[#143] sdk/token: Define bearer token structure

Signed-off-by: Alex Vanin <alexey@nspcc.ru>

pkg/token/bearer.go

@@ -0,0 +1,109 @@
+package token
+
+import (
+	"crypto/ecdsa"
+	"errors"
+
+	"github.com/nspcc-dev/neofs-api-go/pkg/acl/eacl"
+	"github.com/nspcc-dev/neofs-api-go/pkg/owner"
+	"github.com/nspcc-dev/neofs-api-go/util/signature"
+	"github.com/nspcc-dev/neofs-api-go/v2/acl"
+	"github.com/nspcc-dev/neofs-api-go/v2/refs"
+	v2signature "github.com/nspcc-dev/neofs-api-go/v2/signature"
+)
+
+type BearerToken struct {
+	token acl.BearerToken
+}
+
+func (b BearerToken) ToV2() *acl.BearerToken {
+	return &b.token
+}
+
+func (b *BearerToken) SetLifetime(exp, nbf, iat uint64) {
+	body := b.token.GetBody()
+	if body == nil {
+		body = new(acl.BearerTokenBody)
+	}
+
+	lt := new(acl.TokenLifetime)
+	lt.SetExp(exp)
+	lt.SetNbf(nbf)
+	lt.SetIat(iat)
+
+	body.SetLifetime(lt)
+	b.token.SetBody(body)
+}
+
+func (b *BearerToken) SetEACLTable(table *eacl.Table) {
+	body := b.token.GetBody()
+	if body == nil {
+		body = new(acl.BearerTokenBody)
+	}
+
+	body.SetEACL(table.ToV2())
+	b.token.SetBody(body)
+}
+
+func (b *BearerToken) SetOwner(id *owner.ID) {
+	body := b.token.GetBody()
+	if body == nil {
+		body = new(acl.BearerTokenBody)
+	}
+
+	body.SetOwnerID(id.ToV2())
+	b.token.SetBody(body)
+}
+
+func (b *BearerToken) SignToken(key *ecdsa.PrivateKey) error {
+	err := sanityCheck(b)
+	if err != nil {
+		return err
+	}
+
+	signWrapper := v2signature.StableMarshalerWrapper{SM: b.token.GetBody()}
+	return signature.SignDataWithHandler(key, signWrapper, func(key []byte, sig []byte) {
+		bearerSignature := new(refs.Signature)
+		bearerSignature.SetKey(key)
+		bearerSignature.SetSign(sig)
+		b.token.SetSignature(bearerSignature)
+	})
+}
+
+func NewBearerToken() *BearerToken {
+	b := new(BearerToken)
+	b.token = acl.BearerToken{}
+	b.token.SetBody(new(acl.BearerTokenBody))
+
+	return b
+}
+
+func NewBearerTokenFromV2(v2 *acl.BearerToken) *BearerToken {
+	if v2 == nil {
+		v2 = new(acl.BearerToken)
+	}
+
+	return &BearerToken{
+		token: *v2,
+	}
+}
+
+// sanityCheck if bearer token is ready to be issued
+func sanityCheck(b *BearerToken) error {
+	switch {
+	case b == nil:
+		return errors.New("bearer token is not set")
+	case b.token.GetBody() == nil:
+		return errors.New("bearer token body is not set")
+	case b.token.GetBody().GetLifetime() == nil:
+		return errors.New("bearer token lifetime is not set")
+	case b.token.GetBody().GetEACL() == nil:
+		return errors.New("bearer token EACL table is not set")
+	case b.token.GetBody().GetOwnerID() == nil:
+		return errors.New("bearer token owner is not set")
+	}
+
+	// consider checking EACL sanity there, lifetime correctness, etc.
+
+	return nil
+}