storage: add save/load functionality

Prints can now be saved to disk (but you currently must classify which
finger they are) and you can load them later.

Added 2 simple example programs to demonstrate this.

examples/Makefile.am

@@ -1,6 +1,12 @@
 INCLUDES = -I$(top_srcdir)
-noinst_PROGRAMS = verify_live
+noinst_PROGRAMS = verify_live enroll verify
 
 verify_live_SOURCES = verify_live.c
 verify_live_LDADD = ../libfprint/libfprint.la -lfprint
 
+enroll_SOURCES = enroll.c
+enroll_LDADD = ../libfprint/libfprint.la -lfprint
+
+verify_SOURCES = verify.c
+verify_LDADD = ../libfprint/libfprint.la -lfprint
+

examples/enroll.c

@@ -0,0 +1,147 @@
+/*
+ * Example fingerprint enrollment program
+ * Enrolls your right index finger and saves the print to disk
+ * Copyright (C) 2007 Daniel Drake <dsd@gentoo.org>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <libfprint/fprint.h>
+
+struct fp_dscv_dev *discover_device(struct fp_dscv_dev **discovered_devs)
+{
+	struct fp_dscv_dev *ddev = NULL;
+	int i;
+
+	for (i = 0; ddev = discovered_devs[i]; i++) {
+		const struct fp_driver *drv = fp_dscv_dev_get_driver(ddev);
+		printf("Found device claimed by %s driver\n",
+			fp_driver_get_full_name(drv));
+		return ddev;
+	}
+
+	return ddev;
+}
+
+struct fp_print_data *enroll(struct fp_dev *dev) {
+	struct fp_print_data *enrolled_print = NULL;
+	int r;
+
+	printf("You will need to successfully scan your finger %d times to "
+		"complete the process.\n", fp_dev_get_nr_enroll_stages(dev));
+
+	do {
+		sleep(1);
+		printf("\nScan your finger now.\n");
+		r = fp_enroll_finger(dev, &enrolled_print);
+		if (r < 0) {
+			printf("Enroll failed with error %d\n", r);
+			return NULL;
+		}
+		switch (r) {
+		case FP_ENROLL_COMPLETE:
+			printf("Enroll complete!\n");
+			break;
+		case FP_ENROLL_FAIL:
+			printf("Enroll failed, something wen't wrong :(\n");
+			return NULL;
+		case FP_ENROLL_PASS:
+			printf("Enroll stage passed. Yay!\n");
+			break;
+		case FP_ENROLL_RETRY:
+			printf("Didn't quite catch that. Please try again.\n");
+			break;
+		case FP_ENROLL_RETRY_TOO_SHORT:
+			printf("Your swipe was too short, please try again.\n");
+			break;
+		case FP_ENROLL_RETRY_CENTER_FINGER:
+			printf("Didn't catch that, please center your finger on the "
+				"sensor and try again.\n");
+			break;
+		case FP_ENROLL_RETRY_REMOVE_FINGER:
+			printf("Scan failed, please remove your finger and then try "
+				"again.\n");
+			break;
+		}
+	} while (r != FP_ENROLL_COMPLETE);
+
+	if (!enrolled_print) {
+		fprintf(stderr, "Enroll complete but no print?\n");
+		return NULL;
+	}
+
+	printf("Enrollment completed!\n\n");
+	return enrolled_print;
+}
+
+int main(void)
+{
+	int r;
+	struct fp_dscv_dev *ddev;
+	struct fp_dscv_dev **discovered_devs;
+	struct fp_dev *dev;
+	struct fp_print_data *data;
+
+	printf("This program will enroll your right index finger, "
+		"unconditionally overwriting any right-index print that was enrolled "
+		"previously. If you want to continue, press enter, otherwise hit "
+		"Ctrl+C\n");
+	getchar();
+
+	r = fp_init();
+	if (r < 0) {
+		fprintf(stderr, "Failed to initialize libfprint\n");
+		exit(1);
+	}
+
+	discovered_devs = fp_discover_devs();
+	if (!discovered_devs) {
+		fprintf(stderr, "Could not discover devices\n");
+		exit(1);
+	}
+
+	ddev = discover_device(discovered_devs);
+	if (!ddev) {
+		fprintf(stderr, "No devices detected.\n");
+		exit(1);
+	}
+
+	dev = fp_dev_open(ddev);
+	fp_dscv_devs_free(discovered_devs);
+	if (!dev) {
+		fprintf(stderr, "Could not open device.\n");
+		exit(1);
+	}
+
+	printf("Opened device. It's now time to enroll your finger.\n\n");
+	data = enroll(dev);
+	if (!data)
+		goto out_close;
+
+	r = fp_print_data_save(data, RIGHT_INDEX);
+	if (r < 0)
+		fprintf(stderr, "Data save failed, code %d\n", r);
+
+	fp_print_data_free(data);
+out_close:
+	fp_dev_close(dev);
+	return r;
+}
+
+

