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'''StreetPass''' is a feature that allow your 3DS to connect with other 3DS using WiFi in standby mode.
'''StreetPass''' is a feature that allows your 3DS to connect with other 3DS consoles using WiFi in standby mode.
It can be used to share Mii(s) on Mii Plaza for example. Applications' StreetPass data are stored in the CECD module's NAND savegame, applications can move received StreetPass data to an arbitrary savegame. Wifi infrastructure with APs are used to communicate where the data-frames are encrypted with WPA2 CCMP, like [[NWM_Services|UDS]]/[[Download Play]].
It can be used to share Mii(s) on Mii Plaza for example. Applications' StreetPass data are stored in the CECD module's NAND savegame, applications can move received StreetPass data to an arbitrary savegame. Wifi infrastructure with APs are used to communicate where the data-frames are encrypted with WPA2 CCMP, like [[NWM_Services|UDS]]/[[Download Play]].


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Whenever the 3DS is woken from sleep (or turned on), and WiFi is enabled, it sends out a 802.11 Probe Request which include all saved access points, as well a probe to an SSID containing an arbitrary string of data, such as "ic[kSvm9s@*cYD>/~IEVj\(fGG;qDo8j". This string changes at least daily, and most likely every time the device is woken up.
Whenever the 3DS is woken from sleep (or turned on), and WiFi is enabled, it sends out a 802.11 Probe Request which include all saved access points, as well a probe to an SSID containing an arbitrary string of data, such as "ic[kSvm9s@*cYD>/~IEVj\(fGG;qDo8j". This string changes at least daily, and most likely every time the device is woken up.


The MAC address used for these probes is the static MAC address found in the Settings application. Unlike the StreetPass MAC address, it will not change over time. This MAC address OUI also differs from the one used in StreetPass.
The MAC address used for these probes is the static MAC address found in the System Settings application. Unlike the StreetPass MAC address, it will not change over time. This MAC address OUI also differs from the one used in StreetPass.


== CCMP Key ==
== CCMP Key ==
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|-
|-
| 0x0
| 0x0
| 0x10
| 0x8
| Unknown, copied from some structure.
| 8-byte StreetPass consoleID for the host, from the probe frames.
|-
| 0x8
| 0x8
| 8-byte StreetPass consoleID for the client, from the probe frames.
|-
|-
| 0x10
| 0x10
| 0x6
| 0x6
| MAC address for host/client?
| MAC address for host.
|-
|-
| 0x16
| 0x16
| 0x6
| 0x6
| MAC address for client/host?
| MAC address for client.
|}
|}


== StreetPass Exchange ==
== StreetPass Exchange ==


While StreetPass is enabled, the 3DS constantly sends out Probe Requests with an SSID of "Nintendo_3DS_continuous_scan_000". Unlike beacons, which are actively advertising the device's presence, the 3DS is essentially actively looking for other 3DSes. This design is likely to limit impact to non-3DS WiFi capable devices. Each Probe Request contains basic information about that 3DS, including an identifier, and active StreetPass services. If another 3DS is in range, the second 3DS (#2) will respond with a Probe Response, to which the original 3DS (#1), and of the receiving device with every frame thereafter, will respond with an 802.11 Acknowledgement. 3DS(#1) then sends an 802.11 Action frame, as well as an additional Probe Request. The second 3DS sends back another Probe Response that begins the encrypted exchange between the two devices.  
While StreetPass is enabled, the 3DS constantly sends out Probe Requests with an SSID of "Nintendo_3DS_continuous_scan_000". Unlike beacons, which are actively advertising the device's presence, the 3DS is essentially actively looking for other 3DSes. This design is likely to limit impact to non-3DS WiFi capable devices. Each Probe Request contains basic information about that 3DS, including an identifier, and active StreetPass services. If another 3DS is in range, the second 3DS (#2) will respond with a Probe Response, to which the original 3DS (#1), and of the receiving device with every frame thereafter, will respond with an 802.11 Acknowledgement. 3DS(#1) then sends an 802.11 Action frame, as well as an additional Probe Request. The second 3DS sends back another Probe Response that begins the encrypted exchange between the two devices, no authentication/association is done here.


