1 files changed, 79 insertions, 0 deletions
diff --git a/libtomcrypt/src/pk/rsa/rsa_sign_hash.c b/libtomcrypt/src/pk/rsa/rsa_sign_hash.c
new file mode 100644
index 0000000..d31bda3
--- /dev/null
+++ b/libtomcrypt/src/pk/rsa/rsa_sign_hash.c
@@ -0,0 +1,79 @@
+/* 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 rsa_sign_hash.c
+  RSA PKCS v2 PSS sign hash, Tom St Denis
+*/  
+
+#ifdef MRSA
+
+/**
+  (PKCS #1, v2.0) PSS pad then sign 
+  @param in        The hash to sign
+  @param inlen     The length of the hash to sign (octets)
+  @param out       [out] The signature
+  @param outlen    [in/out] The max size and resulting size of the signature 
+  @param prng      An active PRNG state
+  @param prng_idx  The index of the PRNG desired
+  @param hash_idx  The index of the hash desired
+  @param saltlen   The length of the salt desired (octets)
+  @param key       The private RSA key to use
+  @return CRYPT_OK if successful
+*/
+int rsa_sign_hash(const unsigned char *in,       unsigned long  inlen, 
+                        unsigned char *out,      unsigned long *outlen, 
+                        prng_state    *prng,     int            prng_idx,
+                        int            hash_idx, unsigned long  saltlen,
+                        rsa_key *key)
+{
+   unsigned long modulus_bitlen, modulus_bytelen, x;
+   int           err;
+   
+  LTC_ARGCHK(in       != NULL);
+  LTC_ARGCHK(out      != NULL);
+  LTC_ARGCHK(outlen   != NULL);
+  LTC_ARGCHK(key      != NULL);
+  
+  /* valid prng and hash ? */
+  if ((err = prng_is_valid(prng_idx)) != CRYPT_OK) {
+     return err;
+  }
+  if ((err = hash_is_valid(hash_idx)) != CRYPT_OK) {
+     return err;
+  }
+  
+  /* 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 > *outlen) {
+     return CRYPT_BUFFER_OVERFLOW;
+  }
+      
+  /* PSS pad the key */
+  x = *outlen;
+  if ((err = pkcs_1_pss_encode(in, inlen, saltlen, prng, prng_idx,
+                               hash_idx, modulus_bitlen, out, &x)) != CRYPT_OK) {
+     return err;
+  }
+
+  /* RSA encode it */
+  return rsa_exptmod(out, x, out, outlen, PK_PRIVATE, key);
+}
+
+#endif /* MRSA */
+
+/* $Source: /cvs/libtom/libtomcrypt/src/pk/rsa/rsa_sign_hash.c,v $ */
+/* $Revision: 1.3 $ */
+/* $Date: 2005/05/05 14:35:59 $ */