I am interested in integrating the RFID1356MIFARE with the ESP32-EVB and using it as a card reader over UART. Basically reading UIDs, writing commands to UART serial and granting access or not based on what the reader output is. Initially I've tried using this library: https://github.com/elechouse/PN532 but I found out that the RFID1356MIFARE firmware is not compatible with it.
I would like to understand how does a RFID reader grant access to a card, to open a door for example. Thanks to this thread: Mifare 1K authentication keys I am starting to understand how the two Authentication keys work.
What I still don't get is:
who sets the authentication keys ?
are these keys unique to every card ?
are these keys stored in a reader ?
can I read the keys from a card ? If yes, how ?
are these keys the one that grant access to, say, a door that's linked to the reader ? If not, what makes a card to have access or not ?
are these keys the only form of authentication ?
is the UID used only for identification ?
why are there 16 sectors if all the information is available in the first sector ? What is the purpose of being able to set different keys to each sector ?
The most important question I have is: what makes a card reader give "Access Granted" to a card ?
I've found these docs on Mifare Authentication and they mention Load Authentication Keys and Authentication commands for that specific reader. The reader that I am using has no such commands. Looking at this thread Mifare card security also made me realise that my card reader lacks some commands or that they are just very poorly documented.
I have also read the MIFARE docs from NXP, but there is nothing in there that I actually need.
Ok here is answer for your corresponding queries:
KEY A and KEY B are set by card manufacturer at default value(0xFF...). This can be changed later by user.
By default they are same for every card.
Both keys are stored in Card. Reader also needs to know these keys to be able to read your cards.
No you can't read keys from card unless you at least one of keys. reading of keys can be disabled all together even if you have access to any key.
No these key don't grant access to doors. They are used to grant read/write access to reader on their corresponding sector.
These keys are one of the form of authentication, usually for reader.
UID is almost useless for most authentication cases as any one can read and alter them.
Each sector has 3 data block and a pair of keys on last sector. These keys are needed to read data on first three block of sector.
So on overall, First you create a authentication/ Identification string and store it in data block of any sector(let's say sector 4). Then you need to change KEY A/B of that sector so that no one can read data from that sector except your own access control device. Now only reader that know your specific key can read data on sector 4 thus preventing cloning of card. your reader will read data from sector 4 and use the string you stored to check if that card has access or not.
Hope I've cleared your query. The Mifare classic 1k datasheet has great deal of info about this, Check section 8.7 Memory Access.
Related
I have a access control system from act365. I have Mifare Classic 1k RFID tags, the system works like expected. Now I want to create a software to register the tags in the act365 system.
I read the tags on the act365 reader the cloud gives me a decimal number that representing the UID of the tag. To register a new tag in the system I will scan the tag with an "ACS 1252 Reader" and put the UID in the act365 system by the API.
The Problem is when I convert the HEX UID read from the ACS reader to Decimal number, it is not the same number that the act365 cloud gives me, the System does not recognize the given tag number.
What I have done:
I have tried little and big endian, remove bits from both or the
right. But nothing gives me the same decimal number.
I have tried different NFC readers.
Note:
I called the Vanderbilt support, they told me the reader reads the uid send it to the cloud, they have no idea where the problem is.
Numbers:
Read from the ACT365 System:
78575056
Read from the ACS reader:
76:A2:14:5F
I'm happy for every hint or idea!
I am using IBM TPM v1332 + IBM TSS v1470 now and trying to store some essential keywords/passwords to non-volatile memory on TPM.
I found two ways to do so. One is to create a sealed object and use evictcontrol to store it, like:
${PREFIX}evictcontrol -ho $objHandle -hp 81800002 -hi p
Another way is using NV command directly to store something:
${PREFIX}nvdefinespace -hi o -ha 01000000 -pwdn nnn
${PREFIX}nvwrite -ha 01000000 -pwdn nnn
However, I couldn't find any information about the non-volatile spaces available in TPM. Is this described in the TPM spec? Where could I find the information? Thanks.
