feat: gitea client

vendor/cloud.google.com/go/auth/internal/internal.go

@@ -0,0 +1,184 @@
+// Copyright 2023 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 internal
+
+import (
+	"context"
+	"crypto/rsa"
+	"crypto/x509"
+	"encoding/json"
+	"encoding/pem"
+	"errors"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"sync"
+	"time"
+
+	"cloud.google.com/go/compute/metadata"
+)
+
+const (
+	// TokenTypeBearer is the auth header prefix for bearer tokens.
+	TokenTypeBearer = "Bearer"
+
+	// QuotaProjectEnvVar is the environment variable for setting the quota
+	// project.
+	QuotaProjectEnvVar = "GOOGLE_CLOUD_QUOTA_PROJECT"
+	projectEnvVar      = "GOOGLE_CLOUD_PROJECT"
+	maxBodySize        = 1 << 20
+
+	// DefaultUniverseDomain is the default value for universe domain.
+	// Universe domain is the default service domain for a given Cloud universe.
+	DefaultUniverseDomain = "googleapis.com"
+)
+
+// CloneDefaultClient returns a [http.Client] with some good defaults.
+func CloneDefaultClient() *http.Client {
+	return &http.Client{
+		Transport: http.DefaultTransport.(*http.Transport).Clone(),
+		Timeout:   30 * time.Second,
+	}
+}
+
+// ParseKey converts the binary contents of a private key file
+// to an *rsa.PrivateKey. It detects whether the private key is in a
+// PEM container or not. If so, it extracts the the private key
+// from PEM container before conversion. It only supports PEM
+// containers with no passphrase.
+func ParseKey(key []byte) (*rsa.PrivateKey, error) {
+	block, _ := pem.Decode(key)
+	if block != nil {
+		key = block.Bytes
+	}
+	parsedKey, err := x509.ParsePKCS8PrivateKey(key)
+	if err != nil {
+		parsedKey, err = x509.ParsePKCS1PrivateKey(key)
+		if err != nil {
+			return nil, fmt.Errorf("private key should be a PEM or plain PKCS1 or PKCS8: %w", err)
+		}
+	}
+	parsed, ok := parsedKey.(*rsa.PrivateKey)
+	if !ok {
+		return nil, errors.New("private key is invalid")
+	}
+	return parsed, nil
+}
+
+// GetQuotaProject retrieves quota project with precedence being: override,
+// environment variable, creds json file.
+func GetQuotaProject(b []byte, override string) string {
+	if override != "" {
+		return override
+	}
+	if env := os.Getenv(QuotaProjectEnvVar); env != "" {
+		return env
+	}
+	if b == nil {
+		return ""
+	}
+	var v struct {
+		QuotaProject string `json:"quota_project_id"`
+	}
+	if err := json.Unmarshal(b, &v); err != nil {
+		return ""
+	}
+	return v.QuotaProject
+}
+
+// GetProjectID retrieves project with precedence being: override,
+// environment variable, creds json file.
+func GetProjectID(b []byte, override string) string {
+	if override != "" {
+		return override
+	}
+	if env := os.Getenv(projectEnvVar); env != "" {
+		return env
+	}
+	if b == nil {
+		return ""
+	}
+	var v struct {
+		ProjectID string `json:"project_id"` // standard service account key
+		Project   string `json:"project"`    // gdch key
+	}
+	if err := json.Unmarshal(b, &v); err != nil {
+		return ""
+	}
+	if v.ProjectID != "" {
+		return v.ProjectID
+	}
+	return v.Project
+}
+
+// ReadAll consumes the whole reader and safely reads the content of its body
+// with some overflow protection.
+func ReadAll(r io.Reader) ([]byte, error) {
+	return io.ReadAll(io.LimitReader(r, maxBodySize))
+}
+
+// StaticCredentialsProperty is a helper for creating static credentials
+// properties.
+func StaticCredentialsProperty(s string) StaticProperty {
+	return StaticProperty(s)
+}
+
+// StaticProperty always returns that value of the underlying string.
+type StaticProperty string
+
+// GetProperty loads the properly value provided the given context.
+func (p StaticProperty) GetProperty(context.Context) (string, error) {
+	return string(p), nil
+}
+
+// ComputeUniverseDomainProvider fetches the credentials universe domain from
+// the google cloud metadata service.
+type ComputeUniverseDomainProvider struct {
+	universeDomainOnce sync.Once
+	universeDomain     string
+	universeDomainErr  error
+}
+
+// GetProperty fetches the credentials universe domain from the google cloud
+// metadata service.
+func (c *ComputeUniverseDomainProvider) GetProperty(ctx context.Context) (string, error) {
+	c.universeDomainOnce.Do(func() {
+		c.universeDomain, c.universeDomainErr = getMetadataUniverseDomain(ctx)
+	})
+	if c.universeDomainErr != nil {
+		return "", c.universeDomainErr
+	}
+	return c.universeDomain, nil
+}
+
+// httpGetMetadataUniverseDomain is a package var for unit test substitution.
+var httpGetMetadataUniverseDomain = func(ctx context.Context) (string, error) {
+	client := metadata.NewClient(&http.Client{Timeout: time.Second})
+	// TODO(quartzmo): set ctx on request
+	return client.Get("universe/universe_domain")
+}
+
+func getMetadataUniverseDomain(ctx context.Context) (string, error) {
+	universeDomain, err := httpGetMetadataUniverseDomain(ctx)
+	if err == nil {
+		return universeDomain, nil
+	}
+	if _, ok := err.(metadata.NotDefinedError); ok {
+		// http.StatusNotFound (404)
+		return DefaultUniverseDomain, nil
+	}
+	return "", err
+}