path: root/testing/libfprint/uru4500-support.patch

From 401e0912400d7274f163302baed9af63b4d3bbb2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Timo=20Ter=C3=A4s?= <timo.teras@iki.fi>
Date: Wed, 26 Sep 2012 13:41:13 +0300
Subject: [PATCH] lib: Add support for DigitalPersona URU4500

By adding native encryption support, rather than poking at
the firmware to disable it.

This also makes the URU4000B use native encryption.

https://bugs.freedesktop.org/show_bug.cgi?id=55351
---
 libfprint/drivers/uru4000.c | 579 +++++++++++++++++++++++++-------------------
 libfprint/fp_internal.h     |   2 +
 2 files changed, 333 insertions(+), 248 deletions(-)

diff --git a/libfprint/drivers/uru4000.c b/libfprint/drivers/uru4000.c
index 0dbea96..f42b609 100644
--- a/libfprint/drivers/uru4000.c
+++ b/libfprint/drivers/uru4000.c
@@ -1,6 +1,7 @@
 /*
- * Digital Persona U.are.U 4000/4000B driver for libfprint
+ * Digital Persona U.are.U 4000/4000B/4500 driver for libfprint
  * Copyright (C) 2007-2008 Daniel Drake <dsd@gentoo.org>
+ * Copyright (C) 2012 Timo Teräs <timo.teras@iki.fi>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -34,14 +35,14 @@
 #define USB_RQ			0x04
 #define CTRL_IN			(LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_ENDPOINT_IN)
 #define CTRL_OUT		(LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_ENDPOINT_OUT)
-#define CTRL_TIMEOUT	5000
-#define BULK_TIMEOUT	5000
-#define DATABLK_RQLEN	0x1b340
-#define DATABLK_EXPECT	0x1b1c0
-#define CAPTURE_HDRLEN	64
+#define CTRL_TIMEOUT		5000
+#define BULK_TIMEOUT		5000
 #define IRQ_LENGTH		64
 #define CR_LENGTH		16
 
+#define IMAGE_HEIGHT		290
+#define IMAGE_WIDTH		384
+
 enum {
 	IRQDATA_SCANPWR_ON = 0x56aa,
 	IRQDATA_FINGER_ON = 0x0101,
@@ -51,7 +52,10 @@ enum {
 
 enum {
 	REG_HWSTAT = 0x07,
+	REG_SCRAMBLE_DATA_INDEX = 0x33,
+	REG_SCRAMBLE_DATA_KEY = 0x34,
 	REG_MODE = 0x4e,
+	REG_DEVICE_INFO = 0xf0,
 	/* firmware starts at 0x100 */
 	REG_RESPONSE = 0x2000,
 	REG_CHALLENGE = 0x2010,
@@ -62,7 +66,8 @@ enum {
 	MODE_AWAIT_FINGER_ON = 0x10,
 	MODE_AWAIT_FINGER_OFF = 0x12,
 	MODE_CAPTURE = 0x20,
-	MODE_SHUT_UP = 0x30,
+	MODE_CAPTURE_AUX = 0x30,
+	MODE_OFF = 0x70,
 	MODE_READY = 0x80,
 };
 
@@ -78,6 +83,7 @@ enum {
 static const struct uru4k_dev_profile {
 	const char *name;
 	gboolean auth_cr;
+	gboolean encryption;
 } uru4k_dev_info[] = {
 	[MS_KBD] = {
 		.name = "Microsoft Keyboard with Fingerprint Reader",
@@ -102,21 +108,10 @@ static const struct uru4k_dev_profile {
 	[DP_URU4000B] = {
 		.name = "Digital Persona U.are.U 4000B",
 		.auth_cr = FALSE,
+		.encryption = TRUE,
 	},
 };
 
-/* As we don't know the encryption scheme, we have to disable encryption
- * by powering the device down and modifying the firmware. The location of
- * the encryption control byte changes based on device revision.
- *
- * We use a search approach to find it: we look at the 3 bytes of data starting
- * from these addresses, looking for a pattern "ff X7 41" (where X is dontcare)
- * When we find a pattern we know that the encryption byte ius the X7 byte.
- */
-static const uint16_t fwenc_offsets[] = {
-	0x510, 0x62d, 0x792, 0x7f4,
-};
-
 typedef void (*irq_cb_fn)(struct fp_img_dev *dev, int status, uint16_t type,
 	void *user_data);
 typedef void (*irqs_stopped_cb_fn)(struct fp_img_dev *dev);
@@ -125,11 +120,14 @@ struct uru4k_dev {
 	const struct uru4k_dev_profile *profile;
 	uint8_t interface;
 	enum fp_imgdev_state activate_state;
-	unsigned char last_reg_rd;
+	unsigned char last_reg_rd[16];
 	unsigned char last_hwstat;
 
