view libtomcrypt/src/math/ltm_desc.c @ 1653:76189c9ffea2

External Public-Key Authentication API (#72) * Implemented dynamic loading of an external plug-in shared library to delegate public key authentication * Moved conditional compilation of the plugin infrastructure into the configure.ac script to be able to add -ldl to dropbear build only when the flag is enabled * Added tags file to the ignore list * Updated API to have the constructor to return function pointers in the pliugin instance. Added support for passing user name to the checkpubkey function. Added options to the session returned by the plugin and have dropbear to parse and process them * Added -rdynamic to the linker flags when EPKA is enabled * Changed the API to pass a previously created session to the checkPubKey function (created during preauth) * Added documentation to the API * Added parameter addrstring to plugin creation function * Modified the API to retrieve the auth options. Instead of having them as field of the EPKASession struct, they are stored internally (plugin-dependent) in the plugin/session and retrieved through a pointer to a function (in the session) * Changed option string to be a simple char * instead of unsigned char *
author fabriziobertocci <fabriziobertocci@gmail.com>
date Wed, 15 May 2019 09:43:57 -0400
parents 6dba84798cd5
children 1051e4eea25a
line wrap: on
line source

/* 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.
 */

#define DESC_DEF_ONLY
#include "tomcrypt.h"

#ifdef LTM_DESC

#include <tommath.h>

static const struct {
    int mpi_code, ltc_code;
} mpi_to_ltc_codes[] = {
   { MP_OKAY ,  CRYPT_OK},
   { MP_MEM  ,  CRYPT_MEM},
   { MP_VAL  ,  CRYPT_INVALID_ARG},
};

/**
   Convert a MPI error to a LTC error (Possibly the most powerful function ever!  Oh wait... no)
   @param err    The error to convert
   @return The equivalent LTC error code or CRYPT_ERROR if none found
*/
static int mpi_to_ltc_error(int err)
{
   int x;

   for (x = 0; x < (int)(sizeof(mpi_to_ltc_codes)/sizeof(mpi_to_ltc_codes[0])); x++) {
       if (err == mpi_to_ltc_codes[x].mpi_code) {
          return mpi_to_ltc_codes[x].ltc_code;
       }
   }
   return CRYPT_ERROR;
}

static int init(void **a)
{
   int err;

   LTC_ARGCHK(a != NULL);

   *a = XCALLOC(1, sizeof(mp_int));
   if (*a == NULL) {
      return CRYPT_MEM;
   }

   if ((err = mpi_to_ltc_error(mp_init(*a))) != CRYPT_OK) {
      XFREE(*a);
   }
   return err;
}

static void deinit(void *a)
{
   LTC_ARGCHKVD(a != NULL);
   mp_clear(a);
   XFREE(a);
}

static int neg(void *a, void *b)
{
   LTC_ARGCHK(a != NULL);
   LTC_ARGCHK(b != NULL);
   return mpi_to_ltc_error(mp_neg(a, b));
}

static int copy(void *a, void *b)
{
   LTC_ARGCHK(a != NULL);
   LTC_ARGCHK(b != NULL);
   return mpi_to_ltc_error(mp_copy(a, b));
}

static int init_copy(void **a, void *b)
{
   if (init(a) != CRYPT_OK) {
      return CRYPT_MEM;
   }
   return copy(b, *a);
}

/* ---- trivial ---- */
static int set_int(void *a, ltc_mp_digit b)
{
   LTC_ARGCHK(a != NULL);
   return mpi_to_ltc_error(mp_set_int(a, b));
}

static unsigned long get_int(void *a)
{
   LTC_ARGCHK(a != NULL);
   return mp_get_int(a);
}

static ltc_mp_digit get_digit(void *a, int n)
{
   mp_int *A;
   LTC_ARGCHK(a != NULL);
   A = a;
   return (n >= A->used || n < 0) ? 0 : A->dp[n];
}

static int get_digit_count(void *a)
{
   mp_int *A;
   LTC_ARGCHK(a != NULL);
   A = a;
   return A->used;
}

static int compare(void *a, void *b)
{
   int ret;
   LTC_ARGCHK(a != NULL);
   LTC_ARGCHK(b != NULL);
   ret = mp_cmp(a, b);
   switch (ret) {
      case MP_LT: return LTC_MP_LT;
      case MP_EQ: return LTC_MP_EQ;
      case MP_GT: return LTC_MP_GT;
      default:    return 0;
   }
}

static int compare_d(void *a, ltc_mp_digit b)
{
   int ret;
   LTC_ARGCHK(a != NULL);
   ret = mp_cmp_d(a, b);
   switch (ret) {
      case MP_LT: return LTC_MP_LT;
      case MP_EQ: return LTC_MP_EQ;
      case MP_GT: return LTC_MP_GT;
      default:    return 0;
   }
}

static int count_bits(void *a)
{
   LTC_ARGCHK(a != NULL);
   return mp_count_bits(a);
}

static int count_lsb_bits(void *a)
{
   LTC_ARGCHK(a != NULL);
   return mp_cnt_lsb(a);
}


static int twoexpt(void *a, int n)
{
   LTC_ARGCHK(a != NULL);
   return mpi_to_ltc_error(mp_2expt(a, n));
}

