Access Manager v3 API for PubNub C-Core SDK

Access Manager allows you to enforce security controls for client access to resources within the PubNub Platform. With Access Manager v3, your servers can grant their clients tokens with embedded permissions that provide access to individual PubNub resources:

  • For a limited period of time.
  • Through resource lists or patterns (regular expressions).
  • In a single API request, even if permission levels differ (read to channel1 and write to channel2).

You can add the author_uuid parameter to the grant request to restrict the token usage to only one client with a given uuid. Once specified, only this author_uuid will be able to use the token to make API requests for the specified resources, according to permissions given in the grant request.

For more information about Access Manager v3, refer to Manage Permissions with Access Manager v3.

Grant Token

Requires Access Manager add-on

This method requires that the Access Manager add-on is enabled for your key in the Admin Portal. Read the support page on enabling add-on features on your keys.

The pubnub_grant_token() method generates a time-limited authorization token with an embedded access control list. The token defines time to live (ttl_minutes), author_uuid, and a set of permissions giving access to one or more resources:

  • channels
  • groups
  • uuids (other users' object metadata, such as their names or avatars)

Only this author_uuid will be able to use the token with the defined permissions. The authorized client will send the token to PubNub with each request until the token's ttl_minutes expires. Any unauthorized request or a request made with an invalid token will return a 403 with a respective error message.

Permissions

The grant request allows your server to securely grant your clients access to the resources within the PubNub Platform. There is a limited set of operations the clients can perform on every resource:

ResourcePermissions
channelsread, write, get, manage, update, join, delete
groupsread, manage
uuidsget, update, delete

For permissions and API operations mapping, refer to Manage Permissions with Access Manager v3.

TTL

The ttl_minutes (time to live) parameter is the number of minutes before the granted permissions expire. The client will require a new token to be granted before expiration to ensure continued access. ttl_minutes is a required parameter for every grant call and there is no default value set for it. The max value for ttl_minutes is 43,200 (30 days).

danger
Recommended ttl_minutes value

For security reasons, it's recommended to set ttl_minutes between 10 and 60, and create a new token before this ttl_minutes elapses.

For more details, see TTL in Access Manager v3.

RegEx

If you prefer to specify permissions by setting patterns, rather than listing all resources one by one, you can use regular expressions. To do this, define RegEx permissions for a given resource type in the grant request.

For more details, see RegEx in Access Manager v3.

Authorized UUID

Setting an author_uuid in the token helps you specify which client device should use this token in every request to PubNub. This will ensure that all requests to PubNub are authorized before PubNub processes them. If author_uuid isn't specified during the grant request, the token can be used by any client with any uuid. It's recommended to restrict tokens to a single author_uuid to prevent impersonation.

For more details, see Authorized UUID in Access Manager v3.

Method(s)

enum pubnub_res pubnub_grant_token(
pubnub_t* pb,
char const* perm_obj
)
ParameterTypeRequiredDescription
pbpubnub_t*YesPointer to the PubNub context. Can't be NULL.
perm_objconst char*YesPointer to string with the permissions.
Required key/value mappings

For a successful grant request, you must specify permissions for at least one uuid, channel, or group, either as a resource list or as a pattern (RegEx).

Basic Usage

struct pam_permission ch_perm = {.read=true };
int perm_my_channel = pubnub_get_grant_bit_mask_value(ch_perm);
int ttl_minutes = 15; // Max value for ttl_minutes is 43,200 minutes (30 days)
char perm_obj[2000];
char* author_uuid = "my_authorized_uuid";
sprintf(perm_obj,"{\"ttl\":%d, \"uuid\":\"%s\", \"permissions\":{\"resources\":{\"channels\":{ \"my_channel\":%d }, \"groups\":{}, \"users\":{ }, \"spaces\":{}}, \"patterns\":{\"channels\":{}, \"groups\":{}, \"users\":{}, \"spaces\":{}},\"meta\":{}}}", ttl_minutes, author_uuid, perm_my_channel);
res = pubnub_grant_token(gtp, perm_obj);
if (PNR_STARTED == res) {
res = pubnub_await(gtp);
if (PNR_OK == res) {
pubnub_chamebl_t grant_token_resp = pubnub_get_grant_token(gtp);
printf("pubnub_grant_token() Response from Pubnub: %s\n", grant_token_resp.ptr);
}
}

