C++ BN_add_word函數代碼示例

// Generate each party's random numbers. xa is in [0, q), xb is in [1, q).
static void genrand(JPakeUser * user, const JPakeParameters * params)
{
    BIGNUM *qm1;

    // xa in [0, q)
    user->xa = BN_new();
    BN_rand_range(user->xa, params->q);

    // q-1
    qm1 = BN_new();
    BN_copy(qm1, params->q);
    BN_sub_word(qm1, 1);

    // ... and xb in [0, q-1)
    user->xb = BN_new();
    BN_rand_range(user->xb, qm1);
    // [1, q)
    BN_add_word(user->xb, 1);

    // cleanup
    BN_free(qm1);

    // Show
    printf("x%d", user->p.base);
    showbn("", user->xa);
    printf("x%d", user->p.base + 1);
    showbn("", user->xb);
}

static int
probable_prime(BIGNUM *rnd, int bits)
{
	int i;
	prime_t mods[NUMPRIMES];
	BN_ULONG delta, maxdelta;

again:
	if (!BN_rand(rnd, bits, 1, 1))
		return (0);
	/* we now have a random number 'rand' to test. */
	for (i = 1; i < NUMPRIMES; i++)
		mods[i] = (prime_t)BN_mod_word(rnd, (BN_ULONG)primes[i]);
	maxdelta = BN_MASK2 - primes[NUMPRIMES - 1];
	delta = 0;
loop:
	for (i = 1; i < NUMPRIMES; i++) {
		/* check that rnd is not a prime and also
		 * that gcd(rnd-1,primes) == 1 (except for 2) */
		if (((mods[i] + delta) % primes[i]) <= 1) {
			delta += 2;
			if (delta > maxdelta)
				goto again;
			goto loop;
		}
	}
	if (!BN_add_word(rnd, delta))
		return (0);
	bn_check_top(rnd);
	return (1);
}

static int bn_rand_range_with_additional_data(
    BIGNUM *r, BN_ULONG min_inclusive, const BIGNUM *max_exclusive,
    const uint8_t additional_data[32]) {
  if (BN_cmp_word(max_exclusive, min_inclusive) <= 0) {
    OPENSSL_PUT_ERROR(BN, BN_R_INVALID_RANGE);
    return 0;
  }

  /* This function is used to implement steps 4 through 7 of FIPS 186-4
   * appendices B.4.2 and B.5.2. When called in those contexts, |max_exclusive|
   * is n and |min_inclusive| is one. */
  unsigned count = 100;
  unsigned n = BN_num_bits(max_exclusive); /* n > 0 */
  do {
    if (!--count) {
      OPENSSL_PUT_ERROR(BN, BN_R_TOO_MANY_ITERATIONS);
      return 0;
    }

    if (/* steps 4 and 5 */
        !bn_rand_with_additional_data(r, n, BN_RAND_TOP_ANY, BN_RAND_BOTTOM_ANY,
                                      additional_data) ||
        /* step 7 */
        !BN_add_word(r, min_inclusive)) {
      return 0;
    }

    /* Step 6. This loops if |r| >= |max_exclusive|. This is identical to
     * checking |r| > |max_exclusive| - 1 or |r| - 1 > |max_exclusive| - 2, the
     * formulation stated in FIPS 186-4. */
  } while (BN_cmp(r, max_exclusive) >= 0);

  return 1;
}

static int probable_prime(BIGNUM *rnd, int bits)
	{
	int i;
	BN_ULONG mods[NUMPRIMES];
	BN_ULONG delta,d;

again:
	if (!BN_rand(rnd,bits,1,1)) return(0);
	/* we now have a random number 'rand' to test. */
	for (i=1; i<NUMPRIMES; i++)
		mods[i]=BN_mod_word(rnd,(BN_ULONG)primes[i]);
	delta=0;
	loop: for (i=1; i<NUMPRIMES; i++)
		{
		/* check that rnd is not a prime and also
		 * that gcd(rnd-1,primes) == 1 (except for 2) */
		if (((mods[i]+delta)%primes[i]) <= 1)
			{
			d=delta;
			delta+=2;
			/* perhaps need to check for overflow of
			 * delta (but delta can be up to 2^32)
			 * 21-May-98 eay - added overflow check */
			if (delta < d) goto again;
			goto loop;
			}
		}
	if (!BN_add_word(rnd,delta)) return(0);
	return(1);
	}

