示例#1
0
int BN_MONT_CTX_set(BN_MONT_CTX *mont, const BIGNUM *mod, BN_CTX *ctx) {
  int ret = 0;
  BIGNUM *Ri, *R;
  BIGNUM tmod;
  BN_ULONG buf[2];

  if (BN_is_zero(mod)) {
    OPENSSL_PUT_ERROR(BN, BN_R_DIV_BY_ZERO);
    return 0;
  }

  BN_CTX_start(ctx);
  Ri = BN_CTX_get(ctx);
  if (Ri == NULL) {
    goto err;
  }
  R = &mont->RR; /* grab RR as a temp */
  if (!BN_copy(&mont->N, mod)) {
    goto err; /* Set N */
  }
  mont->N.neg = 0;

  BN_init(&tmod);
  tmod.d = buf;
  tmod.dmax = 2;
  tmod.neg = 0;

#if defined(OPENSSL_BN_ASM_MONT) && (BN_BITS2 <= 32)
  /* Only certain BN_BITS2<=32 platforms actually make use of
   * n0[1], and we could use the #else case (with a shorter R
   * value) for the others.  However, currently only the assembler
   * files do know which is which. */

  BN_zero(R);
  if (!BN_set_bit(R, 2 * BN_BITS2)) {
    goto err;
  }

  tmod.top = 0;
  if ((buf[0] = mod->d[0])) {
    tmod.top = 1;
  }
  if ((buf[1] = mod->top > 1 ? mod->d[1] : 0)) {
    tmod.top = 2;
  }

  if (BN_mod_inverse(Ri, R, &tmod, ctx) == NULL) {
    goto err;
  }
  if (!BN_lshift(Ri, Ri, 2 * BN_BITS2)) {
    goto err; /* R*Ri */
  }
  if (!BN_is_zero(Ri)) {
    if (!BN_sub_word(Ri, 1)) {
      goto err;
    }
  } else {
    /* if N mod word size == 1 */
    if (bn_expand(Ri, (int)sizeof(BN_ULONG) * 2) == NULL) {
      goto err;
    }
    /* Ri-- (mod double word size) */
    Ri->neg = 0;
    Ri->d[0] = BN_MASK2;
    Ri->d[1] = BN_MASK2;
    Ri->top = 2;
  }

  if (!BN_div(Ri, NULL, Ri, &tmod, ctx)) {
    goto err;
  }
  /* Ni = (R*Ri-1)/N,
   * keep only couple of least significant words: */
  mont->n0[0] = (Ri->top > 0) ? Ri->d[0] : 0;
  mont->n0[1] = (Ri->top > 1) ? Ri->d[1] : 0;
#else
  BN_zero(R);
  if (!BN_set_bit(R, BN_BITS2)) {
    goto err; /* R */
  }

  buf[0] = mod->d[0]; /* tmod = N mod word size */
  buf[1] = 0;
  tmod.top = buf[0] != 0 ? 1 : 0;
  /* Ri = R^-1 mod N*/
  if (BN_mod_inverse(Ri, R, &tmod, ctx) == NULL) {
    goto err;
  }
  if (!BN_lshift(Ri, Ri, BN_BITS2)) {
    goto err; /* R*Ri */
  }
  if (!BN_is_zero(Ri)) {
    if (!BN_sub_word(Ri, 1)) {
      goto err;
    }
  } else {
    /* if N mod word size == 1 */
    if (!BN_set_word(Ri, BN_MASK2)) {
      goto err; /* Ri-- (mod word size) */
    }
  }
  if (!BN_div(Ri, NULL, Ri, &tmod, ctx)) {
    goto err;
  }
  /* Ni = (R*Ri-1)/N,
   * keep only least significant word: */
  mont->n0[0] = (Ri->top > 0) ? Ri->d[0] : 0;
  mont->n0[1] = 0;
#endif

  /* RR = (2^ri)^2 == 2^(ri*2) == 1 << (ri*2), which has its (ri*2)th bit set. */
  int ri = (BN_num_bits(mod) + (BN_BITS2 - 1)) / BN_BITS2 * BN_BITS2;
  BN_zero(&(mont->RR));
  if (!BN_set_bit(&(mont->RR), ri * 2)) {
    goto err;
  }
  if (!BN_mod(&(mont->RR), &(mont->RR), &(mont->N), ctx)) {
    goto err;
  }

  ret = 1;

err:
  BN_CTX_end(ctx);
  return ret;
}
示例#2
0
int
BN_MONT_CTX_set(BN_MONT_CTX *mont, const BIGNUM *mod, BN_CTX *ctx)
{
	int ret = 0;
	BIGNUM *Ri, *R;

	BN_CTX_start(ctx);
	if ((Ri = BN_CTX_get(ctx)) == NULL)
		goto err;
	R = &(mont->RR);				/* grab RR as a temp */
	if (!BN_copy(&(mont->N), mod))
		 goto err;				/* Set N */
	mont->N.neg = 0;

#ifdef MONT_WORD
	{
		BIGNUM tmod;
		BN_ULONG buf[2];

		BN_init(&tmod);
		tmod.d = buf;
		tmod.dmax = 2;
		tmod.neg = 0;

		mont->ri = (BN_num_bits(mod) +
		    (BN_BITS2 - 1)) / BN_BITS2 * BN_BITS2;

#if defined(OPENSSL_BN_ASM_MONT) && (BN_BITS2<=32)
		/* Only certain BN_BITS2<=32 platforms actually make use of
		 * n0[1], and we could use the #else case (with a shorter R
		 * value) for the others.  However, currently only the assembler
		 * files do know which is which. */

		BN_zero(R);
		if (!(BN_set_bit(R, 2 * BN_BITS2)))
			goto err;

		tmod.top = 0;
		if ((buf[0] = mod->d[0]))
			tmod.top = 1;
		if ((buf[1] = mod->top > 1 ? mod->d[1] : 0))
			tmod.top = 2;

		if ((BN_mod_inverse(Ri, R, &tmod, ctx)) == NULL)
			goto err;
		if (!BN_lshift(Ri, Ri, 2 * BN_BITS2))
			goto err; /* R*Ri */
		if (!BN_is_zero(Ri)) {
			if (!BN_sub_word(Ri, 1))
				goto err;
		}
		else /* if N mod word size == 1 */
		{
			if (bn_expand(Ri, (int)sizeof(BN_ULONG) * 2) == NULL)
				goto err;
			/* Ri-- (mod double word size) */
			Ri->neg = 0;
			Ri->d[0] = BN_MASK2;
			Ri->d[1] = BN_MASK2;
			Ri->top = 2;
		}
		if (!BN_div(Ri, NULL, Ri, &tmod, ctx))
			goto err;
		/* Ni = (R*Ri-1)/N,
		 * keep only couple of least significant words: */
		mont->n0[0] = (Ri->top > 0) ? Ri->d[0] : 0;
		mont->n0[1] = (Ri->top > 1) ? Ri->d[1] : 0;
#else
		BN_zero(R);
		if (!(BN_set_bit(R, BN_BITS2)))
			goto err;	/* R */

