From 904c084711530159256ee3a9576a08ee0154ccdb Mon Sep 17 00:00:00 2001
From: Randall Winkhart <idgr@tutanota.com>
Date: Sat, 7 Feb 2026 23:29:11 -0500
Subject: [PATCH] Use platform-specific implementations of
 securePtrOverwriteAndFree

---
 0.go         |  6 ------
 0_generic.go | 14 ++++++++++++++
 0_ios.go     | 14 ++++++++++++++
 privkey.go   |  4 ++--
 4 files changed, 30 insertions(+), 8 deletions(-)
 create mode 100644 0_generic.go
 create mode 100644 0_ios.go

diff --git a/0.go b/0.go
index 97e2d72..df2acdd 100644
--- a/0.go
+++ b/0.go
@@ -97,10 +97,4 @@ func safeBoolDeref(b *bool) bool {
 	return *b
 }
 
-// securePtrOverwrite securely overwrites the memory at the input pointer and then frees it.
-func securePtrOverwriteAndFree(input unsafe.Pointer, length C.int) {
-	C.explicit_bzero(input, C.size_t(length))
-	C.free(input)
-}
-
 func main() {}
diff --git a/0_generic.go b/0_generic.go
new file mode 100644
index 0000000..7465816
--- /dev/null
+++ b/0_generic.go
@@ -0,0 +1,14 @@
+//go:build !ios
+
+package main
+
+// #include <string.h>
+// #include <stdlib.h>
+import "C"
+import "unsafe"
+
+// securePtrOverwriteAndFree securely overwrites the memory at the input pointer and then frees it.
+func securePtrOverwriteAndFree(input unsafe.Pointer, length C.size_t) {
+	C.explicit_bzero(input, C.size_t(length))
+	C.free(input)
+}
diff --git a/0_ios.go b/0_ios.go
new file mode 100644
index 0000000..d555100
--- /dev/null
+++ b/0_ios.go
@@ -0,0 +1,14 @@
+//go:build ios
+
+package main
+
+// #include <string.h>
+// #include <stdlib.h>
+import "C"
+import "unsafe"
+
+// securePtrOverwriteAndFree securely overwrites the memory at the input pointer and then frees it.
+func securePtrOverwriteAndFree(input unsafe.Pointer, length C.size_t) {
+	C.memset_s(input, length, 0, length)
+	C.free(input)
+}
diff --git a/privkey.go b/privkey.go
index b7e591b..fa981fb 100644
--- a/privkey.go
+++ b/privkey.go
@@ -20,7 +20,7 @@ import (
 func SetPrivKeyDataAndEraseFreeInput(privKeyData C.PascalString) {
 	privKeyDataPtr := unsafe.Pointer(privKeyData.data)
 	privkey.SetBytes(C.GoBytes(privKeyDataPtr, privKeyData.len))
-	securePtrOverwriteAndFree(privKeyDataPtr, privKeyData.len)
+	securePtrOverwriteAndFree(privKeyDataPtr, C.size_t(privKeyData.len))
 	FreePascalString(privKeyData)
 }
 
@@ -46,6 +46,6 @@ func GetPrivKeyDataAndEraseGoCopy() C.PascalString {
 //
 //export EraseFreePrivKeyPascal
 func EraseFreePrivKeyPascal(privKeyPascal C.PascalString) {
-	securePtrOverwriteAndFree(unsafe.Pointer(privKeyPascal.data), privKeyPascal.len)
+	securePtrOverwriteAndFree(unsafe.Pointer(privKeyPascal.data), C.size_t(privKeyPascal.len))
 	FreePascalString(privKeyPascal)
 }