1 files changed, 130 insertions, 0 deletions
diff --git a/extlibs/b64_decode.c b/extlibs/b64_decode.c
new file mode 100644
index 0000000..7fb7b01
--- /dev/null
+++ b/extlibs/b64_decode.c
@@ -0,0 +1,130 @@
+
+/**
+ * `decode.c' - b64
+ *
+ * copyright (c) 2014 joseph werle
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include "b64.h"
+
+#ifdef b64_USE_CUSTOM_MALLOC
+extern void* b64_malloc(size_t);
+#endif
+
+#ifdef b64_USE_CUSTOM_REALLOC
+extern void* b64_realloc(void*, size_t);
+#endif
+
+unsigned char *
+b64_decode (const char *src, size_t len) {
+  return b64_decode_ex(src, len, NULL);
+}
+
+unsigned char *
+b64_decode_ex (const char *src, size_t len, size_t *decsize) {
+  int i = 0;
+  int j = 0;
+  int l = 0;
+  size_t size = 0;
+  unsigned char *dec = NULL;
+  unsigned char buf[3];
+  unsigned char tmp[4];
+
+  // alloc
+  dec = (unsigned char *) b64_malloc(1);
+  if (NULL == dec) { return NULL; }
+
+  // parse until end of source
+  while (len--) {
+    // break if char is `=' or not base64 char
+    if ('=' == src[j]) { break; }
+    if (!(isalnum(src[j]) || '+' == src[j] || '/' == src[j])) { break; }
+
+    // read up to 4 bytes at a time into `tmp'
+    tmp[i++] = src[j++];
+
+    // if 4 bytes read then decode into `buf'
+    if (4 == i) {
+      // translate values in `tmp' from table
+      for (i = 0; i < 4; ++i) {
+        // find translation char in `b64_table'
+        for (l = 0; l < 64; ++l) {
+          if (tmp[i] == b64_table[l]) {
+            tmp[i] = l;
+            break;
+          }
+        }
+      }
+
+      // decode
+      buf[0] = (tmp[0] << 2) + ((tmp[1] & 0x30) >> 4);
+      buf[1] = ((tmp[1] & 0xf) << 4) + ((tmp[2] & 0x3c) >> 2);
+      buf[2] = ((tmp[2] & 0x3) << 6) + tmp[3];
+
+      // write decoded buffer to `dec'
+      dec = (unsigned char *) b64_realloc(dec, size + 3);
+      if (dec != NULL){
+        for (i = 0; i < 3; ++i) {
+          dec[size++] = buf[i];
+        }
+      } else {
+        return NULL;
+      }
+
+      // reset
+      i = 0;
+    }
+  }
+
+  // remainder
+  if (i > 0) {
+    // fill `tmp' with `\0' at most 4 times
+    for (j = i; j < 4; ++j) {
+      tmp[j] = '\0';
+    }
+
+    // translate remainder
+    for (j = 0; j < 4; ++j) {
+        // find translation char in `b64_table'
+        for (l = 0; l < 64; ++l) {
+          if (tmp[j] == b64_table[l]) {
+            tmp[j] = l;
+            break;
+          }
+        }
+    }
+
+    // decode remainder
+    buf[0] = (tmp[0] << 2) + ((tmp[1] & 0x30) >> 4);
+    buf[1] = ((tmp[1] & 0xf) << 4) + ((tmp[2] & 0x3c) >> 2);
+    buf[2] = ((tmp[2] & 0x3) << 6) + tmp[3];
+
+    // write remainer decoded buffer to `dec'
+    dec = (unsigned char *) b64_realloc(dec, size + (i - 1));
+    if (dec != NULL){
+      for (j = 0; (j < i - 1); ++j) {
+        dec[size++] = buf[j];
+      }
+    } else {
+      return NULL;
+    }
+  }
+
+  // Make sure we have enough space to add '\0' character at end.
+  dec = (unsigned char *) b64_realloc(dec, size + 1);
+  if (dec != NULL){
+    dec[size] = '\0';
+  } else {
+    return NULL;
+  }
+
+  // Return back the size of decoded string if demanded.
+  if (decsize != NULL) {
+    *decsize = size;
+  }
+
+  return dec;
+}