rsamain.c

一些封装好的加密函数的源代码

#include "tomcrypt.h"

int  main(void) 
{ 
    int               err,  hash_idx,  prng_idx,       res; 
    unsigned    long  l1,  l2; 
    unsigned    char  pt[16],  pt2[16],     out[1024]; 
    rsa_key           key; 

    /*  register  prng/hash      */ 
    if  (register_prng(&sprng_desc)  ==         -1)  { 
        printf("Error  registering        sprng"); 
		       return  EXIT_FAILURE; 
   } 

   if  (register_hash(&sha1_desc)  ==   -1)  { 
       printf("Error  registering   sha1"); 
       return  EXIT_FAILURE; 
   } 
   hash_idx  =  find_hash("sha1") ; 
   prng_idx  =  find_prng("sprng"); 

   /*  make an  RSA-1024  key */ 
   if  ((err =  rsa_make_key(NULL ,       /*  PRNG state  */ 
                              prng_idx,   /*  PRNG idx  */ 
                              1024/8,     /* 1024-bit  key  */ 
                              65537,      /*  we like e=65537  */ 
                              &key)       /*  where to store  the key  */ 
        ) != CRYPT_OK)  { 
        printf("rsa_make_key  %s",   error_to_string(err)); 
        return  EXIT_FAILURE; 
   } 

   /*  fill in  pt[] with  a  key we want  to send  ...  */ 
   l1  = sizeof(out); 
   if  ((err =  rsa_encrypt_key(pt,       /*  data  we wish to encrypt  */ 
                                  16,     /*  data is 16  bytes long  */ 
                                 out,     /*  where to store  ciphertext  */ 
                                 &l1,     /* length  of ciphertext  */ 
                          "TestApp",      /* our  lparam  for this  program  */ 
                                   7,     /* lparam  is  7  bytes long */ 
                               NULL,      /*  PRNG state  */ 
                           prng_idx,      /*  prng idx  */ 
                           hash_idx,      /*  hash idx  */ 
                               &key)      /* our  RSA key  */ 
        ) != CRYPT_OK)  { 
        printf("rsa_encrypt_key  %s",   error_to_string(err)); 
        return  EXIT_FAILURE; 
   } 

   /*  now let’s  decrypt  the encrypted  key */ 

    l2  = sizeof(pt2); 
    if ((err =   rsa_decrypt_key(out , /*    encrypted  data   */ 
                                     l1,  /* length  of  ciphertext  */ 
                                   pt2,   /*  where to  put plaintext   */ 
                                    &l2,  /*  plaintext  length  */ 
                             "TestApp",  /*  lparam  for  this  program  */ 
                                      7,  /* lparam  is  7  bytes long  */ 
                                  NULL,   /*  PRNG state  */ 
                              prng_idx,   /*  prng idx  */ 
                              hash_idx,   /*  hash idx  */ 
                                  &res,   /*  validity  of  data */ 
                                  &key)   /* our  RSA key  */ 
          ) != CRYPT_OK)  { 
        printf("rsa_decrypt_key  %s",      error_to_string(err)); 
        return  EXIT_FAILURE; 
    } 
    /* if  all  went well  pt  ==  pt2, l2  == 16,  res  ==  1  */ 
}