Returns

{
"data": {
"message": "Success",
"token": "p0thisAkFl043rhDdHRsCkNyZXisRGNoYW6hanNlY3JldAFDZ3Jwsample3KgQ3NwY6BDcGF0pERjaGFuoENnctokenVzcqBDc3BjoERtZXRhoENzaWdYIGOAeTyWGJI"
},
"service": "Access Manager",
"status": 200
}

Other Examples

Grant an authorized client different levels of access to various resources in a single call

The code below grants my-authorized-uuid:

  • Read access to channel-a, channel-group-b, and get to uuid-c.
  • Read/write access to channel-b, channel-c, channel-d, and get/update to uuid-d.
char* author_uuid = "my-authorized-uuid";
struct pam_permission cha_perm = {.read=true };
struct pam_permission cgb_perm = {.read=true };
struct pam_permission uidc_perm = {.get=true };

struct pam_permission chb_perm = {.read=true, .write=true };
struct pam_permission chc_perm = {.read=true, .write=true };
struct pam_permission chd_perm = {.read=true, .write=true };
struct pam_permission uidd_perm = {.get=true, .update=true };

int perm_cha = pubnub_get_grant_bit_mask_value(cha_perm);
int perm_chb = pubnub_get_grant_bit_mask_value(chb_perm);
int perm_chc = pubnub_get_grant_bit_mask_value(chc_perm);
int perm_chd = pubnub_get_grant_bit_mask_value(chd_perm);

show all 31 lines

Grant an authorized client read access to multiple channels using RegEx

The code below grants my-authorized-uuid read access to all channels that match the channel-[A-Za-z0-9] RegEx pattern.

char* author_uuid = "my-authorized-uuid";
struct pam_permission pat_ch_perm = {.read=true };

int perm_ch_pat = pubnub_get_grant_bit_mask_value(pat_ch_perm);

int ttl_minutes = 15;
char perm_obj[2000];
sprintf(perm_obj,"{\"ttl\":%d, \"uuid\":\"%s\", \"permissions\":{\"resources\":{\"channels\":{ }, \"groups\":{ }, \"uuids\":{ }}, \"patterns\":{\"channels\":{ \"channel-[A-Za-z0-9]\":%d }, \"groups\":{ }, \"uuids\":{ }},\"meta\":{ }}}", ttl_minutes, author_uuid, perm_ch_pat);
res = pubnub_grant_token(gtp, perm_obj);
if (PNR_STARTED == res) {
res = pubnub_await(gtp);
if (PNR_OK == res) {
pubnub_chamebl_t grant_token_resp = pubnub_get_grant_token(gtp);
printf("pubnub_grant_token() Response from Pubnub: %s\n", grant_token_resp.ptr);
}
show all 16 lines

Grant an authorized client different levels of access to various resources and read access to channels using RegEx in a single call

The code below grants the my-authorized-uuid:

  • Read access to channel-a, channel-group-b, and get to uuid-c.
  • Read/write access to channel-b, channel-c, channel-d, and get/update to uuid-d.
  • Read access to all channels that match the channel-[A-Za-z0-9] RegEx pattern.
char* author_uuid = "my-authorized-uuid";
struct pam_permission cha_perm = {.read=true };
struct pam_permission cgb_perm = {.read=true };
struct pam_permission uidc_perm = {.get=true };

struct pam_permission chb_perm = {.read=true, .write=true };
struct pam_permission chc_perm = {.read=true, .write=true };
struct pam_permission chd_perm = {.read=true, .write=true };
struct pam_permission uidd_perm = {.get=true, .update=true };

struct pam_permission pat_ch_perm = {.read=true };

int perm_cha = pubnub_get_grant_bit_mask_value(cha_perm);
int perm_chb = pubnub_get_grant_bit_mask_value(chb_perm);
int perm_chc = pubnub_get_grant_bit_mask_value(chc_perm);
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Error responses

If you submit an invalid request, the server returns the 400 error status code with a descriptive message informing which of the provided arguments is missing or incorrect. These can include, for example, issues with a RegEx, a timestamp, or permissions.

