abuild-gzsplit: new tool to split .apk to it's base components

required tool for re-signing packages

1 files changed, 75 insertions, 0 deletions

diff --git a/abuild-gzsplit.c b/abuild-gzsplit.c
new file mode 100644
index 0000000..5e7a698
--- /dev/null
+++ b/abuild-gzsplit.c
@@ -0,0 +1,75 @@
+#include <stdio.h>
+#include <fcntl.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <zlib.h>
+
+int main(void)
+{
+	char obuf[8*1024], ibuf[8*1024];
+	z_stream zs;
+	int r = Z_OK, rc = 1, fd = -1;
+	size_t len;
+
+	if (inflateInit2(&zs, 15+32) != Z_OK)
+		goto err;
+
+	zs.avail_out = sizeof obuf;
+	zs.next_out  = obuf;
+
+	while (1) {
+		if (zs.avail_in == 0) {
+			zs.avail_in = read(STDIN_FILENO, ibuf, sizeof ibuf);
+			zs.next_in = ibuf;
+			if (zs.avail_in < 0) goto err;
+			if (zs.avail_in == 0 && r == Z_STREAM_END) goto ok;
+		}
+
+		r = inflate(&zs, Z_NO_FLUSH);
+		if (r != Z_OK && r != Z_STREAM_END) goto err;
+
+		len = sizeof obuf - zs.avail_out;
+		if (len) {
+			if (fd < 0) {
+				const char *fn;
+				if (strncmp(obuf, ".SIGN.", 6) == 0)
+					fn = "signatures.tar.gz";
+				else if (strncmp(obuf, ".PKGINFO", 8) == 0)
+					fn = "control.tar.gz";
+				else if (rc == 1)
+					fn = "data.tar.gz", rc = 2;
+				else
+					goto err;
+				fd = open(fn, O_CREAT|O_TRUNC|O_WRONLY, 0777);
+				if (fd < 0) goto err;
+			}
+			zs.next_out = obuf;
+			zs.avail_out = sizeof obuf;
+		}
+
+		if (zs.avail_in == 0 || r == Z_STREAM_END) {
+			len = (void *)zs.next_in - (void *)ibuf;
+			if (write(fd, ibuf, len) != len) goto err;
+			memmove(ibuf, zs.next_in, zs.avail_in);
+			zs.next_in = ibuf;
+		}
+
+		if (r == Z_STREAM_END) {
+			if (fd >= 0) {
+				close(fd);
+				fd = -1;
+			}
+			inflateEnd(&zs);
+			if (inflateInit2(&zs, 15+32) != Z_OK) goto err;
+		}
+	}
+ok:
+	rc = 0;
+err:
+	if (fd >= 0) close(fd);
+	inflateEnd(&zs);
+	if (rc) fprintf(stderr, "failed\n");
+	return rc;
+}
+