From f1f146d4534fc925bceffe523852fe2261841008 Mon Sep 17 00:00:00 2001 From: Vorapol Rinsatitnon Date: Sat, 21 Sep 2024 23:56:11 +1000 Subject: [PATCH] Switch ProcessPrng back to RtlGenRandom (revert 693def1) --- src/crypto/rand/rand.go | 2 +- src/crypto/rand/rand_windows.go | 7 +++-- .../syscall/windows/syscall_windows.go | 2 +- .../syscall/windows/zsyscall_windows.go | 7 ++--- src/runtime/os_windows.go | 30 ++++++++++++------- 5 files changed, 29 insertions(+), 19 deletions(-) diff --git a/src/crypto/rand/rand.go b/src/crypto/rand/rand.go index d16d7a1..cdfeb06 100644 --- a/src/crypto/rand/rand.go +++ b/src/crypto/rand/rand.go @@ -16,7 +16,7 @@ import "io" // - On macOS and iOS, Reader uses arc4random_buf(3). // - On OpenBSD and NetBSD, Reader uses getentropy(2). // - On other Unix-like systems, Reader reads from /dev/urandom. -// - On Windows, Reader uses the ProcessPrng API. +// - On Windows, Reader uses the RtlGenRandom API. // - On js/wasm, Reader uses the Web Crypto API. // - On wasip1/wasm, Reader uses random_get from wasi_snapshot_preview1. var Reader io.Reader diff --git a/src/crypto/rand/rand_windows.go b/src/crypto/rand/rand_windows.go index 7380f1f..6c0655c 100644 --- a/src/crypto/rand/rand_windows.go +++ b/src/crypto/rand/rand_windows.go @@ -15,8 +15,11 @@ func init() { Reader = &rngReader{} } type rngReader struct{} -func (r *rngReader) Read(b []byte) (int, error) { - if err := windows.ProcessPrng(b); err != nil { +func (r *rngReader) Read(b []byte) (n int, err error) { + // RtlGenRandom only returns 1<<32-1 bytes at a time. We only read at + // most 1<<31-1 bytes at a time so that this works the same on 32-bit + // and 64-bit systems. + if err := batched(windows.RtlGenRandom, 1<<31-1)(b); err != nil { return 0, err } return len(b), nil diff --git a/src/internal/syscall/windows/syscall_windows.go b/src/internal/syscall/windows/syscall_windows.go index cc26a50..b0b5a64 100644 --- a/src/internal/syscall/windows/syscall_windows.go +++ b/src/internal/syscall/windows/syscall_windows.go @@ -414,7 +414,7 @@ func ErrorLoadingGetTempPath2() error { //sys DestroyEnvironmentBlock(block *uint16) (err error) = userenv.DestroyEnvironmentBlock //sys CreateEvent(eventAttrs *SecurityAttributes, manualReset uint32, initialState uint32, name *uint16) (handle syscall.Handle, err error) = kernel32.CreateEventW -//sys ProcessPrng(buf []byte) (err error) = bcryptprimitives.ProcessPrng +//sys RtlGenRandom(buf []byte) (err error) = advapi32.SystemFunction036 type FILE_ID_BOTH_DIR_INFO struct { NextEntryOffset uint32 diff --git a/src/internal/syscall/windows/zsyscall_windows.go b/src/internal/syscall/windows/zsyscall_windows.go index 414ad26..062641c 100644 --- a/src/internal/syscall/windows/zsyscall_windows.go +++ b/src/internal/syscall/windows/zsyscall_windows.go @@ -38,7 +38,6 @@ func errnoErr(e syscall.Errno) error { var ( modadvapi32 = syscall.NewLazyDLL(sysdll.Add("advapi32.dll")) - modbcryptprimitives = syscall.NewLazyDLL(sysdll.Add("bcryptprimitives.dll")) modiphlpapi = syscall.NewLazyDLL(sysdll.Add("iphlpapi.dll")) modkernel32 = syscall.NewLazyDLL(sysdll.Add("kernel32.dll")) modnetapi32 = syscall.NewLazyDLL(sysdll.Add("netapi32.dll")) @@ -57,7 +56,7 @@ var ( procQueryServiceStatus = modadvapi32.NewProc("QueryServiceStatus") procRevertToSelf = modadvapi32.NewProc("RevertToSelf") procSetTokenInformation = modadvapi32.NewProc("SetTokenInformation") - procProcessPrng = modbcryptprimitives.NewProc("ProcessPrng") + procSystemFunction036 = modadvapi32.NewProc("SystemFunction036") procGetAdaptersAddresses = modiphlpapi.NewProc("GetAdaptersAddresses") procCreateEventW = modkernel32.NewProc("CreateEventW") procGetACP = modkernel32.NewProc("GetACP") @@ -183,12 +182,12 @@ func SetTokenInformation(tokenHandle syscall.Token, tokenInformationClass uint32 return } -func ProcessPrng(buf []byte) (err error) { +func RtlGenRandom(buf []byte) (err error) { var _p0 *byte if len(buf) > 0 { _p0 = &buf[0] } - r1, _, e1 := syscall.Syscall(procProcessPrng.Addr(), 2, uintptr(unsafe.Pointer(_p0)), uintptr(len(buf)), 0) + r1, _, e1 := syscall.Syscall(procSystemFunction036.Addr(), 2, uintptr(unsafe.Pointer(_p0)), uintptr(len(buf)), 0) if r1 == 0 { err = errnoErr(e1) } diff --git a/src/runtime/os_windows.go b/src/runtime/os_windows.go index 4aabc29..0273580 100644 --- a/src/runtime/os_windows.go +++ b/src/runtime/os_windows.go @@ -127,8 +127,15 @@ var ( _WriteFile, _ stdFunction - // Use ProcessPrng to generate cryptographically random data. - _ProcessPrng stdFunction + // Use RtlGenRandom to generate cryptographically random data. + // This approach has been recommended by Microsoft (see issue + // 15589 for details). + // The RtlGenRandom is not listed in advapi32.dll, instead + // RtlGenRandom function can be found by searching for SystemFunction036. + // Also some versions of Mingw cannot link to SystemFunction036 + // when building executable as Cgo. So load SystemFunction036 + // manually during runtime startup. + _RtlGenRandom stdFunction // Load ntdll.dll manually during startup, otherwise Mingw // links wrong printf function to cgo executable (see issue @@ -146,10 +153,11 @@ var ( ) var ( - bcryptprimitivesdll = [...]uint16{'b', 'c', 'r', 'y', 'p', 't', 'p', 'r', 'i', 'm', 'i', 't', 'i', 'v', 'e', 's', '.', 'd', 'l', 'l', 0} - ntdlldll = [...]uint16{'n', 't', 'd', 'l', 'l', '.', 'd', 'l', 'l', 0} - powrprofdll = [...]uint16{'p', 'o', 'w', 'r', 'p', 'r', 'o', 'f', '.', 'd', 'l', 'l', 0} - winmmdll = [...]uint16{'w', 'i', 'n', 'm', 'm', '.', 'd', 'l', 'l', 0} + advapi32dll = [...]uint16{'a', 'd', 'v', 'a', 'p', 'i', '3', '2', '.', 'd', 'l', 'l', 0} + ntdlldll = [...]uint16{'n', 't', 'd', 'l', 'l', '.', 'd', 'l', 'l', 0} + powrprofdll = [...]uint16{'p', 'o', 'w', 'r', 'p', 'r', 'o', 'f', '.', 'd', 'l', 'l', 0} + winmmdll = [...]uint16{'w', 'i', 'n', 'm', 'm', '.', 'd', 'l', 'l', 0} + ws2_32dll = [...]uint16{'w', 's', '2', '_', '3', '2', '.', 'd', 'l', 'l', 0} ) // Function to be called by windows CreateThread @@ -263,11 +271,11 @@ func windows_QueryPerformanceFrequency() int64 { } func loadOptionalSyscalls() { - bcryptPrimitives := windowsLoadSystemLib(bcryptprimitivesdll[:]) - if bcryptPrimitives == 0 { - throw("bcryptprimitives.dll not found") + a32 := windowsLoadSystemLib(advapi32dll[:]) + if a32 == 0 { + throw("advapi32.dll not found") } - _ProcessPrng = windowsFindfunc(bcryptPrimitives, []byte("ProcessPrng\000")) + _RtlGenRandom = windowsFindfunc(a32, []byte("SystemFunction036\000")) n32 := windowsLoadSystemLib(ntdlldll[:]) if n32 == 0 { @@ -500,7 +508,7 @@ func osinit() { //go:nosplit func readRandom(r []byte) int { n := 0 - if stdcall2(_ProcessPrng, uintptr(unsafe.Pointer(&r[0])), uintptr(len(r)))&0xff != 0 { + if stdcall2(_RtlGenRandom, uintptr(unsafe.Pointer(&r[0])), uintptr(len(r)))&0xff != 0 { n = len(r) } return n -- 2.47.0