(), CRYPTCAT_OPEN_EXISTING, 0, 0, 0);

if (!hCat) {

goto error;

}

// Check that member hash exists in this catalog

memberTag.push_back(L'\0');

CRYPTCATMEMBER *pMember = CryptCATGetMemberInfo(hCat, memberTag.data());

if (pMember) {

// Success! Clear the error code and let's go home

err = 0;

break;

}

cleanup:

if (pbHash) LocalFree(pbHash);

if (hCat) CryptCATClose(hCat);

if (hCatAdmin) CryptCATAdminReleaseContext(hCatAdmin, 0);

if (hWintrust) FreeLibrary(hWintrust);

if (hFile != INVALID_HANDLE_VALUE) CloseHandle(hFile);

return err;

error:

err = GetLastError();

goto cleanup;

}

static DWORD extract_certs(

const wchar_t *signed_path,

PCCERT_CONTEXT &leaf_out,

PCCERT_CONTEXT &root_out

) {

leaf_out = NULL;

root_out = NULL;

HCERTSTORE hStore = NULL;

HCRYPTMSG hMsg = NULL;

PCCERT_CONTEXT pLeaf = NULL;

PCCERT_CONTEXT pRoot = NULL;

PCCERT_CONTEXT pRootCtx = NULL;

PCERT_SIMPLE_CHAIN pSimple = NULL;

PCCERT_CHAIN_CONTEXT pChain = NULL;

PCMSG_SIGNER_INFO pSignerInfo = NULL;

DWORD cbSignerInfo = 0;

DWORD dwEncoding = 0, dwContentType = 0, dwFormatType = 0;

DWORD err = 0;

if (!CryptQueryObject(

CERT_QUERY_OBJECT_FILE,

signed_path,

CERT_QUERY_CONTENT_FLAG_PKCS7_SIGNED_EMBED,

CERT_QUERY_FORMAT_FLAG_BINARY,

&dwEncoding, &dwContentType, &dwFormatType,

&hStore, &hMsg, NULL

)) {

err = GetLastError();

if (!err) {

err = ERROR_INVALID_DATA;

}

goto cleanup;

}

if (!CryptMsgGetParam(hMsg, CMSG_SIGNER_INFO_PARAM, 0, NULL, &cbSignerInfo) || !cbSignerInfo) {

err = GetLastError();

if (!err) err = ERROR_INVALID_DATA;

goto cleanup;

}

pSignerInfo = (PCMSG_SIGNER_INFO)LocalAlloc(LPTR, cbSignerInfo);

if (!pSignerInfo) {

err = ERROR_OUTOFMEMORY;

goto cleanup;

}

if (!CryptMsgGetParam(hMsg, CMSG_SIGNER_INFO_PARAM, 0, pSignerInfo, &cbSignerInfo)) {

err = GetLastError();

LocalFree(pSignerInfo);

if (!err) err = ERROR_INVALID_DATA;

goto cleanup;

}

CERT_INFO ci;

memset(&ci, 0, sizeof(ci));

ci.Issuer = pSignerInfo->Issuer;

ci.SerialNumber = pSignerInfo->SerialNumber;

pLeaf = CertFindCertificateInStore(

hStore,

X509_ASN_ENCODING | PKCS_7_ASN_ENCODING,

CERT_FIND_SUBJECT_CERT,

&ci,

NULL

);

LocalFree(pSignerInfo);

if (!pLeaf) {

err = GetLastError();

if (!err) err = ERROR_INVALID_DATA;

goto cleanup;

}

CERT_CHAIN_PARA chainPara;

memset(&chainPara, 0, sizeof(chainPara));

chainPara.cbSize = sizeof(chainPara);

if (!CertGetCertificateChain(

NULL,

pLeaf,

NULL,

pLeaf->hCertStore,

&chainPara,

NULL,

&pChain

) || !pChain || pChain->cChain == 0) {

err = GetLastError();

if (!err) err = ERROR_INVALID_DATA;

goto cleanup;

}

pSimple = pChain->rgpChain[0];

if (!pSimple || pSimple->cElement == 0) {

err = ERROR_INVALID_DATA;

goto cleanup;

}

pRootCtx = pSimple->rgpElement[pSimple->cElement - 1]->pCertContext;

if (!pRootCtx) {

err = ERROR_INVALID_DATA;

goto cleanup;

}

pRoot = CertDuplicateCertificateContext(pRootCtx);

if (!pRoot) {

err = ERROR_OUTOFMEMORY;

goto cleanup;

}

leaf_out = pLeaf;

root_out = pRoot;

pLeaf = NULL; // transferred

pRoot = NULL; // transferred

cleanup:

if (pChain) CertFreeCertificateChain(pChain);

if (pRoot) CertFreeCertificateContext(pRoot);

if (pLeaf) CertFreeCertificateContext(pLeaf);

if (hMsg) CryptMsgClose(hMsg);

if (hStore) CertCloseStore(hStore, 0);

