ec_asn1.c

开源的ssl算法openssl,版本0.9.8H

		{
		if ((buffer_1 = OPENSSL_malloc(len_1)) == NULL)
			{
			ECerr(EC_F_EC_ASN1_GROUP2CURVE,
			      ERR_R_MALLOC_FAILURE);
			goto err;
			}
		if ( (len_1 = BN_bn2bin(tmp_1, buffer_1)) == 0)
			{
			ECerr(EC_F_EC_ASN1_GROUP2CURVE, ERR_R_BN_LIB);
			goto err;
			}
		a_buf = buffer_1;
		}

	if (len_2 == 0)
		{
		/* len_2 == 0 => b == 0 */
		b_buf = &char_zero;
		len_2 = 1;
		}
	else
		{
		if ((buffer_2 = OPENSSL_malloc(len_2)) == NULL)
			{
			ECerr(EC_F_EC_ASN1_GROUP2CURVE,
			      ERR_R_MALLOC_FAILURE);
			goto err;
			}
		if ( (len_2 = BN_bn2bin(tmp_2, buffer_2)) == 0)
			{
			ECerr(EC_F_EC_ASN1_GROUP2CURVE, ERR_R_BN_LIB);
			goto err;
			}
		b_buf = buffer_2;
		}
	
	/* set a and b */
	if (!M_ASN1_OCTET_STRING_set(curve->a, a_buf, len_1) ||
	    !M_ASN1_OCTET_STRING_set(curve->b, b_buf, len_2))
		{
		ECerr(EC_F_EC_ASN1_GROUP2CURVE, ERR_R_ASN1_LIB);
		goto err;
		}
	
	/* set the seed (optional) */
	if (group->seed)
		{	
		if (!curve->seed)
			if ((curve->seed = ASN1_BIT_STRING_new()) == NULL)
				{
				ECerr(EC_F_EC_ASN1_GROUP2CURVE, ERR_R_MALLOC_FAILURE);
				goto err;
				}
		curve->seed->flags &= ~(ASN1_STRING_FLAG_BITS_LEFT|0x07);
		curve->seed->flags |= ASN1_STRING_FLAG_BITS_LEFT;
		if (!ASN1_BIT_STRING_set(curve->seed, group->seed, 
		                         (int)group->seed_len))
			{
			ECerr(EC_F_EC_ASN1_GROUP2CURVE, ERR_R_ASN1_LIB);
			goto err;
			}
		}
	else
		{
		if (curve->seed)
			{
			ASN1_BIT_STRING_free(curve->seed);
			curve->seed = NULL;
			}
		}

	ok = 1;

err:	if (buffer_1)
		OPENSSL_free(buffer_1);
	if (buffer_2)
		OPENSSL_free(buffer_2);
	if (tmp_1)
		BN_free(tmp_1);
	if (tmp_2)
		BN_free(tmp_2);
	return(ok);
	}

static ECPARAMETERS *ec_asn1_group2parameters(const EC_GROUP *group,
                                              ECPARAMETERS *param)
	{
	int	ok=0;
	size_t  len=0;
	ECPARAMETERS   *ret=NULL;
	BIGNUM	       *tmp=NULL;
	unsigned char  *buffer=NULL;
	const EC_POINT *point=NULL;
	point_conversion_form_t form;

	if ((tmp = BN_new()) == NULL)
		{
		ECerr(EC_F_EC_ASN1_GROUP2PARAMETERS, ERR_R_MALLOC_FAILURE);
		goto err;
		}

	if (param == NULL)
	{
		if ((ret = ECPARAMETERS_new()) == NULL)
			{
			ECerr(EC_F_EC_ASN1_GROUP2PARAMETERS, 
			      ERR_R_MALLOC_FAILURE);
			goto err;
			}
	}
	else
		ret = param;

	/* set the version (always one) */
	ret->version = (long)0x1;

	/* set the fieldID */
	if (!ec_asn1_group2fieldid(group, ret->fieldID))
		{
		ECerr(EC_F_EC_ASN1_GROUP2PARAMETERS, ERR_R_EC_LIB);
		goto err;
		}

	/* set the curve */
	if (!ec_asn1_group2curve(group, ret->curve))
		{
		ECerr(EC_F_EC_ASN1_GROUP2PARAMETERS, ERR_R_EC_LIB);
		goto err;
		}