		buf[0] = mod->d[0]; /* tmod = N mod word size */
		buf[1] = 0;
		tmod.top = buf[0] != 0 ? 1 : 0;
		/* Ri = R^-1 mod N*/
		if ((BN_mod_inverse(Ri, R, &tmod, ctx)) == NULL)
			goto err;
		if (!BN_lshift(Ri, Ri, BN_BITS2))
			goto err; /* R*Ri */
		if (!BN_is_zero(Ri)) {
			if (!BN_sub_word(Ri, 1))
				goto err;
		}
		else /* if N mod word size == 1 */
		{
			if (!BN_set_word(Ri, BN_MASK2))
				goto err;  /* Ri-- (mod word size) */
		}
		if (!BN_div(Ri, NULL, Ri, &tmod, ctx))
			goto err;
		/* Ni = (R*Ri-1)/N,
		 * keep only least significant word: */
		mont->n0[0] = (Ri->top > 0) ? Ri->d[0] : 0;
		mont->n0[1] = 0;
#endif
	}
#else /* !MONT_WORD */
	{ /* bignum version */
		mont->ri = BN_num_bits(&mont->N);
		BN_zero(R);
		if (!BN_set_bit(R, mont->ri))
			goto err;  /* R = 2^ri */
		/* Ri = R^-1 mod N*/
		if ((BN_mod_inverse(Ri, R, &mont->N, ctx)) == NULL)
			goto err;
		if (!BN_lshift(Ri, Ri, mont->ri))
			goto err; /* R*Ri */
		if (!BN_sub_word(Ri, 1))
			goto err;
		/* Ni = (R*Ri-1) / N */
		if (!BN_div(&(mont->Ni), NULL, Ri, &mont->N, ctx))
			goto err;
	}
#endif

	/* setup RR for conversions */
	BN_zero(&(mont->RR));
	if (!BN_set_bit(&(mont->RR), mont->ri*2))
		goto err;
	if (!BN_mod(&(mont->RR), &(mont->RR), &(mont->N), ctx))
		goto err;

	ret = 1;

err:
	BN_CTX_end(ctx);
	return ret;
}
示例#3
0
/*
 * Find the bignum ranges that produce a given prefix.
 */
static int
get_prefix_ranges(int addrtype, const char *pfx, BIGNUM **result,
		  BN_CTX *bnctx)
{
	int i, p, c;
	int zero_prefix = 0;
	int check_upper = 0;
	int b58pow, b58ceil, b58top = 0;
	int ret = -1;

	BIGNUM bntarg, bnceil, bnfloor;
	BIGNUM bnbase;
	BIGNUM *bnap, *bnbp, *bntp;
	BIGNUM *bnhigh = NULL, *bnlow = NULL, *bnhigh2 = NULL, *bnlow2 = NULL;
	BIGNUM bntmp, bntmp2;

	BN_init(&bntarg);
	BN_init(&bnceil);
	BN_init(&bnfloor);
	BN_init(&bnbase);
	BN_init(&bntmp);
	BN_init(&bntmp2);

	BN_set_word(&bnbase, 58);

	p = strlen(pfx);

	for (i = 0; i < p; i++) {
		c = vg_b58_reverse_map[(int)pfx[i]];
		if (c == -1) {
			fprintf(stderr,
				"Invalid character '%c' in prefix '%s'\n",
				pfx[i], pfx);
			goto out;
		}
		if (i == zero_prefix) {
			if (c == 0) {
				/* Add another zero prefix */
				zero_prefix++;
				if (zero_prefix > 19) {
					fprintf(stderr,
						"Prefix '%s' is too long\n",
						pfx);
					goto out;
				}
				continue;
			}

			/* First non-zero character */
			b58top = c;
			BN_set_word(&bntarg, c);

		} else {
			BN_set_word(&bntmp2, c);
			BN_mul(&bntmp, &bntarg, &bnbase, bnctx);
			BN_add(&bntarg, &bntmp, &bntmp2);
		}
	}

	/* Power-of-two ceiling and floor values based on leading 1s */
	BN_clear(&bntmp);
	BN_set_bit(&bntmp, 200 - (zero_prefix * 8));
	BN_sub(&bnceil, &bntmp, BN_value_one());
	BN_set_bit(&bnfloor, 192 - (zero_prefix * 8));

	bnlow = BN_new();
	bnhigh = BN_new();

	if (b58top) {
		/*
		 * If a non-zero was given in the prefix, find the
		 * numeric boundaries of the prefix.
		 */

		BN_copy(&bntmp, &bnceil);
		bnap = &bntmp;
		bnbp = &bntmp2;
		b58pow = 0;
		while (BN_cmp(bnap, &bnbase) > 0) {
			b58pow++;
			BN_div(bnbp, NULL, bnap, &bnbase, bnctx);
			bntp = bnap;
			bnap = bnbp;
			bnbp = bntp;
		}
		b58ceil = BN_get_word(bnap);

		if ((b58pow - (p - zero_prefix)) <= 0) {
			/*
			 * Do not allow the prefix to constrain the
			 * check value, this is ridiculous.
			 */
			fprintf(stderr, "Prefix '%s' is too long\n", pfx);
			goto out;
		}

		BN_set_word(&bntmp2, b58pow - (p - zero_prefix));
		BN_exp(&bntmp, &bnbase, &bntmp2, bnctx);
		BN_mul(bnlow, &bntmp, &bntarg, bnctx);
		BN_sub(&bntmp2, &bntmp, BN_value_one());
		BN_add(bnhigh, bnlow, &bntmp2);

		if (b58top <= b58ceil) {
			/* Fill out the upper range too */
			check_upper = 1;
			bnlow2 = BN_new();
			bnhigh2 = BN_new();

			BN_mul(bnlow2, bnlow, &bnbase, bnctx);
			BN_mul(&bntmp2, bnhigh, &bnbase, bnctx);
			BN_set_word(&bntmp, 57);
			BN_add(bnhigh2, &bntmp2, &bntmp);

