// Copyright (c) HashiCorp, Inc. // SPDX-License-Identifier: MPL-2.0 package vault import ( "context" "fmt" "reflect" "sort" "strings" "github.com/armon/go-radix" "github.com/hashicorp/go-multierror" "github.com/hashicorp/go-secure-stdlib/strutil" "github.com/hashicorp/vault/helper/identity" "github.com/hashicorp/vault/helper/namespace" "github.com/hashicorp/vault/sdk/logical" "github.com/mitchellh/copystructure" ) // ACL is used to wrap a set of policies to provide // an efficient interface for access control. type ACL struct { // exactRules contains the path policies that are exact exactRules *radix.Tree // prefixRules contains the path policies that are a prefix prefixRules *radix.Tree segmentWildcardPaths map[string]interface{} // root is enabled if the "root" named policy is present. root bool // Stores policies that are actually RGPs for later fetching rgpPolicies []*Policy } type PolicyCheckOpts struct { RootPrivsRequired bool Unauth bool } type AuthResults struct { ACLResults *ACLResults SentinelResults *SentinelResults Allowed bool RootPrivs bool DeniedError bool Error *multierror.Error } type ACLResults struct { Allowed bool RootPrivs bool IsRoot bool MFAMethods []string ControlGroup *ControlGroup CapabilitiesBitmap uint32 GrantingPolicies []logical.PolicyInfo } type SentinelResults struct { GrantingPolicies []logical.PolicyInfo } // NewACL is used to construct a policy based ACL from a set of policies. func NewACL(ctx context.Context, policies []*Policy) (*ACL, error) { // Initialize a := &ACL{ exactRules: radix.New(), prefixRules: radix.New(), segmentWildcardPaths: make(map[string]interface{}, len(policies)), root: false, } ns, err := namespace.FromContext(ctx) if err != nil { return nil, err } if ns == nil { return nil, namespace.ErrNoNamespace } // Inject each policy for _, policy := range policies { // Ignore a nil policy object if policy == nil { continue } switch policy.Type { case PolicyTypeACL: case PolicyTypeRGP: a.rgpPolicies = append(a.rgpPolicies, policy) continue default: return nil, fmt.Errorf("unable to parse policy (wrong type)") } // Check if this is root if policy.Name == "root" { if ns.ID != namespace.RootNamespaceID { return nil, fmt.Errorf("root policy is only allowed in root namespace") } if len(policies) != 1 { return nil, fmt.Errorf("other policies present along with root") } a.root = true } for _, pc := range policy.Paths { var raw interface{} var ok bool var tree *radix.Tree switch { case pc.HasSegmentWildcards: raw, ok = a.segmentWildcardPaths[pc.Path] default: // Check which tree to use tree = a.exactRules if pc.IsPrefix { tree = a.prefixRules } // Check for an existing policy raw, ok = tree.Get(pc.Path) } if !ok { clonedPerms, err := pc.Permissions.Clone() if err != nil { return nil, fmt.Errorf("error cloning ACL permissions: %w", err) } // Store this policy name as the policy that permits these // capabilities clonedPerms.GrantingPoliciesMap = addGrantingPoliciesToMap(nil, policy, clonedPerms.CapabilitiesBitmap) switch { case pc.HasSegmentWildcards: a.segmentWildcardPaths[pc.Path] = clonedPerms default: tree.Insert(pc.Path, clonedPerms) } continue } // these are the ones already in the tree existingPerms := raw.(*ACLPermissions) switch { case existingPerms.CapabilitiesBitmap&DenyCapabilityInt > 0: // If we are explicitly denied in the existing capability set, // don't save anything else continue case pc.Permissions.CapabilitiesBitmap&DenyCapabilityInt > 0: // If this new policy explicitly denies, only save the deny value existingPerms.CapabilitiesBitmap = DenyCapabilityInt existingPerms.AllowedParameters = nil existingPerms.DeniedParameters = nil goto INSERT default: // Insert the capabilities in this new policy into the existing // value existingPerms.CapabilitiesBitmap = existingPerms.CapabilitiesBitmap | pc.Permissions.CapabilitiesBitmap existingPerms.GrantingPoliciesMap = addGrantingPoliciesToMap(existingPerms.GrantingPoliciesMap, policy, pc.Permissions.CapabilitiesBitmap) } // Note: In these stanzas, we're preferring minimum lifetimes. So // we take the lesser of two specified max values, or we take the // lesser of two specified min values, the idea being, allowing // token lifetime to be minimum