rsa: Use IOS_HeapRealloc for Mini-GMP

ios_mcp/imports.ld

@@ -35,6 +35,7 @@ PROVIDE(IOS_ReadOTP = 0x050568fc);
 PROVIDE(IOS_HeapAlloc = 0x05056924);
 PROVIDE(IOS_HeapAllocAligned = 0x0505692c);
 PROVIDE(IOS_HeapFree = 0x05056934);
+PROVIDE(IOS_HeapRealloc = 0x05056944);
 
 PROVIDE(IOS_Open = 0x05056984);
 PROVIDE(IOS_Close = 0x0505698c);

ios_mcp/source/imports.h

@@ -92,6 +92,7 @@ int IOS_ReadOTP(int index, void* buffer, uint32_t size);
 void* IOS_HeapAlloc(uint32_t heap, uint32_t size);
 void* IOS_HeapAllocAligned(uint32_t heap, uint32_t size, uint32_t alignment);
 void IOS_HeapFree(uint32_t heap, void* ptr);
+void* IOS_HeapRealloc(uint32_t heap, void* ptr, uint32_t size);
 
 int IOS_Open(const char* device, int mode);
 int IOS_Close(int fd);

ios_mcp/source/rsa.c

@@ -46,27 +46,18 @@ static const uint32_t rsa_pubexp = 0x10001;
 
 static void *ios_gmp_alloc(size_t size)
 {
-    return IOS_HeapAlloc(CROSS_PROCESS_HEAP_ID, size);
+    return IOS_HeapAlloc(LOCAL_PROCESS_HEAP_ID, size);
 }
 static void *ios_gmp_realloc(void *buf, size_t old_size, size_t new_size)
 {
-    void *newbuf = IOS_HeapAlloc(CROSS_PROCESS_HEAP_ID, new_size);
-    if (!newbuf)
-        return NULL;
-
-    // Copy the existing buffer into the new buffer.
-    size_t to_copy = (old_size < new_size ? old_size : new_size);
-    if (to_copy > 0) {
-        memcpy(newbuf, buf, to_copy);
-    }
-    IOS_HeapFree(CROSS_PROCESS_HEAP_ID, buf);
-    return newbuf;
+    ((void)old_size);
+    return IOS_HeapRealloc(LOCAL_PROCESS_HEAP_ID, buf, new_size);
 }
 
 static void ios_gmp_free(void *p, size_t unused_size)
 {
     ((void)unused_size);
-    IOS_HeapFree(CROSS_PROCESS_HEAP_ID, p);
+    IOS_HeapFree(LOCAL_PROCESS_HEAP_ID, p);
 }
 
 /**