replace clone() with copy() to better mimic openssl interface

            Ok(CipherCtx::from_ptr(ptr))

            Ok(CipherCtx::from_ptr(ptr))

        }

        }

    }

    }

}

impl CipherCtxRef {

    #[corresponds(EVP_CIPHER_CTX_copy)]

    #[corresponds(EVP_CIPHER_CTX_copy)]

    pub fn clone(&self) -> Result<Self, ErrorStack> {

    pub fn copy(&mut self, src: &CipherCtx) -> Result<(), ErrorStack> {

        let n = CipherCtx::new()?;

        unsafe {

        unsafe {

            cvt(ffi::EVP_CIPHER_CTX_copy(n.as_ptr(), self.as_ptr()))?;

            cvt(ffi::EVP_CIPHER_CTX_copy(self.as_ptr(), src.as_ptr()))?;

        }

            Ok(())

        Ok(n)

        }

        }

    }

    }

impl CipherCtxRef {

    /// Initializes the context for encryption.

    /// Initializes the context for encryption.

    ///

    ///

    /// Normally this is called once to set all of the cipher, key, and IV. However, this process can be split up

    /// Normally this is called once to set all of the cipher, key, and IV. However, this process can be split up