Move checkpoint saving to main thread

Checkpoints will now be saved every 5 minutes and when the program
ends.

main.c

@@ -58,6 +58,11 @@ size_t printlen;      // precalculated, related to printstartpos
 pthread_mutex_t fout_mutex;
 FILE *fout;
 
+#ifdef PASSPHRASE
+u8 orig_determseed[SEED_LEN];
+const char *checkpointfile = 0;
+#endif
+
 static void termhandler(int sig)
 {
 	switch (sig) {
@@ -174,6 +179,35 @@ static void setpassphrase(const char *pass)
 	}
 	fprintf(stderr," done.\n");
 }
+
+static void savecheckpoint(void)
+{
+	if (checkpointfile) {
+		// Open checkpoint file
+		FILE *checkout = fopen(checkpointfile, "w");
+		if (!checkout) {
+			fprintf(stderr,"cannot open checkpoint file for writing\n");
+			exit(1);
+		}
+
+		// Calculate checkpoint as the difference between original seed and the current seed
+		u8 checkpoint[SEED_LEN];
+		bool carry = 0;
+		pthread_mutex_lock(&determseed_mutex);
+		for (int i = 0; i < SEED_LEN; i++) {
+			checkpoint[i] = determseed[i] - orig_determseed[i] - carry;
+			carry = checkpoint[i] > determseed[i];
+		}
+		pthread_mutex_unlock(&determseed_mutex);
+
+		// Write checkpoint file
+		if(fwrite(checkpoint, 1, SEED_LEN, checkout) != SEED_LEN) {
+			fprintf(stderr,"cannot write to checkpoint file\n");
+			exit(1);
+		}
+		fclose(checkout);
+	}
+}
 #endif
 
 VEC_STRUCT(threadvec, pthread_t);
@@ -474,18 +508,6 @@ int main(int argc,char **argv)
 		goto done;
 	}
 
-	if (checkpointfile) {
-		// Read current checkpoint position if file exists
-		FILE *checkout = fopen(checkpointfile, "r");
-		if (checkout) {
-			if(fread(checkpoint, 1, SEED_LEN, checkout) != SEED_LEN) {
-				fprintf(stderr,"failed to read checkpoint file\n");
-				exit(1);
-			}
-			fclose(checkout);
-		}
-	}
-
 	filters_prepare();
 
 	filters_print();
@@ -521,8 +543,27 @@ int main(int argc,char **argv)
 			numthreads,numthreads == 1 ? "thread" : "threads");
 
 #ifdef PASSPHRASE
-	if (!quietflag && deterministic && numneedgenerate != 1)
+	memcpy(orig_determseed, determseed, sizeof(determseed));
-		fprintf(stderr,"CAUTION: avoid using keys generated with same password for unrelated services, as single leaked key may help attacker to regenerate related keys.\n");
+	if (deterministic) {
+		if (!quietflag && numneedgenerate != 1)
+			fprintf(stderr,"CAUTION: avoid using keys generated with same password for unrelated services, as single leaked key may help attacker to regenerate related keys.\n");
+		if (checkpointfile) {
+			// Read current checkpoint position if file exists
+			FILE *checkout = fopen(checkpointfile, "r");
+			if (checkout) {
+				u8 checkpoint[SEED_LEN];
+				if(fread(checkpoint, 1, SEED_LEN, checkout) != SEED_LEN) {
+					fprintf(stderr,"failed to read checkpoint file\n");
+					exit(1);
+				}
+				fclose(checkout);
+
+				// Apply checkpoint to determseed
+				for (int i = 0; i < SEED_LEN; i++)
+					determseed[i] += checkpoint[i];
+			}
+		}
+	}
 #endif
 
 	signal(SIGTERM,termhandler);
@@ -605,11 +646,17 @@ int main(int argc,char **argv)
 	struct timespec ts;
 	memset(&ts,0,sizeof(ts));
 	ts.tv_nsec = 100000000;
+	u16 loopcounter = 0;
 	while (!endwork) {
 		if (numneedgenerate && keysgenerated >= numneedgenerate) {
 			endwork = 1;
 			break;
 		}
+		loopcounter++;
+		if (loopcounter >= 3000) { // Save checkpoint every 5 minutes
+			savecheckpoint();
+			loopcounter = 0;
+		}
 		nanosleep(&ts,0);
 