			/*
			 * Addresses above the ceiling will have one
			 * fewer "1" prefix in front than we require.
			 */
			if (BN_cmp(&bnceil, bnlow2) < 0) {
				/* High prefix is above the ceiling */
				check_upper = 0;
				BN_free(bnhigh2);
				bnhigh2 = NULL;
				BN_free(bnlow2);
				bnlow2 = NULL;
			}
			else if (BN_cmp(&bnceil, bnhigh2) < 0)
				/* High prefix is partly above the ceiling */
				BN_copy(bnhigh2, &bnceil);

			/*
			 * Addresses below the floor will have another
			 * "1" prefix in front instead of our target.
			 */
			if (BN_cmp(&bnfloor, bnhigh) >= 0) {
				/* Low prefix is completely below the floor */
				assert(check_upper);
				check_upper = 0;
				BN_free(bnhigh);
				bnhigh = bnhigh2;
				bnhigh2 = NULL;
				BN_free(bnlow);
				bnlow = bnlow2;
				bnlow2 = NULL;
			}			
			else if (BN_cmp(&bnfloor, bnlow) > 0) {
				/* Low prefix is partly below the floor */
				BN_copy(bnlow, &bnfloor);
			}
		}

	} else {
		BN_copy(bnhigh, &bnceil);
		BN_clear(bnlow);
	}

	/* Limit the prefix to the address type */
	BN_clear(&bntmp);
	BN_set_word(&bntmp, addrtype);
	BN_lshift(&bntmp2, &bntmp, 192);

	if (check_upper) {
		if (BN_cmp(&bntmp2, bnhigh2) > 0) {
			check_upper = 0;
			BN_free(bnhigh2);
			bnhigh2 = NULL;
			BN_free(bnlow2);
			bnlow2 = NULL;
		}
		else if (BN_cmp(&bntmp2, bnlow2) > 0)
			BN_copy(bnlow2, &bntmp2);
	}

	if (BN_cmp(&bntmp2, bnhigh) > 0) {
		if (!check_upper)
			goto not_possible;
		check_upper = 0;
		BN_free(bnhigh);
		bnhigh = bnhigh2;
		bnhigh2 = NULL;
		BN_free(bnlow);
		bnlow = bnlow2;
		bnlow2 = NULL;
	}
	else if (BN_cmp(&bntmp2, bnlow) > 0) {
		BN_copy(bnlow, &bntmp2);
	}

	BN_set_word(&bntmp, addrtype + 1);
	BN_lshift(&bntmp2, &bntmp, 192);

	if (check_upper) {
		if (BN_cmp(&bntmp2, bnlow2) < 0) {
			check_upper = 0;
			BN_free(bnhigh2);
			bnhigh2 = NULL;
			BN_free(bnlow2);
			bnlow2 = NULL;
		}
		else if (BN_cmp(&bntmp2, bnhigh2) < 0)
			BN_copy(bnlow2, &bntmp2);
	}

	if (BN_cmp(&bntmp2, bnlow) < 0) {
		if (!check_upper)
			goto not_possible;
		check_upper = 0;
		BN_free(bnhigh);
		bnhigh = bnhigh2;
		bnhigh2 = NULL;
		BN_free(bnlow);
		bnlow = bnlow2;
		bnlow2 = NULL;
	}
	else if (BN_cmp(&bntmp2, bnhigh) < 0) {
		BN_copy(bnhigh, &bntmp2);
	}

	/* Address ranges are complete */
	assert(check_upper || ((bnlow2 == NULL) && (bnhigh2 == NULL)));
	result[0] = bnlow;
	result[1] = bnhigh;
	result[2] = bnlow2;
	result[3] = bnhigh2;
	bnlow = NULL;
	bnhigh = NULL;
	bnlow2 = NULL;
	bnhigh2 = NULL;
	ret = 0;

	if (0) {
	not_possible:
		ret = -2;
	}

out:
	BN_clear_free(&bntarg);
	BN_clear_free(&bnceil);
	BN_clear_free(&bnfloor);
	BN_clear_free(&bnbase);
	BN_clear_free(&bntmp);
	BN_clear_free(&bntmp2);
	if (bnhigh)
		BN_free(bnhigh);
	if (bnlow)
		BN_free(bnlow);
	if (bnhigh2)
		BN_free(bnhigh2);
	if (bnlow2)
		BN_free(bnlow2);

	return ret;
}
示例#4
0
static isc_result_t
opensslrsa_generate(dst_key_t *key, int exp, void (*callback)(int)) {
#if OPENSSL_VERSION_NUMBER > 0x00908000L
	BN_GENCB cb;
	union {
		void *dptr;
		void (*fptr)(int);
	} u;
	RSA *rsa = RSA_new();
	BIGNUM *e = BN_new();
#if USE_EVP
	EVP_PKEY *pkey = EVP_PKEY_new();
#endif

	if (rsa == NULL || e == NULL)
		goto err;
#if USE_EVP
	if (pkey == NULL)
		goto err;
	if (!EVP_PKEY_set1_RSA(pkey, rsa))
		goto err;
#endif

	if (exp == 0) {
		/* RSA_F4 0x10001 */
		BN_set_bit(e, 0);
		BN_set_bit(e, 16);
	} else {
		/* F5 0x100000001 */
		BN_set_bit(e, 0);
		BN_set_bit(e, 32);
	}

	if (callback == NULL) {
		BN_GENCB_set_old(&cb, NULL, NULL);
	} else {
		u.fptr = callback;
		BN_GENCB_set(&cb, &progress_cb, u.dptr);
	}

	if (RSA_generate_key_ex(rsa, key->key_size, e, &cb)) {
		BN_free(e);
		SET_FLAGS(rsa);
#if USE_EVP
		key->keydata.pkey = pkey;

		RSA_free(rsa);
#else
		key->keydata.rsa = rsa;
#endif
		return (ISC_R_SUCCESS);
	}

err:
#if USE_EVP
	if (pkey != NULL)
		EVP_PKEY_free(pkey);
#endif
	if (e != NULL)
		BN_free(e);
	if (rsa != NULL)
		RSA_free(rsa);
	return (dst__openssl_toresult(DST_R_OPENSSLFAILURE));
#else
	RSA *rsa;
	unsigned long e;
#if USE_EVP
	EVP_PKEY *pkey = EVP_PKEY_new();

