int ssl3_do_change_cipher_spec(SSL *s)
{
    int i;
    const char *sender;
    int slen;

    if (s->state & SSL_ST_ACCEPT)
        i = SSL3_CHANGE_CIPHER_SERVER_READ;
    else
        i = SSL3_CHANGE_CIPHER_CLIENT_READ;

    if (s->s3->tmp.key_block == NULL) {
        if (s->session == NULL || s->session->master_key_length == 0) {
            /* might happen if dtls1_read_bytes() calls this */
            SSLerr(SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC,
                   SSL_R_CCS_RECEIVED_EARLY);
            return (0);
        }

        s->session->cipher = s->s3->tmp.new_cipher;
        if (!s->method->ssl3_enc->setup_key_block(s))
            return (0);
    }

    if (!s->method->ssl3_enc->change_cipher_state(s, i))
        return (0);

    /*
     * we have to record the message digest at this point so we can get it
     * before we read the finished message
     */
    if (s->state & SSL_ST_CONNECT) {
        sender = s->method->ssl3_enc->server_finished_label;
        slen = s->method->ssl3_enc->server_finished_label_len;
    } else {
        sender = s->method->ssl3_enc->client_finished_label;
        slen = s->method->ssl3_enc->client_finished_label_len;
    }

    i = s->method->ssl3_enc->final_finish_mac(s,
                                              sender, slen,
                                              s->s3->tmp.peer_finish_md);
    if (i == 0) {
        SSLerr(SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC, ERR_R_INTERNAL_ERROR);
        return 0;
    }
    s->s3->tmp.peer_finish_md_len = i;

    return (1);
}

Originally addressing errors in controlling program flow through indirect calls or jumps, this CWE has been deprecated and its concerns merged into more precise modern classifications.