/* ---- conversions ---- */

/* read ascii string */
static int read_radix(void *a, const char *b, int radix)
{
   LTC_ARGCHK(a != NULL);
   LTC_ARGCHK(b != NULL);
   return mpi_to_ltc_error(mp_read_radix(a, b, radix));
}

/* write one */
static int write_radix(void *a, char *b, int radix)
{
   LTC_ARGCHK(a != NULL);
   LTC_ARGCHK(b != NULL);
   return mpi_to_ltc_error(mp_toradix(a, b, radix));
}

/* get size as unsigned char string */
static unsigned long unsigned_size(void *a)
{
   LTC_ARGCHK(a != NULL);
   return mp_unsigned_bin_size(a);
}

/* store */
static int unsigned_write(void *a, unsigned char *b)
{
   LTC_ARGCHK(a != NULL);
   LTC_ARGCHK(b != NULL);
   return mpi_to_ltc_error(mp_to_unsigned_bin(a, b));
}

/* read */
static int unsigned_read(void *a, unsigned char *b, unsigned long len)
{
   LTC_ARGCHK(a != NULL);
   LTC_ARGCHK(b != NULL);
   return mpi_to_ltc_error(mp_read_unsigned_bin(a, b, len));
}

/* add */
static int add(void *a, void *b, void *c)
{
   LTC_ARGCHK(a != NULL);
   LTC_ARGCHK(b != NULL);
   LTC_ARGCHK(c != NULL);
   return mpi_to_ltc_error(mp_add(a, b, c));
}

static int addi(void *a, ltc_mp_digit b, void *c)
{
   LTC_ARGCHK(a != NULL);
   LTC_ARGCHK(c != NULL);
   return mpi_to_ltc_error(mp_add_d(a, b, c));
}

/* sub */
static int sub(void *a, void *b, void *c)
{
   LTC_ARGCHK(a != NULL);
   LTC_ARGCHK(b != NULL);
   LTC_ARGCHK(c != NULL);
   return mpi_to_ltc_error(mp_sub(a, b, c));
}

static int subi(void *a, ltc_mp_digit b, void *c)
{
   LTC_ARGCHK(a != NULL);
   LTC_ARGCHK(c != NULL);
   return mpi_to_ltc_error(mp_sub_d(a, b, c));
}

/* mul */
static int mul(void *a, void *b, void *c)
{
   LTC_ARGCHK(a != NULL);
   LTC_ARGCHK(b != NULL);
   LTC_ARGCHK(c != NULL);
   return mpi_to_ltc_error(mp_mul(a, b, c));
}

static int muli(void *a, ltc_mp_digit b, void *c)
{
   LTC_ARGCHK(a != NULL);
   LTC_ARGCHK(c != NULL);
   return mpi_to_ltc_error(mp_mul_d(a, b, c));
}

/* sqr */
static int sqr(void *a, void *b)
{
   LTC_ARGCHK(a != NULL);
   LTC_ARGCHK(b != NULL);
   return mpi_to_ltc_error(mp_sqr(a, b));
}

/* div */
static int divide(void *a, void *b, void *c, void *d)
{
   LTC_ARGCHK(a != NULL);
   LTC_ARGCHK(b != NULL);
   return mpi_to_ltc_error(mp_div(a, b, c, d));
}

static int div_2(void *a, void *b)
{
   LTC_ARGCHK(a != NULL);
   LTC_ARGCHK(b != NULL);
   return mpi_to_ltc_error(mp_div_2(a, b));
}

/* modi */
static int modi(void *a, ltc_mp_digit b, ltc_mp_digit *c)
{
   mp_digit tmp;
   int      err;

   LTC_ARGCHK(a != NULL);
   LTC_ARGCHK(c != NULL);

   if ((err = mpi_to_ltc_error(mp_mod_d(a, b, &tmp))) != CRYPT_OK) {
      return err;
   }
   *c = tmp;
   return CRYPT_OK;
}

/* gcd */
static int gcd(void *a, void *b, void *c)
{
   LTC_ARGCHK(a != NULL);
   LTC_ARGCHK(b != NULL);
   LTC_ARGCHK(c != NULL);
   return mpi_to_ltc_error(mp_gcd(a, b, c));
}

