Sachy's crypto scheme lmao

Cargo.lock

···
 checksum = "320119579fcad9c21884f5c4861d16174d0e06250625266f50fe6898340abefa"
 
 [[package]]
+name = "aead"
+version = "0.6.0-rc.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6b657e772794c6b04730ea897b66a058ccd866c16d1967da05eeeecec39043fe"
+dependencies = [
+ "crypto-common 0.2.1",
+ "inout",
+]
+
+[[package]]
 name = "aho-corasick"
 version = "1.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
···
 ]
 
 [[package]]
+name = "base16ct"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fd307490d624467aa6f74b0eabb77633d1f758a7b25f12bceb0b22e08d9726f6"
+
+[[package]]
 name = "base64ct"
 version = "1.8.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
···
 ]
 
 [[package]]
+name = "block-buffer"
+version = "0.12.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cdd35008169921d80bc60d3d0ab416eecb028c4cd653352907921d95084790be"
+dependencies = [
+ "hybrid-array",
+]
+
+[[package]]
 name = "byteorder"
 version = "1.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
···
 
 [[package]]
 name = "cc"
-version = "1.2.56"
+version = "1.2.57"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "aebf35691d1bfb0ac386a69bac2fde4dd276fb618cf8bf4f5318fe285e821bb2"
+checksum = "7a0dd1ca384932ff3641c8718a02769f1698e7563dc6974ffd03346116310423"
 dependencies = [
  "find-msvc-tools",
  "shlex",
···
 checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
 
 [[package]]
+name = "chacha20"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6f8d983286843e49675a4b7a2d174efe136dc93a18d69130dd18198a6c167601"
+dependencies = [
+ "cfg-if",
+ "cipher",
+ "cpufeatures 0.3.0",
+]
+
+[[package]]
+name = "chacha20poly1305"
+version = "0.11.0-rc.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1c9ed179664f12fd6f155f6dd632edf5f3806d48c228c67ff78366f2a0eb6b5e"
+dependencies = [
+ "aead",
+ "chacha20",
+ "cipher",
+ "poly1305",
+]
+
+[[package]]
+name = "cipher"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e34d8227fe1ba289043aeb13792056ff80fd6de1a9f49137a5f499de8e8c78ea"
+dependencies = [
+ "block-buffer 0.12.0",
+ "crypto-common 0.2.1",
+ "inout",
+]
+
+[[package]]
+name = "cmov"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "de0758edba32d61d1fd9f4d69491b47604b91ee2f7e6b33de7e54ca4ebe55dc3"
+
+[[package]]
+name = "const-oid"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a6ef517f0926dd24a1582492c791b6a4818a4d94e789a334894aa15b0d12f55c"
+
+[[package]]
 name = "core-foundation"
 version = "0.10.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
···
 checksum = "773648b94d0e5d620f64f280777445740e61fe701025087ec8b57f45c791888b"
 
 [[package]]
+name = "cpubits"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5ef0c543070d296ea414df2dd7625d1b24866ce206709d8a4a424f28377f5861"
+
+[[package]]
 name = "cpufeatures"
 version = "0.2.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
···
 ]
 
 [[package]]
+name = "cpufeatures"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8b2a41393f66f16b0823bb79094d54ac5fbd34ab292ddafb9a0456ac9f87d201"
+dependencies = [
+ "libc",
+]
+
+[[package]]
 name = "critical-section"
 version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "790eea4361631c5e7d22598ecd5723ff611904e3344ce8720784c93e3d83d40b"
 
 [[package]]
+name = "crypto-bigint"
+version = "0.7.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e9b6a7421484856c90cb2e996b91068d608539bb4e6f0a111b16d70678824d09"
+dependencies = [
+ "cpubits",
+ "ctutils",
+ "getrandom",
+ "hybrid-array",
+ "num-traits",
+ "rand_core",
+ "subtle",
+ "zeroize",
+]
+
+[[package]]
 name = "crypto-common"
 version = "0.1.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
···
 dependencies = [
  "generic-array",
  "typenum",
+]
+
+[[package]]
+name = "crypto-common"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "77727bb15fa921304124b128af125e7e3b968275d1b108b379190264f4423710"
+dependencies = [
+ "getrandom",
+ "hybrid-array",
+ "rand_core",
+]
+
+[[package]]
+name = "ctutils"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1005a6d4446f5120ef475ad3d2af2b30c49c2c9c6904258e3bb30219bebed5e4"
+dependencies = [
+ "cmov",
+ "subtle",
 ]
 
