How to use bcrypt in OpenSSL?

Question

I want to use bcrypt encryption for storing passwords and I know OpenSSL implements Blowfish Cipher (which I'm assuming is the same thing).

I made some adaptations from the code shown in this page https://wiki.openssl.org/index.php/EVP_Symmetric_Encryption_and_Decryption and came up with this:

int OpenSSLEncrypt(
    unsigned char* plaintext, 
    int plaintext_len, 
    unsigned char* key,
    unsigned char* iv, 
    unsigned char* ciphertext) 
{
    EVP_CIPHER_CTX *ctx;

    int len;

    int ciphertext_len;

    if (!(ctx = EVP_CIPHER_CTX_new())) OpenSSLHandleErrors();

    if (1 != EVP_EncryptInit_ex(ctx, EVP_bf_cbc(), 0, key, 0))
        OpenSSLHandleErrors();

    if (1 != EVP_EncryptUpdate(ctx, ciphertext, &len, plaintext, plaintext_len))
        OpenSSLHandleErrors();
    ciphertext_len = len;

    if (1 != EVP_EncryptFinal_ex(ctx, ciphertext + len, &len)) 
        OpenSSLHandleErrors();

    ciphertext_len += len;

    /* Clean up */
    EVP_CIPHER_CTX_free(ctx);

    return ciphertext_len;
}

int OpenSSLDecrypt(
    unsigned char* ciphertext, 
    int ciphertext_len, 
    unsigned char* key,
    unsigned char* iv, 
    unsigned char* plaintext)
{
    EVP_CIPHER_CTX *ctx;
    int len;
    int plaintext_len;

    if (!(ctx = EVP_CIPHER_CTX_new())) OpenSSLHandleErrors();

    if (1 != EVP_DecryptInit_ex(ctx, EVP_bf_cbc(), NULL, key, 0))
        OpenSSLHandleErrors();

    if (1 != EVP_DecryptUpdate(ctx, plaintext, &len, ciphertext, ciphertext_len))
        OpenSSLHandleErrors();
    plaintext_len = len;

    if (1 != EVP_DecryptFinal_ex(ctx, plaintext + len, &len)) 
        OpenSSLHandleErrors();

    plaintext_len += len;

    /* Clean up */
    EVP_CIPHER_CTX_free(ctx);

    return plaintext_len;
}

But the length of the cipher that I get from OpenSSLEncrypt(...) depends on the length of the plaintext input parameter, which is not what I was expecting. I was expecting the output to be 64 bytes long no matter the length of the password.

Also, I don't know if EVP_EncryptInit_ex needs an iv (initialization vector) or not for EVP_bf_cbc, and I found no documentation that could help me with this.

Answer 1

As it was pointed out in the comments, I was wrong in assuming Blowfish and BCrypt are the same thing, just because I read somewhere B stands for Blowfish.

I ended up following the suggestion from Cinder Biscuits of using the OpenBSD implementation of bcrypt, avaiable at

https://github.com/libressl-portable/openbsd/blob/master/src/lib/libc/crypt/bcrypt.c