possible. // // If we have an existing max, and we either don't have a current // max, or the current is greater than the previous, use the // existing. if pc.Permissions.MaxWrappingTTL > 0 && (existingPerms.MaxWrappingTTL == 0 || pc.Permissions.MaxWrappingTTL < existingPerms.MaxWrappingTTL) { existingPerms.MaxWrappingTTL = pc.Permissions.MaxWrappingTTL } // If we have an existing min, and we either don't have a current // min, or the current is greater than the previous, use the // existing if pc.Permissions.MinWrappingTTL > 0 && (existingPerms.MinWrappingTTL == 0 || pc.Permissions.MinWrappingTTL < existingPerms.MinWrappingTTL) { existingPerms.MinWrappingTTL = pc.Permissions.MinWrappingTTL } if len(pc.Permissions.AllowedParameters) > 0 { if existingPerms.AllowedParameters == nil { clonedAllowed, err := copystructure.Copy(pc.Permissions.AllowedParameters) if err != nil { return nil, err } existingPerms.AllowedParameters = clonedAllowed.(map[string][]interface{}) } else { for key, value := range pc.Permissions.AllowedParameters { pcValue, ok := existingPerms.AllowedParameters[key] // If an empty array exist it should overwrite any other // value. if len(value) == 0 || (ok && len(pcValue) == 0) { existingPerms.AllowedParameters[key] = []interface{}{} } else { // Merge the two maps, appending values on key conflict. existingPerms.AllowedParameters[key] = append(value, existingPerms.AllowedParameters[key]...) } } } } if len(pc.Permissions.DeniedParameters) > 0 { if existingPerms.DeniedParameters == nil { clonedDenied, err := copystructure.Copy(pc.Permissions.DeniedParameters) if err != nil { return nil, err } existingPerms.DeniedParameters = clonedDenied.(map[string][]interface{}) } else { for key, value := range pc.Permissions.DeniedParameters { pcValue, ok := existingPerms.DeniedParameters[key] // If an empty array exist it should overwrite any other // value. if len(value) == 0 || (ok && len(pcValue) == 0) { existingPerms.DeniedParameters[key] = []interface{}{} } else { // Merge the two maps, appending values on key conflict. existingPerms.DeniedParameters[key] = append(value, existingPerms.DeniedParameters[key]...) } } } } if len(pc.Permissions.RequiredParameters) > 0 { if len(existingPerms.RequiredParameters) == 0 { existingPerms.RequiredParameters = pc.Permissions.RequiredParameters } else { for _, v := range pc.Permissions.RequiredParameters { if !strutil.StrListContains(existingPerms.RequiredParameters, v) { existingPerms.RequiredParameters = append(existingPerms.RequiredParameters, v) } } } } if len(pc.Permissions.MFAMethods) > 0 { if existingPerms.MFAMethods == nil { existingPerms.MFAMethods = pc.Permissions.MFAMethods } else { existingPerms.MFAMethods = append(existingPerms.MFAMethods, pc.Permissions.MFAMethods...) } existingPerms.MFAMethods = strutil.RemoveDuplicates(existingPerms.MFAMethods, false) } // No need to dedupe this list since any authorization can satisfy any factor, so long as // the factor matches the specified permission requested. if pc.Permissions.ControlGroup != nil { if len(pc.Permissions.ControlGroup.Factors) > 0 { if existingPerms.ControlGroup == nil { cg, err := pc.Permissions.ControlGroup.Clone() if err != nil { return nil, err } existingPerms.ControlGroup = cg } else { existingPerms.ControlGroup.Factors = append(existingPerms.ControlGroup.Factors, pc.Permissions.ControlGroup.Factors...) } } } INSERT: switch { case pc.HasSegmentWildcards: a.segmentWildcardPaths[pc.Path] = existingPerms default: tree.Insert(pc.Path, existingPerms) } } } return a, nil } func (a *ACL) Capabilities(ctx context.Context, path string) (pathCapabilities []string) { req := &logical.Request{ Path: path, // doesn't matter, but use List to trigger fallback behavior so we can // model real behavior Operation: logical.ListOperation, } res := a.AllowOperation(ctx, req, true) if res.IsRoot { return []string{RootCapability} } capabilities := res.CapabilitiesBitmap if capabilities&SudoCapabilityInt > 0 { pathCapabilities = append(pathCapabilities, SudoCapability) } if capabilities&ReadCapabilityInt > 0 { pathCapabilities = append(pathCapabilities, ReadCapability) } if capabilities&ListCapabilityInt > 0 { pathCapabilities = append(pathCapabilities, ListCapability) } if