 [[package]]
···
 checksum = "10d60334b3b2e7c9d91ef8150abfb6fa4c1c39ebbcf4a81c2e346aad939fee3e"
 dependencies = [
  "thiserror 2.0.18",
+]
+
+[[package]]
+name = "der"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "71fd89660b2dc699704064e59e9dba0147b903e85319429e131620d022be411b"
+dependencies = [
+ "const-oid",
+ "zeroize",
 ]
 
 [[package]]
···
 ]
 
 [[package]]
+name = "dhkem"
+version = "0.1.0-rc.0"
+source = "git+https://github.com/RustCrypto/KEMs?rev=2d277162e0c5ed1c53bb315d0c0dace394cba70a#2d277162e0c5ed1c53bb315d0c0dace394cba70a"
+dependencies = [
+ "elliptic-curve",
+ "hkdf",
+ "k256",
+ "kem",
+ "rand_core",
+ "zeroize",
+]
+
+[[package]]
 name = "digest"
 version = "0.10.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9ed9a281f7bc9b7576e61468ba615a66a5c8cfdff42420a70aa82701a3b1e292"
 dependencies = [
- "block-buffer",
- "crypto-common",
+ "block-buffer 0.10.4",
+ "crypto-common 0.1.7",
+]
+
+[[package]]
+name = "digest"
+version = "0.11.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4850db49bf08e663084f7fb5c87d202ef91a3907271aff24a94eb97ff039153c"
+dependencies = [
+ "block-buffer 0.12.0",
+ "crypto-common 0.2.1",
+ "ctutils",
 ]
 
 [[package]]
···
 ]
 
 [[package]]
+name = "ecdsa"
+version = "0.17.0-rc.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "91bbdd377139884fafcad8dc43a760a3e1e681aa26db910257fa6535b70e1829"
+dependencies = [
+ "der",
+ "elliptic-curve",
+ "signature",
+ "zeroize",
+]
+
+[[package]]
 name = "either"
 version = "1.15.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "48c757948c5ede0e46177b7add2e67155f70e33c07fea8284df6576da70b3719"
 
 [[package]]
+name = "elliptic-curve"
+version = "0.14.0-rc.29"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e84043d573efd4ac9d2d125817979a379204bf7e328b25a4a30487e8d100e618"
+dependencies = [
+ "base16ct",
+ "crypto-bigint",
+ "crypto-common 0.2.1",
+ "digest 0.11.2",
+ "hkdf",
+ "hybrid-array",
+ "rand_core",
+ "rustcrypto-ff",
+ "rustcrypto-group",
+ "sec1",
+ "subtle",
+ "zeroize",
+]
+
+[[package]]
 name = "embassy-net"
 version = "0.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
···
 
 [[package]]
 name = "embassy-time"
-version = "0.5.0"
+version = "0.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f4fa65b9284d974dad7a23bb72835c4ec85c0b540d86af7fc4098c88cff51d65"
+checksum = "592b0c143ec626e821d4d90da51a2bd91d559d6c442b7c74a47d368c9e23d97a"
 dependencies = [
  "cfg-if",
  "critical-section",
···
 
 [[package]]
 name = "embassy-time-driver"
-version = "0.2.1"
+version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a0a244c7dc22c8d0289379c8d8830cae06bb93d8f990194d0de5efb3b5ae7ba6"
+checksum = "6ee71af1b3a0deaa53eaf2d39252f83504c853646e472400b763060389b9fcc9"
 dependencies = [
  "document-features",
 ]
···
  "cfg-if",
  "libc",
  "r-efi",
+ "rand_core",
  "wasip2",
  "wasip3",
 ]
···
 checksum = "2304e00983f87ffb38b55b444b5e3b60a884b5d30c0fca7d82fe33449bbe55ea"
 
