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opensslaes

Can someone give an encryption/decryption example with OpenSSL AES CCM?

I'm looking for an example of using OpenSSL's AES CCM encryption. Apparently, this is one of the two 'custom' cipher modes that require additional setup beyond EVP_CipherInit_ex(). Any suggestions would be appreciated.

Solution

  • In short:

    // Tell the alg we will encrypt Psize bytes
int outl = 0;
EVP_EncryptUpdate(ctx, 0, &outl, 0, Psize);

// Add the AAD
EVP_EncryptUpdate(ctx, 0, &outl, A, Asize);

// Now we encrypt the data in P, placing the output in CT
EVP_EncryptUpdate(ctx, CT, &outl, P, Psize);

    For more details, please see my blog post on this, http://www.fredriks.se/?p=23.