/*
 * Decode a base_n-encoded string into a byte sequence.
 */
bool raw_decode_base_n(BIGNUM *bn, const char *src, size_t len, int base)
{
	const char *enc;

	BN_zero(bn);

	assert(base == 16 || base == 58);
	switch (base) {
	case 16:
		enc = enc_16;
		break;
	case 58:
		enc = enc_58;
		break;
	}

	while (len) {
		char current = *src;

		if (base == 16)
			current = tolower(current);	/* TODO: Not in ccan. */
		int val = decode_char(current, enc);
		if (val < 0) {
			BN_free(bn);
			return false;
		}
		BN_mul_word(bn, base);
		BN_add_word(bn, val);
		src++;
		len--;
	}

	return true;
}

/*
 * Copy the serial number from src certificate to dst certificate
 * and modify it by a random offset.
 * If reading the serial fails for some reason, generate a new
 * random serial and store it in the dst certificate.
 * Using the same serial is not a good idea since some SSL stacks
 * check for duplicate certificate serials.
 * Returns 0 on success, -1 on error.
 */
int
ssl_x509_serial_copyrand(X509 *dstcrt, X509 *srccrt)
{
	ASN1_INTEGER *srcptr, *dstptr;
	BIGNUM *bnserial;
	unsigned int rand;
	int rv;

#ifndef PURIFY
	rv = ssl_rand(&rand, sizeof(rand));
#else /* PURIFY */
	rand = 0xF001;
	rv = 0;
#endif /* PURIFY */
	dstptr = X509_get_serialNumber(dstcrt);
	srcptr = X509_get_serialNumber(srccrt);
	if ((rv == -1) || !dstptr || !srcptr)
		return -1;
	bnserial = ASN1_INTEGER_to_BN(srcptr, NULL);
	if (!bnserial) {
		/* random 32-bit serial */
		ASN1_INTEGER_set(dstptr, rand);
	} else {
		/* original serial plus random 32-bit offset */
		BN_add_word(bnserial, rand);
		BN_to_ASN1_INTEGER(bnserial, dstptr);
		BN_free(bnserial);
	}
	return 0;
}

static ASN1_INTEGER *x509_load_serial(const char *CAfile,
                                      const char *serialfile, int create)
{
    char *buf = NULL;
    ASN1_INTEGER *bs = NULL;
    BIGNUM *serial = NULL;

    if (serialfile == NULL) {
        const char *p = strrchr(CAfile, '.');
        size_t len = p != NULL ? (size_t)(p - CAfile) : strlen(CAfile);

        buf = app_malloc(len + sizeof(POSTFIX), "serial# buffer");
        memcpy(buf, CAfile, len);
        memcpy(buf + len, POSTFIX, sizeof(POSTFIX));
        serialfile = buf;
    }

    serial = load_serial(serialfile, create, NULL);
    if (serial == NULL)
        goto end;

    if (!BN_add_word(serial, 1)) {
        BIO_printf(bio_err, "add_word failure\n");
        goto end;
    }

    if (!save_serial(serialfile, NULL, serial, &bs))
        goto end;

 end:
    OPENSSL_free(buf);
    BN_free(serial);
    return bs;
}

int ec_GFp_simple_group_set_curve(EC_GROUP *group,
                                  const BIGNUM *p, const BIGNUM *a,
                                  const BIGNUM *b, BN_CTX *ctx)
{
    int ret = 0;
    BN_CTX *new_ctx = NULL;
    BIGNUM *tmp_a;

