// Code generated by smithy-go-codegen DO NOT EDIT.

package kms

import (
	"context"
	"fmt"
	awsmiddleware "github.com/aws/aws-sdk-go-v2/aws/middleware"
	"github.com/aws/aws-sdk-go-v2/service/kms/types"
	"github.com/aws/smithy-go/middleware"
	smithyhttp "github.com/aws/smithy-go/transport/http"
)

// Verifies a digital signature that was generated by the Sign operation.
//
// Verification confirms that an authorized user signed the message with the
// specified KMS key and signing algorithm, and the message hasn't changed since it
// was signed. If the signature is verified, the value of the SignatureValid field
// in the response is True . If the signature verification fails, the Verify
// operation fails with an KMSInvalidSignatureException exception.
//
// A digital signature is generated by using the private key in an asymmetric KMS
// key. The signature is verified by using the public key in the same asymmetric
// KMS key. For information about asymmetric KMS keys, see [Asymmetric KMS keys]in the Key Management
// Service Developer Guide.
//
// To use the Verify operation, specify the same asymmetric KMS key, message, and
// signing algorithm that were used to produce the signature. The message type does
// not need to be the same as the one used for signing, but it must indicate
// whether the value of the Message parameter should be hashed as part of the
// verification process.
//
// You can also verify the digital signature by using the public key of the KMS
// key outside of KMS. Use the GetPublicKeyoperation to download the public key in the
// asymmetric KMS key and then use the public key to verify the signature outside
// of KMS. The advantage of using the Verify operation is that it is performed
// within KMS. As a result, it's easy to call, the operation is performed within
// the FIPS boundary, it is logged in CloudTrail, and you can use key policy and
// IAM policy to determine who is authorized to use the KMS key to verify
// signatures.
//
// To verify a signature outside of KMS with an SM2 public key (China Regions
// only), you must specify the distinguishing ID. By default, KMS uses
// 1234567812345678 as the distinguishing ID. For more information, see [Offline verification with SM2 key pairs].
//
// The KMS key that you use for this operation must be in a compatible key state.
// For details, see [Key states of KMS keys]in the Key Management Service Developer Guide.
//
// Cross-account use: Yes. To perform this operation with a KMS key in a different
// Amazon Web Services account, specify the key ARN or alias ARN in the value of
// the KeyId parameter.
//
// Required permissions: [kms:Verify] (key policy)
//
// Related operations: Sign
//
// Eventual consistency: The KMS API follows an eventual consistency model. For
// more information, see [KMS eventual consistency].
//
// [Key states of KMS keys]: https://docs.aws.amazon.com/kms/latest/developerguide/key-state.html
// [Asymmetric KMS keys]: https://docs.aws.amazon.com/kms/latest/developerguide/symmetric-asymmetric.html
// [Offline verification with SM2 key pairs]: https://docs.aws.amazon.com/kms/latest/developerguide/asymmetric-key-specs.html#key-spec-sm-offline-verification
// [kms:Verify]: https://docs.aws.amazon.com/kms/latest/developerguide/kms-api-permissions-reference.html
// [KMS eventual consistency]: https://docs.aws.amazon.com/kms/latest/developerguide/programming-eventual-consistency.html
func (c *Client) Verify(ctx context.Context, params *VerifyInput, optFns ...func(*Options)) (*VerifyOutput, error) {
	if params == nil {
		params = &VerifyInput{}
	}

	result, metadata, err := c.invokeOperation(ctx, "Verify", params, optFns, c.addOperationVerifyMiddlewares)
	if err != nil {
		return nil, err
	}

