Do the following on Linux (this is for Ubuntu/Debian – you might need root access):

• Install pcsclite-dev:

sudo apt-get install libpcsclite-dev

• Then also install these packages:

sudo apt-get install swig python3-dev libudev-dev python3-pip

• Get and install Pyscard using pip (install pip if needed)

pip3 install pyscard

• Install Pyserial

pip3 install pyserial

If this doesn't work, then get pyserial from here

• Install pcsc related libs:

sudo apt-get install libusb-dev libccid pcscd libpcsclite1

• You might also want to install these additional card tools from here:

sudo apt-get install libpcsc-perl pcsc-tools

See details here.

For Windows drivers you can check here. However, we recommend using Linux, as the instructions below apply for the linux installation.

Try this with your card in the smartcard reader:

pcsc_scan

This should show you applications on the card. If not, don't worry, we'll do it ourselves below.

Start with files for accessing card data in this zip file. (for Python 2 you may use the code here, but is obsolete and no longer mantained).

Create a file named terminal.txt that will be populated as mentioned below. This file should end with a line containing the string '0000000000'.

After updating this file (see below), we can run the terminal in this manner:

python3 sclink.py --scterminal terminal.txt gg

We shall now first select the main financial application on the card via the general `1PAY.SYS.DDF01' file available on some EMV cards followed by selection of the Application ID. See EMV Book 1, sections 11.3 and 12 for details.

In summary, the main steps are these:

1. Send the first SELECT command with `1PAY.SYS.DDF01': 00A404000E315041592E5359532E4444463031
2. Decode the response using emvlab. Use the SFI response (e.g. 01, concatenated with the record number encoded in the last 3 bits): (SFI « 3) | REC_NUM. E.g. If SFI=01 and REC_NUM=1, we get the Reference Control parameter (P2) 0x0C for the READ RECORD command, leading to the READ RECORD command 00B2010C00.
3. Check the available apps by sending READ RECORD commands of the form 00B2010C00, 00B2020C00, etc. Check the responses by decoding them with emvlab
4. Eventually select one of them using SELECT, e.g.

• select particular app: 00A4040007XXXXXXXXXXXXXX (replace the X values based on the Application ID response to the 00B2XXX command above).

E.g. to get something like 00A4040007A0000000041010. (If the application has 7 bytes – 14 hex characters for the Application ID).

• 00A4040007A0000000041010 (this must be updated for your card, based on the response to the 00B2XXX command above).
• start transaction with GET PROCESSING OPTS: 80A80000028300

Now your terminal.txt file should look something like this (but again, replace the Application ID with the correct one and also use the correct READ RECORD commands – from your trials).

terminal.txt

00A404000E315041592E5359532E4444463031
00B2010C00
00A4040007A0000000041010
80A80000028300
0000000000

As mentioned above, now run this terminal emulator with the following code:

python3 sclink.py --scterminal terminal.txt gg

Your next goal is to be able to read all the application files with READ RECORD commands (for each file).

In order to find out the present files (which differ from card to card), you need to issue the GET PROCESSING OPTS command above (80A80000028300).

In response you should get the Application Interchange Profile (AIP) bytes (2 bytes, coded according to Book 3, Appendix C) followed by a list of Application File Locators (AFL, coded as explained in Book 3, Section 10.2).

After you decode this (TLV decodeer might help), you will find one or more groups of 4 bytes as follows:

• 1st byte: SFI « 3
• 2nd byte: first record_number
• 3rd byte: last record_number
• 4th byte: [you don't need it]

SFI is like a directory with multiple records that can be read.

To read a file, you need to issue a READ RECORD command which looks like this: 00B2 <record_number> <SFI || 100>

The <record_number> is a byte (you need to write a READ RECORD command for each record_number). <SFI || 100> is a byte which contains the SFI number in the first 5 bits and 100 in the last 3 bits. This is the same as SFI « 3 + 0x04.

For example, if your AFL shows like “10 01 05 01”, then you might want to read records between 01 and 05 using SFI 01 + 0x04, i.e. issuing READ RECORD commands like this:

00 B2 01 14 00

Using the READ RECORD commands mentioned earlier and the TLV decoder, find the public keys in your card, in particular:

• Issuer public key certificate
• Issuer public key exponent
• Issuer public key reminder
• ICC public key certificate
• ICC public key exponent
• ICC public key reminder

After you get all the public key data, use an INTERNAL AUTHENTICATE command similar to this: 00880000043085C163. See the file trace_emv.txt for an example of trace as model for the set of commands you might have to issue (i.e. to add to your terminal.txt file).

