[release-branch.go1.21] crypto/rand,runtime: switch RtlGenRandom for ProcessPrng
RtlGenRandom is a semi-undocumented API, also known as
SystemFunction036, which we use to generate random data on Windows.
It's definition, in cryptbase.dll, is an opaque wrapper for the
documented API ProcessPrng. Instead of using RtlGenRandom, switch to
using ProcessPrng, since the former is simply a wrapper for the latter,
there should be no practical change on the user side, other than a minor
change in the DLLs we load.
Updates #53192
Fixes #64413
Change-Id: Ie6891bf97b1d47f5368cccbe92f374dba2c2672a
Reviewed-on: https://go-review.googlesource.com/c/go/+/536235
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Quim Muntal <quimmuntal@gmail.com>
Auto-Submit: Roland Shoemaker <roland@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
(cherry picked from commit 693def151adff1af707d82d28f55dba81ceb08e1)
Reviewed-on: https://go-review.googlesource.com/c/go/+/545355
Auto-Submit: Dmitri Shuralyov <dmitshur@google.com>
diff --git a/src/crypto/rand/rand.go b/src/crypto/rand/rand.go
index 62738e2..d0dcc7c 100644
--- a/src/crypto/rand/rand.go
+++ b/src/crypto/rand/rand.go
@@ -15,7 +15,7 @@
// available, /dev/urandom otherwise.
// On OpenBSD and macOS, Reader uses getentropy(2).
// On other Unix-like systems, Reader reads from /dev/urandom.
-// On Windows systems, Reader uses the RtlGenRandom API.
+// On Windows systems, Reader uses the ProcessPrng 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 6c0655c..7380f1f 100644
--- a/src/crypto/rand/rand_windows.go
+++ b/src/crypto/rand/rand_windows.go
@@ -15,11 +15,8 @@
type rngReader struct{}
-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 {
+func (r *rngReader) Read(b []byte) (int, error) {
+ if err := windows.ProcessPrng(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 892b878..e9390b0 100644
--- a/src/internal/syscall/windows/syscall_windows.go
+++ b/src/internal/syscall/windows/syscall_windows.go
@@ -373,7 +373,7 @@
//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 RtlGenRandom(buf []byte) (err error) = advapi32.SystemFunction036
+//sys ProcessPrng(buf []byte) (err error) = bcryptprimitives.ProcessPrng
//sys RtlLookupFunctionEntry(pc uintptr, baseAddress *uintptr, table *byte) (ret uintptr) = kernel32.RtlLookupFunctionEntry
//sys RtlVirtualUnwind(handlerType uint32, baseAddress uintptr, pc uintptr, entry uintptr, ctxt uintptr, data *uintptr, frame *uintptr, ctxptrs *byte) (ret uintptr) = kernel32.RtlVirtualUnwind
diff --git a/src/internal/syscall/windows/zsyscall_windows.go b/src/internal/syscall/windows/zsyscall_windows.go
index a5c246b..26ec290 100644
--- a/src/internal/syscall/windows/zsyscall_windows.go
+++ b/src/internal/syscall/windows/zsyscall_windows.go
@@ -37,13 +37,14 @@
}
var (
- modadvapi32 = syscall.NewLazyDLL(sysdll.Add("advapi32.dll"))
- modiphlpapi = syscall.NewLazyDLL(sysdll.Add("iphlpapi.dll"))
- modkernel32 = syscall.NewLazyDLL(sysdll.Add("kernel32.dll"))
- modnetapi32 = syscall.NewLazyDLL(sysdll.Add("netapi32.dll"))
- modpsapi = syscall.NewLazyDLL(sysdll.Add("psapi.dll"))
