Initial commit of files

src/libasn1/uper_get_ext.c

@@ -0,0 +1,142 @@
+/*****************************************************************************
+ * Copyright (C) 2004-2021
+ * ProbeStar Technical Systems, LLC
+ * All Rights Reserved.  Proprietary and Confidential.
+ *============================================================================
+*****************************************************************************/
+
+/*****************************************************************************
+ * includes
+*****************************************************************************/
+
+#include "embtypes.h"
+#include "asn1uper.h"
+
+/*****************************************************************************
+ * defines
+*****************************************************************************/
+
+/*****************************************************************************
+ * macros
+*****************************************************************************/
+
+#define min(A,B)        ((A)<(B)?(A):(B))
+#define max(A,B)        ((A)>(B)?(A):(B))
+
+/*****************************************************************************
+ * structs & typedefs
+*****************************************************************************/
+
+/*****************************************************************************
+ * global constants
+*****************************************************************************/
+
+/*****************************************************************************
+ * global variables
+*****************************************************************************/
+
+/*****************************************************************************
+ * static constants
+*****************************************************************************/
+
+/*****************************************************************************
+ * static variables
+*****************************************************************************/
+
+/*****************************************************************************
+ * static prototypes
+*****************************************************************************/
+
+/*****************************************************************************
+ * C functions
+*****************************************************************************/
+
+// grab extension bits, check for extension defined by ellipses
+uint uper_get_extension(UPER_Stream *uper, UPER_Extension *ext, uint noptions, uint ellipses)
+{
+  if (!uper || !ext)
+    return 0;
+
+  uper_init_extension(ext);
+
+  ellipses &= 1;
+  if ((noptions+ellipses)==0) {
+    uper->error = 1;
+    return 0;
+  }
+  
+  // check for extensions
+  if (ellipses) {
+    ext->ellipses = uper_get_bits_stream(uper, 1);
+  }
+  
+  // check for options
+  if (noptions) {
+    ext->value = uper_get_bits_stream(uper, noptions);
+    ext->options = noptions;
+  }
+  
+  if (ext->ellipses) {
+    uper_get_ext_length(uper, ext);
+    
+    if (_asn1_debug_on_)
+      printf("\tEXT_LEN = %d\n", ext->length);
+    // otherwise no ...
+  }  
+
+  return ellipses + noptions;
+}
+
+uint uper_get_ext_length(UPER_Stream *uper, UPER_Extension *ext)
+{
+  if (!ext->ellipses)
+    return 0;
+  
+  uint len = uper_get_bits_stream(uper, 8);
+  
+  if (len & 0x80) {
+    len = (len & 0x7f) << 8;
+    len |= uper_get_bits_stream(uper, 8);
+  }
+  else
+    len &= 0x7f;
+  ext->length = len;
+  
+  return len;
+}
+
+// if ellipses extension available
+uint uper_get_ext_ellipses(UPER_Extension *ext)
+{
+  if (ext)
+    return ext->ellipses;
+  return 0;
+}
+
+// from the front (high->low bits)
+uint uper_get_ext_optional(UPER_Extension *ext, uint bit)
+{
+  if (!ext || (bit>=ext->options))
+    return 0;
+  
+  return (ext->value & 1<<(ext->options-bit));
+}
+
+uint uper_get_ext_skip(UPER_Stream *uper, UPER_Extension *ext)
+{
+  if (!uper && !ext && !ext->length)
+    return 0;
+  
+  int bits = ext->length;
+  
+  // copy in
+  int sbit = uper->bit;        // bit order in stream (not byte)
+  int ebit = (sbit+bits) % 8; // after last bit
+
+  // copy out
+  uper->ptr += (sbit + bits) / 8;
+  uper->bit = ebit;
+  uper->consumed += bits;
+  
+  return bits;
+}