opensc/opensc-0.23.0-mlock.patch

From 968dc08ee846b483b061fb516bf2d06e99d459a9 Mon Sep 17 00:00:00 2001
From: Davis Gallinghouse <davis@aramid.us>
Date: Thu, 21 Nov 2024 10:24:18 -0600
Subject: [PATCH 1/3] Allocate whole page(s) for each sc_mem_secure_alloc

sc_mem_secure_alloc uses calloc to allocate memory, but then uses
mlock to try to lock the allocated memory. calloc may not necessarily
return a page-aligned pointer, even if we request a whole page of
memory.

Instead of relying on the libc allocator behavior, we directly call
mmap (VirtualAlloc on Windows) to ensure we get whole page(s) to
ourselves for sc_mem_secure_alloc.

Fixes #3267
---
 src/libopensc/sc.c | 42 ++++++++++++------------------------------
 1 file changed, 12 insertions(+), 30 deletions(-)

diff --git a/src/libopensc/sc.c b/src/libopensc/sc.c
index cf3d86a022..c6c51fe1b9 100644
--- a/src/libopensc/sc.c
+++ b/src/libopensc/sc.c
@@ -54,7 +54,6 @@ static const char *sc_version = "(undef)";
 #define PAGESIZE 0
 #endif
 #endif
-static size_t page_size = PAGESIZE;
 
 const char *sc_get_version(void)
 {
@@ -897,40 +896,22 @@ int _sc_parse_atr(sc_reader_t *reader)
 	return SC_SUCCESS;
 }
 
-static void init_page_size()
-{
-	if (page_size == 0) {
-#ifdef _WIN32
-		SYSTEM_INFO system_info;
-		GetSystemInfo(&system_info);
-		page_size = system_info.dwPageSize;
-#else
-		page_size = sysconf(_SC_PAGESIZE);
-		if ((long) page_size < 0) {
-			page_size = 0;
-		}
-#endif
-	}
-}
-
 void *sc_mem_secure_alloc(size_t len)
 {
 	void *p;
 
-	init_page_size();
-	if (page_size > 0) {
-		size_t pages = (len + page_size - 1) / page_size;
-		len = pages * page_size;
-	}
-
-	p = calloc(1, len);
-	if (p == NULL) {
-		return NULL;
-	}
 #ifdef _WIN32
-	VirtualLock(p, len);
+	p = VirtualAlloc(NULL, len, MEM_COMMIT, PAGE_READWRITE);
+	if (p != NULL)
+	{
+		VirtualLock(p, len);
+	}
 #else
-	mlock(p, len);
+	p = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+	if (p != NULL)
+	{
+		mlock(p, len);
+	}
 #endif
 
 	return p;
@@ -940,10 +921,11 @@ void sc_mem_secure_free(void *ptr, size_t len)
 {
 #ifdef _WIN32
 	VirtualUnlock(ptr, len);
+	VirtualFree(ptr, 0, MEM_RELEASE);
 #else
 	munlock(ptr, len);
+	munmap(ptr, len);
 #endif
-	free(ptr);
 }
 
 void sc_mem_clear(void *ptr, size_t len)

From c5037daf2af375177c4a77dafb2b9909ccadf9f5 Mon Sep 17 00:00:00 2001
From: Davis Gallinghouse <davis@aramid.us>
Date: Mon, 9 Dec 2024 10:53:15 -0600
Subject: [PATCH 2/3] Fix code style violations

---
 src/libopensc/sc.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/src/libopensc/sc.c b/src/libopensc/sc.c
index c6c51fe1b9..ec03af0b80 100644
--- a/src/libopensc/sc.c
+++ b/src/libopensc/sc.c
@@ -902,14 +902,12 @@ void *sc_mem_secure_alloc(size_t len)
 
 #ifdef _WIN32
 	p = VirtualAlloc(NULL, len, MEM_COMMIT, PAGE_READWRITE);
-	if (p != NULL)
-	{
+	if (p != NULL) {
 		VirtualLock(p, len);
 	}
 #else
 	p = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
-	if (p != NULL)
-	{
+	if (p != NULL) {
 		mlock(p, len);
 	}
 #endif

From 137d49d843e3de6794d7df4cc97c59ee517ad44c Mon Sep 17 00:00:00 2001
From: Frank Morgner <frankmorgner@gmail.com>
Date: Tue, 3 Dec 2024 22:28:06 +0100
Subject: [PATCH 3/3] fixed usage of free() on data that was created with
 sc_mem_secure_alloc

This will crash applications, which, for example are importing a private
key as reported here
https://github.com/OpenSC/OpenSC/pull/3269#issuecomment-2495074344
---
 src/libopensc/pkcs15.c | 10 ++++------
 src/libopensc/pkcs15.h |  4 ++++
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/src/libopensc/pkcs15.c b/src/libopensc/pkcs15.c
index 3f3198d3bc..0876cf8f88 100644
--- a/src/libopensc/pkcs15.c
+++ b/src/libopensc/pkcs15.c
@@ -2736,12 +2736,9 @@ sc_pkcs15_make_absolute_path(const struct sc_path *parent, struct sc_path *child
 
 void sc_pkcs15_free_object_content(struct sc_pkcs15_object *obj)
 {
-	if (obj->content.value && obj->content.len)   {
-		if (SC_PKCS15_TYPE_AUTH & obj->type
-			|| SC_PKCS15_TYPE_SKEY & obj->type
-			|| SC_PKCS15_TYPE_PRKEY & obj->type) {
-			/* clean everything that potentially contains a secret */
-			sc_mem_secure_clear_free(obj->content.value, obj->content.len);
+	if (obj->content.value && obj->content.len) {
+		if (obj->content_free) {
+			obj->content_free(obj->content.value, obj->content.len);
 		} else {
 			free(obj->content.value);
 		}
@@ -2772,6 +2769,7 @@ sc_pkcs15_allocate_object_content(struct sc_context *ctx, struct sc_pkcs15_objec
 			|| SC_PKCS15_TYPE_SKEY & obj->type
 			|| SC_PKCS15_TYPE_PRKEY & obj->type) {
 		tmp_buf = sc_mem_secure_alloc(len);
+		obj->content_free = sc_mem_secure_free;
 	} else {
 		tmp_buf = malloc(len);
 	}
diff --git a/src/libopensc/pkcs15.h b/src/libopensc/pkcs15.h
index ce107c02a0..e4be6f12aa 100644
--- a/src/libopensc/pkcs15.h
+++ b/src/libopensc/pkcs15.h
@@ -486,6 +486,10 @@ struct sc_pkcs15_object {
 	struct sc_pkcs15_object *next, *prev; /* used only internally */
 
 	struct sc_pkcs15_der content;
+	/* Method for deallocating the object's content.value.
+	 * If no specific function for deallocation is given, then free() is used
+	 * to release content.value */
+	void (*content_free)(void *, size_t);
 
 	int session_object;	/* used internally. if nonzero, object is a session object. */
 };