 	struct libusb_transfer *irq_transfer;
 	struct libusb_transfer *img_transfer;
+	void *img_data;
+	uint16_t img_lines_done, img_block;
+	uint32_t img_enc_seed;
 
 	irq_cb_fn irq_cb;
 	void *irq_cb_data;
@@ -225,7 +223,7 @@ static int write_reg(struct fp_img_dev *dev, uint16_t reg,
 }
 
 typedef void (*read_regs_cb_fn)(struct fp_img_dev *dev, int status,
-	unsigned char *data, void *user_data);
+	uint16_t num_regs, unsigned char *data, void *user_data);
 
 struct read_regs_data {
 	struct fp_img_dev *dev;
@@ -248,7 +246,7 @@ static void read_regs_cb(struct libusb_transfer *transfer)
 	else
 		data = libusb_control_transfer_get_data(transfer);
 
-	rrdata->callback(rrdata->dev, r, data, rrdata->user_data);
+	rrdata->callback(rrdata->dev, r, transfer->actual_length, data, rrdata->user_data);
 	g_free(rrdata);
 	g_free(transfer->buffer);
 	libusb_free_transfer(transfer);
@@ -284,12 +282,6 @@ static int read_regs(struct fp_img_dev *dev, uint16_t first_reg,
 	return r;
 }
 
-static int read_reg(struct fp_img_dev *dev, uint16_t reg,
-	read_regs_cb_fn callback, void *user_data)
-{
-	return read_regs(dev, reg, 1, callback, user_data);
-}
-
 /*
  * HWSTAT
  *
@@ -325,7 +317,7 @@ static void response_cb(struct fp_img_dev *dev, int status, void *user_data)
 }
 
 static void challenge_cb(struct fp_img_dev *dev, int status,
-	unsigned char *data, void *user_data)
+	uint16_t num_regs, unsigned char *data, void *user_data)
 {
 	struct fpi_ssm *ssm = user_data;
 	struct uru4k_dev *urudev = dev->priv;
@@ -469,95 +461,10 @@ static void stop_irq_handler(struct fp_img_dev *dev, irqs_stopped_cb_fn cb)
 	}
 }
 
-/***** IMAGING LOOP *****/
-
-static int start_imaging_loop(struct fp_img_dev *dev);
-
-static void image_cb(struct libusb_transfer *transfer)
-{
-	struct fp_img_dev *dev = transfer->user_data;
-	struct uru4k_dev *urudev = dev->priv;
-	int hdr_skip = CAPTURE_HDRLEN;
-	int image_size = DATABLK_EXPECT - CAPTURE_HDRLEN;
-	struct fp_img *img;
-	int r = 0;
-
-	/* remove the global reference early: otherwise we may report results,
-	 * leading to immediate deactivation of driver, which will potentially
-	 * try to cancel an already-completed transfer */
-	urudev->img_transfer = NULL;
-
-	if (transfer->status == LIBUSB_TRANSFER_CANCELLED) {
-		fp_dbg("cancelled");
-		g_free(transfer->buffer);
-		libusb_free_transfer(transfer);
-		return;
-	} else if (transfer->status != LIBUSB_TRANSFER_COMPLETED) {
-		r = -EIO;
-		goto out;
-	}
-
-	if (transfer->actual_length == image_size) {
-		/* no header! this is rather odd, but it happens sometimes with my MS
-		 * keyboard */
-		fp_dbg("got image with no header!");
-		hdr_skip = 0;
-	} else if (transfer->actual_length != DATABLK_EXPECT) {
-		fp_err("unexpected image capture size (%d)", transfer->actual_length);
-		r = -EPROTO;
-		goto out;
-	}
-
-	img = fpi_img_new(image_size);
-	memcpy(img->data, transfer->buffer + hdr_skip, image_size);
-	img->flags = FP_IMG_V_FLIPPED | FP_IMG_H_FLIPPED | FP_IMG_COLORS_INVERTED;
-	fpi_imgdev_image_captured(dev, img);
-
-out:
-	g_free(transfer->buffer);
-	libusb_free_transfer(transfer);
-	if (r == 0)
-		r = start_imaging_loop(dev);
-
-	if (r)
-		fpi_imgdev_session_error(dev, r);
-}
-
-static int start_imaging_loop(struct fp_img_dev *dev)
-{
-	struct uru4k_dev *urudev = dev->priv;
-	struct libusb_transfer *transfer = libusb_alloc_transfer(0);
-	unsigned char *data;
-	int r;
-
-	if (!transfer)
-		return -ENOMEM;
-	
-	data = g_malloc(DATABLK_RQLEN);
-	libusb_fill_bulk_transfer(transfer, dev->udev, EP_DATA, data,
-		DATABLK_RQLEN, image_cb, dev, 0);
-
-	urudev->img_transfer = transfer;
-	r = libusb_submit_transfer(transfer);
-	if (r < 0) {
-		g_free(data);
-		libusb_free_transfer(transfer);
-	}
-
-	return r;
-}
-
-static void stop_imaging_loop(struct fp_img_dev *dev)
-{
-	struct uru4k_dev *urudev = dev->priv;
-	struct libusb_transfer *transfer = urudev->img_transfer;
-	if (transfer)
-		libusb_cancel_transfer(transfer);
-	/* FIXME: should probably wait for cancellation to complete */
-}
-
 /***** STATE CHANGING *****/
 
