1 files changed, 24 insertions, 0 deletions

diff --git a/nacl/crypto_sign/wrapper-sign-open.cpp b/nacl/crypto_sign/wrapper-sign-open.cpp
new file mode 100644
index 00000000..346e9400
--- /dev/null
+++ b/nacl/crypto_sign/wrapper-sign-open.cpp
@@ -0,0 +1,24 @@
+#include <string>
+using std::string;
+#include "crypto_sign.h"
+
+string crypto_sign_open(const string &sm_string, const string &pk_string)
+{
+  if (pk_string.size() != crypto_sign_PUBLICKEYBYTES) throw "incorrect public-key length";
+  size_t smlen = sm_string.size();
+  unsigned char m[smlen];
+  unsigned long long mlen;
+  for (int i = 0;i < smlen;++i) m[i] = sm_string[i];
+  if (crypto_sign_open(
+        m,
+        &mlen,
+        m,
+        smlen,
+        (const unsigned char *) pk_string.c_str()
+        ) != 0)
+    throw "ciphertext fails verification";
+  return string(
+    (char *) m,
+    mlen
+  );
+}