    /* p must be a prime > 3 */
    if (BN_num_bits(p) <= 2 || !BN_is_odd(p)) {
        ECerr(EC_F_EC_GFP_SIMPLE_GROUP_SET_CURVE, EC_R_INVALID_FIELD);
        return 0;
    }

    if (ctx == NULL) {
        ctx = new_ctx = BN_CTX_new();
        if (ctx == NULL)
            return 0;
    }

    BN_CTX_start(ctx);
    tmp_a = BN_CTX_get(ctx);
    if (tmp_a == NULL)
        goto err;

    /* group->field */
    if (!BN_copy(&group->field, p))
        goto err;
    BN_set_negative(&group->field, 0);

    /* group->a */
    if (!BN_nnmod(tmp_a, a, p, ctx))
        goto err;
    if (group->meth->field_encode) {
        if (!group->meth->field_encode(group, &group->a, tmp_a, ctx))
            goto err;
    } else if (!BN_copy(&group->a, tmp_a))
        goto err;

    /* group->b */
    if (!BN_nnmod(&group->b, b, p, ctx))
        goto err;
    if (group->meth->field_encode)
        if (!group->meth->field_encode(group, &group->b, &group->b, ctx))
            goto err;

    /* group->a_is_minus3 */
    if (!BN_add_word(tmp_a, 3))
        goto err;
    group->a_is_minus3 = (0 == BN_cmp(tmp_a, &group->field));

    ret = 1;

err:
    BN_CTX_end(ctx);
    if (new_ctx != NULL)
        BN_CTX_free(new_ctx);
    return ret;
}

int
test_div(BIO *bp, BN_CTX *ctx)
{
	BIGNUM a, b,c, d, e;
	int i;
	int rc = 1;

	BN_init(&a);
	BN_init(&b);
	BN_init(&c);
	BN_init(&d);
	BN_init(&e);

	for (i = 0; i < num0 + num1; i++) {
		if (i < num1) {
			BN_bntest_rand(&a, 400, 0, 0);
			BN_copy(&b, &a);
			BN_lshift(&a, &a, i);
			BN_add_word(&a, i);
		} else
			BN_bntest_rand(&b, 50 + 3*(i - num1), 0, 0);
		a.neg = rand_neg();
		b.neg = rand_neg();
		BN_div(&d, &c, &a, &b, ctx);
		if (bp != NULL) {
			if (!results) {
				BN_print(bp, &a);
				BIO_puts(bp, " / ");
				BN_print(bp, &b);
				BIO_puts(bp, " - ");
			}
			BN_print(bp, &d);
			BIO_puts(bp, "\n");

			if (!results) {
				BN_print(bp, &a);
				BIO_puts(bp, " % ");
				BN_print(bp, &b);
				BIO_puts(bp, " - ");
			}
			BN_print(bp, &c);
			BIO_puts(bp, "\n");
		}
		BN_mul(&e, &d, &b, ctx);
		BN_add(&d, &e, &c);
		BN_sub(&d, &d, &a);
		if (!BN_is_zero(&d)) {
			fprintf(stderr, "Division test failed!\n");
			rc = 0;
			break;
		}
	}
	BN_free(&a);
	BN_free(&b);
	BN_free(&c);
	BN_free(&d);
	BN_free(&e);
	return (rc);
}

int bn_probable_prime_dh_coprime(BIGNUM *rnd, int bits, BN_CTX *ctx)
{
    int i;
    BIGNUM *offset_index;
    BIGNUM *offset_count;
    int ret = 0;

    OPENSSL_assert(bits > prime_multiplier_bits);

    BN_CTX_start(ctx);
    if ((offset_index = BN_CTX_get(ctx)) == NULL)
        goto err;
    if ((offset_count = BN_CTX_get(ctx)) == NULL)
        goto err;

    if (!BN_add_word(offset_count, prime_offset_count))
        goto err;

 loop:
    if (!BN_rand(rnd, bits - prime_multiplier_bits, 0, 1))
        goto err;
    if (BN_is_bit_set(rnd, bits))
        goto loop;
    if (!BN_rand_range(offset_index, offset_count))
        goto err;

    if (!BN_mul_word(rnd, prime_multiplier)
        || !BN_add_word(rnd, prime_offsets[BN_get_word(offset_index)]))
        goto err;