capabilities&UpdateCapabilityInt > 0 { pathCapabilities = append(pathCapabilities, UpdateCapability) } if capabilities&DeleteCapabilityInt > 0 { pathCapabilities = append(pathCapabilities, DeleteCapability) } if capabilities&CreateCapabilityInt > 0 { pathCapabilities = append(pathCapabilities, CreateCapability) } if capabilities&PatchCapabilityInt > 0 { pathCapabilities = append(pathCapabilities, PatchCapability) } // If "deny" is explicitly set or if the path has no capabilities at all, // set the path capabilities to "deny" if capabilities&DenyCapabilityInt > 0 || len(pathCapabilities) == 0 { pathCapabilities = []string{DenyCapability} } return } // AllowOperation is used to check if the given operation is permitted. func (a *ACL) AllowOperation(ctx context.Context, req *logical.Request, capCheckOnly bool) (ret *ACLResults) { ret = new(ACLResults) // Fast-path root if a.root { ret.Allowed = true ret.RootPrivs = true ret.IsRoot = true ret.GrantingPolicies = []logical.PolicyInfo{{ Name: "root", NamespaceId: "root", Type: "acl", }} return } op := req.Operation // Help is always allowed if op == logical.HelpOperation { ret.Allowed = true return } var permissions *ACLPermissions ns, err := namespace.FromContext(ctx) if err != nil { return } path := ns.Path + req.Path // The request path should take care of this already but this is useful for // tests and as defense in depth for { if len(path) > 0 && path[0] == '/' { path = path[1:] } else { break } } // Find an exact matching rule, look for prefix if no match var capabilities uint32 raw, ok := a.exactRules.Get(path) if ok { permissions = raw.(*ACLPermissions) capabilities = permissions.CapabilitiesBitmap goto CHECK } if op == logical.ListOperation { raw, ok = a.exactRules.Get(strings.TrimSuffix(path, "/")) if ok { permissions = raw.(*ACLPermissions) capabilities = permissions.CapabilitiesBitmap goto CHECK } } permissions = a.CheckAllowedFromNonExactPaths(path, false) if permissions != nil { capabilities = permissions.CapabilitiesBitmap goto CHECK } // No exact, prefix, or segment wildcard paths found, return without // setting allowed return CHECK: // Check if the minimum permissions are met // If "deny" has been explicitly set, only deny will be in the map, so we // only need to check for the existence of other values ret.RootPrivs = capabilities&SudoCapabilityInt > 0 // This is after the RootPrivs check so we can gate on it being from sudo // rather than policy root if capCheckOnly { ret.CapabilitiesBitmap = capabilities return ret } ret.MFAMethods = permissions.MFAMethods ret.ControlGroup = permissions.ControlGroup var grantingPolicies []logical.PolicyInfo operationAllowed := false switch op { case logical.ReadOperation: operationAllowed = capabilities&ReadCapabilityInt > 0 grantingPolicies = permissions.GrantingPoliciesMap[ReadCapabilityInt] case logical.ListOperation: operationAllowed = capabilities&ListCapabilityInt > 0 grantingPolicies = permissions.GrantingPoliciesMap[ListCapabilityInt] case logical.UpdateOperation: operationAllowed = capabilities&UpdateCapabilityInt > 0 grantingPolicies = permissions.GrantingPoliciesMap[UpdateCapabilityInt] case logical.DeleteOperation: operationAllowed = capabilities&DeleteCapabilityInt > 0 grantingPolicies = permissions.GrantingPoliciesMap[DeleteCapabilityInt] case logical.CreateOperation: operationAllowed = capabilities&CreateCapabilityInt > 0 grantingPolicies = permissions.GrantingPoliciesMap[CreateCapabilityInt] case logical.PatchOperation: operationAllowed = capabilities&PatchCapabilityInt > 0 grantingPolicies = permissions.GrantingPoliciesMap[PatchCapabilityInt] // These three re-use UpdateCapabilityInt since that's the most appropriate // capability/operation mapping case logical.RevokeOperation, logical.RenewOperation, logical.RollbackOperation: operationAllowed = capabilities&UpdateCapabilityInt > 0 grantingPolicies = permissions.GrantingPoliciesMap[UpdateCapabilityInt] default: return } if !operationAllowed { return } ret.GrantingPolicies = grantingPolicies if permissions.MaxWrappingTTL > 0 { if req.WrapInfo == nil || req.WrapInfo.TTL > permissions.MaxWrappingTTL { return } } if permissions.MinWrappingTTL > 0 { if