	/* set the base point */
	if ((point = EC_GROUP_get0_generator(group)) == NULL)
		{
		ECerr(EC_F_EC_ASN1_GROUP2PARAMETERS, EC_R_UNDEFINED_GENERATOR);
		goto err;
		}

	form = EC_GROUP_get_point_conversion_form(group);

	len = EC_POINT_point2oct(group, point, form, NULL, len, NULL);
	if (len == 0)
		{
		ECerr(EC_F_EC_ASN1_GROUP2PARAMETERS, ERR_R_EC_LIB);
		goto err;
		}
	if ((buffer = OPENSSL_malloc(len)) == NULL)
		{
		ECerr(EC_F_EC_ASN1_GROUP2PARAMETERS, ERR_R_MALLOC_FAILURE);
		goto err;
		}
	if (!EC_POINT_point2oct(group, point, form, buffer, len, NULL))
		{
		ECerr(EC_F_EC_ASN1_GROUP2PARAMETERS, ERR_R_EC_LIB);
		goto err;
		}
	if (ret->base == NULL && (ret->base = ASN1_OCTET_STRING_new()) == NULL)
		{
		ECerr(EC_F_EC_ASN1_GROUP2PARAMETERS, ERR_R_MALLOC_FAILURE);
		goto err;
		}
	if (!ASN1_OCTET_STRING_set(ret->base, buffer, len))
		{
		ECerr(EC_F_EC_ASN1_GROUP2PARAMETERS, ERR_R_ASN1_LIB);
		goto err;
		}

	/* set the order */
	if (!EC_GROUP_get_order(group, tmp, NULL))
		{
		ECerr(EC_F_EC_ASN1_GROUP2PARAMETERS, ERR_R_EC_LIB);
		goto err;
		}
	ret->order = BN_to_ASN1_INTEGER(tmp, ret->order);
	if (ret->order == NULL)
		{
		ECerr(EC_F_EC_ASN1_GROUP2PARAMETERS, ERR_R_ASN1_LIB);
		goto err;
		}

	/* set the cofactor (optional) */
	if (EC_GROUP_get_cofactor(group, tmp, NULL))
		{
		ret->cofactor = BN_to_ASN1_INTEGER(tmp, ret->cofactor);
		if (ret->cofactor == NULL)
			{
			ECerr(EC_F_EC_ASN1_GROUP2PARAMETERS, ERR_R_ASN1_LIB);
			goto err;
			}
		}

	ok = 1;

err :	if(!ok)
		{
		if (ret && !param)
			ECPARAMETERS_free(ret);
		ret = NULL;
		}
	if (tmp)
		BN_free(tmp);
	if (buffer)
		OPENSSL_free(buffer);
	return(ret);
	}

ECPKPARAMETERS *ec_asn1_group2pkparameters(const EC_GROUP *group, 
                                           ECPKPARAMETERS *params)
	{
	int            ok = 1, tmp;
	ECPKPARAMETERS *ret = params;

	if (ret == NULL)
		{
		if ((ret = ECPKPARAMETERS_new()) == NULL)
			{
			ECerr(EC_F_EC_ASN1_GROUP2PKPARAMETERS, 
			      ERR_R_MALLOC_FAILURE);
			return NULL;
			}
		}
	else
		{
		if (ret->type == 0 && ret->value.named_curve)
			ASN1_OBJECT_free(ret->value.named_curve);
		else if (ret->type == 1 && ret->value.parameters)
			ECPARAMETERS_free(ret->value.parameters);
		}

	if (EC_GROUP_get_asn1_flag(group))
		{
		/* use the asn1 OID to describe the
		 * the elliptic curve parameters
		 */
		tmp = EC_GROUP_get_curve_name(group);
		if (tmp)
			{
			ret->type = 0;
			if ((ret->value.named_curve = OBJ_nid2obj(tmp)) == NULL)
				ok = 0;
			}
		else
			/* we don't kmow the nid => ERROR */
			ok = 0;
		}
	else
		{	
		/* use the ECPARAMETERS structure */
		ret->type = 1;
		if ((ret->value.parameters = ec_asn1_group2parameters(
		     group, NULL)) == NULL)
			ok = 0;
		}

	if (!ok)
		{
		ECPKPARAMETERS_free(ret);
		return NULL;
		}
	return ret;
	}

static EC_GROUP *ec_asn1_parameters2group(const ECPARAMETERS *params)
	{
	int			ok = 0, tmp;
	EC_GROUP		*ret = NULL;
	BIGNUM			*p = NULL, *a = NULL, *b = NULL;
	EC_POINT		*point=NULL;
	long    		field_bits;

	if (!params->fieldID || !params->fieldID->fieldType || 
	    !params->fieldID->p.ptr)
		{
		ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, EC_R_ASN1_ERROR);
		goto err;
		}

	/* now extract the curve parameters a and b */
	if (!params->curve || !params->curve->a || 
	    !params->curve->a->data || !params->curve->b ||
	    !params->curve->b->data)
		{
		ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, EC_R_ASN1_ERROR);
		goto err;
		}
	a = BN_bin2bn(params->curve->a->data, params->curve->a->length, NULL);
	if (a == NULL)
		{
		ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, ERR_R_BN_LIB);
		goto err;
		}
	b = BN_bin2bn(params->curve->b->data, params->curve->b->length, NULL);
	if (b == NULL)
		{
		ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, ERR_R_BN_LIB);
		goto err;
		}

