move base64 functions to base64.c

1 files changed, 80 insertions, 0 deletions

diff --git a/common/base64.c b/common/base64.c
new file mode 100644
index 00000000..4c177f49
--- /dev/null
+++ b/common/base64.c
@@ -0,0 +1,80 @@
+/**
+ * xrdp: A Remote Desktop Protocol server.
+ *
+ * Copyright (C) Koichiro Iwao 2017
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * Base64 encoder / decoder
+ */
+
+#if defined(HAVE_CONFIG_H)
+#include <config_ac.h>
+#endif
+
+#include "os_calls.h"
+
+#include <openssl/bio.h>
+#include <openssl/evp.h>
+
+size_t
+base64_decoded_bytes(const char *src)
+{
+    size_t len;
+    size_t padding;
+
+    len = g_strlen(src);
+    padding = 0;
+
+    if (src[len - 1] == '=')
+    {
+        padding++;
+
+        if (src[len - 2] == '=')
+        {
+            padding++;
+        }
+    }
+
+    return len * 3 / 4 - padding;
+}
+
+/*****************************************************************************/
+char *
+base64_decode(char *dst, const char *src, size_t len)
+{
+    BIO *b64;
+    BIO *bio;
+    char *b64str;
+    size_t estimated_decoded_bytes;
+    size_t decoded_bytes;
+
+    b64str = g_strdup(src);
+    estimated_decoded_bytes = base64_decoded_bytes(b64str);
+    dst[estimated_decoded_bytes] = '\0';
+
+    b64 = BIO_new(BIO_f_base64());
+    bio = BIO_new_mem_buf(b64str, len);
+    bio = BIO_push(b64, bio);
+    BIO_set_flags(bio, BIO_FLAGS_BASE64_NO_NL);
+    decoded_bytes = BIO_read(bio , dst, len);
+    BIO_free_all(bio);
+
+    /* if input is corrupt, return empty string */
+    if (estimated_decoded_bytes != decoded_bytes)
+    {
+    g_strncpy(dst, "", sizeof(""));
+    }
+
+    return dst;
+}