philippe44/libraop

curve25519 with OpenSSL

LinusU opened this issue · 2 comments

LinusU commented

Hey 👋

So I don't know if this is of interest to you, but since I've already made the heavy lifting I figured it would be good to at least post it.

If you are interested in using OpenSSL for the curve25519 functions, I've put together an example app that does the same functions in both libraries.

#include <assert.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <openssl/evp.h>

#include "curve25519/include/curve25519_dh.h"
#include "curve25519/include/ed25519_signature.h"

void print_hex(uint8_t *data, size_t length) {
  printf("  ");
  for (size_t i = 0; i < length; i++) printf("%02X", data[i]);
  printf("\n");
}

void openssl_CreateKeyPair() {
  int status;

  uint8_t secret[32] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F };

  EVP_PKEY *key = EVP_PKEY_new_raw_private_key(EVP_PKEY_ED25519, NULL, secret, 32);

  uint8_t private[64] = { 0 };
  size_t private_size = 32;

  status = EVP_PKEY_get_raw_private_key(key, private, &private_size);
  assert(status == 1);
  assert(private_size == 32);

  status = EVP_PKEY_get_raw_public_key(key, &private[32], &private_size);
  assert(status == 1);
  assert(private_size == 32);

  uint8_t public[32] = { 0 };
  size_t public_size = 32;
  status = EVP_PKEY_get_raw_public_key(key, public, &public_size);
  assert(status == 1);
  assert(public_size == 32);

  printf("OpenSSL CreateKeyPair:\n");
  print_hex(private, 64);
  print_hex(public, 32);
}

void curve25519_CreateKeyPair() {
  uint8_t secret[32] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F };

  uint8_t private[64] = { 0 };
  uint8_t public[64] = { 0 };
  ed25519_CreateKeyPair(public, private, NULL, secret);

  printf("Curve25519 CreateKeyPair:\n");
  print_hex(private, 64);
  print_hex(public, 32);
}

void openssl_CalculatePublicKey() {
  int status;

  uint8_t secret[32] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F };

  EVP_PKEY *key = EVP_PKEY_new_raw_private_key(EVP_PKEY_X25519, NULL, secret, 32);

  uint8_t public[32] = { 0 };
  size_t public_size = 32;
  status = EVP_PKEY_get_raw_public_key(key, public, &public_size);
  assert(status == 1);
  assert(public_size == 32);

  printf("OpenSSL CalculatePublicKey:\n");
  print_hex(public, 32);
}

void curve25519_CalculatePublicKey() {
  uint8_t secret[32] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F };
  uint8_t public[32] = { 0 };

  curve25519_dh_CalculatePublicKey(public, secret);

  printf("Curve25519 CalculatePublicKey:\n");
  print_hex(public, 32);
}

void openssl_CreateSharedKey() {
  int status;

  uint8_t secret[32] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F };
  uint8_t peer_public[32] = { 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x3F };

  EVP_PKEY *key = EVP_PKEY_new_raw_private_key(EVP_PKEY_X25519, NULL, secret, 32);
  EVP_PKEY *peer_key = EVP_PKEY_new_raw_public_key(EVP_PKEY_X25519, NULL, peer_public, 32);

  EVP_PKEY_CTX *ctx = EVP_PKEY_CTX_new(key, NULL);

  status = EVP_PKEY_derive_init(ctx);
  assert(status == 1);

  status = EVP_PKEY_derive_set_peer(ctx, peer_key);
  assert(status == 1);

  uint8_t result[32] = { 0 };
  size_t size = 32;
  status = EVP_PKEY_derive(ctx, result, &size);
  assert(status == 1);
  assert(size == 32);

  printf("OpenSSL CreateSharedKey:\n");
  print_hex(result, 32);
}

void curve25519_CreateSharedKey() {
  uint8_t secret[32] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F };
  uint8_t peer_public[32] = { 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x3F };

  uint8_t result[32] = { 0 };
  curve25519_dh_CreateSharedKey(result, peer_public, secret);

  printf("Curve25519 CreateSharedKey:\n");
  print_hex(result, 32);
}

void openssl_SignMessage() {
  int status;

  uint8_t secret[32] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F };
  uint8_t msg[32] = { 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F };

  EVP_MD_CTX *ctx = EVP_MD_CTX_new();
  assert(ctx != NULL);
  EVP_PKEY *pkey = EVP_PKEY_new_raw_private_key(EVP_PKEY_ED25519, NULL, secret, 32);
  assert(pkey != NULL);

  status = EVP_DigestSignInit(ctx, NULL, NULL, NULL, pkey);
  assert(status == 1);

  uint8_t signature[64] = { 0 };
  size_t signature_length = 64;

  status = EVP_DigestSign(ctx, signature, &signature_length, msg, 32);
  assert(status == 1);
  assert(signature_length == 64);

  printf("OpenSSL SignMessage:\n");
  print_hex(signature, 64);
}

void curve25519_SignMessage() {
  uint8_t key[64] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x03, 0xA1, 0x07, 0xBF, 0xF3, 0xCE, 0x10, 0xBE, 0x1D, 0x70, 0xDD, 0x18, 0xE7, 0x4B, 0xC0, 0x99, 0x67, 0xE4, 0xD6, 0x30, 0x9B, 0xA5, 0x0D, 0x5F, 0x1D, 0xDC, 0x86, 0x64, 0x12, 0x55, 0x31, 0xB8 };
  uint8_t msg[32] = { 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F, 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F };

  uint8_t signature[64] = { 0 };
  ed25519_SignMessage(signature, key, NULL, msg, 32);

  printf("Curve25519 SignMessage:\n");
  print_hex(signature, 64);
}

int main() {
  printf("\n");
  curve25519_CreateKeyPair();
  openssl_CreateKeyPair();
  printf("\n");
  curve25519_CalculatePublicKey();
  openssl_CalculatePublicKey();
  printf("\n");
  curve25519_CreateSharedKey();
  openssl_CreateSharedKey();
  printf("\n");
  curve25519_SignMessage();
  openssl_SignMessage();
  printf("\n");
}

If you don't want this, just go ahead and close the issue ☺️

kimi20071025 commented

thank you ,it is quiet useful to me.

  • 👍1
philippe44 commented

Thanks - It's in now

  • 🎉1