 [[package]]
+name = "hkdf"
+version = "0.13.0-rc.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cbb55385998ae66b8d2d5143c05c94b9025ab863966f0c94ce7a5fde30105092"
+dependencies = [
+ "hmac",
+]
+
+[[package]]
+name = "hmac"
+version = "0.13.0-rc.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "60017b071c523c9e5a55dd1253582bff6150c5e96a7e8511e419de1ab5ee97f9"
+dependencies = [
+ "digest 0.11.2",
+]
+
+[[package]]
 name = "home"
 version = "0.5.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cc627f471c528ff0c4a49e1d5e60450c8f6461dd6d10ba9dcd3a61d3dff7728d"
 dependencies = [
  "windows-sys 0.61.2",
+]
+
+[[package]]
+name = "hybrid-array"
+version = "0.4.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8655f91cd07f2b9d0c24137bd650fe69617773435ee5ec83022377777ce65ef1"
+dependencies = [
+ "subtle",
+ "typenum",
+ "zeroize",
 ]
 
 [[package]]
···
 ]
 
 [[package]]
+name = "inout"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4250ce6452e92010fdf7268ccc5d14faa80bb12fc741938534c58f16804e03c7"
+dependencies = [
+ "hybrid-array",
+]
+
+[[package]]
 name = "io-kit-sys"
 version = "0.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
···
 
 [[package]]
 name = "itoa"
-version = "1.0.17"
+version = "1.0.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "92ecc6618181def0457392ccd0ee51198e065e016d1d527a7ac1b6dc7c1f09d2"
+checksum = "8f42a60cbdf9a97f5d2305f08a87dc4e09308d1276d28c869c684d7777685682"
 
 [[package]]
 name = "jiff"
···
 ]
 
 [[package]]
+name = "k256"
+version = "0.14.0-rc.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f7d2c6c227649d5ec80eaae541f1736232641a0bcdb3062a52b34edb42054158"
+dependencies = [
+ "cpubits",
+ "ecdsa",
+ "elliptic-curve",
+]
+
+[[package]]
+name = "kem"
+version = "0.3.0-rc.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e3ae2c3347ff4a7af4f679a9e397c2c7e6034a00b773dd2dd3c001d7f40897c9"
+dependencies = [
+ "crypto-common 0.2.1",
+ "rand_core",
+]
+
+[[package]]
 name = "leb128fmt"
 version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
···
 
 [[package]]
 name = "libc"
-version = "0.2.182"
+version = "0.2.183"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6800badb6cb2082ffd7b6a67e6125bb39f18782f793520caee8cb8846be06112"
+checksum = "b5b646652bf6661599e1da8901b3b9522896f01e736bad5f723fe7a3a27f899d"
 
 [[package]]
 name = "libm"
···
 
 [[package]]
 name = "once_cell"
-version = "1.21.3"
+version = "1.21.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "42f5e15c9953c5e4ccceeb2e7382a716482c34515315f7b03532b8b4e8393d2d"
+checksum = "9f7c3e4beb33f85d45ae3e3a1792185706c8e16d043238c593331cc7cd313b50"
 
 [[package]]
 name = "owo-colors"
···
 checksum = "89815c69d36021a140146f26659a81d6c2afa33d216d736dd4be5381a7362220"
 dependencies = [
  "pest",
- "sha2",
+ "sha2 0.10.9",
 ]
 
 [[package]]
···
 checksum = "8b870d8c151b6f2fb93e84a13146138f05d02ed11c7e7c54f8826aaaf7c9f184"
 
 [[package]]
+name = "poly1305"
+version = "0.9.0-rc.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "19feddcbdf17fad33f40041c7f9e768faf19455f32a6d52ba1b8b65ffc7b1cae"
+dependencies = [
+ "cpufeatures 0.3.0",
+ "universal-hash",
+]
+
+[[package]]
 name = "portable-atomic"
 version = "1.13.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
···
 