+static int execute_state_change(struct fp_img_dev *dev);
+
 static void finger_presence_irq_cb(struct fp_img_dev *dev, int status,
 	uint16_t type, void *user_data)
 {
@@ -582,33 +489,22 @@ static int dev_change_state(struct fp_img_dev *dev, enum fp_imgdev_state state)
 {
 	struct uru4k_dev *urudev = dev->priv;
 
-	stop_imaging_loop(dev);
-
 	switch (state) {
+	case IMGDEV_STATE_INACTIVE:
 	case IMGDEV_STATE_AWAIT_FINGER_ON:
-		if (!IRQ_HANDLER_IS_RUNNING(urudev))
-			return -EIO;
-		urudev->irq_cb = finger_presence_irq_cb;
-		return write_reg(dev, REG_MODE, MODE_AWAIT_FINGER_ON,
-			change_state_write_reg_cb, NULL);
-
-	case IMGDEV_STATE_CAPTURE:
-		urudev->irq_cb = NULL;
-		start_imaging_loop(dev);
-		return write_reg(dev, REG_MODE, MODE_CAPTURE, change_state_write_reg_cb,
-			NULL);
-
 	case IMGDEV_STATE_AWAIT_FINGER_OFF:
-		if (!IRQ_HANDLER_IS_RUNNING(urudev))
-			return -EIO;
-		urudev->irq_cb = finger_presence_irq_cb;
-		return write_reg(dev, REG_MODE, MODE_AWAIT_FINGER_OFF,
-			change_state_write_reg_cb, NULL);
-
+	case IMGDEV_STATE_CAPTURE:
+		break;
 	default:
 		fp_err("unrecognised state %d", state);
 		return -EINVAL;
 	}
+
+	urudev->activate_state = state;
+	if (urudev->img_transfer != NULL)
+		return 0;
+
+	return execute_state_change(dev);
 }
 
 /***** GENERIC STATE MACHINE HELPER FUNCTIONS *****/
@@ -623,17 +519,23 @@ static void sm_write_reg_cb(struct fp_img_dev *dev, int result, void *user_data)
 		fpi_ssm_next_state(ssm);
 }
 
-static void sm_write_reg(struct fpi_ssm *ssm, uint16_t reg,
-	unsigned char value)
+static void sm_write_regs(struct fpi_ssm *ssm, uint16_t first_reg, uint16_t num_regs,
+	void *data)
 {
 	struct fp_img_dev *dev = ssm->priv;
-	int r = write_reg(dev, reg, value, sm_write_reg_cb, ssm);
+	int r = write_regs(dev, first_reg, num_regs, data, sm_write_reg_cb, ssm);
 	if (r < 0)
 		fpi_ssm_mark_aborted(ssm, r);
 }
 
+static void sm_write_reg(struct fpi_ssm *ssm, uint16_t reg,
+	unsigned char value)
+{
+	sm_write_regs(ssm, reg, 1, &value);
+}
+
 static void sm_read_reg_cb(struct fp_img_dev *dev, int result,
-	unsigned char *data, void *user_data)
+	uint16_t num_regs, unsigned char *data, void *user_data)
 {
 	struct fpi_ssm *ssm = user_data;
 	struct uru4k_dev *urudev = dev->priv;
@@ -641,27 +543,32 @@ static void sm_read_reg_cb(struct fp_img_dev *dev, int result,
 	if (result) {
 		fpi_ssm_mark_aborted(ssm, result);
 	} else {
-		urudev->last_reg_rd = *data;
-		fp_dbg("reg value %x", urudev->last_reg_rd);
+		memcpy(urudev->last_reg_rd, data, num_regs);
+		fp_dbg("reg value %x", urudev->last_reg_rd[0]);
 		fpi_ssm_next_state(ssm);
 	}
 }
 