Revoke Token

Requires Access Manager add-on

This method requires that the Access Manager add-on is enabled for your key in the Admin Portal. Read the support page on enabling add-on features on your keys.

Enable token revoke

To revoke tokens, you must first enable this feature on the Admin Portal. To do that, navigate to your app's keyset and mark the Revoke v3 Token checkbox in the ACCESS MANAGER section.

The pubnub_revoke_token() method allows you to disable an existing token and revoke all permissions embedded within. You can only revoke a valid token previously obtained using the pubnub_grant_token method.

Use this method for tokens with ttl less than or equal to 30 days. If you need to revoke a token with a longer ttl, contact support.

For more information, refer to Revoke permissions.

Method(s)

pubnub_revoke_token(char const* token)
ParameterTypeRequiredDefaultDescription
tokenchar const*Yesn/aExisting token with embedded permissions.

Basic Usage

pbresult = pubnub_grant_token(ctx, "p0thisAkFl043rhDdHRsCkNyZXisRGNoYW6hanNlY3JldAFDZ3Jwsample3KgQ3NwY6BDcGF0pERjaGFuoENnctokenV");
if (PNR_STARTED == res) {
pbresult = pubnub_await(ctx);
if (PNR_OK == res) {
printf("Access token permissions revoked! Response from Pubnub: %s\n",
pubnub_get_revoke_token_response(ctx).ptr);
}
}

Rest Response from Server

{
"data": {
"message": "Success"
},
"service": "Access Manager",
"status": 200
}

Error Responses

If you submit an invalid request, the server returns an error status code with a descriptive message informing which of the provided arguments is missing or incorrect. Depending on the root cause, this operation may return the following errors:

  • 400 Bad Request
  • 403 Forbidden
  • 503 Service Unavailable

Parse Token

The pubnub_parse_token() method decodes an existing token and returns the object containing permissions embedded in that token. The client can use this method for debugging to check the permissions to the resources or find out the token's ttl_minutes details.

Method(s)

char* pubnub_parse_token(
pubnub_t* pb,
char const* token
)
ParameterTypeRequiredDescription
pbpubnub_t*YesPointer to the PubNub context. Can't be NULL.
tokenconst char*YesCurrent token with embedded permissions.

Basic Usage

char* cbor_data = pubnub_parse_token(<pubnub_context>, "p0thisAkFl043rhDdHRsCkNyZXisRGNoYW6hanNlY3JldAFDZ3Jwsample3KgQ3NwY6BDcGF0pERjaGFuoENnctokenVzcqBDc3BjoERtZXRhoENzaWdYIGOAeTyWGJI");

Returns

The server returns the permissions in CBOR format. You can Base 64 decode it, and parse with any CBOR parser.

{
"v":2,
"t":1619718521,
"ttl":15,
"res":{
"usr":{},
"spc":{},
"chan":{{"ch1":19}},
"grp":{}
},
"pat":{
"usr":{},
"spc":{},
"chan":{},
"grp":{}
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Error Responses

If you receive an error while parsing the token, it may suggest that the token is damaged. In that case, request the server to issue a new one.

Set Token

The pubnub_set_auth_token() method is used by the client devices to update the authentication token granted by the server.

Method(s)

void pubnub_set_auth_token(
pubnub_t* pb,
char const* token
)
ParameterTypeRequiredDescription
pbpubnub_t*YesPointer to the PubNub context. Can't be NULL.
tokenconst char*YesCurrent token with embedded permissions.

Basic Usage

pubnub.pubnub_set_auth_token(<pubnub_context>, "p0thisAkFl043rhDdHRsCkNyZXisRGNoYW6hanNlY3JldAFDZ3Jwsample3KgQ3NwY6BDcGF0pERjaGFuoENnctokenVzcqBDc3BjoERtZXRhoENzaWdYIGOAeTyWGJI")

Returns

This method doesn't return any response value.

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