crypto: define XMALLOC & XFREE for sw_crypto

Use the same memory allocation in sw_crypto driver as what is used in
src/lib/crypto libraries

In addition, in nuttx protected build, allocate all memory from kernel heap

Signed-off-by: Jukka Laitinen <jukkax@ssrc.tii.ae>

src/drivers/sw_crypto/crypto.c

@@ -52,11 +52,11 @@ extern void libtomcrypt_init(void);
 #define KEY_CACHE_LEN 16
 
 #ifndef SECMEM_ALLOC
-#define SECMEM_ALLOC malloc
+#define SECMEM_ALLOC XMALLOC
 #endif
 
 #ifndef SECMEM_FREE
-#define SECMEM_FREE free
+#define SECMEM_FREE XFREE
 #endif
 
 /*
@@ -156,7 +156,7 @@ crypto_session_handle_t crypto_open(px4_crypto_algorithm_t algorithm)
 
 	switch (algorithm) {
 	case CRYPTO_XCHACHA20: {
-			chacha20_context_t *context = malloc(sizeof(chacha20_context_t));
+			chacha20_context_t *context = XMALLOC(sizeof(chacha20_context_t));
 
 			if (!context) {
 				ret.handle = 0;
@@ -188,7 +188,7 @@ void crypto_close(crypto_session_handle_t *handle)
 	crypto_open_count--;
 	handle->handle = 0;
 	keystore_close(&handle->keystore_handle);
-	free(handle->context);
+	XFREE(handle->context);
 	handle->context = NULL;
 }
 

src/lib/crypto/CMakeLists.txt

@@ -99,4 +99,14 @@ target_link_libraries(libtomcrypt
 # "der_encode_asn1_identifier.c:39:18: error: comparison is always false due to limited range of data type"
 target_compile_options(libtomcrypt PRIVATE -Wno-type-limits)
 
+# Re-define memory allocation macros if we are building for
+# memory protected build in nuttx. All allocations happen in
+# kernel heap there
+
+if (NOT DEFINED CONFIG_BUILD_FLAT AND "${PX4_PLATFORM}" MATCHES "nuttx")
+	target_compile_options(libtomcrypt PUBLIC -DXMALLOC=kmm_malloc -DXFREE=kmm_free -DXREALLOC=kmm_realloc -DXCALLOC=kmm_calloc)
+	target_compile_options(libtommath PUBLIC -DMP_MALLOC=kmm_malloc -DMP_FREE\(p,s\)=kmm_free\(p\) -DMP_REALLOC\(p,o,n\)=kmm_realloc\(p,n\) -DMP_CALLOC=kmm_calloc)
+	target_link_libraries(libtommath PRIVATE nuttx_kmm)
+endif()
+
 endif()