The TPM PC platform specification says:
"1.The TPM SHALL provide a minimum of 6962 (dec) bytes of NV Storage."
If you use evictcontrol you should note that the TPM allows only a small number of persitstent objects at the same time (at least 7, of which 4 are reserved).
You can get the number of available persistent slots using the TPM2_GetCapability command with TPM_CAP_TPM_PROPERTIES as capability. TPM_PT_HR_PERSISTENT_AVAIL will be at least 1 if you can store another object.
The amount of available NV memory is device dependant, you have to check the data sheets. I suggest to work with the numbers from the PC platform specification, they are valid for every device.
I'm sorting out how to achieve the following, I want to use smart or memory cards in a project. The cards should be read by standardized card readers (for example ACR38). When they are read by the computer ( command line or by a software (processing or p5js or similar), there should be a popup a window which shows the contents of the card being a picture and a text. Bit similar when I use my regular ID to be read by my E-idsoftware.
For the moment the card I have is this one SLE4428 (at the bottom instructions from the vendor)
These have no data on it yet and are bought blank
=> datasheet
The software I found but don't know if it's suited for my project and how to specifically use it is the following.
Opensource tools that I found when searching for SC cards software (no id how to use them.)
https://linux.die.net/man/1/opensc-tool
https://linux.die.net/man/1/opensc-explorer
I looked at my smartcard reader and found that http://www.acr38u.com/
is a platform but has to be payed for and I'm unable to found sofware for this on linux or apple.
Again here I found a datasheet with hex code to connect to the card, but still not how to physically connect to the cards.
This site shows many points of a working shell but I can't find the installer for it. opendsc
Then lastly this is the most promising and I already contacted the maker of it. But installation gets stuck in the make process (which I've already searched for and is not solution yet, being at it for a week now so therefore this post, maybe the community can help with an alternative look)
This is the explanation from the vendor side (Aliexpress) which is kind of specific. Though I don't know where to input these hex codes to write or read from the card. (there is a software but it's windows (If there is somebody that can say, that the way to solve the core question of my project then I'll try to get a windows pc to work on it via that way))
ISO7816 SLE 4442 Chip PVC Contact Smart Card (0.8* 85.5 * 54mm)
If you need write the 4442 cards,you should buy the contact smart reader writer!! 4442 cards not support 13.56mhz rfid writer!!!
NOTE:There is NO magnetic strip behind the card.
Graphics Quality Cards For All Photo ID Card Printers Including
DataCard, Zebra, Fargo, Evolis, Magicard, NBS & etc.
(These Cards Will Not Work In Inkjet Printers)
If you need 100pcs 4442 cards,pls check the links below:
[https://www.aliexpress.com/store/product/100-pcs-lot-ISO7816-RFID-Contact-SLE-4442-Chip-PVC-Smart-Card/516120_32425491077.html?spm=2114.12010608.0.0.R0bzFx][1]
Features:
Standard:ISO7816
Product Chip:SLE4442
Color:White
Dimension: L 85.5 x W 54 x H 0.80±0.04mm
256 × 8-bit EEPROM organization
32 × 1-bit organization of protection memory
erase cycles more than 100,000 times
Data retention for minimum of ten years
Default passwords: FFFFFF
3 bytes for error counter and card secret code area
1,Write protected area (first 32 bytes) of each byte can be individually write protected, After write,the data can't be changed.
2, Before checking the password, all the data can be read, if necessary,you could encryption data.
3, After confirm password is correct,the data could be write or modify.
4, The 3 bytes of user passwords, after confirm is correct,it could be change.
5, The password error counter, the initial value of 3, check the error code 1, then subtract 1, if the counter value is 0, the card is automatically locked, the data just read out, no longer change can no longer be password verification; if zero, the one time password verification is correct, restore to the initial value.
6, The byte address 0-5,6-7 factory prior written by the manufacturers can not be changed.