 [[package]]
 name = "portable-atomic-util"
-version = "0.2.5"
+version = "0.2.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7a9db96d7fa8782dd8c15ce32ffe8680bbd1e978a43bf51a34d39483540495f5"
+checksum = "091397be61a01d4be58e7841595bd4bfedb15f1cd54977d79b8271e94ed799a3"
 dependencies = [
  "portable-atomic",
 ]
···
 checksum = "f8dcc9c7d52a811697d2151c701e0d08956f92b0e24136cf4cf27b57a6a0d9bf"
 
 [[package]]
+name = "rand_core"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0c8d0fd677905edcbeedbf2edb6494d676f0e98d54d5cf9bda0b061cb8fb8aba"
+
+[[package]]
 name = "regex"
 version = "1.12.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
···
 checksum = "b50b8869d9fc858ce7266cce0194bd74df58b9d0e3f6df3a9fc8eb470d95c09d"
 
 [[package]]
+name = "rustcrypto-ff"
+version = "0.14.0-rc.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c5db129183b2c139d7d87d08be57cba626c715789db17aec65c8866bfd767d1f"
+dependencies = [
+ "rand_core",
+ "subtle",
+]
+
+[[package]]
+name = "rustcrypto-group"
+version = "0.14.0-rc.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "57c4b1463f274a3ff6fb2f44da43e576cb9424367bd96f185ead87b52fe00523"
+dependencies = [
+ "rand_core",
+ "rustcrypto-ff",
+ "subtle",
+]
+
+[[package]]
 name = "rustix"
 version = "0.38.44"
 source = "registry+https://github.com/rust-lang/crates.io-index"
···
 ]
 
 [[package]]
+name = "sachy-crypto"
+version = "0.1.0"
+dependencies = [
+ "chacha20poly1305",
+ "dhkem",
+ "elliptic-curve",
+ "k256",
+ "sha2 0.11.0-rc.5",
+]
+
+[[package]]
 name = "sachy-esphome"
 version = "0.1.0"
 dependencies = [
···
  "defmt 1.0.1",
  "embassy-time",
  "sachy-fmt",
- "winnow",
+ "winnow 0.7.15",
 ]
 
 [[package]]
···
 checksum = "94143f37725109f92c262ed2cf5e59bce7498c01bcc1502d7b9afe439a4e9f49"
 
 [[package]]
+name = "sec1"
+version = "0.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f46b9a5ab87780a3189a1d704766579517a04ad59de653b7aad7d38e8a15f7dc"
+dependencies = [
+ "base16ct",
+ "ctutils",
+ "der",
+ "hybrid-array",
+ "subtle",
+ "zeroize",
+]
+
+[[package]]
 name = "semver"
 version = "1.0.27"
 source = "registry+https://github.com/rust-lang/crates.io-index"
···
 
 [[package]]
 name = "serialport"
-version = "4.7.3"
+version = "4.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2acaf3f973e8616d7ceac415f53fc60e190b2a686fbcf8d27d0256c741c5007b"
+checksum = "a4d91116f97173694f1642263b2ff837f80d933aa837e2314969f6728f661df3"
 dependencies = [
  "bitflags 2.11.0",
  "cfg-if",
···
  "nix 0.26.4",
  "scopeguard",
  "unescaper",
- "winapi",
+ "windows-sys 0.52.0",
 ]
 
 [[package]]
···
 checksum = "a7507d819769d01a365ab707794a4084392c824f54a7a6a7862f8c3d0892b283"
 dependencies = [
  "cfg-if",
- "cpufeatures",
- "digest",
+ "cpufeatures 0.2.17",
+ "digest 0.10.7",
+]
+
+[[package]]
+name = "sha2"
+version = "0.11.0-rc.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7c5f3b1e2dc8aad28310d8410bd4d7e180eca65fca176c52ab00d364475d0024"
+dependencies = [
+ "cfg-if",
+ "cpufeatures 0.2.17",
+ "digest 0.11.2",
 ]
 
 [[package]]
···
 version = "1.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0fda2ff0d084019ba4d7c6f371c95d8fd75ce3524c3cb8fb653a3023f6323e64"
+
+[[package]]
+name = "signature"
+version = "3.0.0-rc.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7f1880df446116126965eeec169136b2e0251dba37c6223bcc819569550edea3"
+dependencies = [
+ "rand_core",
+]
 
