1 files changed, 55 insertions, 0 deletions
diff --git a/src/pk/pkcs1/pkcs_1_i2osp.c b/src/pk/pkcs1/pkcs_1_i2osp.c
new file mode 100644
index 0000000..3e68eb8
--- /dev/null
+++ b/src/pk/pkcs1/pkcs_1_i2osp.c
@@ -0,0 +1,55 @@
+/* LibTomCrypt, modular cryptographic library -- Tom St Denis
+ *
+ * LibTomCrypt is a library that provides various cryptographic
+ * algorithms in a highly modular and flexible manner.
+ *
+ * The library is free for all purposes without any express
+ * guarantee it works.
+ *
+ * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.org
+ */
+#include "tomcrypt.h"
+
+/** 
+  @file pkcs_1_i2osp.c
+  Integer to Octet I2OSP, Tom St Denis 
+*/
+
+#ifdef PKCS_1
+
+/* always stores the same # of bytes, pads with leading zero bytes
+   as required
+ */
+
+/**
+   PKCS #1 Integer to binary
+   @param n             The integer to store
+   @param modulus_len   The length of the RSA modulus
+   @param out           [out] The destination for the integer
+   @return CRYPT_OK if successful
+*/
+int pkcs_1_i2osp(mp_int *n, unsigned long modulus_len, unsigned char *out)
+{
+   int err;
+   unsigned long size;
+
+   size = mp_unsigned_bin_size(n);
+
+   if (size > modulus_len) {
+      return CRYPT_BUFFER_OVERFLOW;
+   }
+
+   /* store it */
+   zeromem(out, modulus_len);
+   if ((err = mp_to_unsigned_bin(n, out+(modulus_len-size))) != MP_OKAY) {
+      return mpi_to_ltc_error(err);
+   }
+   return CRYPT_OK;
+}
+
+#endif /* PKCS_1 */
+
+
+/* $Source: /cvs/libtom/libtomcrypt/src/pk/pkcs1/pkcs_1_i2osp.c,v $ */
+/* $Revision: 1.3 $ */
+/* $Date: 2005/05/05 14:35:59 $ */