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Diffstat (limited to 'libtomcrypt/src/pk/pkcs1/pkcs_1_i2osp.c')
-rw-r--r--libtomcrypt/src/pk/pkcs1/pkcs_1_i2osp.c55
1 files changed, 55 insertions, 0 deletions
diff --git a/libtomcrypt/src/pk/pkcs1/pkcs_1_i2osp.c b/libtomcrypt/src/pk/pkcs1/pkcs_1_i2osp.c
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+++ b/libtomcrypt/src/pk/pkcs1/pkcs_1_i2osp.c
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+/* 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 $ */