com.google.crypto.tink.signature.EcdsaParameters Maven / Gradle / Ivy
// Copyright 2022 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
////////////////////////////////////////////////////////////////////////////////
package com.google.crypto.tink.signature;
import com.google.crypto.tink.annotations.Alpha;
import com.google.crypto.tink.internal.EllipticCurvesUtil;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import com.google.errorprone.annotations.Immutable;
import java.security.GeneralSecurityException;
import java.security.spec.ECParameterSpec;
import java.util.Objects;
/**
* Describes the parameters of an ECDSA signature primitive.
*
* This API is annotated with Alpha because it is not yet stable and might be changed in the
* future.
*/
@Alpha
public final class EcdsaParameters extends SignatureParameters {
/**
* Describes details of the ECDSA signature computation.
*
*
The standard ECDSA key is used for variant "NO_PREFIX". Other variants slightly change how
* the signature is computed, or add a prefix to every computation depending on the key id.
*/
@Immutable
public static final class Variant {
public static final Variant TINK = new Variant("TINK");
public static final Variant CRUNCHY = new Variant("CRUNCHY");
public static final Variant LEGACY = new Variant("LEGACY");
public static final Variant NO_PREFIX = new Variant("NO_PREFIX");
private final String name;
private Variant(String name) {
this.name = name;
}
@Override
public String toString() {
return name;
}
}
/** The encoding used in the signature. */
@Immutable
public static final class SignatureEncoding {
public static final SignatureEncoding IEEE_P1363 = new SignatureEncoding("IEEE_P1363");
public static final SignatureEncoding DER = new SignatureEncoding("DER");
private final String name;
private SignatureEncoding(String name) {
this.name = name;
}
@Override
public String toString() {
return name;
}
}
/** The elliptic curve and its parameters. */
@Immutable
public static final class CurveType {
public static final CurveType NIST_P256 =
new CurveType("NIST_P256", EllipticCurvesUtil.NIST_P256_PARAMS);
public static final CurveType NIST_P384 =
new CurveType("NIST_P384", EllipticCurvesUtil.NIST_P384_PARAMS);
public static final CurveType NIST_P521 =
new CurveType("NIST_P521", EllipticCurvesUtil.NIST_P521_PARAMS);
private final String name;
@SuppressWarnings("Immutable") // ECParameterSpec is immutable
private final ECParameterSpec spec;
private CurveType(String name, ECParameterSpec spec) {
this.name = name;
this.spec = spec;
}
@Override
public String toString() {
return name;
}
public ECParameterSpec toParameterSpec() {
return spec;
}
public static CurveType fromParameterSpec(ECParameterSpec spec)
throws GeneralSecurityException {
if (EllipticCurvesUtil.isSameEcParameterSpec(spec, NIST_P256.toParameterSpec())) {
return NIST_P256;
}
if (EllipticCurvesUtil.isSameEcParameterSpec(spec, NIST_P384.toParameterSpec())) {
return NIST_P384;
}
if (EllipticCurvesUtil.isSameEcParameterSpec(spec, NIST_P521.toParameterSpec())) {
return NIST_P521;
}
throw new GeneralSecurityException("unknown ECParameterSpec");
}
}
/** The Hash algorithm used. */
@Immutable
public static final class HashType {
public static final HashType SHA256 = new HashType("SHA256");
public static final HashType SHA384 = new HashType("SHA384");
public static final HashType SHA512 = new HashType("SHA512");
private final String name;
private HashType(String name) {
this.name = name;
}
@Override
public String toString() {
return name;
}
}
/** Builds a new EcdsaParameters instance. */
public static final class Builder {
private SignatureEncoding signatureEncoding = null;
private CurveType curveType = null;
private HashType hashType = null;
private Variant variant = Variant.NO_PREFIX;
private Builder() {}
@CanIgnoreReturnValue
public Builder setSignatureEncoding(SignatureEncoding signatureEncoding) {
this.signatureEncoding = signatureEncoding;
return this;
}
@CanIgnoreReturnValue
public Builder setCurveType(CurveType curveType) {
this.curveType = curveType;
return this;
}
@CanIgnoreReturnValue
public Builder setHashType(HashType hashType) {
this.hashType = hashType;
return this;
}
@CanIgnoreReturnValue
public Builder setVariant(Variant variant) {
this.variant = variant;
return this;
}
public EcdsaParameters build() throws GeneralSecurityException {
if (signatureEncoding == null) {
throw new GeneralSecurityException("signature encoding is not set");
}
if (curveType == null) {
throw new GeneralSecurityException("EC curve type is not set");
}
if (hashType == null) {
throw new GeneralSecurityException("hash type is not set");
}
if (variant == null) {
throw new GeneralSecurityException("variant is not set");
}
if (curveType == CurveType.NIST_P256) {
if (hashType != HashType.SHA256) {
throw new GeneralSecurityException("NIST_P256 requires SHA256");
}
}
if (curveType == CurveType.NIST_P384) {
if (hashType != HashType.SHA384 && hashType != HashType.SHA512) {
throw new GeneralSecurityException("NIST_P384 requires SHA384 or SHA512");
}
}
if (curveType == CurveType.NIST_P521) {
if (hashType != HashType.SHA512) {
throw new GeneralSecurityException("NIST_P521 requires SHA512");
}
}
return new EcdsaParameters(signatureEncoding, curveType, hashType, variant);
}
}
private final SignatureEncoding signatureEncoding;
private final CurveType curveType;
private final HashType hashType;
private final Variant variant;
private EcdsaParameters(
SignatureEncoding signatureEncoding,
CurveType curveType,
HashType hashType,
Variant variant) {
this.signatureEncoding = signatureEncoding;
this.curveType = curveType;
this.hashType = hashType;
this.variant = variant;
}
public static Builder builder() {
return new Builder();
}
public SignatureEncoding getSignatureEncoding() {
return signatureEncoding;
}
public CurveType getCurveType() {
return curveType;
}
public HashType getHashType() {
return hashType;
}
public Variant getVariant() {
return variant;
}
@Override
public boolean equals(Object o) {
if (!(o instanceof EcdsaParameters)) {
return false;
}
EcdsaParameters that = (EcdsaParameters) o;
return that.getSignatureEncoding() == getSignatureEncoding()
&& that.getCurveType() == getCurveType()
&& that.getHashType() == getHashType()
&& that.getVariant() == getVariant();
}
@Override
public int hashCode() {
return Objects.hash(EcdsaParameters.class, signatureEncoding, curveType, hashType, variant);
}
@Override
public boolean hasIdRequirement() {
return variant != Variant.NO_PREFIX;
}
@Override
public String toString() {
return "ECDSA Parameters (variant: "
+ variant
+ ", hashType: "
+ hashType
+ ", encoding: "
+ signatureEncoding
+ ", curve: "
+ curveType
+ ")";
}
}