1 files changed, 60 insertions, 0 deletions
diff --git a/lib/dns/sec/dnssafe/bigtocan.c b/lib/dns/sec/dnssafe/bigtocan.c
new file mode 100644
index 00000000..13e8315d
--- /dev/null
+++ b/lib/dns/sec/dnssafe/bigtocan.c
@@ -0,0 +1,60 @@
+/* Copyright (C) RSA Data Security, Inc. created 1990, 1996.  This is an
+   unpublished work protected as such under copyright law.  This work
+   contains proprietary, confidential, and trade secret information of
+   RSA Data Security, Inc.  Use, disclosure or reproduction without the
+   express written authorization of RSA Data Security, Inc. is
+   prohibited.
+ */
+
+#include "global.h"
+#include "algae.h"
+#include "bigmath.h"
+
+
+/* BigToCanonical () copies a word vector to a byte vector while REVERSING the
+     order of significance.  The word vector is input LSWord first and the
+     byte vector is written out MSByte first. It also removes a leading zero
+     sign bit. (The byte vector must represent a nonnegative number.)
+   Returns 0, AE_DATA.
+ */
+int BigToCanonical (bytePointer, numBytes, wordPointer, wordCount)
+unsigned char *bytePointer;
+unsigned int numBytes;
+UINT2 *wordPointer;
+unsigned int wordCount;
+{
+  unsigned int copyCount;
+  
+  if (BigSign (wordPointer, wordCount) < 0 ||
+      (BigLen (wordPointer, wordCount) + 7) / 8 > numBytes)
+    return (AE_DATA);
+
+  /* start at end of byte vector */
+  bytePointer += numBytes-1;
+  
+  /* copy as much as possible */
+  copyCount = (wordCount < numBytes / 2) ? wordCount : numBytes / 2;
+  wordCount -= copyCount;
+  numBytes -= 2 * copyCount;
+  while (copyCount--) {
+    /* Copy two bytes.*/
+    *bytePointer-- = (unsigned char)*wordPointer;
+    *bytePointer-- = (unsigned char)(*wordPointer >> 8);
+    wordPointer++;
+  }
+  
+  if (wordCount && numBytes & 1) {
+    /* The number of output bytes was odd. Copy one last byte */
+    *bytePointer-- = (unsigned char)*wordPointer++;
+    wordCount--;
+    numBytes--;
+  }
+  
+  /* zero fill remainder of byte vector */
+  while (numBytes--)
+    *bytePointer-- = 0;
+  
+  return (0);
+}
+
+