	UNUSED(callback);

	if (pkey == NULL)
		return (ISC_R_NOMEMORY);
#else
	UNUSED(callback);
#endif

	if (exp == 0)
	       e = RSA_F4;
	else
	       e = 0x40000003;
	rsa = RSA_generate_key(key->key_size, e, NULL, NULL);
	if (rsa == NULL) {
#if USE_EVP
		EVP_PKEY_free(pkey);
#endif
		return (dst__openssl_toresult(DST_R_OPENSSLFAILURE));
	}
	SET_FLAGS(rsa);
#if USE_EVP
	if (!EVP_PKEY_set1_RSA(pkey, rsa)) {
		EVP_PKEY_free(pkey);
		RSA_free(rsa);
		return (dst__openssl_toresult(DST_R_OPENSSLFAILURE));
	}
	key->keydata.pkey = pkey;
	RSA_free(rsa);
#else
	key->keydata.rsa = rsa;
#endif

	return (ISC_R_SUCCESS);
#endif
}
示例#5
0
/*
 * Supplemental function to return BIGNUM containing value n = RndOddNum(k) algorithm
 * @param: k numbits and char pointer to binary read in using x = ceil(k/8) bytes
 * @return: BIGNUM n
 */
BIGNUM *RndOddNum(int k, char *temp, int x_byte)
{
	BIGNUM *result = NULL;

	result = BN_new();
	if(result == NULL)
	{
		fprintf(stderr, "Can't allocate space to hold returned result for RndOddNum function\n");
		return NULL;
	}
	BN_zero(result);

	if(BN_bin2bn((unsigned char*)temp, x_byte, result) != NULL)
	{
		//Set bit 0 and k-1
		if(BN_set_bit(result, 0))
		{
			if(BN_set_bit(result, k-1))
			{
				//Get total number of bits in result
				int total_num_bits = BN_num_bits(result);
				//Clear all higher order bit
				while(k < total_num_bits)
				{
					if(BN_clear_bit(result, k) == 0) //error: can't clear bit
					{
						//error: can't clear bit
						fprintf(stderr, "ERROR: can't clear bit %dth\n", k);
						BN_free(result);
						return NULL;
					}
					k += 1;
				}

			}
			else
			{
				//error: can't set bit k-1
				fprintf(stderr, "ERROR: can't set bit k-1\n");
				BN_free(result);
				return NULL;
			}
		}
		else
		{
			//error: can't set bit 0
			fprintf(stderr, "ERROR: can't set bit 0\n");
			BN_free(result);
			return NULL;
		}
	}
	else
	{
		//error: can't convert from bin to bn
		fprintf(stderr, "ERROR: can't convert binary read from rndfile to bn\n");
		BN_free(result);
		return NULL;
	}

	return result; //It is the calling function responsibility to free BIGNUM result
}
示例#6
0
static int
vg_prefix_context_add_patterns(vg_context_t *vcp,
			       const char ** const patterns, int npatterns)
{
	vg_prefix_context_t *vcpp = (vg_prefix_context_t *) vcp;
	prefix_case_iter_t caseiter;
	vg_prefix_t *vp, *vp2;
	BN_CTX *bnctx;
	BIGNUM bntmp, bntmp2, bntmp3;
	BIGNUM *ranges[4];
	int ret = 0;
	int i, impossible = 0;
	int case_impossible;
	unsigned long npfx;
	char *dbuf;

	bnctx = BN_CTX_new();
	BN_init(&bntmp);
	BN_init(&bntmp2);
	BN_init(&bntmp3);

	npfx = 0;
	for (i = 0; i < npatterns; i++) {
		if (!vcpp->vcp_caseinsensitive) {
			vp = NULL;
			ret = get_prefix_ranges(vcpp->base.vc_addrtype,
						patterns[i],
						ranges, bnctx);
			if (!ret) {
				vp = vg_prefix_add_ranges(&vcpp->vcp_avlroot,
							  patterns[i],
							  ranges, NULL);
			}

		} else {
			/* Case-enumerate the prefix */
			if (!prefix_case_iter_init(&caseiter, patterns[i])) {
				fprintf(stderr,
					"Prefix '%s' is too long\n",
					patterns[i]);
				continue;
			}

			if (caseiter.ci_nbits > 16) {
				fprintf(stderr,
					"WARNING: Prefix '%s' has "
					"2^%d case-varied derivatives\n",
					patterns[i], caseiter.ci_nbits);
			}

			case_impossible = 0;
			vp = NULL;
			do {
				ret = get_prefix_ranges(vcpp->base.vc_addrtype,
							caseiter.ci_prefix,
							ranges, bnctx);
				if (ret == -2) {
					case_impossible++;
					ret = 0;
					continue;
				}
				if (ret)
					break;
				vp2 = vg_prefix_add_ranges(&vcpp->vcp_avlroot,
							   patterns[i],
							   ranges,
							   vp);
				if (!vp2) {
					ret = -1;
					break;
				}
				if (!vp)
					vp = vp2;

			} while (prefix_case_iter_next(&caseiter));

			if (!vp && case_impossible)
				ret = -2;

			if (ret && vp) {
				vg_prefix_delete(&vcpp->vcp_avlroot, vp);
				vp = NULL;
			}
		}

		if (ret == -2) {
			fprintf(stderr,
				"Prefix '%s' not possible\n", patterns[i]);
			impossible++;
		}

		if (!vp)
			continue;

		npfx++;

		/* Determine the probability of finding a match */
		vg_prefix_range_sum(vp, &bntmp, &bntmp2);
		BN_add(&bntmp2, &vcpp->vcp_difficulty, &bntmp);
		BN_copy(&vcpp->vcp_difficulty, &bntmp2);

		if (vcp->vc_verbose > 1) {
			BN_clear(&bntmp2);
			BN_set_bit(&bntmp2, 192);
			BN_div(&bntmp3, NULL, &bntmp2, &bntmp, bnctx);

			dbuf = BN_bn2dec(&bntmp3);
			fprintf(stderr,
				"Prefix difficulty: %20s %s\n",
				dbuf, patterns[i]);
			OPENSSL_free(dbuf);
		}
	}

	vcpp->base.vc_npatterns += npfx;
	vcpp->base.vc_npatterns_start += npfx;

	if (!npfx && impossible) {
		const char *ats = "bitcoin", *bw = "\"1\"";
		switch (vcpp->base.vc_addrtype) {
		case 5:
			ats = "bitcoin script";
			bw = "\"3\"";
			break;
		case 111:
			ats = "testnet";
			bw = "\"m\" or \"n\"";
			break;
		case 52:
			ats = "namecoin";
			bw = "\"M\" or \"N\"";
			break;
		case 48:
			ats = "litecoin";
			bw = "\"L\"";
			break;
		default:
			break;
		}
		fprintf(stderr,
			"Hint: valid %s addresses begin with %s\n", ats, bw);
	}

	if (npfx)
		vg_prefix_context_next_difficulty(vcpp, &bntmp, &bntmp2, bnctx);

	ret = (npfx != 0);

