session-android/libaxolotl/jni/curve25519-donna-jni.c
Moxie Marlinspike d902c12941 Break core ratchet out into libaxolotol.
1) Break the core cryptography functions out into libaxolotol.

2) The objective for this code is a Java library that isn't
   dependent on any Android functions.  However, while the
   code has been separated from any Android functionality,
   it is still an 'android library project' because of the
   JNI.
2014-10-20 12:10:02 -07:00

76 lines
2.7 KiB
C

/**
* Copyright (C) 2013 Open Whisper Systems
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <string.h>
#include <stdint.h>
#include <jni.h>
#include "curve25519-donna.h"
JNIEXPORT jbyteArray JNICALL Java_org_whispersystems_libaxolotl_ecc_Curve25519_generatePrivateKey
(JNIEnv *env, jclass clazz, jbyteArray random, jboolean ephemeral)
{
uint8_t* privateKey = (uint8_t*)(*env)->GetByteArrayElements(env, random, 0);
privateKey[0] &= 248;
if (ephemeral) {
privateKey[0] |= 1;
}
privateKey[31] &= 127;
privateKey[31] |= 64;
(*env)->ReleaseByteArrayElements(env, random, privateKey, 0);
return random;
}
JNIEXPORT jbyteArray JNICALL Java_org_whispersystems_libaxolotl_ecc_Curve25519_generatePublicKey
(JNIEnv *env, jclass clazz, jbyteArray privateKey)
{
static const uint8_t basepoint[32] = {9};
jbyteArray publicKey = (*env)->NewByteArray(env, 32);
uint8_t* publicKeyBytes = (uint8_t*)(*env)->GetByteArrayElements(env, publicKey, 0);
uint8_t* privateKeyBytes = (uint8_t*)(*env)->GetByteArrayElements(env, privateKey, 0);
curve25519_donna(publicKeyBytes, privateKeyBytes, basepoint);
(*env)->ReleaseByteArrayElements(env, publicKey, publicKeyBytes, 0);
(*env)->ReleaseByteArrayElements(env, privateKey, privateKeyBytes, 0);
return publicKey;
}
JNIEXPORT jbyteArray JNICALL Java_org_whispersystems_libaxolotl_ecc_Curve25519_calculateAgreement
(JNIEnv *env, jclass clazz, jbyteArray privateKey, jbyteArray publicKey)
{
jbyteArray sharedKey = (*env)->NewByteArray(env, 32);
uint8_t* sharedKeyBytes = (uint8_t*)(*env)->GetByteArrayElements(env, sharedKey, 0);
uint8_t* privateKeyBytes = (uint8_t*)(*env)->GetByteArrayElements(env, privateKey, 0);
uint8_t* publicKeyBytes = (uint8_t*)(*env)->GetByteArrayElements(env, publicKey, 0);
curve25519_donna(sharedKeyBytes, privateKeyBytes, publicKeyBytes);
(*env)->ReleaseByteArrayElements(env, sharedKey, sharedKeyBytes, 0);
(*env)->ReleaseByteArrayElements(env, publicKey, publicKeyBytes, 0);
(*env)->ReleaseByteArrayElements(env, privateKey, privateKeyBytes, 0);
return sharedKey;
}