/* lcm */
static int lcm(void *a, void *b, void *c)
{
   LTC_ARGCHK(a != NULL);
   LTC_ARGCHK(b != NULL);
   LTC_ARGCHK(c != NULL);
   return mpi_to_ltc_error(mp_lcm(a, b, c));
}

static int addmod(void *a, void *b, void *c, void *d)
{
   LTC_ARGCHK(a != NULL);
   LTC_ARGCHK(b != NULL);
   LTC_ARGCHK(c != NULL);
   LTC_ARGCHK(d != NULL);
   return mpi_to_ltc_error(mp_addmod(a,b,c,d));
}

static int submod(void *a, void *b, void *c, void *d)
{
   LTC_ARGCHK(a != NULL);
   LTC_ARGCHK(b != NULL);
   LTC_ARGCHK(c != NULL);
   LTC_ARGCHK(d != NULL);
   return mpi_to_ltc_error(mp_submod(a,b,c,d));
}

static int mulmod(void *a, void *b, void *c, void *d)
{
   LTC_ARGCHK(a != NULL);
   LTC_ARGCHK(b != NULL);
   LTC_ARGCHK(c != NULL);
   LTC_ARGCHK(d != NULL);
   return mpi_to_ltc_error(mp_mulmod(a,b,c,d));
}

static int sqrmod(void *a, void *b, void *c)
{
   LTC_ARGCHK(a != NULL);
   LTC_ARGCHK(b != NULL);
   LTC_ARGCHK(c != NULL);
   return mpi_to_ltc_error(mp_sqrmod(a,b,c));
}

/* invmod */
static int invmod(void *a, void *b, void *c)
{
   LTC_ARGCHK(a != NULL);
   LTC_ARGCHK(b != NULL);
   LTC_ARGCHK(c != NULL);
   return mpi_to_ltc_error(mp_invmod(a, b, c));
}

/* setup */
static int montgomery_setup(void *a, void **b)
{
   int err;
   LTC_ARGCHK(a != NULL);
   LTC_ARGCHK(b != NULL);
   *b = XCALLOC(1, sizeof(mp_digit));
   if (*b == NULL) {
      return CRYPT_MEM;
   }
   if ((err = mpi_to_ltc_error(mp_montgomery_setup(a, (mp_digit *)*b))) != CRYPT_OK) {
      XFREE(*b);
   }
   return err;
}

/* get normalization value */
static int montgomery_normalization(void *a, void *b)
{
   LTC_ARGCHK(a != NULL);
   LTC_ARGCHK(b != NULL);
   return mpi_to_ltc_error(mp_montgomery_calc_normalization(a, b));
}

/* reduce */
static int montgomery_reduce(void *a, void *b, void *c)
{
   LTC_ARGCHK(a != NULL);
   LTC_ARGCHK(b != NULL);
   LTC_ARGCHK(c != NULL);
   return mpi_to_ltc_error(mp_montgomery_reduce(a, b, *((mp_digit *)c)));
}

/* clean up */
static void montgomery_deinit(void *a)
{
   XFREE(a);
}

static int exptmod(void *a, void *b, void *c, void *d)
{
   LTC_ARGCHK(a != NULL);
   LTC_ARGCHK(b != NULL);
   LTC_ARGCHK(c != NULL);
   LTC_ARGCHK(d != NULL);
   return mpi_to_ltc_error(mp_exptmod(a,b,c,d));
}

static int isprime(void *a, int b, int *c)
{
   int err;
   LTC_ARGCHK(a != NULL);
   LTC_ARGCHK(c != NULL);
   if (b == 0) {
       b = LTC_MILLER_RABIN_REPS;
   } /* if */
   err = mpi_to_ltc_error(mp_prime_is_prime(a, b, c));
   *c = (*c == MP_YES) ? LTC_MP_YES : LTC_MP_NO;
   return err;
}

static int set_rand(void *a, int size)
{
   LTC_ARGCHK(a != NULL);
   return mpi_to_ltc_error(mp_rand(a, size));
}

const ltc_math_descriptor ltm_desc = {

   "LibTomMath",
   (int)DIGIT_BIT,

   &init,
   &init_copy,
   &deinit,

   &neg,
   &copy,

   &set_int,
   &get_int,
   &get_digit,
   &get_digit_count,
   &compare,
   &compare_d,
   &count_bits,
   &count_lsb_bits,
   &twoexpt,

   &read_radix,
   &write_radix,
   &unsigned_size,
   &unsigned_write,
   &unsigned_read,

   &add,
   &addi,
   &sub,
   &subi,
   &mul,
   &muli,
   &sqr,
   &divide,
   &div_2,
   &modi,
   &gcd,
   &lcm,

   &mulmod,
   &sqrmod,
   &invmod,

   &montgomery_setup,
   &montgomery_normalization,
   &montgomery_reduce,
   &montgomery_deinit,

   &exptmod,
   &isprime,

#ifdef LTC_MECC
#ifdef LTC_MECC_FP
   &ltc_ecc_fp_mulmod,
#else
   &ltc_ecc_mulmod,
#endif
   &ltc_ecc_projective_add_point,
   &ltc_ecc_projective_dbl_point,
   &ltc_ecc_map,
#ifdef LTC_ECC_SHAMIR
#ifdef LTC_MECC_FP
   &ltc_ecc_fp_mul2add,
#else
   &ltc_ecc_mul2add,
#endif /* LTC_MECC_FP */
#else
   NULL,
#endif /* LTC_ECC_SHAMIR */
#else
   NULL, NULL, NULL, NULL, NULL,
#endif /* LTC_MECC */

#ifdef LTC_MRSA
   &rsa_make_key,
   &rsa_exptmod,
#else
   NULL, NULL,
#endif
   &addmod,
   &submod,

   &set_rand,

};


#endif

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