Create decryptto function

1 files changed, 29 insertions, 3 deletions

diff --git a/src/encryption.c b/src/encryption.c
index 606be03..c176d6e 100644
--- a/src/encryption.c
+++ b/src/encryption.c
@@ -29,7 +29,7 @@ int checksodiumcb(const vxgg_naclfailcb callback, void *data, unsigned char set)
     static vxgg_naclfailcb cb = naclfaildefault;
     static void *usr = NULL;
     int ret;
-    
+
     if(set) {
         cb = callback;
         usr = data;
@@ -73,7 +73,7 @@ int maketmp(const char * const dest) {
     return open(dest, (O_TMPFILE | O_WRONLY | O_CLOEXEC | O_SYNC), (S_IRUSR | S_IWUSR));
 }
 
-int encrypttotmp(const char * const target, const char * const output, const unsigned char key[crypto_secretstream_xchacha20poly1305_KEYBYTES]) {
+int encryptviatmp(const char * const target, const char * const output, const unsigned char key[crypto_secretstream_xchacha20poly1305_KEYBYTES]) {
     #if ___VXGG___ALWAYS_CHECK_LIBSODIUM___ > 0
     checksodium();
     #endif
@@ -106,7 +106,6 @@ int encrypttotmp(const char * const target, const char * const output, const uns
     asprintf(&path, "/proc/self/fd/%d", tfd);
     if(!path)
         return -1;
-
     remove(output); // Make sure an old version isn't sticking around
     linkat(AT_FDCWD, path, AT_FDCWD, output, AT_SYMLINK_FOLLOW);
 
@@ -118,6 +117,33 @@ int encrypttotmp(const char * const target, const char * const output, const uns
     return 0;
 }
 
+int decryptto(const char * const encrypted, const char * const target, const unsigned char key[crypto_secretstream_xchacha20poly1305_KEYBYTES]) {
+    #if ___VXGG___ALWAYS_CHECK_LIBSODIUM___ > 0
+        checksodium();
+    #endif
+
+    if(!encrypted)
+        RETURNWERR(EINVAL, -1);
+    if(!target)
+        RETURNWERR(EINVAL, -1);
+    if(!key)
+        RETURNWERR(EINVAL, -1);
+
+    FILE *src, *dst;
+    if(!(src = fopen(encrypted, "rb")))
+        ERROR(1, errno, "Could not open \"%s\" for decryption", , encrypted);
+    if(!(dst = fopen(target, "wb")))
+        ERROR(1, errno, "Could not open \"%s\" for writing decrypted data", , target);
+    
+    if(decrypttofile(src, dst, key) < 0)
+        ERROR(1, errno, "How did you even cause an error?",);
+
+    fclose(dst);
+    fclose(src);
+
+    return 0;
+}
+
 int encrypttofile(FILE *dst, FILE *src, unsigned char key[crypto_secretstream_xchacha20poly1305_KEYBYTES]) {
     unsigned char  buf[CHUNKSIZE], cbuf[CHUNKSIZE + crypto_secretstream_xchacha20poly1305_ABYTES];
     unsigned char  header[crypto_secretstream_xchacha20poly1305_HEADERBYTES];