req.WrapInfo == nil || req.WrapInfo.TTL < permissions.MinWrappingTTL { return } } // This situation can happen because of merging, even though in a single // path statement we check on ingress if permissions.MinWrappingTTL != 0 && permissions.MaxWrappingTTL != 0 && permissions.MaxWrappingTTL < permissions.MinWrappingTTL { return } // Only check parameter permissions for operations that can modify // parameters. if op == logical.ReadOperation || op == logical.UpdateOperation || op == logical.CreateOperation || op == logical.PatchOperation { for _, parameter := range permissions.RequiredParameters { if _, ok := req.Data[strings.ToLower(parameter)]; !ok { return } } // If there are no data fields, allow if len(req.Data) == 0 { ret.Allowed = true return } if len(permissions.DeniedParameters) == 0 { goto ALLOWED_PARAMETERS } // Check if all parameters have been denied if _, ok := permissions.DeniedParameters["*"]; ok { return } for parameter, value := range req.Data { // Check if parameter has been explicitly denied if valueSlice, ok := permissions.DeniedParameters[strings.ToLower(parameter)]; ok { // If the value exists in denied values slice, deny if valueInParameterList(value, valueSlice) { return } } } ALLOWED_PARAMETERS: // If we don't have any allowed parameters set, allow if len(permissions.AllowedParameters) == 0 { ret.Allowed = true return } _, allowedAll := permissions.AllowedParameters["*"] if len(permissions.AllowedParameters) == 1 && allowedAll { ret.Allowed = true return } for parameter, value := range req.Data { valueSlice, ok := permissions.AllowedParameters[strings.ToLower(parameter)] // Requested parameter is not in allowed list if !ok && !allowedAll { return } // If the value doesn't exists in the allowed values slice, // deny if ok && !valueInParameterList(value, valueSlice) { return } } } ret.Allowed = true return } type wcPathDescr struct { firstWCOrGlob int wildcards int isPrefix bool wcPath string perms *ACLPermissions } // CheckAllowedFromNonExactPaths returns permissions corresponding to a // matching path with wildcards/globs. If bareMount is true, the path should // correspond to a mount prefix, and what is returned is either a non-nil set // of permissions from some allowed path underneath the mount (for use in mount // access checks), or nil indicating no non-deny permissions were found. func (a *ACL) CheckAllowedFromNonExactPaths(path string, bareMount bool) *ACLPermissions { wcPathDescrs := make([]wcPathDescr, 0, len(a.segmentWildcardPaths)+1) less := func(i, j int) bool { // In the case of multiple matches, we use this priority order, // which tries to most closely match longest-prefix: // // * First glob or wildcard position (prefer foo/a* over foo/+, // foo/bar/+/baz over foo/+/bar/baz) // * Whether it's a prefix (prefer foo/+/bar over foo/+/ba*, // foo/+ over foo/*) // * Number of wildcard segments (prefer foo/bar/+/baz over foo/+/+/baz) // * Length check (prefer foo/+/bar/ba* over foo/+/bar/b*) // * Lexicographical ordering (preferring less, arbitrarily) // // That final case (lexigraphical) should never really come up. It's more // of a throwing-up-hands scenario akin to panic("should not be here") // statements, but less panicky. pdi, pdj := wcPathDescrs[i], wcPathDescrs[j] // If the first wildcard (+) or glob (*) occurs earlier in pdi, // pdi is lower priority if pdi.firstWCOrGlob < pdj.firstWCOrGlob { return true } else if pdi.firstWCOrGlob > pdj.firstWCOrGlob { return false } // If pdi ends in * and pdj doesn't, pdi is lower priority if pdi.isPrefix && !pdj.isPrefix { return true } else if !pdi.isPrefix && pdj.isPrefix { return false } // If pdi has more wc segs, pdi is lower priority if pdi.wildcards > pdj.wildcards { return true } else if pdi.wildcards < pdj.wildcards { return false } // If pdi is shorter, it is lower priority if len(pdi.wcPath) < len(pdj.wcPath) { return true } else if len(pdi.wcPath) > len(pdj.wcPath) { return false } // If pdi is smaller lexicographically, it is lower priority if pdi.wcPath < pdj.wcPath { return true } else if pdi.wcPath > pdj.wcPath { return false } return false } // Find a prefix rule if any. { prefix, raw, ok := a.prefixRules.LongestPrefix(path) if ok { if len(a.segmentWildcardPaths) == 0 { return raw.