[PATCH BlueZ v2 3/3] tools: add bluez-quirkctl for managing quirk profiles

From: Pakrohk <[email protected]>

Add bluez-quirkctl, a CLI tool for managing external gamepad quirk
profiles. This tool validates JSON profiles, manages HMAC-SHA256 keys,
and installs/removes signed profiles to the system directory.

Usage:
  bluez-quirkctl install <file.json>   - validate, sign, install
  bluez-quirkctl remove <name>         - uninstall a profile
  bluez-quirkctl list                  - list installed profiles
  bluez-quirkctl validate <file.json>  - check without installing

Security model:
  - Install/remove requires root (checked via getuid())
  - HMAC key auto-generated in /var/lib/bluez/quirks/.hmac_key (0600)
  - Profiles installed to /var/lib/bluez/quirks/ (0644)
  - HMAC-SHA256 computed using bt_crypto (kernel AF_ALG)
  - Symlinks rejected during loading
  - Descriptor size capped at 2048 bytes

The tool links against libbluetooth-internal and libshared-mainloop
for access to bt_crypto_hmac_sha256().

Signed-off-by: Pakrohk <[email protected]>
diff --git a/Makefile.tools b/Makefile.tools
index 44da0ce..ecce5b4 100644
--- a/Makefile.tools
+++ b/Makefile.tools
@@ -581,5 +581,6 @@ bin_PROGRAMS += tools/bluez-quirkctl
 
 tools_bluez_quirkctl_SOURCES = tools/quirkctl.c
 tools_bluez_quirkctl_CFLAGS = $(JSONC_CFLAGS)
-tools_bluez_quirkctl_LDADD = $(JSONC_LIBS)
+tools_bluez_quirkctl_LDADD = lib/libbluetooth-internal.la \
+				src/libshared-mainloop.la $(JSONC_LIBS)
 endif
diff --git a/tools/quirkctl.c b/tools/quirkctl.c
index 5c35e97..93f3207 100644
--- a/tools/quirkctl.c
+++ b/tools/quirkctl.c
@@ -30,10 +30,16 @@
 #include <fcntl.h>
 #include <sys/stat.h>
 #include <sys/types.h>
+#include <sys/sendfile.h>
 #include <pwd.h>
 
 #include <json-c/json.h>
 
+#include "src/shared/crypto.h"
+
+static const char *prog;
+static struct bt_crypto *crypto;
+
 #define QUIRK_DIR "/var/lib/bluez/quirks"
 #define USER_QUIRK_DIR "/.config/bluez/quirks"
 #define HMAC_KEY_PATH QUIRK_DIR "/.hmac_key"
@@ -42,7 +48,166 @@
 #define JSON_EXT ".json"
 #define SIG_EXT ".sig"
 
-static const char *prog;
+/*
+ * Copy file using sendfile(2).
+ */
+static int copy_file(const char *src, const char *dst)
+{
+	int fd_in, fd_out;
+	struct stat st;
+	ssize_t sent;
+
+	fd_in = open(src, O_RDONLY);
+	if (fd_in < 0)
+		return -1;
+
+	if (fstat(fd_in, &st) < 0) {
+		close(fd_in);
+		return -1;
+	}
+
+	fd_out = open(dst, O_WRONLY | O_CREAT | O_TRUNC, 0644);
+	if (fd_out < 0) {
+		close(fd_in);
+		return -1;
+	}
+
+	sent = sendfile(fd_out, fd_in, NULL, st.st_size);
+	close(fd_in);
+	close(fd_out);
+
+	return (sent == st.st_size) ? 0 : -1;
+}
+
+/*
+ * Load HMAC key from disk. Returns key length or -1 on failure.
+ */
+static int load_hmac_key(uint8_t *key, int max_len)
+{
+	FILE *f;
+	long fsize;
+	char *hex;
+	int key_len, i;
+	char *end;
+
+	f = fopen(HMAC_KEY_PATH, "re");
+	if (!f)
+		return -1;
+
+	fseek(f, 0, SEEK_END);
+	fsize = ftell(f);
+	if (fsize < 0 || fsize > 1024) {
+		fclose(f);
+		return -1;
+	}
+	rewind(f);
+
+	hex = malloc(fsize + 1);
+	if (!hex) {
+		fclose(f);
+		return -1;
+	}
+
+	if (fread(hex, 1, fsize, f) != (size_t)fsize) {
+		free(hex);
+		fclose(f);
+		return -1;
+	}
+	fclose(f);
+	hex[fsize] = '\0';
+
+	end = hex + strlen(hex) - 1;
+	while (end > hex && (*end == '\n' || *end == '\r' || *end == ' '))
+		*end-- = '\0';
+
+	key_len = strlen(hex) / 2;
+	if (key_len > max_len)
+		key_len = max_len;
+
+	for (i = 0; i < key_len; i++) {
+		unsigned int byte;
+		char buf[3];
+
+		buf[0] = hex[i * 2];
+		buf[1] = hex[i * 2 + 1];
+		buf[2] = '\0';
+		if (sscanf(buf, "%2x", &byte) != 1) {
+			free(hex);
+			return -1;
+		}
+		key[i] = (uint8_t)byte;
+	}
+
+	free(hex);
+	return key_len;
+}
+
+/*
+ * Compute HMAC-SHA256 using bt_crypto (kernel AF_ALG).
+ * Returns hex string of 32-byte digest, or NULL on failure.
+ */
+static char *compute_hmac(const char *file_path)
+{
+	FILE *f;
+	long fsize;
+	uint8_t *data;
+	uint8_t key[HMAC_KEY_SIZE];
+	uint8_t digest[32];
+	char hex[HMAC_KEY_SIZE * 2 + 1];
+	char *result;
+	int key_len, i;
+
+	if (!crypto)
+		return NULL;
+
+	/* Read the file */
+	f = fopen(file_path, "re");
+	if (!f)
+		return NULL;
+
+	fseek(f, 0, SEEK_END);
+	fsize = ftell(f);
+	if (fsize < 0 || fsize > 1024 * 1024) {
+		fclose(f);
+		return NULL;
+	}
+	rewind(f);
+
+	data = malloc(fsize);
+	if (!data) {
+		fclose(f);
+		return NULL;
+	}
+
+	if (fread(data, 1, fsize, f) != (size_t)fsize) {
+		free(data);
+		fclose(f);
+		return NULL;
+	}
+	fclose(f);
+
+	/* Load the HMAC key */
+	key_len = load_hmac_key(key, HMAC_KEY_SIZE);
+	if (key_len <= 0) {
+		free(data);
+		return NULL;
+	}
+
+	/* Compute HMAC-SHA256 */
+	if (!bt_crypto_hmac_sha256(crypto, key, key_len, data, fsize, digest)) {
+		free(data);
+		return NULL;
+	}
+	free(data);
+
+	/* Convert to hex string */
+	for (i = 0; i < 32; i++)
+		snprintf(hex + i * 2, 3, "%02x", digest[i]);
+	hex[64] = '\0';
+
+	result = strdup(hex);
+	return result;
+}
 