	BN_clear_free(&bntmp);
	BN_clear_free(&bntmp2);
	BN_clear_free(&bntmp3);
	BN_CTX_free(bnctx);
	return ret;
}
示例#7
0
文件: ecdsa_ossl.c 项目: tcmx/openssl
static int ecdsa_sign_setup(EC_KEY *eckey, BN_CTX *ctx_in,
                            BIGNUM **kinvp, BIGNUM **rp,
                            const unsigned char *dgst, int dlen)
{
    BN_CTX *ctx = NULL;
    BIGNUM *k = NULL, *r = NULL, *X = NULL;
    const BIGNUM *order;
    EC_POINT *tmp_point = NULL;
    const EC_GROUP *group;
    int ret = 0;
    int order_bits;

    if (eckey == NULL || (group = EC_KEY_get0_group(eckey)) == NULL) {
        ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_PASSED_NULL_PARAMETER);
        return 0;
    }

    if (!EC_KEY_can_sign(eckey)) {
        ECerr(EC_F_ECDSA_SIGN_SETUP, EC_R_CURVE_DOES_NOT_SUPPORT_SIGNING);
        return 0;
    }

    if (ctx_in == NULL) {
        if ((ctx = BN_CTX_new()) == NULL) {
            ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_MALLOC_FAILURE);
            return 0;
        }
    } else
        ctx = ctx_in;

    k = BN_new();               /* this value is later returned in *kinvp */
    r = BN_new();               /* this value is later returned in *rp */
    X = BN_new();
    if (k == NULL || r == NULL || X == NULL) {
        ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_MALLOC_FAILURE);
        goto err;
    }
    if ((tmp_point = EC_POINT_new(group)) == NULL) {
        ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
        goto err;
    }
    order = EC_GROUP_get0_order(group);
    if (order == NULL) {
        ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
        goto err;
    }

    /* Preallocate space */
    order_bits = BN_num_bits(order);
    if (!BN_set_bit(k, order_bits)
        || !BN_set_bit(r, order_bits)
        || !BN_set_bit(X, order_bits))
        goto err;

    do {
        /* get random k */
        do
            if (dgst != NULL) {
                if (!BN_generate_dsa_nonce
                    (k, order, EC_KEY_get0_private_key(eckey), dgst, dlen,
                     ctx)) {
                    ECerr(EC_F_ECDSA_SIGN_SETUP,
                             EC_R_RANDOM_NUMBER_GENERATION_FAILED);
                    goto err;
                }
            } else {
                if (!BN_priv_rand_range(k, order)) {
                    ECerr(EC_F_ECDSA_SIGN_SETUP,
                             EC_R_RANDOM_NUMBER_GENERATION_FAILED);
                    goto err;
                }
            }
        while (BN_is_zero(k));

        /* compute r the x-coordinate of generator * k */
        if (!EC_POINT_mul(group, tmp_point, k, NULL, NULL, ctx)) {
            ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
            goto err;
        }
        if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) ==
            NID_X9_62_prime_field) {
            if (!EC_POINT_get_affine_coordinates_GFp
                (group, tmp_point, X, NULL, ctx)) {
                ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
                goto err;
            }
        }
#ifndef OPENSSL_NO_EC2M
        else {                  /* NID_X9_62_characteristic_two_field */

            if (!EC_POINT_get_affine_coordinates_GF2m(group,
                                                      tmp_point, X, NULL,
                                                      ctx)) {
                ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_EC_LIB);
                goto err;
            }
        }
#endif
        if (!BN_nnmod(r, X, order, ctx)) {
            ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
            goto err;
        }
    }
    while (BN_is_zero(r));

    /* Check if optimized inverse is implemented */
    if (EC_GROUP_do_inverse_ord(group, k, k, ctx) == 0) {
        /* compute the inverse of k */
        if (group->mont_data != NULL) {
            /*
             * We want inverse in constant time, therefore we utilize the fact
             * order must be prime and use Fermats Little Theorem instead.
             */
            if (!BN_set_word(X, 2)) {
                ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
                goto err;
            }
            if (!BN_mod_sub(X, order, X, order, ctx)) {
                ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
                goto err;
            }
            BN_set_flags(X, BN_FLG_CONSTTIME);
            if (!BN_mod_exp_mont_consttime(k, k, X, order, ctx,
                                           group->mont_data)) {
                ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
                goto err;
            }
        } else {
            if (!BN_mod_inverse(k, k, order, ctx)) {
                ECerr(EC_F_ECDSA_SIGN_SETUP, ERR_R_BN_LIB);
                goto err;
            }
        }
    }

    /* clear old values if necessary */
    BN_clear_free(*rp);
    BN_clear_free(*kinvp);
    /* save the pre-computed values  */
    *rp = r;
    *kinvp = k;
    ret = 1;
 err:
    if (!ret) {
        BN_clear_free(k);
        BN_clear_free(r);
    }
    if (ctx != ctx_in)
        BN_CTX_free(ctx);
    EC_POINT_free(tmp_point);
    BN_clear_free(X);
    return ret;
}
RSA *RSA_generate_key(int bits, unsigned long e_value,
	     void (*callback)(int,int,void *), void *cb_arg)
	{
	RSA *rsa=NULL;
	BIGNUM *r0=NULL,*r1=NULL,*r2=NULL,*r3=NULL,*tmp;
	int bitsp,bitsq,ok= -1,n=0;
	unsigned i;
	BN_CTX *ctx=NULL,*ctx2=NULL;

	ctx=BN_CTX_new();
	if (ctx == NULL) goto err;
	ctx2=BN_CTX_new();
	if (ctx2 == NULL) goto err;
	BN_CTX_start(ctx);
	r0 = BN_CTX_get(ctx);
	r1 = BN_CTX_get(ctx);
	r2 = BN_CTX_get(ctx);
	r3 = BN_CTX_get(ctx);
	if (r3 == NULL) goto err;

	bitsp=(bits+1)/2;
	bitsq=bits-bitsp;
	rsa=RSA_new();
	if (rsa == NULL) goto err;

	/* set e */ 
	rsa->e=BN_new();
	if (rsa->e == NULL) goto err;

#if 1
	/* The problem is when building with 8, 16, or 32 BN_ULONG,
	 * unsigned long can be larger */
	for (i=0; i<sizeof(unsigned long)*8; i++)
		{
		if (e_value & (((unsigned long)1)<<i))
			BN_set_bit(rsa->e,i);
		}
#else
	if (!BN_set_word(rsa->e,e_value)) goto err;
#endif