(*ACLPermissions) } wcPathDescrs = append(wcPathDescrs, wcPathDescr{ firstWCOrGlob: len(prefix), wcPath: prefix, isPrefix: true, perms: raw.(*ACLPermissions), }) } } if len(a.segmentWildcardPaths) == 0 { return nil } pathParts := strings.Split(path, "/") SWCPATH: for fullWCPath := range a.segmentWildcardPaths { if fullWCPath == "" { continue } pd := wcPathDescr{firstWCOrGlob: strings.Index(fullWCPath, "+")} currWCPath := fullWCPath if currWCPath[len(currWCPath)-1] == '*' { pd.isPrefix = true currWCPath = currWCPath[0 : len(currWCPath)-1] } pd.wcPath = currWCPath splitCurrWCPath := strings.Split(currWCPath, "/") if !bareMount && len(pathParts) < len(splitCurrWCPath) { // check if the path coming in is shorter; if so it can't match continue } if !bareMount && !pd.isPrefix && len(splitCurrWCPath) != len(pathParts) { // If it's not a prefix we expect the same number of segments continue } segments := make([]string, 0, len(splitCurrWCPath)) for i, aclPart := range splitCurrWCPath { switch { case aclPart == "+": pd.wildcards++ segments = append(segments, pathParts[i]) case aclPart == pathParts[i]: segments = append(segments, pathParts[i]) case pd.isPrefix && i == len(splitCurrWCPath)-1 && strings.HasPrefix(pathParts[i], aclPart): segments = append(segments, pathParts[i:]...) case !bareMount: // Found a mismatch, give up on this segmentWildcardPath continue SWCPATH } // -2 because we're always invoked with a trailing "/" in case bareMount. if bareMount && i == len(pathParts)-2 { joinedPath := strings.Join(segments, "/") + "/" // Check the current joined path so far. If we find a prefix, // check permissions. If they're defined but not deny, success. if strings.HasPrefix(joinedPath, path) { permissions := a.segmentWildcardPaths[fullWCPath].(*ACLPermissions) if permissions.CapabilitiesBitmap&DenyCapabilityInt == 0 && permissions.CapabilitiesBitmap > 0 { return permissions } } continue SWCPATH } } pd.perms = a.segmentWildcardPaths[fullWCPath].(*ACLPermissions) wcPathDescrs = append(wcPathDescrs, pd) } if bareMount || len(wcPathDescrs) == 0 { return nil } // We don't do this in the bare mount check because we don't care about // priority, we only care about any capability at all. sort.Slice(wcPathDescrs, less) return wcPathDescrs[len(wcPathDescrs)-1].perms } func (c *Core) performPolicyChecks(ctx context.Context, acl *ACL, te *logical.TokenEntry, req *logical.Request, inEntity *identity.Entity, opts *PolicyCheckOpts) *AuthResults { ret := new(AuthResults) // First, perform normal ACL checks if requested. The only time no ACL // should be applied is if we are only processing EGPs against a login // path in which case opts.Unauth will be set. if acl != nil && !opts.Unauth { ret.ACLResults = acl.AllowOperation(ctx, req, false) ret.RootPrivs = ret.ACLResults.RootPrivs // Root is always allowed; skip Sentinel/MFA checks if ret.ACLResults.IsRoot { // logger.Warn("token is root, skipping checks") ret.Allowed = true return ret } if !ret.ACLResults.Allowed { return ret } // Since HelpOperation was fast-pathed inside AllowOperation, RootPrivs will not have been populated in this // case, so we need to special-case that here as well, or we'll block HelpOperation on all sudo-protected paths. if !ret.RootPrivs && opts.RootPrivsRequired && req.Operation != logical.HelpOperation { return ret } } c.performEntPolicyChecks(ctx, acl, te, req, inEntity, opts, ret) return ret } func valueInParameterList(v interface{}, list []interface{}) bool { // Empty list is equivalent to the item always existing in the list if len(list) == 0 { return true } return valueInSlice(v, list) } func valueInSlice(v interface{}, list []interface{}) bool { for _, el := range list { if el == nil || v == nil { // It doesn't seem possible to set up a nil entry in the list, but it is possible // to pass in a null entry in the API request being checked. Just in case, // nil will match nil. if el == v { return true } } else if reflect.TypeOf(el).String() == "string" && reflect.TypeOf(v).String() == "string" { item := el.(string) val := v.(string) if strutil.GlobbedStringsMatch(item, val) { return true } } else if reflect.DeepEqual(el, v) { return true } } return false }