1use poulpy_hal::{
  2    api::{
  3        DFT, IDFTConsume, ScratchAvailable, SvpApplyInplace, SvpPPolAllocBytes, SvpPrepare, TakeScalarZnx, TakeVecZnx,
  4        TakeVecZnxDft, VecZnxAddInplace, VecZnxAddNormal, VecZnxAddScalarInplace, VecZnxBigNormalize, VecZnxDftAllocBytes,
  5        VecZnxFillUniform, VecZnxNormalize, VecZnxNormalizeInplace, VecZnxNormalizeTmpBytes, VecZnxSub, VecZnxSubABInplace,
  6        VecZnxSwithcDegree,
  7    },
  8    layouts::{Backend, DataMut, DataRef, Module, ScalarZnx, Scratch},
  9    source::Source,
 10};
 11
 12use crate::{
 13    TakeGLWESecretPrepared,
 14    layouts::{GGLWECiphertext, GLWESecret, compressed::GGLWESwitchingKeyCompressed, prepared::GLWESecretPrepared},
 15};
 16
 17impl GGLWESwitchingKeyCompressed<Vec<u8>> {
 18    pub fn encrypt_sk_scratch_space<B: Backend>(
 19        module: &Module<B>,
 20        basek: usize,
 21        k: usize,
 22        rank_in: usize,
 23        rank_out: usize,
 24    ) -> usize
 25    where
 26        Module<B>: VecZnxNormalizeTmpBytes + VecZnxDftAllocBytes + VecZnxNormalizeTmpBytes + SvpPPolAllocBytes,
 27    {
 28        (GGLWECiphertext::encrypt_sk_scratch_space(module, basek, k) | ScalarZnx::alloc_bytes(module.n(), 1))
 29            + ScalarZnx::alloc_bytes(module.n(), rank_in)
 30            + GLWESecretPrepared::bytes_of(module, rank_out)
 31    }
 32}
 33
 34impl<DataSelf: DataMut> GGLWESwitchingKeyCompressed<DataSelf> {
 35    #[allow(clippy::too_many_arguments)]
 36    pub fn encrypt_sk<DataSkIn: DataRef, DataSkOut: DataRef, B: Backend>(
 37        &mut self,
 38        module: &Module<B>,
 39        sk_in: &GLWESecret<DataSkIn>,
 40        sk_out: &GLWESecret<DataSkOut>,
 41        seed_xa: [u8; 32],
 42        source_xe: &mut Source,
 43        scratch: &mut Scratch<B>,
 44    ) where
 45        Module<B>: SvpPrepare<B>
 46            + SvpPPolAllocBytes
 47            + VecZnxSwithcDegree
 48            + VecZnxDftAllocBytes
 49            + VecZnxBigNormalize<B>
 50            + DFT<B>
 51            + SvpApplyInplace<B>
 52            + IDFTConsume<B>
 53            + VecZnxNormalizeTmpBytes
 54            + VecZnxFillUniform
 55            + VecZnxSubABInplace
 56            + VecZnxAddInplace
 57            + VecZnxNormalizeInplace<B>
 58            + VecZnxAddNormal
 59            + VecZnxNormalize<B>
 60            + VecZnxSub
 61            + VecZnxAddScalarInplace,
 62        Scratch<B>: TakeVecZnxDft<B> + ScratchAvailable + TakeVecZnx + TakeScalarZnx + TakeGLWESecretPrepared<B>,
 63    {
 64        #[cfg(debug_assertions)]
 65        {
 66            use crate::layouts::{GGLWESwitchingKey, Infos};
 67
 68            assert!(sk_in.n() <= module.n());
 69            assert!(sk_out.n() <= module.n());
 70            assert!(
 71                scratch.available()
 72                    >= GGLWESwitchingKey::encrypt_sk_scratch_space(
 73                        module,
 74                        self.basek(),
 75                        self.k(),
 76                        self.rank_in(),
 77                        self.rank_out()
 78                    ),
 79                "scratch.available()={} < GLWESwitchingKey::encrypt_sk_scratch_space={}",
 80                scratch.available(),
 81                GGLWESwitchingKey::encrypt_sk_scratch_space(
 82                    module,
 83                    self.basek(),
 84                    self.k(),
 85                    self.rank_in(),
 86                    self.rank_out()
 87                )
 88            )
 89        }
 90
 91        let n: usize = sk_in.n().max(sk_out.n());
 92
 93        let (mut sk_in_tmp, scratch1) = scratch.take_scalar_znx(n, sk_in.rank());
 94        (0..sk_in.rank()).for_each(|i| {
 95            module.vec_znx_switch_degree(
 96                &mut sk_in_tmp.as_vec_znx_mut(),
 97                i,
 98                &sk_in.data.as_vec_znx(),
 99                i,
100            );
101        });
102
103        let (mut sk_out_tmp, scratch2) = scratch1.take_glwe_secret_prepared(n, sk_out.rank());
104        {
105            let (mut tmp, _) = scratch2.take_scalar_znx(n, 1);
106            (0..sk_out.rank()).for_each(|i| {
107                module.vec_znx_switch_degree(&mut tmp.as_vec_znx_mut(), 0, &sk_out.data.as_vec_znx(), i);
108                module.svp_prepare(&mut sk_out_tmp.data, i, &tmp, 0);
109            });
110        }
111
112        self.key.encrypt_sk(
113            module,
114            &sk_in_tmp,
115            &sk_out_tmp,
116            seed_xa,
117            source_xe,
118            scratch2,
119        );
120        self.sk_in_n = sk_in.n();
121        self.sk_out_n = sk_out.n();
122    }
123}