    /* we now have a random number 'rand' to test. */

    /* skip coprimes */
    for (i = first_prime_index; i < NUMPRIMES; i++) {
        /* check that rnd is a prime */
        if (BN_mod_word(rnd, (BN_ULONG)primes[i]) <= 1) {
            goto loop;
        }
    }
    ret = 1;

 err:
    BN_CTX_end(ctx);
    bn_check_top(rnd);
    return ret;
}

int BN_solinas2bn(const BN_SOLINAS *solinas, BIGNUM *bn)
{
	int ret = 0;
	BIGNUM *tmp = NULL;

	if (!solinas || !bn) {
		BNerr(BN_F_BN_SOLINAS2BN, ERR_R_MALLOC_FAILURE);
		return 0;
	}

	if (solinas->b <= 0 || solinas->a <= solinas->b
		|| (solinas->s != 1 && solinas->s != -1)
		|| (solinas->c != 1 && solinas->c != -1)) {
		BNerr(BN_F_BN_SOLINAS2BN, BN_R_INVALID_SOLINAS_PARAMETERS);
		return 0;
	}

	if (!(tmp = BN_new())) {
		BNerr(BN_F_BN_SOLINAS2BN, ERR_R_MALLOC_FAILURE);
		goto end;
	}

	BN_one(tmp);

	if (!BN_lshift(bn, tmp, solinas->a)) {
		BNerr(BN_F_BN_SOLINAS2BN, ERR_R_BN_LIB);
		goto end;
	}

	if (!BN_lshift(tmp, tmp, solinas->b)) {
		BNerr(BN_F_BN_SOLINAS2BN, ERR_R_BN_LIB);
		goto end;
	}

	if (!BN_add_word(tmp, solinas->c)) {
		BNerr(BN_F_BN_SOLINAS2BN, ERR_R_BN_LIB);
		goto end;
	}

	if (solinas->s > 0) {
		if (!BN_add(bn, bn, tmp)) {
			BNerr(BN_F_BN_SOLINAS2BN, ERR_R_BN_LIB);
			goto end;
		}
	} else {
		if (!BN_sub(bn, bn, tmp)) {
			BNerr(BN_F_BN_SOLINAS2BN, ERR_R_BN_LIB);
			goto end;
		}
	}

	/* check if it is a prime */

	ret = 1;
end:
	BN_free(tmp);
	return ret;
}

int BN_dec2bn(BIGNUM **bn, const char *a)
	{
	BIGNUM *ret=NULL;
	BN_ULONG l=0;
	int neg=0,i,j;
	int num;

	if ((a == NULL) || (*a == '\0')) return(0);
	if (*a == '-') { neg=1; a++; }

	for (i=0; isdigit((unsigned char) a[i]); i++)
		;

	num=i+neg;
	if (bn == NULL) return(num);

	/* a is the start of the digits, and it is 'i' long.
	 * We chop it into BN_DEC_NUM digits at a time */
	if (*bn == NULL)
		{
		if ((ret=BN_new()) == NULL) return(0);
		}
	else
		{
		ret= *bn;
		BN_zero(ret);
		}

