pickle for the EncryptionParameters

Author: Huelse

setup.py

@@ -25,7 +25,7 @@
 ext_modules = [
     Extension(
         name='seal',
-        sources=['src/wrapper.cpp'],
+        sources=['src/base64.cpp', 'src/wrapper.cpp'],
         include_dirs=include_dirs,
         language='c++',
         extra_compile_args=cpp_args,

src/base64.cpp

@@ -0,0 +1,112 @@
+/*
+   base64.cpp and base64.h
+   base64 encoding and decoding with C++.
+   Version: 1.01.00
+   Copyright (C) 2004-2017 René Nyffenegger
+   This source code is provided 'as-is', without any express or implied
+   warranty. In no event will the author be held liable for any damages
+   arising from the use of this software.
+   Permission is granted to anyone to use this software for any purpose,
+   including commercial applications, and to alter it and redistribute it
+   freely, subject to the following restrictions:
+   1. The origin of this source code must not be misrepresented; you must not
+      claim that you wrote the original source code. If you use this source code
+      in a product, an acknowledgment in the product documentation would be
+      appreciated but is not required.
+   2. Altered source versions must be plainly marked as such, and must not be
+      misrepresented as being the original source code.
+   3. This notice may not be removed or altered from any source distribution.
+   René Nyffenegger [email protected]
+*/
+
+#include "base64.h"
+#include <iostream>
+
+static const std::string base64_chars =
+             "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+             "abcdefghijklmnopqrstuvwxyz"
+             "0123456789+/";
+
+
+static inline bool is_base64(unsigned char c) {
+  return (isalnum(c) || (c == '+') || (c == '/'));
+}
+
+std::string base64_encode(unsigned char const* bytes_to_encode, unsigned int in_len) {
+  std::string ret;
+  int i = 0;
+  int j = 0;
+  unsigned char char_array_3[3];
+  unsigned char char_array_4[4];
+
+  while (in_len--) {
+    char_array_3[i++] = *(bytes_to_encode++);
+    if (i == 3) {
+      char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
+      char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
+      char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
+      char_array_4[3] = char_array_3[2] & 0x3f;
+
+      for(i = 0; (i <4) ; i++)
+        ret += base64_chars[char_array_4[i]];
+      i = 0;
+    }
+  }
+
+  if (i)
+  {
+    for(j = i; j < 3; j++)
+      char_array_3[j] = '\0';
+
+    char_array_4[0] = ( char_array_3[0] & 0xfc) >> 2;
+    char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
+    char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
+
+    for (j = 0; (j < i + 1); j++)
+      ret += base64_chars[char_array_4[j]];
+
+    while((i++ < 3))
+      ret += '=';
+
+  }
+
+  return ret;
+
+}
+
+std::string base64_decode(std::string const& encoded_string) {
+  int in_len = encoded_string.size();
+  int i = 0;
+  int j = 0;
+  int in_ = 0;
+  unsigned char char_array_4[4], char_array_3[3];
+  std::string ret;
+
+  while (in_len-- && ( encoded_string[in_] != '=') && is_base64(encoded_string[in_])) {
+    char_array_4[i++] = encoded_string[in_]; in_++;
+    if (i ==4) {
+      for (i = 0; i <4; i++)
+        char_array_4[i] = base64_chars.find(char_array_4[i]);
+
+      char_array_3[0] = ( char_array_4[0] << 2       ) + ((char_array_4[1] & 0x30) >> 4);
+      char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
+      char_array_3[2] = ((char_array_4[2] & 0x3) << 6) +   char_array_4[3];
+
+      for (i = 0; (i < 3); i++)
+        ret += char_array_3[i];
+      i = 0;
+    }
+  }
+
+  if (i) {
+    for (j = 0; j < i; j++)
+      char_array_4[j] = base64_chars.find(char_array_4[j]);
+
+    char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
+    char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
+
+    for (j = 0; (j < i - 1); j++) ret += char_array_3[j];
+  }
+
+  return ret;
+}

src/base64.h

@@ -0,0 +1,14 @@
+//
+//  base64 encoding and decoding with C++.
+//  Version: 1.01.00
+//
+
+#ifndef BASE64_H_C0CE2A47_D10E_42C9_A27C_C883944E704A
+#define BASE64_H_C0CE2A47_D10E_42C9_A27C_C883944E704A
+
+#include <string>
+
+std::string base64_encode(unsigned char const* , unsigned int len);
+std::string base64_decode(std::string const& s);
+
+#endif /* BASE64_H_C0CE2A47_D10E_42C9_A27C_C883944E704A */

src/wrapper.cpp

@@ -4,6 +4,7 @@
 #include <pybind11/numpy.h>
 #include <pybind11/stl.h>
 #include "seal/seal.h"
+#include "base64.h"
 #include <fstream>
 
 using namespace std;
@@ -18,6 +19,30 @@ PYBIND11_MAKE_OPAQUE(std::vector<std::int64_t>);
 
 using parms_id_type = std::array<std::uint64_t, 4>;
 
+template <class T>
+py::tuple serialize(T &c)
+{
+	std::stringstream output(std::ios::binary | std::ios::out);
+	c.save(output);
+	std::string str1 = output.str();
+	std::string base64_encoded_str = base64_encode(reinterpret_cast<const unsigned char *>(str1.c_str()), (unsigned int)str1.length());
+	return py::make_tuple(base64_encoded_str);
+}
+
+template <class T>
+T deserialize(py::tuple t)
+{
+	if (t.size() != 1)
+		throw std::runtime_error("(Pickle) Invalid input tuple!");
+	T c = T();
+	std::string encoded_str = t[0].cast<std::string>();
+	std::string decoded_str = base64_decode(cipherstr_encoded);
+	std::stringstream input(std::ios::binary | std::ios::in);
+	input.str(decoded_str);
+	c.load(input);
+	return c;
+}
+
 PYBIND11_MODULE(seal, m)
 {
 	m.doc() = "Microsoft SEAL (3.4.5) For Python. From https://github.com/Huelse/SEAL-Python";
@@ -61,7 +86,8 @@ PYBIND11_MODULE(seal, m)
 			std::ifstream in(path, std::ifstream::binary);
 			p.load(in);
 			in.close();
-		});
+		})
+		.def(py::pickle(&serialize<EncryptionParameters>, &deserialize<EncryptionParameters>));;
 
 	// context.h
 	py::class_<EncryptionParameterQualifiers, std::unique_ptr<EncryptionParameterQualifiers, py::nodelete>>(m, "EncryptionParameterQualifiers")