| // Copyright (C) 2022 The Android Open Source Project |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| use anyhow::{ensure, Result}; |
| use bssl_ffi as bssl_sys; |
| |
| pub const ENTROPY_LEN: usize = bssl_sys::CTR_DRBG_ENTROPY_LEN as usize; |
| |
| pub type Entropy = [u8; ENTROPY_LEN]; |
| |
| pub struct Drbg(*mut bssl_sys::CTR_DRBG_STATE); |
| |
| impl Drbg { |
| pub fn new(entropy: &Entropy) -> Result<Drbg> { |
| let p = unsafe { bssl_sys::CTR_DRBG_new(entropy.as_ptr(), std::ptr::null(), 0) }; |
| ensure!(!p.is_null(), "CTR_DRBG_new failed"); |
| Ok(Drbg(p)) |
| } |
| |
| pub fn reseed(&mut self, entropy: &Entropy) -> Result<()> { |
| ensure!( |
| unsafe { bssl_sys::CTR_DRBG_reseed(self.0, entropy.as_ptr(), std::ptr::null(), 0) } |
| == 1, |
| "CTR_DRBG_reseed failed" |
| ); |
| Ok(()) |
| } |
| |
| pub fn generate(&mut self, buf: &mut [u8]) -> Result<()> { |
| ensure!( |
| unsafe { |
| bssl_sys::CTR_DRBG_generate( |
| self.0, |
| buf.as_mut_ptr(), |
| buf.len(), |
| std::ptr::null(), |
| 0, |
| ) |
| } == 1, |
| "CTR_DRBG_generate failed" |
| ); |
| Ok(()) |
| } |
| } |
| |
| impl Drop for Drbg { |
| fn drop(&mut self) { |
| unsafe { |
| bssl_sys::CTR_DRBG_free(self.0); |
| } |
| } |
| } |
| |
| unsafe impl Send for Drbg {} |