The MAC address used in sleep-mode seems to change every time there's a StreetPass hit, as well as the last 8-bytes of the Nintendo tag data. The MAC address + 8-byte ID for StreetPass is seen to change every time the user enters and exits and Settings application if they have not had a StreetPass in an observed time period of 24 hours. It is uncertain how the 3DS determines when it can do a StreetPass again with another 3DS, or what information is actually used to track that. It may be related to how long that 3DS was in range constantly/out of range. 3DSes that are constantly in range of each other in sleep-mode, usually do StreetPass every 11 hours.
The MAC address used in sleep-mode seems to change every time there's a StreetPass hit, as well as the last 8-bytes(StreetPass consoleID) of the Nintendo tag data. The MAC address + 8-byte StreetPass consoleID is seen to change every time the user enters and exits and Settings application if they have not had a StreetPass in an observed time period of 24 hours. It is uncertain how the 3DS determines when it can do a StreetPass again with another 3DS, or what information is actually used to track that. It may be related to how long that 3DS was in range constantly/out of range. 3DSes that are constantly in range of each other in sleep-mode, usually do StreetPass every 11 hours.


=== Probe Request Frame ===
=== Probe Request Frame ===
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|  -0x08
|  -0x08
|  0x08
|  0x08
|  '''StreetPass ID'''
|  '''StreetPass consoleID'''
|  Seen to change when the Settings app is used if there has not been a StreetPass tag recently. Also may change after each StreetPass hit and system power-off?
|  Seen to change when the Settings app is used if there has not been a StreetPass tag recently. Also may change after each StreetPass hit and system power-off?
|  0f c9 c6 80 5b 6f bc 5a
|  0f c9 c6 80 5b 6f bc 5a
|}
|}


Of note, there is a 4 byte sequence unaccounted for prior to the StreetPass ID and after the currently unknown field. These four bytes may be part of the StreetPass ID, although captures of other 3DS units show the StreetPass ID at a fixed 8-byte value, and not 12-bytes as shown in the example above.
Of note, there is a 4 byte sequence unaccounted for prior to the StreetPass consoleID and after the currently unknown field.


===== Protocol Version =====
===== Protocol Version =====
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The purpose of this field is not known yet. It has remained the same across all devices thus far. The value has always been observed as '''f008'''.
The purpose of this field is not known yet. It has remained the same across all devices thus far. The value has always been observed as '''f008'''.


===== StreetPass ID =====
===== StreetPass consoleID =====
 
When there's a StreetPass hit, and no StreetPass data changed on either of the 3DSes, no data is transferred besides probes? Perhaps there's some ID in the Nintendo tag that gets updated every-time the 3DS' StreetPass data changes? After turning off power, then powering on and entering sleepmode, the MAC doesn't change from prior to power off but the last 8-bytes of the Nintendo tag changes. This tag has been seen to not be sequential over time. After one of the new StreetPass content is handled, (running one of the StreetPass titles etc) the 8bytes in the Nintendo tag changes?


The value in this field may be used as part of the key generation for the upcoming encrypted exchange. Not much additional information outside of what is in this tag is exchanged between the two 3DS systems before the encrypted session begins.
When there's a StreetPass hit, and no StreetPass data changed on either of the 3DSes, no data is transferred besides probes? After turning off power, then powering on and entering sleepmode, the MAC doesn't change from prior to power off but the last 8-bytes of the Nintendo tag changes. This tag has been seen to not be sequential over time. After one of the new StreetPass content is handled, (running one of the StreetPass titles etc) this 8-byte StreetPass consoleID changes?


=== Initial Probe Response Frame ===
=== Initial Probe Response Frame ===
Retrieved from "https://www.3dbrew.org/wiki/StreetPass"