-static void sm_read_reg(struct fpi_ssm *ssm, uint16_t reg)
+static void sm_read_regs(struct fpi_ssm *ssm, uint16_t reg, uint16_t num_regs)
 {
 	struct fp_img_dev *dev = ssm->priv;
+	struct uru4k_dev *urudev = dev->priv;
 	int r;
-	
-	fp_dbg("read reg %x", reg);
-	r = read_reg(dev, reg, sm_read_reg_cb, ssm);
+
+	if (num_regs > sizeof(urudev->last_reg_rd)) {
+		fpi_ssm_mark_aborted(ssm, -EIO);
+		return;
+	}
+
+	fp_dbg("read %d regs at %x", num_regs, reg);
+	r = read_regs(dev, reg, num_regs, sm_read_reg_cb, ssm);
 	if (r < 0)
 		fpi_ssm_mark_aborted(ssm, r);
 }
 
-static void sm_set_mode(struct fpi_ssm *ssm, unsigned char mode)
+static void sm_read_reg(struct fpi_ssm *ssm, uint16_t reg)
 {
-	fp_dbg("mode %02x", mode);
-	sm_write_reg(ssm, REG_MODE, mode);
+	sm_read_regs(ssm, reg, 1);
 }
 
 static void sm_set_hwstat(struct fpi_ssm *ssm, unsigned char value)
@@ -670,77 +577,232 @@ static void sm_set_hwstat(struct fpi_ssm *ssm, unsigned char value)
 	sm_write_reg(ssm, REG_HWSTAT, value);
 }
 
-/***** INITIALIZATION *****/
+/***** IMAGING LOOP *****/
 
-enum fwfixer_states {
-	FWFIXER_INIT,
-	FWFIXER_READ_NEXT,
-	FWFIXER_WRITE,
-	FWFIXER_NUM_STATES,
+enum imaging_states {
+	IMAGING_CAPTURE,
+	IMAGING_SEND_INDEX,
+	IMAGING_READ_KEY,
+	IMAGING_DECODE,
+	IMAGING_REPORT_IMAGE,
+	IMAGING_NUM_STATES
 };
 
-static void fwfixer_read_cb(struct fp_img_dev *dev, int status,
-	unsigned char *data, void *user_data)
+static void image_transfer_cb(struct libusb_transfer *transfer)
 {
-	struct fpi_ssm *ssm = user_data;
-	struct uru4k_dev *urudev = dev->priv;
-
-	if (status != 0)
-		fpi_ssm_mark_aborted(ssm, status);
+	struct fpi_ssm *ssm = transfer->user_data;
 
-	fp_dbg("data: %02x %02x %02x", data[0], data[1], data[2]);
-	if (data[0] == 0xff && (data[1] & 0x0f) == 0x07 && data[2] == 0x41) {
-		fp_dbg("using offset %x", fwenc_offsets[urudev->fwfixer_offset]);
-		urudev->fwfixer_value = data[1];
-		fpi_ssm_jump_to_state(ssm, FWFIXER_WRITE);
+	if (transfer->status == LIBUSB_TRANSFER_CANCELLED) {
+		fp_dbg("cancelled");
+		fpi_ssm_mark_aborted(ssm, -ECANCELED);
+	} else if (transfer->status != LIBUSB_TRANSFER_COMPLETED) {
+		fp_dbg("error");
+		fpi_ssm_mark_aborted(ssm, -EIO);
 	} else {
-		fpi_ssm_jump_to_state(ssm, FWFIXER_READ_NEXT);
+		fpi_ssm_next_state(ssm);
+	}
+}
+
+enum {
+	BLOCKF_CHANGE_KEY	= 0x80,
+	BLOCKF_NO_KEY_UPDATE	= 0x04,
+	BLOCKF_ENCRYPTED		= 0x02,
+	BLOCKF_NOT_PRESENT	= 0x01,
+};
+
+struct uru4k_image {
+	uint8_t		unknown_00[4];
+	uint16_t	num_lines;
+	uint8_t		key_number;
+	uint8_t		unknown_07[9];
+	struct {
+		uint8_t	flags;
+		uint8_t	num_lines;
+	} block_info[15];
+	uint8_t		unknown_2E[18];
+	uint8_t		data[IMAGE_HEIGHT][IMAGE_WIDTH];
+};
+
+static uint32_t update_key(uint32_t key)
+{
+	/* linear feedback shift register
+	 * taps at bit positions 1 3 4 7 11 13 20 23 26 29 32 */
+	uint32_t bit = key & 0x9248144d;
+	bit ^= bit << 16;
+	bit ^= bit << 8;
+	bit ^= bit << 4;
+	bit ^= bit << 2;
+	bit ^= bit << 1;
+	return (bit & 0x80000000) | (key >> 1);
+}
+
+static uint32_t do_decode(uint8_t *data, int num_bytes, uint32_t key)
+{
+	uint8_t xorbyte;
+	int i;
+
+	for (i = 0; i < num_bytes - 1; i++) {
+		/* calculate xor byte and update key */
+		xorbyte  = ((key >>  4) & 1) << 0;
+		xorbyte |= ((key >>  8) & 1) << 1;
+		xorbyte |= ((key >> 11) & 1) << 2;
+		xorbyte |= ((key >> 14) & 1) << 3;
+		xorbyte |= ((key >> 18) & 1) << 4;
+		xorbyte |= ((key >> 21) & 1) << 5;
+		xorbyte |= ((key >> 24) & 1) << 6;
+		xorbyte |= ((key >> 29) & 1) << 7;
+		key = update_key(key);
+
+		/* decrypt data */
+		data[i] = data[i+1] ^ xorbyte;
 	}
+
+	/* the final byte is implictly zero */
+	data[i] = 0;
+	return update_key(key);
 }
 