	out := result.(*VerifyOutput)
	out.ResultMetadata = metadata
	return out, nil
}

type VerifyInput struct {

	// Identifies the asymmetric KMS key that will be used to verify the signature.
	// This must be the same KMS key that was used to generate the signature. If you
	// specify a different KMS key, the signature verification fails.
	//
	// To specify a KMS key, use its key ID, key ARN, alias name, or alias ARN. When
	// using an alias name, prefix it with "alias/" . To specify a KMS key in a
	// different Amazon Web Services account, you must use the key ARN or alias ARN.
	//
	// For example:
	//
	//   - Key ID: 1234abcd-12ab-34cd-56ef-1234567890ab
	//
	//   - Key ARN:
	//   arn:aws:kms:us-east-2:111122223333:key/1234abcd-12ab-34cd-56ef-1234567890ab
	//
	//   - Alias name: alias/ExampleAlias
	//
	//   - Alias ARN: arn:aws:kms:us-east-2:111122223333:alias/ExampleAlias
	//
	// To get the key ID and key ARN for a KMS key, use ListKeys or DescribeKey. To get the alias name
	// and alias ARN, use ListAliases.
	//
	// This member is required.
	KeyId *string

	// Specifies the message that was signed. You can submit a raw message of up to
	// 4096 bytes, or a hash digest of the message. If you submit a digest, use the
	// MessageType parameter with a value of DIGEST .
	//
	// If the message specified here is different from the message that was signed,
	// the signature verification fails. A message and its hash digest are considered
	// to be the same message.
	//
	// This member is required.
	Message []byte

	// The signature that the Sign operation generated.
	//
	// This member is required.
	Signature []byte

	// The signing algorithm that was used to sign the message. If you submit a
	// different algorithm, the signature verification fails.
	//
	// This member is required.
	SigningAlgorithm types.SigningAlgorithmSpec

	// Checks if your request will succeed. DryRun is an optional parameter.
	//
	// To learn more about how to use this parameter, see [Testing your KMS API calls] in the Key Management
	// Service Developer Guide.
	//
	// [Testing your KMS API calls]: https://docs.aws.amazon.com/kms/latest/developerguide/programming-dryrun.html
	DryRun *bool

	// A list of grant tokens.
	//
	// Use a grant token when your permission to call this operation comes from a new
	// grant that has not yet achieved eventual consistency. For more information, see [Grant token]
	// and [Using a grant token]in the Key Management Service Developer Guide.
	//
	// [Grant token]: https://docs.aws.amazon.com/kms/latest/developerguide/grants.html#grant_token
	// [Using a grant token]: https://docs.aws.amazon.com/kms/latest/developerguide/grant-manage.html#using-grant-token
	GrantTokens []string

	// Tells KMS whether the value of the Message parameter should be hashed as part
	// of the signing algorithm. Use RAW for unhashed messages; use DIGEST for message
	// digests, which are already hashed.
	//
	// When the value of MessageType is RAW , KMS uses the standard signing algorithm,
	// which begins with a hash function. When the value is DIGEST , KMS skips the
	// hashing step in the signing algorithm.
	//
	// Use the DIGEST value only when the value of the Message parameter is a message
	// digest. If you use the DIGEST value with an unhashed message, the security of
	// the verification operation can be compromised.
	//
	// When the value of MessageType is DIGEST , the length of the Message value must
	// match the length of hashed messages for the specified signing algorithm.
	//
	// You can submit a message digest and omit the MessageType or specify RAW so the
	// digest is hashed again while signing. However, if the signed message is hashed
	// once while signing, but twice while verifying, verification fails, even when the
	// message hasn't changed.
	//
	// The hashing algorithm in that Verify uses is based on the SigningAlgorithm
	// value.
	//
	//   - Signing algorithms that end in SHA_256 use the SHA_256 hashing algorithm.
	//
	//   - Signing algorithms that end in SHA_384 use the SHA_384 hashing algorithm.
	//
	//   - Signing algorithms that end in SHA_512 use the SHA_512 hashing algorithm.
	//
	//   - SM2DSA uses the SM3 hashing algorithm. For details, see [Offline verification with SM2 key pairs].
	//
	// [Offline verification with SM2 key pairs]: https://docs.aws.amazon.com/kms/latest/developerguide/asymmetric-key-specs.html#key-spec-sm-offline-verification
	MessageType types.MessageType

	noSmithyDocumentSerde
}

type VerifyOutput struct {

	// The Amazon Resource Name ([key ARN] ) of the asymmetric KMS key that was used to verify
	// the signature.
	//
	// [key ARN]: https://docs.aws.amazon.com/kms/latest/developerguide/concepts.html#key-id-key-ARN
	KeyId *string

