CCM

CCM is an algorithm that extends the block cipher AES with authentication, so that it ensures both confidentiality and integrity.

🎯 Features

• Authenticated AES encryption
• Decryption using 128-bit block ciphers

🚀 Getting Started

🔧 Installation

As a prerequisite, the library OpenSSL must be installed, since this algorithm accesses functions of this toolkit.

To compile and link CCM just type make or make debug for debugging purposes.

Note: Object files and other intermediate files can be removed using the command make clean.

💻 Usage

The CLI can be used according to the following scheme:

$ ./ccm -d|-e [-h] <key> <nonce> <file>

• -d: decryption
• -e: encryption
• -h: hexadecimal format
• <key>: cipher key
• <nonce>: random number
• <file>: ciphertext or plaintext

The file is read in as an input stream and either encrypted or decrypted depending on the parameters.

✅ Tests

In the following, the test vector testdata.txt is to be encrypted. The password settings according to RFC 3610 are as follows:

Cipher: AES-128 M=8 L=5 K_LEN=16 N_LEN=10 K=0x001234567890abcdefdcaffeed3921ee N=0x00112233445566778899

Now the file will be encrypted applying the aforementioned settings:

$ ./ccm -e -h 001234567890abcdefdcaffeed3921ee 00112233445566778899 < testdata.txt > encrypted

key:00:12:34:56:78:90:ab:cd:ef:dc:af:fe:ed:39:21:ee
nonce:00:11:22:33:44:55:66:77:88:99
length:38
content:Ein kleiner Text
zum Testen von CCM.

b-blocks:
1c:00:11:22:33:44:55:66:77:88:99:00:00:00:00:25
45:69:6e:20:6b:6c:65:69:6e:65:72:20:54:65:78:74
0a:7a:75:6d:20:54:65:73:74:65:6e:20:76:6f:6e:20
43:43:4d:2e:0a:00:00:00:00:00:00:00:00:00:00:00
mac:bb:78:19:d3:01:cf:c8:ab
a-blocks:
04:00:11:22:33:44:55:66:77:88:99:00:00:00:00:00:
04:00:11:22:33:44:55:66:77:88:99:00:00:00:00:01:
04:00:11:22:33:44:55:66:77:88:99:00:00:00:00:02:
04:00:11:22:33:44:55:66:77:88:99:00:00:00:00:03:
04:00:11:22:33:44:55:66:77:88:99:00:00:00:00:04:
s-blocks:
6a:0c:4a:ff:a2:7f:07:12:8e:47:9d:56:8e:6f:8a:f3:
01:13:ec:50:76:bc:50:12:06:92:47:6d:eb:bc:6e:61:
9d:3b:48:73:a9:95:40:94:a2:c2:b0:b0:68:9e:07:49:
dc:8d:0d:f2:fa:0d:95:7e:70:84:1f:41:71:c5:a7:50:
79:06:4d:38:1c:11:83:29:7a:76:77:df:43:0b:6a:6a:
DzÇp�–5{h˜5MøŸ��óA=�â¡%Á÷ßfiê�ÒiiüŒ@‹—tS,£∞œπ

The respective block types, keys, and random number are displayed. The ciphertext is at the bottom. The decryption works analogously.

📖 Documentation

The CCM documentation becomes available by typing the following commands in the terminal:

$ cd ccm
$ doxygen doxygen.config

⚠️ License

CCM is licensed under the terms of the MIT license.