From ae2ba1bc296cb33021661fc32371797c9fc23ccd Mon Sep 17 00:00:00 2001
From: bnnm <bananaman255@gmail.com>
Date: Sat, 20 Jan 2018 20:06:15 +0100
Subject: [PATCH] Update read_key_file for variable-sized keys

---
 src/meta/adx.c   |  2 +-
 src/meta/ahx.c   |  2 +-
 src/meta/hca.c   |  2 +-
 src/streamfile.c | 24 +++++++++++-------------
 src/streamfile.h |  2 +-
 5 files changed, 15 insertions(+), 17 deletions(-)

diff --git a/src/meta/adx.c b/src/meta/adx.c
index 683e5cc0..5e6a875c 100644
--- a/src/meta/adx.c
+++ b/src/meta/adx.c
@@ -249,7 +249,7 @@ static int find_key(STREAMFILE *file, uint8_t type, uint16_t *xor_start, uint16_
     {
         uint8_t keybuf[6];
 
-        if ( read_key_file(keybuf, 6, file) ) {
+        if (read_key_file(keybuf, 6, file) == 6) {
             *xor_start = get_16bitBE(keybuf+0);
             *xor_mult = get_16bitBE(keybuf+2);
             *xor_add = get_16bitBE(keybuf+4);
diff --git a/src/meta/ahx.c b/src/meta/ahx.c
index 516773e0..59570750 100644
--- a/src/meta/ahx.c
+++ b/src/meta/ahx.c
@@ -56,7 +56,7 @@ VGMSTREAM * init_vgmstream_ahx(STREAMFILE *streamFile) {
 
         if (cfg.encryption) {
             uint8_t keybuf[6];
-            if (read_key_file(keybuf, 6, streamFile)) {
+            if (read_key_file(keybuf, 6, streamFile) == 6) {
                 cfg.cri_key1 = get_16bitBE(keybuf+0);
                 cfg.cri_key2 = get_16bitBE(keybuf+2);
                 cfg.cri_key3 = get_16bitBE(keybuf+4);
diff --git a/src/meta/hca.c b/src/meta/hca.c
index 10261460..fcd599be 100644
--- a/src/meta/hca.c
+++ b/src/meta/hca.c
@@ -54,7 +54,7 @@ VGMSTREAM * init_vgmstream_hca(STREAMFILE *streamFile) {
     /* find decryption key in external file or preloaded list */
     {
         uint8_t keybuf[8];
-        if ( read_key_file(keybuf, 8, streamFile) ) {
+        if (read_key_file(keybuf, 8, streamFile) == 8) {
             ciphKey2 = get_32bitBE(keybuf+0);
             ciphKey1 = get_32bitBE(keybuf+4);
         } else {
diff --git a/src/streamfile.c b/src/streamfile.c
index 79e349fb..61e8b3bf 100644
--- a/src/streamfile.c
+++ b/src/streamfile.c
@@ -546,17 +546,15 @@ STREAMFILE * open_stream_name(STREAMFILE *streamFile, const char * name) {
     return streamFile->open(streamFile,filename,STREAMFILE_DEFAULT_BUFFER_SIZE);
 }
 
-/**
- * open file containing decryption keys and copy to buffer
- * tries combinations of keynames based on the original filename
- *
- * returns true if found and copied
- */
-int read_key_file(uint8_t * buf, size_t bufsize, STREAMFILE *streamFile) {
+/* Opens a file containing decryption keys and copies to buffer.
+ * Tries combinations of keynames based on the original filename.
+ * returns size of key if found and copied */
+size_t read_key_file(uint8_t * buf, size_t bufsize, STREAMFILE *streamFile) {
     char keyname[PATH_LIMIT];
     char filename[PATH_LIMIT];
     const char *path, *ext;
     STREAMFILE * streamFileKey = NULL;
+    size_t keysize;
 
     streamFile->get_name(streamFile,filename,sizeof(filename));
 
@@ -609,17 +607,17 @@ int read_key_file(uint8_t * buf, size_t bufsize, STREAMFILE *streamFile) {
     }
 
 found:
-    if (get_streamfile_size(streamFileKey) != bufsize) goto fail;
+    keysize = get_streamfile_size(streamFileKey);
+    if (keysize > bufsize) goto fail;
 
-    if (read_streamfile(buf, 0, bufsize, streamFileKey)!=bufsize) goto fail;
+    if (read_streamfile(buf, 0, keysize, streamFileKey) != keysize)
+        goto fail;
 
     close_streamfile(streamFileKey);
-
-    return 1;
+    return keysize;
 
 fail:
-    if (streamFileKey) close_streamfile(streamFileKey);
-
+    close_streamfile(streamFileKey);
     return 0;
 }
 
diff --git a/src/streamfile.h b/src/streamfile.h
index 349ea584..fa9da54f 100644
--- a/src/streamfile.h
+++ b/src/streamfile.h
@@ -155,7 +155,7 @@ STREAMFILE * open_stream_name(STREAMFILE *streamFile, const char * ext);
 
 int read_string(char * buf, size_t bufsize, off_t offset, STREAMFILE *streamFile);
 
-int read_key_file(uint8_t * buf, size_t bufsize, STREAMFILE *streamFile);
+size_t read_key_file(uint8_t * buf, size_t bufsize, STREAMFILE *streamFile);
 int read_pos_file(uint8_t * buf, size_t bufsize, STREAMFILE *streamFile);
 
 int check_extensions(STREAMFILE *streamFile, const char * cmp_exts);