	/* generate p and q */
	for (;;)
		{
		rsa->p=BN_generate_prime(NULL,bitsp,0,NULL,NULL,callback,cb_arg);
		if (rsa->p == NULL) goto err;
		if (!BN_sub(r2,rsa->p,BN_value_one())) goto err;
		if (!BN_gcd(r1,r2,rsa->e,ctx)) goto err;
		if (BN_is_one(r1)) break;
		if (callback != NULL) callback(2,n++,cb_arg);
		BN_free(rsa->p);
		}
	if (callback != NULL) callback(3,0,cb_arg);
	for (;;)
		{
		rsa->q=BN_generate_prime(NULL,bitsq,0,NULL,NULL,callback,cb_arg);
		if (rsa->q == NULL) goto err;
		if (!BN_sub(r2,rsa->q,BN_value_one())) goto err;
		if (!BN_gcd(r1,r2,rsa->e,ctx)) goto err;
		if (BN_is_one(r1) && (BN_cmp(rsa->p,rsa->q) != 0))
			break;
		if (callback != NULL) callback(2,n++,cb_arg);
		BN_free(rsa->q);
		}
	if (callback != NULL) callback(3,1,cb_arg);
	if (BN_cmp(rsa->p,rsa->q) < 0)
		{
		tmp=rsa->p;
		rsa->p=rsa->q;
		rsa->q=tmp;
		}

	/* calculate n */
	rsa->n=BN_new();
	if (rsa->n == NULL) goto err;
	if (!BN_mul(rsa->n,rsa->p,rsa->q,ctx)) goto err;

	/* calculate d */
	if (!BN_sub(r1,rsa->p,BN_value_one())) goto err;	/* p-1 */
	if (!BN_sub(r2,rsa->q,BN_value_one())) goto err;	/* q-1 */
	if (!BN_mul(r0,r1,r2,ctx)) goto err;	/* (p-1)(q-1) */

/* should not be needed, since gcd(p-1,e) == 1 and gcd(q-1,e) == 1 */
/*	for (;;)
		{
		if (!BN_gcd(r3,r0,rsa->e,ctx)) goto err;
		if (BN_is_one(r3)) break;

		if (1)
			{
			if (!BN_add_word(rsa->e,2L)) goto err;
			continue;
			}
		RSAerr(RSA_F_RSA_GENERATE_KEY,RSA_R_BAD_E_VALUE);
		goto err;
		}
*/
	rsa->d=BN_mod_inverse(NULL,rsa->e,r0,ctx2);	/* d */
	if (rsa->d == NULL) goto err;

	/* calculate d mod (p-1) */
	rsa->dmp1=BN_new();
	if (rsa->dmp1 == NULL) goto err;
	if (!BN_mod(rsa->dmp1,rsa->d,r1,ctx)) goto err;

	/* calculate d mod (q-1) */
	rsa->dmq1=BN_new();
	if (rsa->dmq1 == NULL) goto err;
	if (!BN_mod(rsa->dmq1,rsa->d,r2,ctx)) goto err;

	/* calculate inverse of q mod p */
	rsa->iqmp=BN_mod_inverse(NULL,rsa->q,rsa->p,ctx2);
	if (rsa->iqmp == NULL) goto err;

	ok=1;
err:
	if (ok == -1)
		{
		RSAerr(RSA_F_RSA_GENERATE_KEY,ERR_LIB_BN);
		ok=0;
		}
	BN_CTX_end(ctx);
	BN_CTX_free(ctx);
	BN_CTX_free(ctx2);
	
	if (!ok)
		{
		if (rsa != NULL) RSA_free(rsa);
		return(NULL);
		}
	else
		return(rsa);
	}
示例#9
0
int BN_MONT_CTX_set(BN_MONT_CTX *mont, const BIGNUM *mod, BN_CTX *ctx) {
  int ret = 0;
  BIGNUM *Ri, *R;
  BIGNUM tmod;
  BN_ULONG buf[2];

  if (BN_is_zero(mod)) {
    OPENSSL_PUT_ERROR(BN, BN_R_DIV_BY_ZERO);
    return 0;
  }

  BN_CTX_start(ctx);
  Ri = BN_CTX_get(ctx);
  if (Ri == NULL) {
    goto err;
  }
  R = &mont->RR; /* grab RR as a temp */
  if (!BN_copy(&mont->N, mod)) {
    goto err; /* Set N */
  }
  mont->N.neg = 0;

  BN_init(&tmod);
  tmod.d = buf;
  tmod.dmax = 2;
  tmod.neg = 0;

  BN_zero(R);
  if (!BN_set_bit(R, BN_MONT_CTX_N0_LIMBS * BN_BITS2)) {
    goto err;
  }

  tmod.top = 0;
  buf[0] = mod->d[0];
  if (buf[0] != 0) {
    tmod.top = 1;
  }

  buf[1] = 0;
  if (BN_MONT_CTX_N0_LIMBS == 2 && mod->top > 1 && mod->d[1] != 0) {
    buf[1] = mod->d[1];
    tmod.top = 2;
  }

  if (BN_mod_inverse(Ri, R, &tmod, ctx) == NULL) {
    goto err;
  }
  if (!BN_lshift(Ri, Ri, BN_MONT_CTX_N0_LIMBS * BN_BITS2)) {
    goto err; /* R*Ri */
  }
  const BIGNUM *Ri_dividend;
  if (!BN_is_zero(Ri)) {
    if (!BN_sub_word(Ri, 1)) {
      goto err;
    }
    Ri_dividend = Ri;
  } else {
    /* Ri == 0 so Ri - 1 == -1. -1 % tmod == 0xff..ff. */
    static const BN_ULONG kMinusOneLimbs[BN_MONT_CTX_N0_LIMBS] = {
      BN_MASK2,
#if BN_MONT_CTX_N0_LIMBS == 2
      BN_MASK2
#endif
    };
    STATIC_BIGNUM_DIAGNOSTIC_PUSH
    static const BIGNUM kMinusOne = STATIC_BIGNUM(kMinusOneLimbs);
    STATIC_BIGNUM_DIAGNOSTIC_POP
    Ri_dividend = &kMinusOne;
  }

  if (!BN_div(Ri, NULL, Ri_dividend, &tmod, ctx)) {
    goto err;
  }

  mont->n0[0] = 0;
  if (Ri->top > 0) {
    mont->n0[0] = Ri->d[0];
  }
  mont->n0[1] = 0;
  if (BN_MONT_CTX_N0_LIMBS == 2 && Ri->top > 1) {
    mont->n0[1] = Ri->d[1];
  }