-static void fwfixer_run_state(struct fpi_ssm *ssm)
+static void imaging_run_state(struct fpi_ssm *ssm)
 {
 	struct fp_img_dev *dev = ssm->priv;
 	struct uru4k_dev *urudev = dev->priv;
-	int r;
+	struct uru4k_image *img = urudev->img_data;
+	struct fp_img *fpimg;
+	uint32_t key;
+	uint8_t flags, num_lines;
+	int i, r, to;
+	char buf[5];
 
 	switch (ssm->cur_state) {
-	case FWFIXER_INIT:
-		urudev->fwfixer_offset = -1;
-		fpi_ssm_next_state(ssm);
+	case IMAGING_CAPTURE:
+		urudev->img_lines_done = 0;
+		urudev->img_block = 0;
+		libusb_fill_bulk_transfer(urudev->img_transfer, dev->udev, EP_DATA,
+			urudev->img_data, sizeof(struct uru4k_image), image_transfer_cb, ssm, 0);
+		r = libusb_submit_transfer(urudev->img_transfer);
+		if (r < 0)
+			fpi_ssm_mark_aborted(ssm, -EIO);
 		break;
-	case FWFIXER_READ_NEXT: ;
-		int offset = ++urudev->fwfixer_offset;
-		uint16_t try_addr;
-
-		if (offset == G_N_ELEMENTS(fwenc_offsets)) {
-			fp_err("could not find encryption byte");
-			fpi_ssm_mark_aborted(ssm, -ENODEV);
+	case IMAGING_SEND_INDEX:
+		fp_dbg("hw header lines %d", img->num_lines);
+
+		if (img->num_lines >= IMAGE_HEIGHT ||
+		    urudev->img_transfer->actual_length != img->num_lines * IMAGE_WIDTH + 64) {
+			fp_err("bad captured image (%d lines) or size mismatch %d != %d",
+				img->num_lines,
+				urudev->img_transfer->actual_length,
+				img->num_lines * IMAGE_WIDTH + 64);
+			fpi_ssm_jump_to_state(ssm, IMAGING_CAPTURE);
 			return;
 		}
-
-		try_addr = fwenc_offsets[offset];
-		fp_dbg("looking for encryption byte at %x", try_addr);
-
-		r = read_regs(dev, try_addr, 3, fwfixer_read_cb, ssm);
-		if (r < 0)
-			fpi_ssm_mark_aborted(ssm, r);
+		if (!urudev->profile->encryption) {
+			fpi_ssm_jump_to_state(ssm, IMAGING_REPORT_IMAGE);
+			return;
+		}
+		buf[0] = img->key_number;
+		buf[1] = urudev->img_enc_seed;
+		buf[2] = urudev->img_enc_seed >> 8;
+		buf[3] = urudev->img_enc_seed >> 16;
+		buf[4] = urudev->img_enc_seed >> 24;
+		sm_write_regs(ssm, REG_SCRAMBLE_DATA_INDEX, 5, buf);
 		break;
-	case FWFIXER_WRITE: ;
-		uint16_t enc_addr = fwenc_offsets[urudev->fwfixer_offset] + 1;
-		unsigned char cur = urudev->fwfixer_value;
-		unsigned char new = cur & 0xef;
-		if (new == cur) {
-			fp_dbg("encryption is already disabled");
-			fpi_ssm_next_state(ssm);
-		} else {
-			fp_dbg("fixing encryption byte at %x to %02x", enc_addr, new);
-			sm_write_reg(ssm, enc_addr, new);
+	case IMAGING_READ_KEY:
+		sm_read_regs(ssm, REG_SCRAMBLE_DATA_KEY, 4);
+		break;
+	case IMAGING_DECODE:
+		key  = urudev->last_reg_rd[0];
+		key |= urudev->last_reg_rd[1] << 8;
+		key |= urudev->last_reg_rd[2] << 16;
+		key |= urudev->last_reg_rd[3] << 24;
+		key ^= urudev->img_enc_seed;
+
+		fp_dbg("encryption id %02x -> key %08x", img->key_number, key);
+		while (urudev->img_block < array_n_elements(img->block_info) &&
+				urudev->img_lines_done < img->num_lines) {
+			flags = img->block_info[urudev->img_block].flags;
+			num_lines = img->block_info[urudev->img_block].num_lines;
+			if (num_lines == 0)
+				break;
+
+			fp_dbg("%d %02x %d", urudev->img_block, flags, num_lines);
+			if (flags & BLOCKF_CHANGE_KEY) {
+				fp_dbg("changing encryption keys.\n");
+				img->block_info[urudev->img_block].flags &= ~BLOCKF_CHANGE_KEY;
+				img->key_number++;
+				urudev->img_enc_seed = rand();
+				fpi_ssm_jump_to_state(ssm, IMAGING_SEND_INDEX);
+				return;
+			}
+			switch (flags & (BLOCKF_NO_KEY_UPDATE | BLOCKF_ENCRYPTED)) {
+			case BLOCKF_ENCRYPTED:
+				fp_dbg("decoding %d lines", num_lines);
+				key = do_decode(&img->data[urudev->img_lines_done][0],
+						IMAGE_WIDTH*num_lines, key);
+				break;
+			case 0:
+				fp_dbg("skipping %d lines", num_lines);
+				for (r = 0; r < IMAGE_WIDTH*num_lines; r++)
+					key = update_key(key);
+				break;
+			}
+			if ((flags & BLOCKF_NOT_PRESENT) == 0)
+				urudev->img_lines_done += num_lines;
+			urudev->img_block++;
+		}
+		fpi_ssm_next_state(ssm);
+		break;
+	case IMAGING_REPORT_IMAGE:
+		fpimg = fpi_img_new_for_imgdev(dev);
+
+		to = r = 0;
+		for (i = 0; i < array_n_elements(img->block_info) && r < img->num_lines; i++) {
+			flags = img->block_info[i].flags;
+			num_lines = img->block_info[i].num_lines;
+			if (num_lines == 0)
+				break;
+			memcpy(&fpimg->data[to], &img->data[r][0],
+				num_lines * IMAGE_WIDTH);
+			if (!(flags & BLOCKF_NOT_PRESENT))
+				r += num_lines;
+			to += num_lines * IMAGE_WIDTH;
 		}
+
+		fpimg->flags = FP_IMG_COLORS_INVERTED;
+		if (!urudev->profile->encryption)
+			fpimg->flags |= FP_IMG_V_FLIPPED | FP_IMG_H_FLIPPED;
+		fpi_imgdev_image_captured(dev, fpimg);
+
+		if (urudev->activate_state == IMGDEV_STATE_CAPTURE)
+			fpi_ssm_jump_to_state(ssm, IMAGING_CAPTURE);
+		else
+			fpi_ssm_mark_completed(ssm);
 		break;
 	}
 }
 
