--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/pk/rsa/rsa_v15_decrypt_key.c	Fri May 06 13:23:02 2005 +0000
@@ -0,0 +1,73 @@
+   /* 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, [email protected], http://libtomcrypt.org
+ */
+#include "tomcrypt.h"
+
+/**
+  @file rsa_v15_decrypt_key.c
+  RSA PKCS v1.5 Decryption, Tom St Denis
+*/  
+
+#ifdef MRSA
+
+/**
+   RSA decrypt then PKCS #1 v1.5 depad 
+   @param in        The ciphertext
+   @param inlen     The length of the ciphertext (octets)
+   @param out       [out] The plaintext
+   @param outlen    The length of the plaintext (you have to tell this function as it's not part of PKCS #1 v1.0 padding!)
+   @param stat      [out] Status of decryption, 1==valid, 0==invalid
+   @param key       The corresponding private RSA key
+   @return CRYPT_OK if successful (even if invalid)   
+*/
+int rsa_v15_decrypt_key(const unsigned char *in,     unsigned long  inlen,
+                              unsigned char *out,    unsigned long  outlen, 
+                              int           *stat,   rsa_key       *key)
+{
+  unsigned long modulus_bitlen, modulus_bytelen, x;
+  int           err;
+  unsigned char *tmp;
+  
+  LTC_ARGCHK(out    != NULL);
+  LTC_ARGCHK(key    != NULL);
+  LTC_ARGCHK(stat   != NULL);
+ 
+  /* default to invalid */
+  *stat = 0;
+
+  /* get modulus len in bits */
+  modulus_bitlen = mp_count_bits(&(key->N));
+
+  /* outlen must be at least the size of the modulus */
+  modulus_bytelen = mp_unsigned_bin_size(&(key->N));
+  if (modulus_bytelen != inlen) {
+     return CRYPT_INVALID_PACKET;
+  }
+
+  /* allocate ram */
+  tmp = XMALLOC(inlen);
+  if (tmp == NULL) {
+     return CRYPT_MEM;
+  }
+
+  /* rsa decode the packet */
+  x = inlen;
+  if ((err = rsa_exptmod(in, inlen, tmp, &x, PK_PRIVATE, key)) != CRYPT_OK) {
+     XFREE(tmp);
+     return err;
+  }
+
+  /* PKCS #1 v1.5 depad */
+  err = pkcs_1_v15_es_decode(tmp, x, modulus_bitlen, out, outlen, stat);
+  XFREE(tmp);
+  return err;
+}
+
+#endif