s/getkey/genkey/

1 files changed, 83 insertions, 0 deletions

diff --git a/genkey.c b/genkey.c
new file mode 100644
index 0000000..ef19e9e
--- /dev/null
+++ b/genkey.c
@@ -0,0 +1,83 @@
+#include <ctype.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include "deonebook.h"
+
+#define SCR_SIZE 8
+#define CSD_SIZE 16
+#define CID_SIZE 16
+#define KEY_SIZE 16
+
+static unsigned char twiddle(unsigned char buf[2])
+{
+	unsigned char c = 0;
+
+	if (isdigit(buf[0])) {
+		c = buf[0];
+	} else if (isupper(buf[0])) {
+		c = buf[0] - 0x37;
+	} else if (islower(buf[0])) {
+		c = buf[0] - 0x57;
+	}
+	c *= 0x10;
+
+	if (isdigit(buf[1])) {
+		c |= buf[1] - 0x30;
+	} else if (isupper(buf[1])) {
+		c |= buf[1] - 0x37;
+	} else if (islower(buf[1])) {
+		c |= buf[1] + 0xa9;
+	}
+
+	return c;
+}
+
+static void get_sd_register(const char *dev, const char *reg, size_t n, unsigned char buf[n])
+{
+	char path[256];
+	snprintf(path, sizeof(path), "/sys/block/%s/device/%s", dev, reg);
+
+	FILE *f = fopen(path, "r");
+	if (f == NULL) {
+		return;
+	}
+
+	for (size_t i = 0; i < n; i++) {
+		unsigned char hex[2];
+		fread(hex, 2, 1, f);
+		buf[i] = twiddle(hex);
+	}
+
+	fclose(f);
+}
+
+unsigned char * genkey(const char *dev)
+{
+	static unsigned char key[KEY_SIZE];
+	const unsigned char keycode[] = "eone";
+	size_t codelen = sizeof(keycode) - 1;
+
+	unsigned char scr[SCR_SIZE] = "testtest";
+	unsigned char csd[CSD_SIZE] = "testtesttesttest";
+	unsigned char cid[CID_SIZE] = "testtesttesttest";
+
+	get_sd_register(dev, "cid", sizeof(cid), cid);
+	get_sd_register(dev, "csd", sizeof(csd), csd);
+	get_sd_register(dev, "scr", sizeof(scr), scr);
+
+	memcpy(key, cid + 3, 10);
+	memcpy(key + 10, csd + 7, 3);
+	key[13] = scr[0];
+	memcpy(key + 0xe, scr + 2, 2);
+
+	for (size_t i = 0; i < KEY_SIZE; i++) {
+		if (i < codelen) {
+			key[i] += keycode[i];
+		} else {
+			key[i] += i - (codelen - 1);
+		}
+	}
+
+	return key;
+}