+static void imaging_complete(struct fpi_ssm *ssm)
+{
+	struct fp_img_dev *dev = ssm->priv;
+	struct uru4k_dev *urudev = dev->priv;
+	int r = ssm->error;
+	fpi_ssm_free(ssm);
+
+	g_free(urudev->img_data);
+	urudev->img_data = NULL;
+
+	libusb_free_transfer(urudev->img_transfer);
+	urudev->img_transfer = NULL;
+
+	if (r)
+		fpi_imgdev_session_error(dev, r);
+
+	r = execute_state_change(dev);
+	if (r)
+		fpi_imgdev_session_error(dev, r);
+}
+
+/***** INITIALIZATION *****/
+
 /* After closing an app and setting hwstat to 0x80, my ms keyboard gets in a
  * confused state and returns hwstat 0x85. On next app run, we don't get the
  * 56aa interrupt. This is the best way I've found to fix it: mess around
@@ -793,7 +855,7 @@ static void rebootpwr_run_state(struct fpi_ssm *ssm)
 		sm_read_reg(ssm, REG_HWSTAT);
 		break;
 	case REBOOTPWR_CHECK_HWSTAT:
-		urudev->last_hwstat = urudev->last_reg_rd;
+		urudev->last_hwstat = urudev->last_reg_rd[0];
 		if (urudev->last_hwstat & 0x1)
 			fpi_ssm_mark_completed(ssm);
 		else
@@ -876,8 +938,8 @@ static void powerup_run_state(struct fpi_ssm *ssm)
 		sm_read_reg(ssm, REG_HWSTAT);
 		break;
 	case POWERUP_CHECK_HWSTAT:
-		urudev->last_hwstat = urudev->last_reg_rd;
-		if ((urudev->last_reg_rd & 0x80) == 0)
+		urudev->last_hwstat = urudev->last_reg_rd[0];
+		if ((urudev->last_reg_rd[0] & 0x80) == 0)
 			fpi_ssm_mark_completed(ssm);
 		else
 			fpi_ssm_next_state(ssm);
@@ -890,7 +952,7 @@ static void powerup_run_state(struct fpi_ssm *ssm)
 		sm_do_challenge_response(ssm);
 		break;
 	case POWERUP_CHALLENGE_RESPONSE_SUCCESS:
-		fpi_ssm_jump_to_state(ssm, POWERUP_SET_HWSTAT);		
+		fpi_ssm_jump_to_state(ssm, POWERUP_SET_HWSTAT);
 		break;
 	}
 }
@@ -908,12 +970,6 @@ static void powerup_run_state(struct fpi_ssm *ssm)
 	if ((status & 0x80) == 0)
 		set_hwstat(status | 0x80);
 