	// A Boolean value that indicates whether the signature was verified. A value of
	// True indicates that the Signature was produced by signing the Message with the
	// specified KeyID and SigningAlgorithm. If the signature is not verified, the
	// Verify operation fails with a KMSInvalidSignatureException exception.
	SignatureValid bool

	// The signing algorithm that was used to verify the signature.
	SigningAlgorithm types.SigningAlgorithmSpec

	// Metadata pertaining to the operation's result.
	ResultMetadata middleware.Metadata

	noSmithyDocumentSerde
}

func (c *Client) addOperationVerifyMiddlewares(stack *middleware.Stack, options Options) (err error) {
	if err := stack.Serialize.Add(&setOperationInputMiddleware{}, middleware.After); err != nil {
		return err
	}
	err = stack.Serialize.Add(&awsAwsjson11_serializeOpVerify{}, middleware.After)
	if err != nil {
		return err
	}
	err = stack.Deserialize.Add(&awsAwsjson11_deserializeOpVerify{}, middleware.After)
	if err != nil {
		return err
	}
	if err := addProtocolFinalizerMiddlewares(stack, options, "Verify"); err != nil {
		return fmt.Errorf("add protocol finalizers: %v", err)
	}

	if err = addlegacyEndpointContextSetter(stack, options); err != nil {
		return err
	}
	if err = addSetLoggerMiddleware(stack, options); err != nil {
		return err
	}
	if err = addClientRequestID(stack); err != nil {
		return err
	}
	if err = addComputeContentLength(stack); err != nil {
		return err
	}
	if err = addResolveEndpointMiddleware(stack, options); err != nil {
		return err
	}
	if err = addComputePayloadSHA256(stack); err != nil {
		return err
	}
	if err = addRetry(stack, options); err != nil {
		return err
	}
	if err = addRawResponseToMetadata(stack); err != nil {
		return err
	}
	if err = addRecordResponseTiming(stack); err != nil {
		return err
	}
	if err = addClientUserAgent(stack, options); err != nil {
		return err
	}
	if err = smithyhttp.AddErrorCloseResponseBodyMiddleware(stack); err != nil {
		return err
	}
	if err = smithyhttp.AddCloseResponseBodyMiddleware(stack); err != nil {
		return err
	}
	if err = addSetLegacyContextSigningOptionsMiddleware(stack); err != nil {
		return err
	}
	if err = addTimeOffsetBuild(stack, c); err != nil {
		return err
	}
	if err = addUserAgentRetryMode(stack, options); err != nil {
		return err
	}
	if err = addOpVerifyValidationMiddleware(stack); err != nil {
		return err
	}
	if err = stack.Initialize.Add(newServiceMetadataMiddleware_opVerify(options.Region), middleware.Before); err != nil {
		return err
	}
	if err = addRecursionDetection(stack); err != nil {
		return err
	}
	if err = addRequestIDRetrieverMiddleware(stack); err != nil {
		return err
	}
	if err = addResponseErrorMiddleware(stack); err != nil {
		return err
	}
	if err = addRequestResponseLogging(stack, options); err != nil {
		return err
	}
	if err = addDisableHTTPSMiddleware(stack, options); err != nil {
		return err
	}
	return nil
}

func newServiceMetadataMiddleware_opVerify(region string) *awsmiddleware.RegisterServiceMetadata {
	return &awsmiddleware.RegisterServiceMetadata{
		Region:        region,
		ServiceID:     ServiceID,
		OperationName: "Verify",
	}
}