	/* i is the number of digests, a bit of an over expand; */
	if (bn_expand(ret,i*4) == NULL) goto err;

	j=BN_DEC_NUM-(i%BN_DEC_NUM);
	if (j == BN_DEC_NUM) j=0;
	l=0;
	while (*a)
		{
		l*=10;
		l+= *a-'0';
		a++;
		if (++j == BN_DEC_NUM)
			{
			BN_mul_word(ret,BN_DEC_CONV);
			BN_add_word(ret,l);
			l=0;
			j=0;
			}
		}
	ret->neg=neg;

	bn_correct_top(ret);
	*bn=ret;
	bn_check_top(ret);
	return(num);
err:
	if (*bn == NULL) BN_free(ret);
	return(0);
	}

int test_div(BIO *bp, BN_CTX *ctx)
{
    BIGNUM *a, *b, *c, *d, *e;
    int i;

    a = BN_new();
    b = BN_new();
    c = BN_new();
    d = BN_new();
    e = BN_new();

    for (i = 0; i < num0 + num1; i++) {
        if (i < num1) {
            BN_bntest_rand(a, 400, 0, 0);
            BN_copy(b, a);
            BN_lshift(a, a, i);
            BN_add_word(a, i);
        } else
            BN_bntest_rand(b, 50 + 3 * (i - num1), 0, 0);
        a->neg = rand_neg();
        b->neg = rand_neg();
        BN_div(d, c, a, b, ctx);
        if (bp != NULL) {
            if (!results) {
                BN_print(bp, a);
                BIO_puts(bp, " / ");
                BN_print(bp, b);
                BIO_puts(bp, " - ");
            }
            BN_print(bp, d);
            BIO_puts(bp, "\n");

            if (!results) {
                BN_print(bp, a);
                BIO_puts(bp, " % ");
                BN_print(bp, b);
                BIO_puts(bp, " - ");
            }
            BN_print(bp, c);
            BIO_puts(bp, "\n");
        }
        BN_mul(e, d, b, ctx);
        BN_add(d, e, c);
        BN_sub(d, d, a);
        if (!BN_is_zero(d)) {
            fprintf(stderr, "Division test failed!\n");
            return 0;
        }
    }
    BN_free(a);
    BN_free(b);
    BN_free(c);
    BN_free(d);
    BN_free(e);
    return (1);
}

static int probable_prime_dh(BIGNUM *rnd, int bits, const BIGNUM *add,
                             const BIGNUM *rem, BN_CTX *ctx) {
  int i, ret = 0;
  BIGNUM *t1;

  BN_CTX_start(ctx);
  if ((t1 = BN_CTX_get(ctx)) == NULL) {
    goto err;
  }

  if (!BN_rand(rnd, bits, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ODD)) {
    goto err;
  }

  /* we need ((rnd-rem) % add) == 0 */

  if (!BN_mod(t1, rnd, add, ctx)) {
    goto err;
  }
  if (!BN_sub(rnd, rnd, t1)) {
    goto err;
  }
  if (rem == NULL) {
    if (!BN_add_word(rnd, 1)) {
      goto err;
    }
  } else {
    if (!BN_add(rnd, rnd, rem)) {
      goto err;
    }
  }
  /* we now have a random number 'rand' to test. */

loop:
  for (i = 1; i < NUMPRIMES; i++) {
    /* check that rnd is a prime */
    BN_ULONG mod = BN_mod_word(rnd, (BN_ULONG)primes[i]);
    if (mod == (BN_ULONG)-1) {
      goto err;
    }
    if (mod <= 1) {
      if (!BN_add(rnd, rnd, add)) {
        goto err;
      }
      goto loop;
    }
  }

  ret = 1;

err:
  BN_CTX_end(ctx);
  return ret;
}

static int bn_x931_derive_pi(BIGNUM *pi, const BIGNUM *Xpi, BN_CTX *ctx,
                             BN_GENCB *cb)
{
    int i = 0;
    if (!BN_copy(pi, Xpi))
        return 0;
    if (!BN_is_odd(pi) && !BN_add_word(pi, 1))
        return 0;
    for (;;) {
        i++;
        BN_GENCB_call(cb, 0, i);
        /* NB 27 MR is specificed in X9.31 */
        if (BN_is_prime_fasttest_ex(pi, 27, ctx, 1, cb))
            break;
        if (!BN_add_word(pi, 2))
            return 0;
    }
    BN_GENCB_call(cb, 2, i);
    return 1;
}