CODEWITHSUNDEEP
cencryptionopenssl
seedhom
seedhom

Reputation: 349

EVP_PKEY_keygen() generate key pair into a string?

Here is the code snippet I have now and it is working well

/* Generate key */
if (EVP_PKEY_keygen(ctx, &pkey) <= 0)
    goto cleanup;


// write rsa private key to file
bio_private = BIO_new_file("private_new.pem", "w+");
ret = PEM_write_bio_PrivateKey(bio_private, pkey, NULL, NULL, 0, NULL, NULL);
if (ret != 1) {
    goto cleanup;
}
BIO_flush(bio_private);

// write rsa public key to file
bio_public = BIO_new_file("public_new.pem", "w+");

ret = PEM_write_bio_PUBKEY(bio_public, pkey);
if (ret != 1) {
    goto cleanup;
}
BIO_flush(bio_public);

instead of using 

PEM_write_bio_PrivateKey(bio_private, pkey, NULL, NULL, 0, NULL, NULL);

I want the generated key text to be put into a string and NOT a file. I don't want it written to disk, just to a string in memory. Is there a PEM_ function to do this? or any other way? Thanks a lot for your help

Upvotes: 2

Views: 3112

Answers (2)

seedhom
seedhom

Reputation: 349

Thanks for Artjom's answer above. It worked! Here is the relevant code with the change :

/* Generate key */
if (EVP_PKEY_keygen(ctx, &pkey) <= 0)
    goto cleanup;

// write private key to memory
bio_private = BIO_new(BIO_s_mem());
ret = PEM_write_bio_PrivateKey(bio_private, pkey, NULL, NULL, 0, NULL, NULL);
if (ret != 1)
{
goto cleanup;
}
BIO_flush(bio_private);

BIO_get_mem_data(bio_private, &private_key_text);
cout << "PRIVE KEY :\n" << private_key_text << endl;
// write public key to memory
bio_public = BIO_new(BIO_s_mem());    
ret = PEM_write_bio_PUBKEY(bio_public, pkey);
if (ret != 1)
{
goto cleanup;
}
BIO_flush(bio_public);

BIO_get_mem_data(bio_public, &public_key_text);

cout << "PUBLIC KEY :\n" << public_key_text << endl;

Upvotes: 0

Artjom B.
Artjom B.

Reputation: 61952

Use 

bio_private = BIO_new(BIO_s_mem());

instead of 

bio_private = BIO_new_file("private_new.pem", "w+");

as seen here.

You can use long BIO_get_mem_data(BIO *b, char **pp) to access the data in the BIO:

BIO_get_mem_data() sets pp to a pointer to the start of the memory BIOs data and returns the total amount of data available. It is implemented as a macro.

Upvotes: 4

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