  /* RR = (2^ri)^2 == 2^(ri*2) == 1 << (ri*2), which has its (ri*2)th bit set. */
  int ri = (BN_num_bits(mod) + (BN_BITS2 - 1)) / BN_BITS2 * BN_BITS2;
  BN_zero(&(mont->RR));
  if (!BN_set_bit(&(mont->RR), ri * 2)) {
    goto err;
  }
  if (!BN_mod(&(mont->RR), &(mont->RR), &(mont->N), ctx)) {
    goto err;
  }

  ret = 1;

err:
  BN_CTX_end(ctx);
  return ret;
}
示例#10
0
static int
test_BN_bit(void)
{
    BIGNUM *bn;
    int ret = 0;

    bn = BN_new();

    /* test setting and getting of "word" */
    if (!BN_set_word(bn, 1))
	return 1;
    if (!BN_is_bit_set(bn, 0))
	ret += 1;
    if (!BN_is_bit_set(bn, 0))
	ret += 1;

    if (!BN_set_word(bn, 2))
	return 1;
    if (!BN_is_bit_set(bn, 1))
	ret += 1;

    if (!BN_set_word(bn, 3))
	return 1;
    if (!BN_is_bit_set(bn, 0))
	ret += 1;
    if (!BN_is_bit_set(bn, 1))
	ret += 1;

    if (!BN_set_word(bn, 0x100))
	return 1;
    if (!BN_is_bit_set(bn, 8))
	ret += 1;

    if (!BN_set_word(bn, 0x1000))
	return 1;
    if (!BN_is_bit_set(bn, 12))
	ret += 1;

    /* test bitsetting */
    if (!BN_set_word(bn, 1))
	return 1;
    if (!BN_set_bit(bn, 1))
	return 1;
    if (BN_get_word(bn) != 3)
	return 1;
    if (!BN_clear_bit(bn, 0))
	return 1;
    if (BN_get_word(bn) != 2)
	return 1;

    /* test bitsetting past end of current end */
    BN_clear(bn);
    if (!BN_set_bit(bn, 12))
	return 1;
    if (BN_get_word(bn) != 0x1000)
	return 1;

    /* test bit and byte counting functions */
    if (BN_num_bits(bn) != 13)
	return 1;
    if (BN_num_bytes(bn) != 2)
	return 1;

    BN_free(bn);
    return ret;
}
示例#11
0
CHECK_RETVAL_BOOL \
static BOOLEAN selfTestGeneralOps2( void )
	{
	BIGNUM a;
	int status;

	/* More complex tests that need higher-level routines like importBignum(),
	   run after the tests of components of importBignum() have concluded */
	BN_init( &a );
#if BN_BITS2 == 64
	status = importBignum( &a, "\x01\x00\x00\x00\x00\x00\x00\x00\x00", 9, 
						   1, 128, NULL, KEYSIZE_CHECK_NONE );
#else
	status = importBignum( &a, "\x01\x00\x00\x00\x00", 5, 1, 128, NULL, 
						   KEYSIZE_CHECK_NONE );
#endif /* 64- vs 32-bit */
	if( cryptStatusError( status ) )
		return( FALSE );
	if( BN_is_zero( &a ) || BN_is_one( &a ) )
		return( FALSE );
	if( BN_is_word( &a, 0 ) || BN_is_word( &a, 1 ) )
		return( FALSE );
	if( BN_is_odd( &a ) )
		return( FALSE );
	if( BN_get_word( &a ) != BN_NAN )
		return( FALSE );
	if( BN_num_bytes( &a ) != ( BN_BITS2 / 8 ) + 1 )
		return( FALSE );
	if( BN_num_bits( &a ) != BN_BITS2 + 1 )
		return( FALSE );
	if( !BN_is_bit_set( &a, BN_BITS2 ) )
		return( FALSE );
	if( BN_is_bit_set( &a, 17 ) || !BN_set_bit( &a, 17 ) || \
		!BN_is_bit_set( &a, 17 ) )
		return( FALSE );
#if BN_BITS2 == 64
	status = importBignum( &a, "\x01\x00\x00\x00\x00\x00\x00\x00\x01", 9, 
						   1, 128, NULL, KEYSIZE_CHECK_NONE );
#else
	status = importBignum( &a,	"\x01\x00\x00\x00\x01", 5, 1, 128, NULL,
						   KEYSIZE_CHECK_NONE );
#endif /* 64- vs 32-bit */
	if( cryptStatusError( status ) )
		return( FALSE );
	if( BN_is_zero( &a ) || BN_is_one( &a ) )
		return( FALSE );
	if( BN_is_word( &a, 0 ) || BN_is_word( &a, 1 ) )
		return( FALSE );
	if( !BN_is_odd( &a ) )
		return( FALSE );
	if( BN_num_bytes( &a ) != ( BN_BITS2 / 8 ) + 1 )
		return( FALSE );
	if( BN_get_word( &a ) != BN_NAN )
		return( FALSE );
	if( BN_num_bits( &a ) != BN_BITS2 + 1 )
		return( FALSE );
	if( !BN_is_bit_set( &a, BN_BITS2 ) )
		return( FALSE );
	if( BN_is_bit_set( &a, BN_BITS2 + 27 ) || \
		!BN_set_bit( &a, BN_BITS2 + 27 ) || \
		!BN_is_bit_set( &a, BN_BITS2 + 27 ) )
		return( FALSE );
	/* Setting a bit off the end of a bignum extends its size, which is why
	   the following value doesn't match the one from a few lines earlier */
	if( BN_num_bytes( &a ) != ( BN_BITS2 / 8 ) + 4 )
		return( FALSE );
	/* The bit index for indexing bits is zero-based (since 1 == 1 << 0) but
	   for counting bits is one-based, which is why the following comparison
	   looks wrong.  Yet another one of OpenSSL's many booby-traps */
	if( BN_num_bits( &a ) != BN_BITS2 + 28 )
		return( FALSE );
	BN_clear( &a );

	return( TRUE );
	}
示例#12
0
static isc_result_t
opensslrsa_generate(dst_key_t *key, int exp, void (*callback)(int)) {
#if OPENSSL_VERSION_NUMBER > 0x00908000L
	isc_result_t ret = DST_R_OPENSSLFAILURE;
	union {
		void *dptr;
		void (*fptr)(int);
	} u;
	RSA *rsa = RSA_new();
	BIGNUM *e = BN_new();
#if OPENSSL_VERSION_NUMBER < 0x10100000L || defined(LIBRESSL_VERSION_NUMBER)
	BN_GENCB _cb;
#endif
	BN_GENCB *cb = BN_GENCB_new();
#if USE_EVP
	EVP_PKEY *pkey = EVP_PKEY_new();
#endif

