Add wrappers for reinterpret_cast between char* and uint8_t*

Generally speaking reinterpret_cast is sketchy stuff. But the
special case of char*/uint8_t* is both common and safe. By
isolating those, the remaining (likely sketchy) cases are easier
to grep for.

2 files changed, 6 insertions, 5 deletions

diff --git a/src/lib/ffi/ffi_mp.cpp b/src/lib/ffi/ffi_mp.cpp
index 00ad786ab..0b55c1d69 100644
--- a/src/lib/ffi/ffi_mp.cpp
+++ b/src/lib/ffi/ffi_mp.cpp
@@ -63,7 +63,7 @@ int botan_mp_set_from_radix_str(botan_mp_t mp, const char* str, size_t radix)
       else
          return BOTAN_FFI_ERROR_NOT_IMPLEMENTED;
 
-      const uint8_t* bytes = reinterpret_cast<const uint8_t*>(str);
+      const uint8_t* bytes = Botan::cast_char_ptr_to_uint8(str);
       const size_t len = strlen(str);
 
       bn = Botan::BigInt::decode(bytes, len, base);
diff --git a/src/lib/ffi/ffi_util.h b/src/lib/ffi/ffi_util.h
index ae48ab01a..b52c319fe 100644
--- a/src/lib/ffi/ffi_util.h
+++ b/src/lib/ffi/ffi_util.h
@@ -176,19 +176,20 @@ int write_vec_output(uint8_t out[], size_t* out_len, const std::vector<uint8_t,
 inline int write_str_output(uint8_t out[], size_t* out_len, const std::string& str)
    {
    return write_output(out, out_len,
-                       reinterpret_cast<const uint8_t*>(str.c_str()),
+                       Botan::cast_char_ptr_to_uint8(str.data()),
                        str.size() + 1);
    }
 
 inline int write_str_output(char out[], size_t* out_len, const std::string& str)
    {
-   return write_str_output(reinterpret_cast<uint8_t*>(out), out_len, str);
+   return write_str_output(Botan::cast_char_ptr_to_uint8(out), out_len, str);
    }
 
 inline int write_str_output(char out[], size_t* out_len, const std::vector<uint8_t>& str_vec)
    {
-   return write_output(reinterpret_cast<uint8_t*>(out), out_len,
-                       reinterpret_cast<const uint8_t*>(str_vec.data()),
+   return write_output(Botan::cast_char_ptr_to_uint8(out),
+                       out_len,
+                       str_vec.data(),
                        str_vec.size());
    }