I am doing AES Key Generation in c# and passing the key generated for AES 128 bit Encryption. The case is while generating the key I am getting byte length as 16 while the key string length is getting higher than 16. While trying online I am getting length as 16 itself. What I have tried: Core Code is as below: AES Key 128 bit Generation. Mar 12, 2020 Generating AES keys and password Use the OpenSSL command-line tool, which is included with InfoSphere® MDM, to generate AES 128-, 192-, or 256-bit keys. The madpwd3 utility is used to create the password. An AES key, and an IV for symmetric encryption, are just bunchs of random bytes. So any cryptographically strong random number generator will do the trick. OpenSSL provides such a random number generator (which itself feeds on whatever the operating system provides, e.g. An AES key, and an IV for symmetric encryption, are just bunchs of random bytes. So any cryptographically strong random number generator will do the trick. OpenSSL provides such a random number generator (which itself feeds on whatever the operating system provides, e.g. The all-in-one ultimate online toolbox that generates all kind of keys! Every coder needs All Keys Generator in its favorites! It is provided for free and only supported by ads and donations.
Here is the simple “How to do AES-128 bit CBC mode encryption in c programming code with OpenSSL”
First you need to download standard cryptography library called OpenSSL to perform robust AES(Advanced Encryption Standard) encryption, But before that i will tell you to take a look at simple C code for AES encryption and decryption, so that you are familiar with AES cryptography APIs which is quite simple. Here i use AES-128 bit CBC mode Encryption, where 128 bit is AES key length. We can also use 192 and 256 bit AES key for encryption in which size and length of key is increased with minor modification in following code.
AES Sample code in C programming
2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 | #include <stdlib.h> #include <openssl/aes.h> /* AES key for Encryption and Decryption */ conststaticunsignedcharaes_key[]={0x00,0x11,0x22,0x33,0x44,0x55,0x66,0x77,0x88,0x99,0xAA,0xBB,0xCC,0xDD,0xEE,0xFF}; /* Print Encrypted and Decrypted data packets */ voidprint_data(constchar*tittle,constvoid*data,intlen); intmain() /* Input data to encrypt */ unsignedcharaes_input[]={0x0,0x1,0x2,0x3,0x4,0x5}; /* Init vector */ memset(iv,0x00,AES_BLOCK_SIZE); /* Buffers for Encryption and Decryption */ unsignedchardec_out[sizeof(aes_input)]; /* AES-128 bit CBC Encryption */ AES_set_encrypt_key(aes_key,sizeof(aes_key)*8,&enc_key); AES_cbc_encrypt(aes_input,enc_out,sizeof(aes_input),&enc_key,iv,AES_ENCRYPT); memset(iv,0x00,AES_BLOCK_SIZE);// don't forget to set iv vector again, else you can't decrypt data properly AES_set_decrypt_key(aes_key,sizeof(aes_key)*8,&dec_key);// Size of key is in bits AES_cbc_encrypt(enc_out,dec_out,sizeof(aes_input),&dec_key,iv,AES_DECRYPT); /* Printing and Verifying */ print_data('n Original ',aes_input,sizeof(aes_input));// you can not print data as a string, because after Encryption its not ASCII print_data('n Encrypted',enc_out,sizeof(enc_out)); print_data('n Decrypted',dec_out,sizeof(dec_out)); return0; voidprint_data(constchar*tittle,constvoid*data,intlen) printf('%s : ',tittle); inti=0; for(;i<len;++i) } |
Compiling and Installing OpenSSL
Before compiling this code, you need OpenSSL library which you can download from here
i am using openssl-1.0.1i which i have downloaded in form of tar file because my development OS is Linux(Ubuntu). So after downloading tar file we have to compile and install OpenSSL. To do so follow instruction below.