 #ifdef STATISTICS
@@ -675,6 +722,10 @@ int main(int argc,char **argv)
 #endif
 	}
 
+#ifdef PASSPHRASE
+	savecheckpoint();
+#endif
+
 	if (!quietflag)
 		fprintf(stderr,"waiting for threads to finish...");
 	for (size_t i = 0;i < VEC_LENGTH(threads);++i)

worker.c

@@ -63,8 +63,6 @@ void worker_init(void)
 
 pthread_mutex_t determseed_mutex;
 u8 determseed[SEED_LEN];
-u8 checkpoint[SEED_LEN];
-const char *checkpointfile = 0;
 #endif
 
 

worker.h

@@ -33,8 +33,6 @@ VEC_STRUCT(statsvec,struct statstruct);
 #ifdef PASSPHRASE
 extern pthread_mutex_t determseed_mutex;
 extern u8 determseed[SEED_LEN];
-extern u8 checkpoint[SEED_LEN];
-extern const char *checkpointfile;
 #endif
 
 extern void worker_init(void);

worker_batch_pass.inc.h

@@ -36,39 +36,18 @@ void *worker_batch_pass(void *task)
 
 	sname = makesname();
 
-	// load checkpoint
-	pthread_mutex_lock(&determseed_mutex);
-	for (int i = 0; i < SEED_LEN; i++)
-		determseed[i] += checkpoint[i];
-	pthread_mutex_unlock(&determseed_mutex);
-
 initseed:
 #ifdef STATISTICS
 	++st->numrestart.v;
 #endif
 
 	pthread_mutex_lock(&determseed_mutex);
-	for (int i = 0; i < SEED_LEN; i++) {
+	for (int i = 0; i < SEED_LEN; i++)
-		++checkpoint[i];
 		if (++determseed[i])
 			break;
-	}
 	memcpy(seed, determseed, SEED_LEN);
 	pthread_mutex_unlock(&determseed_mutex);
 
-	if (checkpointfile) {
-		FILE *checkout = fopen(checkpointfile, "w");
-		if (!checkout) {
-			fprintf(stderr,"cannot open checkpoint file for writing\n");
-			exit(1);
-		}
-		if(fwrite(checkpoint, 1, SEED_LEN, checkout) != SEED_LEN) {
-			fprintf(stderr,"cannot write to checkpoint file\n");
-			exit(1);
-		}
-		fclose(checkout);
-	}
-
 	ed25519_seckey_expand(sk,seed);
 
 	ge_scalarmult_base(&ge_public,sk);

worker_fast_pass.inc.h

@@ -33,39 +33,18 @@ void *worker_fast_pass(void *task)
 
 	sname = makesname();
 
-	// load checkpoint
-	pthread_mutex_lock(&determseed_mutex);
-	for (int i = 0; i < SEED_LEN; i++)
-		determseed[i] += checkpoint[i];
-	pthread_mutex_unlock(&determseed_mutex);
-
 initseed:
 #ifdef STATISTICS
 	++st->numrestart.v;
 #endif
 
 	pthread_mutex_lock(&determseed_mutex);
-	for (int i = 0; i < SEED_LEN; i++) {
+	for (int i = 0; i < SEED_LEN; i++)
-		++checkpoint[i];
 		if (++determseed[i])
 			break;
-	}
 	memcpy(seed, determseed, SEED_LEN);
 	pthread_mutex_unlock(&determseed_mutex);
 
-	if (checkpointfile) {
-		FILE *checkout = fopen(checkpointfile, "w");
-		if (!checkout) {
-			fprintf(stderr,"cannot open checkpoint file for writing\n");
-			exit(1);
-		}
-		if(fwrite(checkpoint, 1, SEED_LEN, checkout) != SEED_LEN) {
-			fprintf(stderr,"cannot write to checkpoint file\n");
-			exit(1);
-		}
-		fclose(checkout);
-	}
-
 	ed25519_seckey_expand(sk,seed);
 
 	ge_scalarmult_base(&ge_public,sk);