- moduserenv = syscall.NewLazyDLL(sysdll.Add("userenv.dll"))
- modws2_32 = syscall.NewLazyDLL(sysdll.Add("ws2_32.dll"))
+ 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"))
+ modpsapi = syscall.NewLazyDLL(sysdll.Add("psapi.dll"))
+ moduserenv = syscall.NewLazyDLL(sysdll.Add("userenv.dll"))
+ modws2_32 = syscall.NewLazyDLL(sysdll.Add("ws2_32.dll"))
procAdjustTokenPrivileges = modadvapi32.NewProc("AdjustTokenPrivileges")
procDuplicateTokenEx = modadvapi32.NewProc("DuplicateTokenEx")
@@ -52,7 +53,7 @@
procOpenThreadToken = modadvapi32.NewProc("OpenThreadToken")
procRevertToSelf = modadvapi32.NewProc("RevertToSelf")
procSetTokenInformation = modadvapi32.NewProc("SetTokenInformation")
- procSystemFunction036 = modadvapi32.NewProc("SystemFunction036")
+ procProcessPrng = modbcryptprimitives.NewProc("ProcessPrng")
procGetAdaptersAddresses = modiphlpapi.NewProc("GetAdaptersAddresses")
procCreateEventW = modkernel32.NewProc("CreateEventW")
procGetACP = modkernel32.NewProc("GetACP")
@@ -148,12 +149,12 @@
return
}
-func RtlGenRandom(buf []byte) (err error) {
+func ProcessPrng(buf []byte) (err error) {
var _p0 *byte
if len(buf) > 0 {
_p0 = &buf[0]
}
- r1, _, e1 := syscall.Syscall(procSystemFunction036.Addr(), 2, uintptr(unsafe.Pointer(_p0)), uintptr(len(buf)), 0)
+ r1, _, e1 := syscall.Syscall(procProcessPrng.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 f5c2429..735a905 100644
--- a/src/runtime/os_windows.go
+++ b/src/runtime/os_windows.go
@@ -127,15 +127,8 @@
_AddVectoredContinueHandler,
_ 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
+ // Use ProcessPrng to generate cryptographically random data.
+ _ProcessPrng stdFunction
// Load ntdll.dll manually during startup, otherwise Mingw
// links wrong printf function to cgo executable (see issue
@@ -152,12 +145,12 @@
)
var (
- advapi32dll = [...]uint16{'a', 'd', 'v', 'a', 'p', 'i', '3', '2', '.', 'd', 'l', 'l', 0}
- kernel32dll = [...]uint16{'k', 'e', 'r', 'n', 'e', 'l', '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}
+ bcryptprimitivesdll = [...]uint16{'b', 'c', 'r', 'y', 'p', 't', 'p', 'r', 'i', 'm', 'i', 't', 'i', 'v', 'e', 's', '.', 'd', 'l', 'l', 0}
+ kernel32dll = [...]uint16{'k', 'e', 'r', 'n', 'e', 'l', '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
@@ -256,11 +249,11 @@
}
_AddVectoredContinueHandler = windowsFindfunc(k32, []byte("AddVectoredContinueHandler\000"))
- a32 := windowsLoadSystemLib(advapi32dll[:])
- if a32 == 0 {
- throw("advapi32.dll not found")
+ bcryptPrimitives := windowsLoadSystemLib(bcryptprimitivesdll[:])
+ if bcryptPrimitives == 0 {
+ throw("bcryptprimitives.dll not found")
}
- _RtlGenRandom = windowsFindfunc(a32, []byte("SystemFunction036\000"))
+ _ProcessPrng = windowsFindfunc(bcryptPrimitives, []byte("ProcessPrng\000"))
n32 := windowsLoadSystemLib(ntdlldll[:])
if n32 == 0 {
@@ -617,7 +610,7 @@
//go:nosplit
func getRandomData(r []byte) {
n := 0
- if stdcall2(_RtlGenRandom, uintptr(unsafe.Pointer(&r[0])), uintptr(len(r)))&0xff != 0 {
+ if stdcall2(_ProcessPrng, uintptr(unsafe.Pointer(&r[0])), uintptr(len(r)))&0xff != 0 {
n = len(r)
}
extendRandom(r, n)
