Signed-off-by: Zebediah Figura zfigura@codeweavers.com --- According to my limited understanding of certificates, this is safe, but I'd certainly appreciate a second opinion.
The part about nextUpdate is informed by [1].
[1] https://security.stackexchange.com/questions/20958/x-509-crls-next-update
dlls/cryptnet/Makefile.in | 2 +- dlls/cryptnet/cryptnet_main.c | 127 ++++++++++++++++++++++++++++++++++ 2 files changed, 128 insertions(+), 1 deletion(-)
diff --git a/dlls/cryptnet/Makefile.in b/dlls/cryptnet/Makefile.in index 8482882cdce..1e97f26d9df 100644 --- a/dlls/cryptnet/Makefile.in +++ b/dlls/cryptnet/Makefile.in @@ -1,6 +1,6 @@ MODULE = cryptnet.dll IMPORTLIB = cryptnet -IMPORTS = crypt32 +IMPORTS = crypt32 shell32 ole32 DELAYIMPORTS = wininet
EXTRADLLFLAGS = -mno-cygwin diff --git a/dlls/cryptnet/cryptnet_main.c b/dlls/cryptnet/cryptnet_main.c index b1e2829d881..2f4e2d895f7 100644 --- a/dlls/cryptnet/cryptnet_main.c +++ b/dlls/cryptnet/cryptnet_main.c @@ -21,6 +21,7 @@ #define NONAMELESSUNION #define CERT_REVOCATION_PARA_HAS_EXTRA_FIELDS
+#include <share.h> #include <stdio.h> #include <stdarg.h>
@@ -31,6 +32,9 @@ #include "wininet.h" #include "objbase.h" #include "wincrypt.h" +#include "initguid.h" +#include "knownfolders.h" +#include "shlobj.h"
#include "wine/debug.h"
@@ -1514,6 +1518,124 @@ BOOL WINAPI CryptRetrieveObjectByUrlW(LPCWSTR pszURL, LPCSTR pszObjectOid, return ret; }
+/* Store successful revocation checks (whether the certificate was revoked or + * not) in an on-disk cache. This is not because of network latency—we already + * have a cache for that—but rather because parsing very large CRLs can take a + * long time (at the time of writing, 20 MB CRLs have been seen in the wild and + * can take several hundred milliseconds) and applications expect chain building + * to be much faster. + * + * The cache is treated as invalid once we pass the nextUpdate field of the CRL. + * This isn't quite what the field is meant for (it's rather meant to specify a + * later bound for the next time the CRL will be reissued, and doesn't prescribe + * a date by which the CRL is invalid; see RFC 5280 § 5.1.2.5) but it's the way + * it's used in practice. + * + * The location of the cache roughly matches Windows, but the file name and + * contents do not. + */ + +static const char revocation_cache_signature[] = "Wine cached revocation"; + +static FILE *open_cached_revocation_file(const CRYPT_INTEGER_BLOB *serial, const WCHAR *mode, int sharing) +{ + WCHAR path[MAX_PATH]; + WCHAR *appdata_path; + DWORD len, i; + HRESULT hr; + + if (FAILED(hr = SHGetKnownFolderPath(&FOLDERID_LocalAppDataLow, 0, NULL, &appdata_path))) + { + ERR("Failed to get LocalAppDataLow path, hr %#x.\n", hr); + return INVALID_HANDLE_VALUE; + } + + len = swprintf(path, ARRAY_SIZE(path), L"%s\Microsoft\CryptnetUrlCache\Content\", appdata_path); + CoTaskMemFree(appdata_path); + + if (len + serial->cbData * 2 * sizeof(WCHAR) > ARRAY_SIZE(path) - 1) + { + WARN("Serial length exceeds static buffer; not caching.\n"); + return INVALID_HANDLE_VALUE; + } + + SHCreateDirectoryExW(NULL, path, NULL); + + for (i = 0; i < serial->cbData; ++i) + { + swprintf(path + len, 3, L"%02x", serial->pbData[i]); + len += 2; + } + + return _wfsopen(path, mode, sharing); +} + +static BOOL find_cached_revocation_status(const CRYPT_INTEGER_BLOB *serial, + const FILETIME *time, CERT_REVOCATION_STATUS *status) +{ + char buffer[sizeof(revocation_cache_signature)]; + FILETIME update_time; + FILE *file; + int len; + + if (!(file = open_cached_revocation_file(serial, L"r", _SH_DENYWR))) + return FALSE; + + if ((len = fread(buffer, 1, sizeof(buffer), file)) != sizeof(buffer) + || memcmp(buffer, revocation_cache_signature, len)) + { + ERR("Invalid cache signature.\n"); + fclose(file); + return FALSE; + } + + if (fread(&update_time, sizeof(update_time), 1, file) != 1) + { + ERR("Failed to read update time.\n"); + fclose(file); + return FALSE; + } + + if (CompareFileTime(time, &update_time) > 0) + { + TRACE("Cached revocation status is potentially out of date.\n"); + fclose(file); + return FALSE; + } + + if (fread(&status->dwError, sizeof(status->dwError), 1, file) != 1) + { + ERR("Failed to read error code.\n"); + fclose(file); + return FALSE; + } + + if (status->dwError == CERT_E_REVOKED && fread(&status->dwReason, sizeof(status->dwReason), 1, file) != 1) + { + ERR("Failed to read revocation reason.\n"); + fclose(file); + return FALSE; + } + + TRACE("Using cached status %#x, reason %#x.\n", status->dwError, status->dwReason); + return TRUE; +} + +static void cache_revocation_status(const CRYPT_INTEGER_BLOB *serial, + const FILETIME *time, const CERT_REVOCATION_STATUS *status) +{ + FILE *file; + + if (!(file = open_cached_revocation_file(serial, L"w", _SH_DENYRW))) + return; + fwrite(revocation_cache_signature, 1, sizeof(revocation_cache_signature), file); + fwrite(time, sizeof(*time), 1, file); + fwrite(&status->dwError, sizeof(status->dwError), 1, file); + if (status->dwError == CERT_E_REVOKED) + fwrite(&status->dwReason, sizeof(status->dwReason), 1, file); + fclose(file); +} + static DWORD verify_cert_revocation_with_crl_online(const CERT_CONTEXT *cert, const CRL_CONTEXT *crl, FILETIME *pTime, CERT_REVOCATION_STATUS *pRevStatus) { @@ -1591,6 +1713,8 @@ static DWORD verify_cert_revocation_from_dist_points_ext(const CRYPT_DATA_BLOB *
error = verify_cert_revocation_with_crl_online(cert, crl, time, status);
+ cache_revocation_status(&cert->pCertInfo->SerialNumber, &crl->pCrlInfo->NextUpdate, status); + CertFreeCRLContext(crl); CryptMemFree(url_array); return error; @@ -1663,6 +1787,9 @@ static DWORD verify_cert_revocation(const CERT_CONTEXT *cert, FILETIME *pTime, DWORD error = ERROR_SUCCESS; PCERT_EXTENSION ext;
+ if (find_cached_revocation_status(&cert->pCertInfo->SerialNumber, pTime, pRevStatus)) + return pRevStatus->dwError; + if ((ext = CertFindExtension(szOID_CRL_DIST_POINTS, cert->pCertInfo->cExtension, cert->pCertInfo->rgExtension))) {