	/* get the field parameters */
	tmp = OBJ_obj2nid(params->fieldID->fieldType);

	if (tmp == NID_X9_62_characteristic_two_field)
		{
		X9_62_CHARACTERISTIC_TWO *char_two;

		char_two = params->fieldID->p.char_two;

		field_bits = char_two->m;
		if (field_bits > OPENSSL_ECC_MAX_FIELD_BITS)
			{
			ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, EC_R_FIELD_TOO_LARGE);
			goto err;
			}

		if ((p = BN_new()) == NULL)
			{
			ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, ERR_R_MALLOC_FAILURE);
			goto err;
			}

		/* get the base type */
		tmp = OBJ_obj2nid(char_two->type);

		if (tmp ==  NID_X9_62_tpBasis)
			{
			long tmp_long;

			if (!char_two->p.tpBasis)
				{
				ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, EC_R_ASN1_ERROR);
				goto err;
				}

			tmp_long = ASN1_INTEGER_get(char_two->p.tpBasis);

			if (!(char_two->m > tmp_long && tmp_long > 0))
				{
				ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, EC_R_INVALID_TRINOMIAL_BASIS);
				goto err;
				}
			
			/* create the polynomial */
			if (!BN_set_bit(p, (int)char_two->m))
				goto err;
			if (!BN_set_bit(p, (int)tmp_long))
				goto err;
			if (!BN_set_bit(p, 0))
				goto err;
			}
		else if (tmp == NID_X9_62_ppBasis)
			{
			X9_62_PENTANOMIAL *penta;

			penta = char_two->p.ppBasis;
			if (!penta)
				{
				ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, EC_R_ASN1_ERROR);
				goto err;
				}

			if (!(char_two->m > penta->k3 && penta->k3 > penta->k2 && penta->k2 > penta->k1 && penta->k1 > 0))
				{
				ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, EC_R_INVALID_PENTANOMIAL_BASIS);
				goto err;
				}
			
			/* create the polynomial */
			if (!BN_set_bit(p, (int)char_two->m)) goto err;
			if (!BN_set_bit(p, (int)penta->k1)) goto err;
			if (!BN_set_bit(p, (int)penta->k2)) goto err;
			if (!BN_set_bit(p, (int)penta->k3)) goto err;
			if (!BN_set_bit(p, 0)) goto err;
			}
		else if (tmp == NID_X9_62_onBasis)
			{
			ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, EC_R_NOT_IMPLEMENTED);
			goto err;
			}
		else /* error */
			{
			ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, EC_R_ASN1_ERROR);
			goto err;
			}

		/* create the EC_GROUP structure */
		ret = EC_GROUP_new_curve_GF2m(p, a, b, NULL);
		}
	else if (tmp == NID_X9_62_prime_field)
		{
		/* we have a curve over a prime field */
		/* extract the prime number */
		if (!params->fieldID->p.prime)
			{
			ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, EC_R_ASN1_ERROR);
			goto err;
			}
		p = ASN1_INTEGER_to_BN(params->fieldID->p.prime, NULL);
		if (p == NULL)
			{
			ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, ERR_R_ASN1_LIB);
			goto err;
			}

		if (BN_is_negative(p) || BN_is_zero(p))
			{
			ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, EC_R_INVALID_FIELD);
			goto err;
			}

		field_bits = BN_num_bits(p);
		if (field_bits > OPENSSL_ECC_MAX_FIELD_BITS)
			{
			ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, EC_R_FIELD_TOO_LARGE);
			goto err;
			}

		/* create the EC_GROUP structure */
		ret = EC_GROUP_new_curve_GFp(p, a, b, NULL);
		}
	else
		{
		ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, EC_R_INVALID_FIELD);
		goto err;
		}

	if (ret == NULL)
		{
		ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, ERR_R_EC_LIB);
		goto err;
		}

	/* extract seed (optional) */
	if (params->curve->seed != NULL)
		{
		if (ret->seed != NULL)
			OPENSSL_free(ret->seed);
		if (!(ret->seed = OPENSSL_malloc(params->curve->seed->length)))
			{
			ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, 
			      ERR_R_MALLOC_FAILURE);
			goto err;
			}
		memcpy(ret->seed, params->curve->seed->data, 
		       params->curve->seed->length);
		ret->seed_len = params->curve->seed->length;
		}

	if (!params->order || !params->base || !params->base->data)
		{
		ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, EC_R_ASN1_ERROR);
		goto err;
		}

	if ((point = EC_POINT_new(ret)) == NULL) goto err;

	/* set the point conversion form */
	EC_GROUP_set_point_conversion_form(ret, (point_conversion_form_t)
				(params->base->data[0] & ~0x01));

	/* extract the ec point */
	if (!EC_POINT_oct2point(ret, point, params->base->data, 
		                params->base->length, NULL))
		{
		ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, ERR_R_EC_LIB);
		goto err;
		}

	/* extract the order */
	if ((a = ASN1_INTEGER_to_BN(params->order, a)) == NULL)
		{
		ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, ERR_R_ASN1_LIB);
		goto err;
		}
	if (BN_is_negative(a) || BN_is_zero(a))
		{
		ECerr(EC_F_EC_ASN1_PARAMETERS2GROUP, EC_R_INVALID_GROUP_ORDER);
		goto err;