-	// disable encryption
-	fwenc = read_firmware_encryption_byte();
-	new = fwenc & 0xef;
-	if (new != fwenc)
-		write_firmware_encryption_byte(new);
-
 	// power device up
 	run_powerup_sm();
 	await_irq(IRQDATA_SCANPWR_ON);
@@ -924,10 +980,11 @@ enum init_states {
 	INIT_CHECK_HWSTAT_REBOOT,
 	INIT_REBOOT_POWER,
 	INIT_CHECK_HWSTAT_POWERDOWN,
-	INIT_FIX_FIRMWARE,
 	INIT_POWERUP,
 	INIT_AWAIT_SCAN_POWER,
 	INIT_DONE,
+	INIT_GET_VERSION,
+	INIT_REPORT_VERSION,
 	INIT_NUM_STATES,
 };
 
@@ -975,7 +1032,7 @@ static void init_run_state(struct fpi_ssm *ssm)
 		sm_read_reg(ssm, REG_HWSTAT);
 		break;
 	case INIT_CHECK_HWSTAT_REBOOT:
-		urudev->last_hwstat = urudev->last_reg_rd;
+		urudev->last_hwstat = urudev->last_reg_rd[0];
 		if ((urudev->last_hwstat & 0x84) == 0x84)
 			fpi_ssm_next_state(ssm);
 		else
@@ -993,12 +1050,6 @@ static void init_run_state(struct fpi_ssm *ssm)
 		else
 			fpi_ssm_next_state(ssm);
 		break;
-	case INIT_FIX_FIRMWARE: ;
-		struct fpi_ssm *fwsm = fpi_ssm_new(dev->dev, fwfixer_run_state,
-			FWFIXER_NUM_STATES);
-		fwsm->priv = dev;
-		fpi_ssm_start_subsm(ssm, fwsm);
-		break;
 	case INIT_POWERUP: ;
 		struct fpi_ssm *powerupsm = fpi_ssm_new(dev->dev, powerup_run_state,
 			POWERUP_NUM_STATES);
@@ -1029,6 +1080,17 @@ static void init_run_state(struct fpi_ssm *ssm)
 		urudev->scanpwr_irq_timeout = NULL;
 		urudev->irq_cb_data = NULL;
 		urudev->irq_cb = NULL;
+		fpi_ssm_next_state(ssm);
+		break;
+	case INIT_GET_VERSION:
+		sm_read_regs(ssm, REG_DEVICE_INFO, 16);
+		break;
+	case INIT_REPORT_VERSION:
+		/* Likely hardware revision, and firmware version.
+		 * Not sure which is which. */
+		fp_info("Versions %02x%02x and %02x%02x",
+			urudev->last_reg_rd[10], urudev->last_reg_rd[11],
+			urudev->last_reg_rd[4],  urudev->last_reg_rd[5]);
 		fpi_ssm_mark_completed(ssm);
 		break;
 	}
@@ -1037,7 +1099,6 @@ static void init_run_state(struct fpi_ssm *ssm)
 static void activate_initsm_complete(struct fpi_ssm *ssm)
 {
 	struct fp_img_dev *dev = ssm->priv;
-	struct uru4k_dev *urudev = dev->priv;
 	int r = ssm->error;
 	fpi_ssm_free(ssm);
 
@@ -1046,7 +1107,7 @@ static void activate_initsm_complete(struct fpi_ssm *ssm)
 		return;
 	}
 
-	r = dev_change_state(dev, urudev->activate_state);
+	r = execute_state_change(dev);
 	fpi_imgdev_activate_complete(dev, r);
 }
 
@@ -1074,47 +1135,69 @@ static int dev_activate(struct fp_img_dev *dev, enum fp_imgdev_state state)
 