The specifics for this question lies in either
A: How can I achieve a working environment on linux or mac (first) to read and write data on an sc card (the one I have or !B: a working alternative)
C: Create a viewer program or webapp, etc.. to view or route the data to when the SC card is being read. (This would be a valid question, If i where to chose a Windows based existing program, I think)
Because this is not code specific, but I still want people that have the same questions to be able to see this page to show them pletora of scripts and ways to approach this or similar SC project.
This guy knows a lot about OpenSC!
I am trying to figure out a way to implement decent crypto on a micro-controller project. I have an ARMv4 based MCU that will control my garage door and receive commands over a WiFi module.
The MCU will run a TCP/IP server, that will listen for commands from Android clients that can connect from anywhere on the Internet, which is why I need to implement crypto.
I understand how to use AES with shared secret key to properly encrypt traffic, but I am finding it difficult to deal with Replay Attacks. All solutions I see so far have serious drawbacks.
There are two fundamental problems which prevent me from using well
established methods like session tokens, timestamps or nonces:
The MCU has no reliable source of entropy, so I can't generate
quality random numbers.
The attacker can reset the MCU by cutting power to the garage,
thus erasing any stored state at will, and resetting time counter to
zero (or just wait 49 days until it loops).
With these restrictions in mind, I can see only one approach that seems
ok to me (i.e. I don't see how to break it yet). Unfortunately, this
requires non-volatile storage, which means writing to external flash,
which introduces some serious complexity due to a variety of technical details.
I would love to get some feedback on the following solution. Even better, is there a solution I am missing that does not require non-volatile storage?
Please note that the primary purpose of this project is education. I realize that I could simplify this problem by setting up a secure relay inside my firewall, and let that handle Internet traffic, instead of exposing the MCU directly. But what would be the fun in that? ;)
= Proposed Solution =
A pair of shared AES keys will be used. One key to turn a Nonce into an IV for the CBC stage, and another for encrypting the messages themselves:
Shared message Key
Shared IV_Key
Here's a picture of what I am doing:
https://www.youtube.com/watch?v=JNsUrOVQKpE#t=10m11s
1) Android takes current time in milliseconds (Ti) (64-bit long) and
uses it as a nonce input into the CBC stage to encrypt the command:
a) IV(i) = AES_ECB(IV_Key, Ti)
b) Ci = AES_CBC(Key, IV(i), COMMAND)
2) Android utilizes /dev/random to generate the IV_Response that the
MCU will use to answer current request.
3) Android sends [<Ti, IV_Response, Ci>, <== HMAC(K)]
4) MCU receives and verifies integrity using HMAC, so attacker can't
modify plain text Ti.
5) MCU checks that Ti > T(i-1) stored in flash. This ensures that
recorded messages can't be replayed.
6) MCU calculates IV(i) = AES_ECB(IV_Key, Ti) and decrypts Ci.
7) MCU responds using AES_CBC(Key, IV_Response, RESPONSE)
8) MCU stores Ti in external flash memory.
Does this work? Is there a simpler approach?
EDIT: It was already shown in comments that this approach is vulnerable to a Delayed Playback Attack. If the attacker records and blocks messages from reaching the MCU, then the messages can be played back at any later time and still be considered valid, so this algorithm is no good.
As suggested by #owlstead, a challenge/response system is likely required. Unless I can find a way around that, I think I need to do the following:
Port or implement a decent PRGA. (Any recommendations?)
Pre-compute a lot of random seed values for the PRGA. A new seed will be used for every MCU restart. Assuming 128-bit seeds, 16K of storage buys be a 1000 unique seeds, so the values won't loop until the MCU successfully uses at least one PRGA output value and restarts a 1000 times. That doesn't seem too bad.
Use the output of PRGA to generate the challenges.
Does that sound about right?
Having an IV_KEY is unnecessary. IVs (and similar constructs, such as salts) do not need to be encrypted, and if you look at image you linked to in the youtube video you'll see their description of the payload includes the IV in plaintext. They are used so that the same plaintext does not encode to the same ciphertext under the same key every time, which presents information to an attacker. The protection against the IV being altered is the HMAC on the message, not the encryption. As such, you can remove that requirement. EDIT: This paragraph is incorrect, see discussion below. As noted though, your approach described above will work fine.
