// 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/aws/signer/v4"
	"github.com/aws/aws-sdk-go-v2/service/kms/types"
	"github.com/aws/smithy-go/middleware"
	smithyhttp "github.com/aws/smithy-go/transport/http"
)

// Creates a digital signature (https://en.wikipedia.org/wiki/Digital_signature)
// for a message or message digest by using the private key in an asymmetric
// signing KMS key. To verify the signature, use the Verify operation, or use the
// public key in the same asymmetric KMS key outside of KMS. For information about
// asymmetric KMS keys, see Asymmetric KMS keys (https://docs.aws.amazon.com/kms/latest/developerguide/symmetric-asymmetric.html)
// in the Key Management Service Developer Guide. Digital signatures are generated
// and verified by using asymmetric key pair, such as an RSA or ECC pair that is
// represented by an asymmetric KMS key. The key owner (or an authorized user) uses
// their private key to sign a message. Anyone with the public key can verify that
// the message was signed with that particular private key and that the message
// hasn't changed since it was signed. To use the Sign operation, provide the
// following information:
//   - Use the KeyId parameter to identify an asymmetric KMS key with a KeyUsage
//     value of SIGN_VERIFY . To get the KeyUsage value of a KMS key, use the
//     DescribeKey operation. The caller must have kms:Sign permission on the KMS
//     key.
//   - Use the Message parameter to specify the message or message digest to sign.
//     You can submit messages of up to 4096 bytes. To sign a larger message, generate
//     a hash digest of the message, and then provide the hash digest in the Message
//     parameter. To indicate whether the message is a full message or a digest, use
//     the MessageType parameter.
//   - Choose a signing algorithm that is compatible with the KMS key.
//
// When signing a message, be sure to record the KMS key and the signing
// algorithm. This information is required to verify the signature. Best practices
// recommend that you limit the time during which any signature is effective. This
// deters an attack where the actor uses a signed message to establish validity
// repeatedly or long after the message is superseded. Signatures do not include a
// timestamp, but you can include a timestamp in the signed message to help you
// detect when its time to refresh the signature. To verify the signature that this
// operation generates, use the Verify operation. Or use the GetPublicKey
// operation to download the public key and then use the public key to verify the
// signature outside of KMS. The KMS key that you use for this operation must be in
// a compatible key state. For details, see Key states of KMS keys (https://docs.aws.amazon.com/kms/latest/developerguide/key-state.html)
// 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:Sign (https://docs.aws.amazon.com/kms/latest/developerguide/kms-api-permissions-reference.html)
// (key policy) Related operations: Verify Eventual consistency: The KMS API
// follows an eventual consistency model. For more information, see KMS eventual
// consistency (https://docs.aws.amazon.com/kms/latest/developerguide/programming-eventual-consistency.html)
// .
func (c *Client) Sign(ctx context.Context, params *SignInput, optFns ...func(*Options)) (*SignOutput, error) {
	if params == nil {
		params = &SignInput{}
	}

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

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

type SignInput struct {

	// Identifies an asymmetric KMS key. KMS uses the private key in the asymmetric
	// KMS key to sign the message. The KeyUsage type of the KMS key must be
	// SIGN_VERIFY . To find the KeyUsage of a KMS key, use the DescribeKey operation.
	// 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 or message digest to sign. Messages can be 0-4096 bytes.
	// To sign a larger message, provide a message digest. If you provide a message
	// digest, use the DIGEST value of MessageType to prevent the digest from being
	// hashed again while signing.
	//
	// This member is required.
	Message []byte

	// Specifies the signing algorithm to use when signing the message. Choose an
	// algorithm that is compatible with the type and size of the specified asymmetric
	// KMS key. When signing with RSA key pairs, RSASSA-PSS algorithms are preferred.
	// We include RSASSA-PKCS1-v1_5 algorithms for compatibility with existing
	// applications.
	//
	// 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 (https://docs.aws.amazon.com/kms/latest/developerguide/programming-dryrun.html)
	// in the Key Management Service Developer Guide.
	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 (https://docs.aws.amazon.com/kms/latest/developerguide/grants.html#grant_token)
	// and Using a grant token (https://docs.aws.amazon.com/kms/latest/developerguide/grant-manage.html#using-grant-token)
	// in the Key Management Service Developer Guide.
	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
	// signing 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, this can cause verification failures when verifying with a system that
	// assumes a single hash. The hashing algorithm in that Sign 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 (https://docs.aws.amazon.com/kms/latest/developerguide/asymmetric-key-specs.html#key-spec-sm-offline-verification)
	//   .
	MessageType types.MessageType

	noSmithyDocumentSerde
}

type SignOutput struct {

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

	// The cryptographic signature that was generated for the message.
	//   - When used with the supported RSA signing algorithms, the encoding of this
	//   value is defined by PKCS #1 in RFC 8017 (https://tools.ietf.org/html/rfc8017)
	//   .
	//   - When used with the ECDSA_SHA_256 , ECDSA_SHA_384 , or ECDSA_SHA_512 signing
	//   algorithms, this value is a DER-encoded object as defined by ANSI X9.62–2005 and
	//   RFC 3279 Section 2.2.3 (https://tools.ietf.org/html/rfc3279#section-2.2.3) .
	//   This is the most commonly used signature format and is appropriate for most
	//   uses.
	// When you use the HTTP API or the Amazon Web Services CLI, the value is
	// Base64-encoded. Otherwise, it is not Base64-encoded.
	Signature []byte

	// The signing algorithm that was used to sign the message.
	SigningAlgorithm types.SigningAlgorithmSpec

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

	noSmithyDocumentSerde
}

func (c *Client) addOperationSignMiddlewares(stack *middleware.Stack, options Options) (err error) {
	if err := stack.Serialize.Add(&setOperationInputMiddleware{}, middleware.After); err != nil {
		return err
	}
	err = stack.Serialize.Add(&awsAwsjson11_serializeOpSign{}, middleware.After)
	if err != nil {
		return err
	}
	err = stack.Deserialize.Add(&awsAwsjson11_deserializeOpSign{}, middleware.After)
	if err != nil {
		return err
	}
	if err := addProtocolFinalizerMiddlewares(stack, options, "Sign"); 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 = awsmiddleware.AddClientRequestIDMiddleware(stack); err != nil {
		return err
	}
	if err = smithyhttp.AddComputeContentLengthMiddleware(stack); err != nil {
		return err
	}
	if err = addResolveEndpointMiddleware(stack, options); err != nil {
		return err
	}
	if err = v4.AddComputePayloadSHA256Middleware(stack); err != nil {
		return err
	}
	if err = addRetryMiddlewares(stack, options); err != nil {
		return err
	}
	if err = awsmiddleware.AddRawResponseToMetadata(stack); err != nil {
		return err
	}
	if err = awsmiddleware.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 = addOpSignValidationMiddleware(stack); err != nil {
		return err
	}
	if err = stack.Initialize.Add(newServiceMetadataMiddleware_opSign(options.Region), middleware.Before); err != nil {
		return err
	}
	if err = awsmiddleware.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_opSign(region string) *awsmiddleware.RegisterServiceMetadata {
	return &awsmiddleware.RegisterServiceMetadata{
		Region:        region,
		ServiceID:     ServiceID,
		OperationName: "Sign",
	}
}