examples/verify.c

@@ -0,0 +1,138 @@
+/*
+ * Example fingerprint verification program, which verifies the right index
+ * finger which has been previously enrolled to disk.
+ * Copyright (C) 2007 Daniel Drake <dsd@gentoo.org>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <libfprint/fprint.h>
+
+struct fp_dscv_dev *discover_device(struct fp_dscv_dev **discovered_devs)
+{
+	struct fp_dscv_dev *ddev = NULL;
+	int i;
+
+	for (i = 0; ddev = discovered_devs[i]; i++) {
+		const struct fp_driver *drv = fp_dscv_dev_get_driver(ddev);
+		printf("Found device claimed by %s driver\n",
+			fp_driver_get_full_name(drv));
+		return ddev;
+	}
+
+	return ddev;
+}
+
+int verify(struct fp_dev *dev, struct fp_print_data *data)
+{
+	int r;
+
+	do {
+		sleep(1);
+		printf("\nScan your finger now.\n");
+		r = fp_verify_finger(dev, data);
+		if (r < 0) {
+			printf("verification failed with error %d :(\n", r);
+			return r;
+		}
+		switch (r) {
+		case FP_VERIFY_NO_MATCH:
+			printf("NO MATCH!\n");
+			return 0;
+		case FP_VERIFY_MATCH:
+			printf("MATCH!\n");
+			return 0;
+		case FP_VERIFY_RETRY:
+			printf("Scan didn't quite work. Please try again.\n");
+			break;
+		case FP_VERIFY_RETRY_TOO_SHORT:
+			printf("Swipe was too short, please try again.\n");
+			break;
+		case FP_VERIFY_RETRY_CENTER_FINGER:
+			printf("Please center your finger on the sensor and try again.\n");
+			break;
+		case FP_VERIFY_RETRY_REMOVE_FINGER:
+			printf("Please remove finger from the sensor and try again.\n");
+			break;
+		}
+	} while (1);
+}
+
+int main(void)
+{
+	int r;
+	struct fp_dscv_dev *ddev;
+	struct fp_dscv_dev **discovered_devs;
+	struct fp_dev *dev;
+	struct fp_print_data *data;
+
+	r = fp_init();
+	if (r < 0) {
+		fprintf(stderr, "Failed to initialize libfprint\n");
+		exit(1);
+	}
+
+	discovered_devs = fp_discover_devs();
+	if (!discovered_devs) {
+		fprintf(stderr, "Could not discover devices\n");
+		exit(1);
+	}
+
+	ddev = discover_device(discovered_devs);
+	if (!ddev) {
+		fprintf(stderr, "No devices detected.\n");
+		exit(1);
+	}
+
+	dev = fp_dev_open(ddev);
+	fp_dscv_devs_free(discovered_devs);
+	if (!dev) {
+		fprintf(stderr, "Could not open device.\n");
+		exit(1);
+	}
+
+	printf("Opened device. Loading previously enrolled right index finger "
+		"data...\n");
+
+	r = fp_print_data_load(dev, RIGHT_INDEX, &data);
+	if (r != 0) {
+		fprintf(stderr, "Failed to load fingerprint, error %d\n", r);
+		fprintf(stderr, "Did you remember to enroll your right index finger "
+			"first?\n");
+		goto out_close;
+	}
+
+	printf("Print loaded. Time to verify!\n");
+	do {
+		char buffer[20];
+
+		verify(dev, data);
+		printf("Verify again? [Y/n]? ");
+		fgets(buffer, sizeof(buffer), stdin);
+		if (buffer[0] != '\n' && buffer[0] != 'y' && buffer[0] != 'Y')
+			break;
+	} while (1);
+
+	fp_print_data_free(data);
+out_close:
+	fp_dev_close(dev);
+	return r;
+}
+
+

examples/verify_live.c

@@ -127,7 +127,6 @@ int verify(struct fp_dev *dev, struct fp_print_data *data)
 int main(void)
 {
 	int r;
-	int ret = 1;
 	struct fp_dscv_dev *ddev;
 	struct fp_dscv_dev **discovered_devs;
 	struct fp_dev *dev;
@@ -175,7 +174,6 @@ int main(void)
 		verify(dev, data);
 		printf("Verify again? [Y/n]? ");
 		fgets(buffer, sizeof(buffer), stdin);
-		buffer[sizeof(buffer) - 1] = 0; /* null-terminate */
 		if (buffer[0] != '\n' && buffer[0] != 'y' && buffer[0] != 'Y')
 			break;
 	} while (1);
@@ -183,7 +181,7 @@ int main(void)
 	fp_print_data_free(data);
 out_close:
 	fp_dev_close(dev);
-	return ret;
+	return r;
 }
 
 

libfprint/data.c

@@ -18,12 +18,55 @@
  */
 
 #include <config.h>
+#include <errno.h>
 #include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
 
 #include <glib.h>
 
 #include "fp_internal.h"
 