// Ensure outputs are NULL on failure

if (err != 0) {

if (leaf_out) { CertFreeCertificateContext(leaf_out); leaf_out = NULL; }

if (root_out) { CertFreeCertificateContext(root_out); root_out = NULL; }

}

return err;

}

PyObject *verify_trust(PyObject *, PyObject *args, PyObject *kwargs) {

static const char * keywords[] = {"path", "cat_path", "root_subject", "leaf_subject", "leaf_eku", NULL};

wchar_t *path = NULL;

wchar_t *cat_path = NULL;

wchar_t *root_subject = NULL;

wchar_t *leaf_subject = NULL;

wchar_t *leaf_eku = NULL;

if (!PyArg_ParseTupleAndKeywords(args, kwargs, "O&O&O&O&O&:verify_trust", keywords,

as_utf16, &path, as_utf16, &cat_path,

as_utf16, &root_subject, as_utf16, &leaf_subject, as_utf16, &leaf_eku

)) {

return NULL;

}

PyObject *r = Py_NewRef(Py_None);

PCCERT_CONTEXT pLeafCert = NULL;

PCCERT_CONTEXT pRootCert = NULL;

DWORD err = 0;

// 1) Validate catalog file signature.

{

GUID policy = WINTRUST_ACTION_GENERIC_VERIFY_V2;

WINTRUST_FILE_INFO fi;

memset(&fi, 0, sizeof(fi));

fi.cbStruct = sizeof(fi);

fi.pcwszFilePath = cat_path;

fi.hFile = NULL;

WINTRUST_DATA wd;

memset(&wd, 0, sizeof(wd));

wd.cbStruct = sizeof(wd);

wd.dwUnionChoice = WTD_CHOICE_FILE;

wd.pFile = &fi;

wd.dwUIChoice = WTD_UI_NONE;

// Do a real validation pass (including revocation).

wd.fdwRevocationChecks = WTD_REVOKE_WHOLECHAIN;

wd.dwStateAction = WTD_STATEACTION_VERIFY;

wd.dwUIChoice = WTD_UI_NONE;

wd.dwProvFlags = WTD_USE_DEFAULT_OSVER_CHECK;

LONG st = WinVerifyTrust(NULL, &policy, &wd);

wd.dwStateAction = WTD_STATEACTION_CLOSE;

(void)WinVerifyTrust(NULL, &policy, &wd);

if (st != ERROR_SUCCESS) {

err_SetFromWindowsErrWithMessage(st, "WinVerifyTrust failed for catalog: 0x%08lX", NULL);

Py_CLEAR(r);

goto done;

}

// 2) Extract signer leaf and chain root certs from the signed catalog

err = extract_certs(cat_path, pLeafCert, pRootCert);

if (err) {

err_SetFromWindowsErrWithMessage(err, "Failed to extract certificates from catalog signature", NULL);

Py_CLEAR(r);

goto done;

}

// 3) Optional subject checks

if (!cert_subject_matches(pRootCert, root_subject)) {

// Strictly speaking ValueError makes more sense here, but we're already

// going to be catching OSError so may as well be consistent.

PyErr_SetString(PyExc_OSError, "Catalog root certificate subject mismatch");

Py_CLEAR(r);

goto done;

}

if (!cert_subject_matches(pLeafCert, leaf_subject)) {

PyErr_SetString(PyExc_OSError, "Catalog leaf certificate subject mismatch");

Py_CLEAR(r);

goto done;

}

// 4) Optional EKU check (strict: if specified, must be explicitly present; otherwise skip entirely)

if (!cert_has_explicit_eku(pLeafCert, leaf_eku)) {

PyErr_SetString(PyExc_OSError, "Leaf certificate does not explicitly include required EKU");

Py_CLEAR(r);

goto done;

}

// 5) Ensure the target file’s catalog hash is present in the provided catalog file.

err = file_hash_in_catalog(path, cat_path);

if (err) {

err_SetFromWindowsErrWithMessage(err, "File hash not present in the specified catalog", NULL);

Py_CLEAR(r);

goto done;

}

done:

if (pRootCert) CertFreeCertificateContext(pRootCert);

if (pLeafCert) CertFreeCertificateContext(pLeafCert);

PyMem_Free(path);

PyMem_Free(cat_path);

PyMem_Free(root_subject);

PyMem_Free(leaf_subject);

PyMem_Free(leaf_eku);

return r;

}

pymanager/src/_native/verify_trust.cpp at main · python/pymanager · GitHub

Repository navigation

Expand file tree

Breadcrumbs

verify_trust.cpp

Latest commit

History

Breadcrumbs

verify_trust.cpp

File metadata and controls