policy-engine/iam/converter.go

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2023-10-19 13:15:21 +00:00
package iam
import (
"errors"
"fmt"
"strconv"
"strings"
"time"
policyengine "git.frostfs.info/TrueCloudLab/policy-engine"
)
const (
FrostFSPrincipal = "FrostFS"
RequestOwnerProperty = "Owner"
)
const (
// String condition operators.
CondStringEquals string = "StringEquals"
CondStringNotEquals string = "StringNotEquals"
CondStringEqualsIgnoreCase string = "StringEqualsIgnoreCase"
CondStringNotEqualsIgnoreCase string = "StringNotEqualsIgnoreCase"
CondStringLike string = "StringLike"
CondStringNotLike string = "StringNotLike"
// Numeric condition operators.
CondNumericEquals string = "NumericEquals"
CondNumericNotEquals string = "NumericNotEquals"
CondNumericLessThan string = "NumericLessThan"
CondNumericLessThanEquals string = "NumericLessThanEquals"
CondNumericGreaterThan string = "NumericGreaterThan"
CondNumericGreaterThanEquals string = "NumericGreaterThanEquals"
// Date condition operators.
CondDateEquals string = "DateEquals"
CondDateNotEquals string = "DateNotEquals"
CondDateLessThan string = "DateLessThan"
CondDateLessThanEquals string = "DateLessThanEquals"
CondDateGreaterThan string = "DateGreaterThan"
CondDateGreaterThanEquals string = "DateGreaterThanEquals"
// Bolean condition operators.
CondBool string = "Bool"
// IP address condition operators.
CondIPAddress string = "IpAddress"
CondNotIPAddress string = "NotIpAddress"
// ARN condition operators.
CondArnEquals string = "ArnEquals"
CondArnLike string = "ArnLike"
CondArnNotEquals string = "ArnNotEquals"
CondArnNotLike string = "ArnNotLike"
)
func (p Policy) ToChain() (*policyengine.Chain, error) {
var chain policyengine.Chain
for _, statement := range p.Statement {
status := policyengine.AccessDenied
if statement.Effect == AllowEffect {
status = policyengine.Allow
}
if len(statement.Principal) != 1 {
return nil, errors.New("currently supported exactly one principal type")
}
var principals []string
var op policyengine.ConditionType
if _, ok := statement.Principal[Wildcard]; ok {
principals = []string{Wildcard}
op = policyengine.CondStringLike
} else if frostfsPrincipals, ok := statement.Principal[FrostFSPrincipal]; ok {
principals = frostfsPrincipals
op = policyengine.CondStringEquals
} else {
return nil, errors.New("currently supported only FrostFS or all (wildcard) principals")
}
var conditions []policyengine.Condition
for _, principal := range principals {
conditions = append(conditions, policyengine.Condition{
Op: op,
Object: policyengine.ObjectRequest,
Key: RequestOwnerProperty,
Value: principal,
})
}
conds, err := statement.Conditions.ToChainCondition()
if err != nil {
return nil, err
}
conditions = append(conditions, conds...)
r := policyengine.Rule{
Status: status,
Action: statement.Action,
Resource: statement.Resource,
Any: true,
Condition: conditions,
}
chain.Rules = append(chain.Rules, r)
}
return &chain, nil
}
func (c Conditions) ToChainCondition() ([]policyengine.Condition, error) {
var conditions []policyengine.Condition
var convertValue convertFunction
for op, KVs := range c {
var condType policyengine.ConditionType
switch {
case strings.HasPrefix(op, "String"):
convertValue = noConvertFunction
switch op {
case CondStringEquals:
condType = policyengine.CondStringEquals
case CondStringNotEquals:
condType = policyengine.CondStringNotEquals
case CondStringEqualsIgnoreCase:
condType = policyengine.CondStringEqualsIgnoreCase
case CondStringNotEqualsIgnoreCase:
condType = policyengine.CondStringNotEqualsIgnoreCase
case CondStringLike:
condType = policyengine.CondStringLike
case CondStringNotLike:
condType = policyengine.CondStringNotLike
default:
return nil, fmt.Errorf("unsupported condition operator: '%s'", op)
}
case strings.HasPrefix(op, "Arn"):
convertValue = noConvertFunction
switch op {
case CondArnEquals:
condType = policyengine.CondStringEquals
case CondArnNotEquals:
condType = policyengine.CondStringNotEquals
case CondArnLike:
condType = policyengine.CondStringLike
case CondArnNotLike:
condType = policyengine.CondStringNotLike
default:
return nil, fmt.Errorf("unsupported condition operator: '%s'", op)
}
case strings.HasPrefix(op, "Numeric"):
// TODO
case strings.HasPrefix(op, "Date"):
convertValue = dateConvertFunction
switch op {
case CondDateEquals:
condType = policyengine.CondStringEquals
case CondDateNotEquals:
condType = policyengine.CondStringNotEquals
case CondDateLessThan:
condType = policyengine.CondStringLessThan
case CondDateLessThanEquals:
condType = policyengine.CondStringLessThanEquals
case CondDateGreaterThan:
condType = policyengine.CondStringGreaterThan
case CondDateGreaterThanEquals:
condType = policyengine.CondStringGreaterThanEquals
default:
return nil, fmt.Errorf("unsupported condition operator: '%s'", op)
}
case op == CondBool:
convertValue = noConvertFunction
condType = policyengine.CondStringEqualsIgnoreCase
case op == CondIPAddress:
// todo consider using converters
// "203.0.113.0/24" -> "203.0.113.*",
// "2001:DB8:1234:5678::/64" -> "2001:DB8:1234:5678:*"
// or having specific condition type for IP
convertValue = noConvertFunction
condType = policyengine.CondStringLike
case op == CondNotIPAddress:
convertValue = noConvertFunction
condType = policyengine.CondStringNotLike
default:
return nil, fmt.Errorf("unsupported condition operator: '%s'", op)
}
for key, values := range KVs {
for _, val := range values {
converted, err := convertValue(val)
if err != nil {
return nil, err
}
conditions = append(conditions, policyengine.Condition{
Op: condType,
Object: policyengine.ObjectRequest,
Key: key,
Value: converted,
})
}
}
}
return conditions, nil
}
type convertFunction func(string) (string, error)
func noConvertFunction(val string) (string, error) {
return val, nil
}
func dateConvertFunction(val string) (string, error) {
if _, err := strconv.ParseInt(val, 10, 64); err == nil {
return val, nil
}
parsed, err := time.Parse(time.RFC3339, val)
if err != nil {
return "", err
}
return strconv.FormatInt(parsed.UTC().Unix(), 10), nil
}