+#define DIR_PERMS 0700
+
+/* FIXME: should free this during library shutdown */
+static char *base_store = NULL;
+
+static void storage_setup(void)
+{
+	const char *homedir;
+
+	homedir = g_getenv("HOME");
+	if (!homedir)
+		homedir = g_get_home_dir();
+	if (!homedir)
+		return;
+
+	base_store = g_build_filename(homedir, ".fprint/prints", NULL);
+	g_mkdir_with_parents(base_store, DIR_PERMS);
+	/* FIXME handle failure */
+}
+
+static const char *finger_code_to_str(enum fp_finger finger)
+{
+	const char *names[] = {
+		[LEFT_THUMB] = "lthu",
+		[LEFT_INDEX] = "lind",
+		[LEFT_MIDDLE] = "lmid",
+		[LEFT_RING] = "lrin",
+		[LEFT_LITTLE] = "llit",
+		[RIGHT_THUMB] = "rthu",
+		[RIGHT_INDEX] = "rind",
+		[RIGHT_MIDDLE] = "rmid",
+		[RIGHT_RING] = "rrin",
+		[RIGHT_LITTLE] = "rlit",
+	};
+	if (finger < LEFT_THUMB || finger > RIGHT_LITTLE)
+		return NULL;
+	return names[finger];
+}
+
 struct fp_print_data *fpi_print_data_new(struct fp_dev *dev, size_t length)
 {
 	struct fp_print_data *data = g_malloc(sizeof(*data) + length);
@@ -33,6 +76,82 @@ struct fp_print_data *fpi_print_data_new(struct fp_dev *dev, size_t length)
 	return data;
 }
 
+API_EXPORTED int fp_print_data_save(struct fp_print_data *data,
+	enum fp_finger finger)
+{
+	GError *err = NULL;
+	char *path;
+	char *dirpath;
+	const char *fingerstr = finger_code_to_str(finger);
+	int r;
+
+	if (!fingerstr)
+		return -EINVAL;
+
+	if (!base_store)
+		storage_setup();
+
+	fp_dbg("save %s print from %s", fingerstr, data->driver_name);
+	dirpath = g_build_filename(base_store, data->driver_name, NULL);
+	r = g_mkdir_with_parents(dirpath, DIR_PERMS);
+	if (r < 0) {
+		fp_err("couldn't create storage directory");
+		g_free(dirpath);
+		return r;
+	}
+
+	path = g_build_filename(dirpath, fingerstr, NULL);
+	fp_dbg("saving to %s", path);
+	g_file_set_contents(path, data->buffer, data->length, &err);
+	g_free(dirpath);
+	g_free(path);
+	if (err) {
+		r = err->code;
+		fp_err("%s save failed: %s", fingerstr, err->message);
+		g_error_free(err);
+		return r;
+	}
+
+	return 0;
+}
+
+API_EXPORTED int fp_print_data_load(struct fp_dev *dev,
+	enum fp_finger finger, struct fp_print_data **data)
+{
+	const char *fingerstr = finger_code_to_str(finger);
+	gchar *path;
+	gsize length;
+	gchar *contents;
+	GError *err = NULL;
+	struct fp_print_data *fdata;
+
+	if (!fingerstr)
+		return -EINVAL;
+
+	if (!base_store)
+		storage_setup();
+
+	path = g_build_filename(base_store, dev->drv->name, fingerstr, NULL);
+	fp_dbg("from %s", path);
+	g_file_get_contents(path, &contents, &length, &err);
+	g_free(path);
+	if (err) {
+		int r = err->code;
+		fp_err("%s load failed: %s", fingerstr, err->message);
+		g_error_free(err);
+		if (r == G_FILE_ERROR_NOENT)
+			return -ENOENT;
+		else
+			return r;
+	}
+
+	fdata = fpi_print_data_new(dev, length);
+	memcpy(fdata->buffer, contents, length);
+	g_free(contents);
+	*data = fdata;
+	return 0;
+}
+
 API_EXPORTED void fp_print_data_free(struct fp_print_data *data)
 {
 	g_free(data);

libfprint/fprint.h

@@ -26,6 +26,20 @@ struct fp_dev;
 struct fp_driver;
 struct fp_print_data;
 
+/* misc/general stuff */
+enum fp_finger {
+	LEFT_THUMB = 1,
+	LEFT_INDEX,
+	LEFT_MIDDLE,
+	LEFT_RING,
+	LEFT_LITTLE,
+	RIGHT_THUMB,
+	RIGHT_INDEX,
+	RIGHT_MIDDLE,
+	RIGHT_RING,
+	RIGHT_LITTLE,
+};
+
 /* Device discovery */
 struct fp_dscv_dev **fp_discover_devs(void);
 void fp_dscv_devs_free(struct fp_dscv_dev **devs);
@@ -67,6 +81,9 @@ enum fp_verify_result {
 int fp_verify_finger(struct fp_dev *dev, struct fp_print_data *enrolled_print);
 
 /* Data handling */
+int fp_print_data_load(struct fp_dev *dev, enum fp_finger finger,
+	struct fp_print_data **data);
+int fp_print_data_save(struct fp_print_data *data, enum fp_finger finger);
 void fp_print_data_free(struct fp_print_data *data);
 
 /* Library */