olm/lib/curve25519-donna/contrib/Curve25519Donna.c

119 lines
3.1 KiB
C
Raw Normal View History

/*
James Robson
Public domain.
*/
#include "Curve25519Donna.h"
#include <stdio.h>
#include <stdlib.h>
extern void curve25519_donna(unsigned char *output, const unsigned char *a,
const unsigned char *b);
unsigned char*
as_unsigned_char_array(JNIEnv* env, jbyteArray array, int* len);
jbyteArray as_byte_array(JNIEnv* env, unsigned char* buf, int len);
jbyteArray as_byte_array(JNIEnv* env, unsigned char* buf, int len) {
jbyteArray array = (*env)->NewByteArray(env, len);
(*env)->SetByteArrayRegion(env, array, 0, len, (jbyte*)buf);
//int i;
//for (i = 0;i < len;++i) printf("%02x",(unsigned int) buf[i]); printf(" ");
//printf("\n");
return array;
}
unsigned char*
as_unsigned_char_array(JNIEnv* env, jbyteArray array, int* len) {
*len = (*env)->GetArrayLength(env, array);
unsigned char* buf = (unsigned char*)calloc(*len+1, sizeof(char));
(*env)->GetByteArrayRegion (env, array, 0, *len, (jbyte*)buf);
return buf;
}
JNIEXPORT jbyteArray JNICALL Java_Curve25519Donna_curve25519Donna
(JNIEnv *env, jobject obj, jbyteArray a, jbyteArray b) {
unsigned char o[32] = {0};
int l1, l2;
unsigned char* a1 = as_unsigned_char_array(env, a, &l1);
unsigned char* b1 = as_unsigned_char_array(env, b, &l2);
if ( !(l1 == 32 && l2 == 32) ) {
fprintf(stderr, "Error, must be length 32");
return NULL;
}
curve25519_donna(o, (const unsigned char*)a1, (const unsigned char*)b1);
free(a1);
free(b1);
return as_byte_array(env, (unsigned char*)o, 32);
}
JNIEXPORT jbyteArray JNICALL Java_Curve25519Donna_makePrivate
(JNIEnv *env, jobject obj, jbyteArray secret) {
int len;
unsigned char* k = as_unsigned_char_array(env, secret, &len);
if (len != 32) {
fprintf(stderr, "Error, must be length 32");
return NULL;
}
k[0] &= 248;
k[31] &= 127;
k[31] |= 64;
return as_byte_array(env, k, 32);
}
JNIEXPORT jbyteArray JNICALL Java_Curve25519Donna_getPublic
(JNIEnv *env, jobject obj, jbyteArray privkey) {
int len;
unsigned char* private = as_unsigned_char_array(env, privkey, &len);
if (len != 32) {
fprintf(stderr, "Error, must be length 32");
return NULL;
}
unsigned char pubkey[32];
unsigned char basepoint[32] = {9};
curve25519_donna(pubkey, private, basepoint);
return as_byte_array(env, (unsigned char*)pubkey, 32);
}
JNIEXPORT jbyteArray JNICALL Java_Curve25519Donna_makeSharedSecret
(JNIEnv *env, jobject obj, jbyteArray privkey, jbyteArray their_pubkey) {
unsigned char shared_secret[32];
int l1, l2;
unsigned char* private = as_unsigned_char_array(env, privkey, &l1);
unsigned char* pubkey = as_unsigned_char_array(env, their_pubkey, &l2);
if ( !(l1 == 32 && l2 == 32) ) {
fprintf(stderr, "Error, must be length 32");
return NULL;
}
curve25519_donna(shared_secret, private, pubkey);
return as_byte_array(env, (unsigned char*)shared_secret, 32);
}
JNIEXPORT void JNICALL Java_Curve25519Donna_helowrld
(JNIEnv *env, jobject obj) {
printf("helowrld\n");
}