Native-hashes-for-Java/native/md2-jni.c at master · java-code-help/Native-hashes-for-Java · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
/*
 * Native hash functions for Java
 *
 * Copyright (c) Project Nayuki. (MIT License)
 * https://www.nayuki.io/page/native-hash-functions-for-java
 */

#include <stdint.h>
#include <jni.h>


#define STATE_LEN 48
#define CHECKSUM_LEN 16
extern void md2_compress_block(const jbyte *block, uint8_t state[STATE_LEN], uint8_t checksum[CHECKSUM_LEN]);


/*
 * Class:     nayuki_nativehash_Md2
 * Method:    compress
 * Signature: ([B[B[BII)Z
 */
JNIEXPORT jboolean JNICALL Java_nayuki_nativehash_Md2_compress(JNIEnv *env, jclass thisClass, jbyteArray stateArray, jbyteArray checksumArray, jbyteArray msg, jint off, jint len) {
	jboolean status = JNI_FALSE;
	if (len < 0 || (len & 15) != 0)  // Block size is 16 bytes
		goto cleanup0;
	JNIEnv theEnv = *env;
	(void)thisClass;

	// Get state and checksum arrays and convert to uint8_t
	jbyte *stateJava = theEnv->GetByteArrayElements(env, stateArray, NULL);
	if (stateJava == NULL)
		goto cleanup0;
	jbyte *checksumJava = theEnv->GetByteArrayElements(env, checksumArray, NULL);
	if (checksumJava == NULL)
		goto cleanup1;
	uint8_t state[STATE_LEN];
	uint8_t checksum[CHECKSUM_LEN];
	for (int i = 0; i < STATE_LEN; i++)
		state[i] = (uint8_t)stateJava[i];
	for (int i = 0; i < CHECKSUM_LEN; i++)
		checksum[i] = (uint8_t)checksumJava[i];

	// Iterate over each block in msg
	jbyte *block = theEnv->GetPrimitiveArrayCritical(env, msg, NULL);
	if (block == NULL)
		goto cleanup2;
	for (jint end = off + len; off < end; off += 16)
		md2_compress_block(&block[off], state, checksum);
	theEnv->ReleasePrimitiveArrayCritical(env, msg, block, JNI_ABORT);

	// Convert state and checksum arrays to jbyte and clean up
	for (int i = 0; i < STATE_LEN; i++)
		stateJava[i] = (jbyte)state[i];
	for (int i = 0; i < CHECKSUM_LEN; i++)
		checksumJava[i] = (jbyte)checksum[i];
	status = JNI_TRUE;
cleanup2:
	theEnv->ReleaseByteArrayElements(env, stateArray, stateJava, 0);
cleanup1:
	theEnv->ReleaseByteArrayElements(env, checksumArray, checksumJava, 0);
cleanup0:
	return status;
}