	/*
	 * Reject incorrect RSA key lengths.
	 */
	switch (key->key_alg) {
	case DST_ALG_RSAMD5:
	case DST_ALG_RSASHA1:
	case DST_ALG_NSEC3RSASHA1:
		/* From RFC 3110 */
		if (key->key_size > 4096)
			goto err;
		break;
	case DST_ALG_RSASHA256:
		/* From RFC 5702 */
		if ((key->key_size < 512) ||
		    (key->key_size > 4096))
			goto err;
		break;
	case DST_ALG_RSASHA512:
		/* From RFC 5702 */
		if ((key->key_size < 1024) ||
		    (key->key_size > 4096))
			goto err;
		break;
	default:
		INSIST(0);
	}

	if (rsa == NULL || e == NULL || cb == NULL)
		goto err;
#if USE_EVP
	if (pkey == NULL)
		goto err;
	if (!EVP_PKEY_set1_RSA(pkey, rsa))
		goto err;
#endif

	if (exp == 0) {
		/* RSA_F4 0x10001 */
		BN_set_bit(e, 0);
		BN_set_bit(e, 16);
	} else {
		/* (phased-out) F5 0x100000001 */
		BN_set_bit(e, 0);
		BN_set_bit(e, 32);
	}

	if (callback == NULL) {
		BN_GENCB_set_old(cb, NULL, NULL);
	} else {
		u.fptr = callback;
		BN_GENCB_set(cb, &progress_cb, u.dptr);
	}

	if (RSA_generate_key_ex(rsa, key->key_size, e, cb)) {
		BN_free(e);
		BN_GENCB_free(cb);
		SET_FLAGS(rsa);
#if USE_EVP
		key->keydata.pkey = pkey;

		RSA_free(rsa);
#else
		key->keydata.rsa = rsa;
#endif
		return (ISC_R_SUCCESS);
	}
	BN_GENCB_free(cb);
	ret = dst__openssl_toresult2("RSA_generate_key_ex",
				     DST_R_OPENSSLFAILURE);

 err:
#if USE_EVP
	if (pkey != NULL)
		EVP_PKEY_free(pkey);
#endif
	if (e != NULL)
		BN_free(e);
	if (rsa != NULL)
		RSA_free(rsa);
	if (cb != NULL)
		BN_GENCB_free(cb);
	return (dst__openssl_toresult(ret));
#else
	RSA *rsa;
	unsigned long e;
#if USE_EVP
	EVP_PKEY *pkey = EVP_PKEY_new();

	UNUSED(callback);

	if (pkey == NULL)
		return (ISC_R_NOMEMORY);
#else
	UNUSED(callback);
#endif

	if (exp == 0)
	       e = RSA_F4;
	else
	       e = 0x40000003;
	rsa = RSA_generate_key(key->key_size, e, NULL, NULL);
	if (rsa == NULL) {
#if USE_EVP
		EVP_PKEY_free(pkey);
#endif
		return (dst__openssl_toresult2("RSA_generate_key",
					       DST_R_OPENSSLFAILURE));
	}
	SET_FLAGS(rsa);
#if USE_EVP
	if (!EVP_PKEY_set1_RSA(pkey, rsa)) {
		EVP_PKEY_free(pkey);
		RSA_free(rsa);
		return (dst__openssl_toresult(DST_R_OPENSSLFAILURE));
	}
	key->keydata.pkey = pkey;
	RSA_free(rsa);
#else
	key->keydata.rsa = rsa;
#endif

	return (ISC_R_SUCCESS);
#endif
}
示例#13
0
int BN_MONT_CTX_set(BN_MONT_CTX *mont, const BIGNUM *mod, BN_CTX *ctx)
	{
	int ret = 0;
	BIGNUM *Ri,*R;

	BN_CTX_start(ctx);
	if((Ri = BN_CTX_get(ctx)) == NULL) goto err;
	R= &(mont->RR);					/* grab RR as a temp */
	if (!BN_copy(&(mont->N),mod)) goto err;		/* Set N */
	mont->N.neg = 0;

#ifdef MONT_WORD
		{
		BIGNUM tmod;
		BN_ULONG buf[2];

		mont->ri=(BN_num_bits(mod)+(BN_BITS2-1))/BN_BITS2*BN_BITS2;
		BN_zero(R);
		if (!(BN_set_bit(R,BN_BITS2))) goto err;	/* R */

		buf[0]=mod->d[0]; /* tmod = N mod word size */
		buf[1]=0;
		tmod.d=buf;
		tmod.top = buf[0] != 0 ? 1 : 0;
		tmod.dmax=2;
		tmod.neg=0;
							/* Ri = R^-1 mod N*/
		if ((BN_mod_inverse(Ri,R,&tmod,ctx)) == NULL)
			goto err;
		if (!BN_lshift(Ri,Ri,BN_BITS2)) goto err; /* R*Ri */
		if (!BN_is_zero(Ri))
			{
			if (!BN_sub_word(Ri,1)) goto err;
			}
		else /* if N mod word size == 1 */
			{
			if (!BN_set_word(Ri,BN_MASK2)) goto err;  /* Ri-- (mod word size) */
			}
		if (!BN_div(Ri,NULL,Ri,&tmod,ctx)) goto err;
		/* Ni = (R*Ri-1)/N,
		 * keep only least significant word: */
		mont->n0 = (Ri->top > 0) ? Ri->d[0] : 0;
		}
#else /* !MONT_WORD */
		{ /* bignum version */
		mont->ri=BN_num_bits(&mont->N);
		BN_zero(R);
		if (!BN_set_bit(R,mont->ri)) goto err;  /* R = 2^ri */
		                                        /* Ri = R^-1 mod N*/
		if ((BN_mod_inverse(Ri,R,&mont->N,ctx)) == NULL)
			goto err;
		if (!BN_lshift(Ri,Ri,mont->ri)) goto err; /* R*Ri */
		if (!BN_sub_word(Ri,1)) goto err;
							/* Ni = (R*Ri-1) / N */
		if (!BN_div(&(mont->Ni),NULL,Ri,&mont->N,ctx)) goto err;
		}
#endif

	/* setup RR for conversions */
	BN_zero(&(mont->RR));
	if (!BN_set_bit(&(mont->RR),mont->ri*2)) goto err;
	if (!BN_mod(&(mont->RR),&(mont->RR),&(mont->N),ctx)) goto err;

	ret = 1;
err:
	BN_CTX_end(ctx);
	return ret;
	}