/*

* 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 4

extern void md4_compress_block(const jbyte *block, uint32_t state[STATE_LEN]);

/*

* Class: nayuki_nativehash_Md4

* Method: compress

* Signature: ([I[BII)Z

*/

JNIEXPORT jboolean JNICALL Java_nayuki_nativehash_Md4_compress(JNIEnv *env, jclass thisClass, jintArray stateArray, jbyteArray msg, jint off, jint len) {

jboolean status = JNI_FALSE;

if (len < 0 || (len & 63) != 0) // Block size is 64 bytes

goto cleanup0;

JNIEnv theEnv = *env;

(void)thisClass;

// Get state array and convert to uint32_t

jint *stateJava = theEnv->GetIntArrayElements(env, stateArray, NULL);

if (stateJava == NULL)

goto cleanup0;

uint32_t state[STATE_LEN];

for (int i = 0; i < STATE_LEN; i++)

state[i] = (uint32_t)stateJava[i];

// Iterate over each block in msg

jbyte *block = theEnv->GetPrimitiveArrayCritical(env, msg, NULL);

if (block == NULL)

goto cleanup1;

for (jint end = off + len; off < end; off += 64)

md4_compress_block(&block[off], state);

theEnv->ReleasePrimitiveArrayCritical(env, msg, block, JNI_ABORT);

// Convert state array to jint and clean up

for (int i = 0; i < STATE_LEN; i++)

stateJava[i] = (jint)state[i];

status = JNI_TRUE;

cleanup1:

theEnv->ReleaseIntArrayElements(env, stateArray, stateJava, 0);

cleanup0:

return status;

}