As discussed in class (see also the EMV book 2, section 6), modern EMV cards generally support dynamic signature generation (DDA). This works as follows:

• The terminal issues the INTERNAL AUTHENTICATE command with some random data (typically 4 bytes)
• The ICC makes a signature over some internal ICC data and the random bytes from the terminal
• The ICC sends the signature (signed dynamic data) to the terminal in response to the INTERNAL AUTHENTICATE command
• The terminal verifies the signature using a chain of certificates

An example of an INTERNAL AUTHENTICATE command similar is the following: 00880000043085C163. You can look at the file trace_emv.txt for an example of trace.

// EMV.AIDLIST:
EMV.AIDLIST = new Array();
EMV.AIDLIST[0] = { aid : "A00000002501", partial : true, name : "AMEX" };
EMV.AIDLIST[1] = { aid : "A0000000031010", partial : false, name : "VISA" };
EMV.AIDLIST[2] = { aid : "A0000000041010", partial : false, name : "MC" };

The process to verify a DDA signature is as follows:

• The terminal verifies (RSA decrypts) the signed Issuer public key data (read from the ICC) using the CA public key, obtaining the Issuer public key
• The terminal verifies (RSA decrypts) the signed ICC public key data (read from the ICC) using the Issuer public key, obtaining the ICC public key
• The terminal verifies (RSA decrypts) the signed DDA data using the ICC public key (read from the ICC via the INTERNAL AUTHENTICATE command)

At each step, the verification step includes decryption of the data and checking that the hash over the fields mentioned in Book 2 of EMV matches the hash in the decrypted data.

In short, you need to do the following (see EMV Book 2, sections 6, 6.1, 6.2, 6.3, 6.4 and 6.5)

• Decrypt Issuer public key from Issuer Certificate Public key using the root CA public key of your card scheme (section 6.3)
• Decrypt ICC public key from ICC Certificate Public Key using the Issuer public key (section 6.4)
• Decrypt DDA signature returned by the card using the ICC public key (section 6.5)
• Verify the DDA signature (section 6.5)

To recover the data from the issuer public key certificate (same applies to the other signatures), you may also find useful the following notes (which are based on the EMV specs mentioned above, please refer to those).

• First, generate a template ASN1 file as follows:

'template.asn1'

# Start with a SEQUENCE
asn1=SEQUENCE:pubkeyinfo
 
# pubkeyinfo contains an algorithm identifier and the public key wrapped
# in a BIT STRING
[pubkeyinfo]
algorithm=SEQUENCE:rsa_alg
pubkey=BITWRAP,SEQUENCE:rsapubkey
 
# algorithm ID for RSA is just an OID and a NULL
[rsa_alg]
algorithm=OID:rsaEncryption
parameter=NULL
 
# Actual public key: modulus and exponent
[rsapubkey]
n=INTEGER:0x%%MODULUS%%
 
e=INTEGER:0x%%EXPONENT%%

• Then use this template for all the keys you need to generate. For example, for the CA root key, use the template and replace the MODULUS and EXPONENT part by the modulus and exponent bytes given in the list of public CA root public keys for your card. Say the resulting file is named ca_pk.asn1.
• Then use openssl asn1 parser to obtain a public key in DER format as follows:

  openssl asn1parse -genconf ca_pk.asn1 -out ca_pk.der -noout
  

• Now copy the Issuer Certificate Public Key bytes obtained from the card into a file, say issuer_pk.bytes and then convert this to a binary file like this:

  cat issuer_pk.bytes | xxd -r -p > issuer_pk.bin
  

• At this point you can verify/decrypt the issuer certificate using openssl as follows:

  openssl rsautl -verify -in issuer_pk_cert.bin -inkey ca_pk.der -pubin -keyform DER -raw
  

Although it might be more convenient to see the output in hexa, using something like this:
<code>
openssl rsautl -verify -in issuer_pk_cert.bin -inkey ca_pk.der -pubin -keyform DER -raw | xxd -p
</code>

To understand the meaning of the decrypted bytes, please refer to the respective EMV documentation (in particular sections 6.2-6.5 in book 2). For example, for the Issuer public key certificate, to obtain the actual issuer public key you need to ignore the first 15 bytes (metadata) as well as the last 21 bytes (hash result and trailer value “BC”). The reminder bytes are the first part of the Issuer Public key. For the second part of the Issuer Public key (which you need to concatenate to the first part to get the full public key), please see the card response with tag 92 (Issuer Public Key reminder).

Apply the same/similar process to get the ICC public key and finally to decrypt/verify the DDA signature.