 static void usage(void)
 {
@@ -139,43 +304,6 @@ static int ensure_hmac_key(void)
 	return 0;
 }
 
-/*
- * Compute HMAC-SHA256 via openssl CLI.
- */
-static char *compute_hmac(const char *file_path)
-{
-	char cmd[1024];
-	char line[256];
-	char *result = NULL;
-	FILE *p;
-	char *eq;
-
-	snprintf(cmd, sizeof(cmd),
-		"openssl dgst -sha256 -hmac \"$(cat " HMAC_KEY_PATH ")\" "
-		"-hex < '%s' 2>/dev/null", file_path);
-
-	p = popen(cmd, "r");
-	if (!p)
-		return NULL;
-
-	while (fgets(line, sizeof(line), p)) {
-		eq = strstr(line, "= ");
-		if (eq) {
-			eq += 2;
-			/* trim */
-			char *end = eq + strlen(eq) - 1;
-			while (end > eq && (*end == '\n' || *end == '\r'
-						|| *end == ' '))
-				*end-- = '\0';
-			result = strdup(eq);
-			break;
-		}
-	}
-
-	pclose(p);
-	return result;
-}
-
 /*
  * Validate JSON profile structure.
  */
@@ -390,14 +518,10 @@ static int cmd_install(const char *path)
 		return 1;
 	}
 
-	{
-		char cmd[1024];
-		snprintf(cmd, sizeof(cmd), "cp '%s' '%s'", path, dest);
-		if (system(cmd) != 0) {
-			fprintf(stderr, "Failed to copy profile\n");
-			free(name);
-			return 1;
-		}
+	if (copy_file(path, dest) < 0) {
+		fprintf(stderr, "Failed to copy profile\n");
+		free(name);
+		return 1;
 	}
 
 	if (chmod(dest, 0644) < 0) {
@@ -510,6 +634,8 @@ static int cmd_list(void)
 
 int main(int argc, char *argv[])
 {
+	int ret;
+
 	prog = argv[0];
 
 	if (argc < 2) {
@@ -522,7 +648,14 @@ int main(int argc, char *argv[])
 			fprintf(stderr, "Usage: %s install <file.json>\n", prog);
 			return 1;
 		}
-		return cmd_install(argv[2]);
+		crypto = bt_crypto_new();
+		if (!crypto) {
+			fprintf(stderr, "Failed to init crypto\n");
+			return 1;
+		}
+		ret = cmd_install(argv[2]);
+		bt_crypto_unref(crypto);
+		return ret;
 	}
 
 	if (strcmp(argv[1], "remove") == 0) {
@@ -533,9 +666,8 @@ int main(int argc, char *argv[])
 		return cmd_remove(argv[2]);
 	}
 
-	if (strcmp(argv[1], "list") == 0) {
+	if (strcmp(argv[1], "list") == 0)
 		return cmd_list();
-	}
 
 	if (strcmp(argv[1], "validate") == 0) {
 		if (argc < 3) {