Your system does have a flaw though, namely the IV_Response. I assume, from that you include it in your system, that it serves some purpose. However, because it is not in any way encoded, it allows an attacker to respond affirmatively to a device's request without the MCU receiving it. Let's say that your device's were instructing an MCU that was running a small robot to throw a ball. Your commands might look like.
1) Move to loc (x,y).
2) Lower anchor to secure bot table.
3) Throw ball
Our attacker can allow messages 1 and 3 to pass as expected, and block 2 from getting to the MCU while still responding affirmatively, causing our bot to be damaged when it tosses the ball without being anchored. This does have an imperfect solution. Append the response (which should fit into a single block) to the command so that it is encrypted as well, and have the MCU respond with AES_ECB(Key, Response), which the device will verify. As such, the attacker will not be able to forge (feasibly) a valid response. Note that as you consider /dev/random untrustworthy this could provide an attacker with plaintext-ciphertext pairs, which can be used for linear cryptanalysis of the key provided an attacker has a large set of pairs to work with. As such, you'll need to change the key with some regularity.
Other than that, your approach looks good. Just remember it is crucial that you use the stored Ti to protect against the replay attack, and not the MCU's clock. Otherwise you run into synchronization problems.
I need to read serial number of MiFare card usin WinSCard. I am able to read 7B UID from the MiFare card.
The confusion is that i dont know if the UID and the serial number of
MiFare card are same?!!
I have googled the issue but only could get partial success. I found a question on stackoverflow also but it did not help.
I found a document of NXP online which says UID and serial number are different. (on page number 3, line number 5)
There is an application of OmniKey that reads the serial number of the card, and it also returns UID only.
NXP documentation says UID <> Serial Number and a other standard OmniKey application returns UID as Serial Number.
I have started pulling my hair off on the issue. I'd greatly appreciate if anyone could help.
Each smart card contains an integrated chip with a unique permanent identification (UID) number burned-in during the manufacturing process. This UID is often referred to as the Card Serial Number (CSN). The card serial number is not encrypted and any reader that is ISO compliant can read the card serial number.
Edit 1:
Mifare Card Serial Number is the unique identifier defined in ISO 14443-3A. There are 3 types of UID defined in the standard - single (4 bytes), double (7 bytes) and triple (10 bytes). Only in first versions of the Mifare card, the UID was 4 bytes but now have migrated to 7 bytes.
EDIT 2:
It might be helpful to you...
What is the difference between a 4 byte UID and a 4 byte ID?
A 4 byte UID is an identifier which has been assigned by the card
manufacturer using a controlled database. This database ensures that a
single identifier is not used twice. In contradiction, a 4 byte ID is an
identifier which may be assigned to more then one contactless chip over
the production time of a product so that more then one card with the same
identified may be deployed into one particular contactless system.
The differentiation in this case comes from the fact that a "Serial Number" implies that the numbers are a series, thus sequentially assigned.
MIFARE cards have Unique Identification Numbers (or in short UID), which are generated by an internal rule which is not necessarily sequential. This means that if you see a card with UID 01020304050607 it does not mean that there are at least that many cards produced so far.
If you ever see someone referring to the Card Serial Number, they are in fact referring to the UID.
The only last confusion can come from the fact that MIFARE cards can be configured to return Random IDs during activation. If that is the case, you would get different "UID" each time you activate the card. In that scenario you need to read the data contained in Block 0 (for which you will need to know the key to sector 0) to get the real UID of the card.
For DesFire cards:
UID is analogous to ethernet MAC address. It is assigned by the chip
manufacturer from a database. Everyone who creates applications for
the card has access to the UID.
The Card Serial Number is specific
to the application loaded on to the card. It can only be accessed by
that application via an encryption key. If the card had several applications loaded on to
it (unlikely but possible), then each could have a different CSN.