 /***** DEINITIALIZATION *****/
 
-enum deinit_states {
-	DEINIT_SET_MODE_INIT = 0,
-	DEINIT_POWERDOWN,
-	DEINIT_NUM_STATES,
-};
-
-static void deinit_run_state(struct fpi_ssm *ssm)
-{
-	switch (ssm->cur_state) {
-	case DEINIT_SET_MODE_INIT:
-		sm_set_mode(ssm, MODE_INIT);
-		break;
-	case DEINIT_POWERDOWN:
-		sm_set_hwstat(ssm, 0x80);
-		break;
-	}
-}
-
 static void deactivate_irqs_stopped(struct fp_img_dev *dev)
 {
 	fpi_imgdev_deactivate_complete(dev);
 }
 
-static void deactivate_deinitsm_complete(struct fpi_ssm *ssm)
+static void deactivate_write_reg_cb(struct fp_img_dev *dev, int status,
+	void *user_data)
 {
-	struct fp_img_dev *dev = ssm->priv;
-	fpi_ssm_free(ssm);
 	stop_irq_handler(dev, deactivate_irqs_stopped);
 }
 
 static void dev_deactivate(struct fp_img_dev *dev)
 {
+	dev_change_state(dev, IMGDEV_STATE_INACTIVE);
+}
+
+static int execute_state_change(struct fp_img_dev *dev)
+{
 	struct uru4k_dev *urudev = dev->priv;
-	struct fpi_ssm *ssm = fpi_ssm_new(dev->dev, deinit_run_state,
-		DEINIT_NUM_STATES);
+	struct fpi_ssm *ssm;
 
-	stop_imaging_loop(dev);
-	urudev->irq_cb = NULL;
-	urudev->irq_cb_data = NULL;
-	ssm->priv = dev;
-	fpi_ssm_start(ssm, deactivate_deinitsm_complete);
+	switch (urudev->activate_state) {
+	case IMGDEV_STATE_INACTIVE:
+		fp_dbg("deactivating");
+		urudev->irq_cb = NULL;
+		urudev->irq_cb_data = NULL;
+		return write_reg(dev, REG_MODE, MODE_OFF,
+			deactivate_write_reg_cb, NULL);
+		break;
+
+	case IMGDEV_STATE_AWAIT_FINGER_ON:
+		fp_dbg("wait finger on");
+		if (!IRQ_HANDLER_IS_RUNNING(urudev))
+			return -EIO;
+		urudev->irq_cb = finger_presence_irq_cb;
+		return write_reg(dev, REG_MODE, MODE_AWAIT_FINGER_ON,
+			change_state_write_reg_cb, NULL);
+
+	case IMGDEV_STATE_CAPTURE:
+		fp_dbg("starting capture");
+		urudev->irq_cb = NULL;
+
+		urudev->img_transfer = libusb_alloc_transfer(0);
+		urudev->img_data = g_malloc(sizeof(struct uru4k_image));
+		urudev->img_enc_seed = rand();
+
+		ssm = fpi_ssm_new(dev->dev, imaging_run_state, IMAGING_NUM_STATES);
+		ssm->priv = dev;
+		fpi_ssm_start(ssm, imaging_complete);
+
+		return write_reg(dev, REG_MODE, MODE_CAPTURE,
+			change_state_write_reg_cb, NULL);
+
+	case IMGDEV_STATE_AWAIT_FINGER_OFF:
+		fp_dbg("await finger off");
+		if (!IRQ_HANDLER_IS_RUNNING(urudev))
+			return -EIO;
+		urudev->irq_cb = finger_presence_irq_cb;
+		return write_reg(dev, REG_MODE, MODE_AWAIT_FINGER_OFF,
+			change_state_write_reg_cb, NULL);
+	}
+
+	return 0;
 }
 
 /***** LIBRARY STUFF *****/
@@ -1278,13 +1361,13 @@ struct fp_img_driver uru4000_driver = {
 	.driver = {
 		.id = 2,
 		.name = FP_COMPONENT,
-		.full_name = "Digital Persona U.are.U 4000/4000B",
+		.full_name = "Digital Persona U.are.U 4000/4000B/4500",
 		.id_table = id_table,
 		.scan_type = FP_SCAN_TYPE_PRESS,
 	},
 	.flags = FP_IMGDRV_SUPPORTS_UNCONDITIONAL_CAPTURE,
-	.img_height = 289,
-	.img_width = 384,
+	.img_height = IMAGE_HEIGHT,
+	.img_width = IMAGE_WIDTH,
 
 	.open = dev_init,
 	.close = dev_deinit,
diff --git a/libfprint/fp_internal.h b/libfprint/fp_internal.h
index 44881cd..8e714ec 100644
--- a/libfprint/fp_internal.h
+++ b/libfprint/fp_internal.h
@@ -28,6 +28,8 @@
 
 #include <fprint.h>
 
+#define array_n_elements(array) (sizeof(array) / sizeof(array[0]))
+
 #define container_of(ptr, type, member) ({                      \
         const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
         (type *)( (char *)__mptr - offsetof(type,member) );})
-- 
1.7.12