179 lines
3.3 KiB
Go
179 lines
3.3 KiB
Go
package storage
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import (
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"encoding/json"
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"io"
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"strings"
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)
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// User - AWS canonical
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type User struct {
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AWS string
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}
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// Statement - AWS policy statement
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type Statement struct {
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Sid string
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Effect string
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Principal User
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Action []string
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Resource []string
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// TODO fix it in future if necessary - Condition {}
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}
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// BucketPolicy - AWS policy collection
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type BucketPolicy struct {
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Version string // date in 0000-00-00 format
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Statement []Statement
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}
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// Resource delimiter
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const (
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AwsResource = "arn:aws:s3:::"
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MinioResource = "minio:::"
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)
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// TODO support canonical user
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// Principal delimiter
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const (
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AwsPrincipal = "arn:aws:iam::"
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MinioPrincipal = "minio::"
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)
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// Action map
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var SupportedActionMap = map[string]bool{
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"*": true,
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"s3:GetObject": true,
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"s3:ListBucket": true,
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"s3:PutObject": true,
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"s3:CreateBucket": true,
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"s3:GetBucketPolicy": true,
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"s3:DeleteBucketPolicy": true,
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"s3:ListAllMyBuckets": true,
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"s3:PutBucketPolicy": true,
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}
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// Effect map
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var SupportedEffectMap = map[string]bool{
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"Allow": true,
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"Deny": true,
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}
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func isValidAction(action []string) bool {
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for _, a := range action {
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if !SupportedActionMap[a] {
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return false
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}
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}
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return true
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}
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func isValidEffect(effect string) bool {
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if SupportedEffectMap[effect] {
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return true
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}
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return false
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}
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func isValidResource(resources []string) bool {
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var ok bool
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for _, resource := range resources {
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switch true {
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case strings.HasPrefix(resource, AwsResource):
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bucket := strings.SplitAfter(resource, AwsResource)[1]
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ok = true
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if len(bucket) == 0 {
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ok = false
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}
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case strings.HasPrefix(resource, MinioResource):
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bucket := strings.SplitAfter(resource, MinioResource)[1]
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ok = true
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if len(bucket) == 0 {
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ok = false
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}
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default:
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ok = false
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}
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}
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return ok
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}
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func isValidPrincipal(principal string) bool {
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var ok bool
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if principal == "*" {
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return true
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}
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switch true {
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case strings.HasPrefix(principal, AwsPrincipal):
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username := strings.SplitAfter(principal, AwsPrincipal)[1]
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ok = true
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if len(username) == 0 {
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ok = false
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}
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case strings.HasPrefix(principal, MinioPrincipal):
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username := strings.SplitAfter(principal, MinioPrincipal)[1]
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ok = true
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if len(username) == 0 {
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ok = false
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}
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default:
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ok = false
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}
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return ok
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}
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// Parsepolicy - validate request body is proper JSON and in accordance with policy standards
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func Parsepolicy(data io.Reader) (BucketPolicy, bool) {
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var policy BucketPolicy
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decoder := json.NewDecoder(data)
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err := decoder.Decode(&policy)
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if err != nil {
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goto error
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}
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if len(policy.Version) == 0 {
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goto error
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}
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_, err = parseDate(policy.Version)
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if err != nil {
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goto error
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}
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if len(policy.Statement) == 0 {
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goto error
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}
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for _, statement := range policy.Statement {
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if len(statement.Sid) == 0 {
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goto error
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}
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if len(statement.Effect) == 0 {
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goto error
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}
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if !isValidEffect(statement.Effect) {
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goto error
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}
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if len(statement.Principal.AWS) == 0 {
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goto error
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}
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if !isValidPrincipal(statement.Principal.AWS) {
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goto error
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}
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if len(statement.Action) == 0 {
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goto error
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}
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if !isValidAction(statement.Action) {
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goto error
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}
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if len(statement.Resource) == 0 {
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goto error
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}
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if !isValidResource(statement.Resource) {
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goto error
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}
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}
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return policy, true
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error:
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return BucketPolicy{}, false
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}
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