If you don't manage to get a signature from your card, use these responses from a card (decode them with TLV decode):

Start from the following responses of a card (decode them with TLV decode)

> 00 B2 01 14 8A
< 70 81 87 5F 25 03 08 02 01 5F 24 03 12 02 29 5A 08 54 00 49 51 48 65 15 96 5F 34 01 00 9F 07 02 FF 00 8E 14 00 00 00 00 00 00 00 00 42 01 44 03 41 03 42 03 5E 03 1F 03 8C 21 9F 02 06 9F 03 06 9F 1A 02 95 05 5F 2A 02 9A 03 9C 01 9F 37 04 9F 35 01 9F 45 02 9F 4C 08 9F 34 03 8D 0C 91 0A 8A 02 95 05 9F 37 04 9F 4C 08 9F 0D 05 F8 50 AC 08 00 9F 0E 05 00 00 00 00 00 9F 0F 05 F8 70 AC 98 00 5F 28 02 06 42 9F 4A 01 82

> 00 B2 02 14 47
< 70 45 9F 08 02 00 02 57 13 54 00 49 51 48 65 15 96 D1 20 22 01 00 00 08 28 00 00 0F 5F 20 17 43 48 4F 55 44 41 52 59 20 2F 4F 4D 41 52 20 53 41 4C 49 4D 20 44 4C 5F 30 02 02 01 9F 42 02 09 78 9F 44 01 02 8F 01 04

> 00 B2 03 14 96
< 70 81 93 90 81 90 0B 69 37 0D CF E1 E7 B0 9C 00 6F CC 12 91 38 C0 7A 69 80 87 3C 1E 0A 60 04 E6 8E 23 F5 BF B7 51 08 28 00 8B 37 F4 C3 D3 30 6A 0D AE 70 92 51 2F FB B1 E8 1E AE 26 23 1A 0D BF C8 30 B3 1C F1 F6 81 9C F3 12 37 FE 74 B3 5C 5B 57 62 0A 4D C1 96 ED 06 CC 94 45 AC 0A 5B 00 BB 8E BA 7F B4 1D 97 4C A1 F9 DD A4 45 1E B3 2E FC 55 5A 16 9D 60 09 47 4E 97 09 2B 33 21 AD D5 9D 1C 35 30 11 CC C1 C1 D6 19 65 B9 12 0E 07 FC 8F B3 72 4A C0 3A 15

> 00 B2 04 14 CA
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

> 00 B2 05 14 B4
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

> 00 88 00 00 04 30 85 C1 63
<  [] 61 87
135
> 00 C0 00 00 87
< 77 81 84 9F 4B 81 80 99 0B 9E 27 E7 51 B7 45 5F F8 64 82 3C 82 35 94 CD E0 26 AB 9A D9 1D 02 7F 6E B8 5E DE 27 23 B7 81 40 0D BD 85 FD 20 21 07 08 A3 6C B3 09 51 33 B2 D7 30 BF 12 8B 23 C9 4D 87 3F 28 56 63 1C 19 F5 21 BB BC E2 2F 45 B2 C9 0A 7E B2 F5 C7 02 03 3C B3 AB 1C 06 F5 5A CB 44 3A E0 93 84 42 33 FF 16 D0 CE BB 75 6C E1 39 09 A6 39 5A 89 48 D1 9A BF D8 5E 29 43 0F A0 CC 16 90 7A 5C 92 CA 74 3F

For this card the public key modulus is this (1152 bit):

A6DA428387A502D7DDFB7A74D3F412BE762627197B25435B7A81716A700157DDD06F7CC99D6CA28C2470527E2C03616B9C59217357C2674F583B3BA5C7DCF2838692D023E3562420B4615C439CA97C44DC9A249CFCE7B3BFB22F68228C3AF13329AA4A613CF8DD853502373D62E49AB256D2BC17120E54AEDCED6D96A4287ACC5C04677D4A5A320DB8BEE2F775E5FEC5

And the exponent is 0x03.

In case of big big trouble, is the ASN1 file that you should obtain for the Issuer Public Key:

issuer_pk.asn1

# Start with a SEQUENCE
asn1=SEQUENCE:pubkeyinfo
 
# pubkeyinfo contains an algorithm identifier and the public key wrapped
# in a BIT STRING
[pubkeyinfo]
algorithm=SEQUENCE:rsa_alg
pubkey=BITWRAP,SEQUENCE:rsapubkey
 
# algorithm ID for RSA is just an OID and a NULL
[rsa_alg]
algorithm=OID:rsaEncryption
parameter=NULL
 
# Actual public key: modulus and exponent
[rsapubkey]
n=INTEGER:0xcb3a3f60cceccabb300a57d0c7c7fc974a34d8fa4728b9bb4719fec80a41b0cd04eb2c9fdfdd9139f87de2b3cbee69ecdf2889a37888beadc7a5ed5cc51da52940b000ef806ab277d0276386493da941f390f8a1354a3040dc84a7611b0a6e46874efd463a0f0607459ea58eEF2FD9E83BD90C88A1A65884B35A636908403659831AFB41743C61E50FCE32491CD39A81
 
e=INTEGER:0x3