 [[package]]
 name = "smoltcp"
···
 checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
 
 [[package]]
+name = "subtle"
+version = "2.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "13c2bddecc57b384dee18652358fb23172facb8a2c51ccc10d74c157bdea3292"
+
+[[package]]
 name = "supports-color"
 version = "3.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
···
 
 [[package]]
 name = "tempfile"
-version = "3.26.0"
+version = "3.27.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "82a72c767771b47409d2345987fda8628641887d5466101319899796367354a0"
+checksum = "32497e9a4c7b38532efcdebeef879707aa9f794296a4f0244f6f69e9bc8574bd"
 dependencies = [
  "fastrand",
  "getrandom",
···
 
 [[package]]
 name = "terminal_size"
-version = "0.4.3"
+version = "0.4.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "60b8cb979cb11c32ce1603f8137b22262a9d131aaa5c37b5678025f22b8becd0"
+checksum = "230a1b821ccbd75b185820a1f1ff7b14d21da1e442e22c0863ea5f08771a8874"
 dependencies = [
  "rustix 1.1.4",
- "windows-sys 0.60.2",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
···
 
 [[package]]
 name = "toml_datetime"
-version = "1.0.0+spec-1.1.0"
+version = "1.1.0+spec-1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "32c2555c699578a4f59f0cc68e5116c8d7cabbd45e1409b989d4be085b53f13e"
+checksum = "97251a7c317e03ad83774a8752a7e81fb6067740609f75ea2b585b569a59198f"
 dependencies = [
  "serde_core",
 ]
 
 [[package]]
 name = "toml_edit"
-version = "0.25.4+spec-1.1.0"
+version = "0.25.8+spec-1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7193cbd0ce53dc966037f54351dbbcf0d5a642c7f0038c382ef9e677ce8c13f2"
+checksum = "16bff38f1d86c47f9ff0647e6838d7bb362522bdf44006c7068c2b1e606f1f3c"
 dependencies = [
  "indexmap",
  "toml_datetime",
  "toml_parser",
  "toml_writer",
- "winnow",
+ "winnow 1.0.0",
 ]
 
 [[package]]
 name = "toml_parser"
-version = "1.0.9+spec-1.1.0"
+version = "1.1.0+spec-1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "702d4415e08923e7e1ef96cd5727c0dfed80b4d2fa25db9647fe5eb6f7c5a4c4"
+checksum = "2334f11ee363607eb04df9b8fc8a13ca1715a72ba8662a26ac285c98aabb4011"
 dependencies = [
- "winnow",
+ "winnow 1.0.0",
 ]
 
 [[package]]
 name = "toml_writer"
-version = "1.0.6+spec-1.1.0"
+version = "1.1.0+spec-1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ab16f14aed21ee8bfd8ec22513f7287cd4a91aa92e44edfe2c17ddd004e92607"
+checksum = "d282ade6016312faf3e41e57ebbba0c073e4056dab1232ab1cb624199648f8ed"
 
 [[package]]
 name = "typenum"
···
 version = "0.2.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ebc1c04c71510c7f702b52b7c350734c9ff1295c464a03335b00bb84fc54f853"
+
+[[package]]
+name = "universal-hash"
+version = "0.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f4987bdc12753382e0bec4a65c50738ffaabc998b9cdd1f952fb5f39b0048a96"
+dependencies = [
+ "crypto-common 0.2.1",
+ "ctutils",
+]
 
 [[package]]
 name = "version_check"
···
 ]
 
 [[package]]
-name = "winapi"
-version = "0.3.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5c839a674fcd7a98952e593242ea400abe93992746761e38641405d28b00f419"
-dependencies = [
- "winapi-i686-pc-windows-gnu",
- "winapi-x86_64-pc-windows-gnu",
-]
-
-[[package]]
-name = "winapi-i686-pc-windows-gnu"
-version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ac3b87c63620426dd9b991e5ce0329eff545bccbbb34f3be09ff6fb6ab51b7b6"
-
-[[package]]
-name = "winapi-x86_64-pc-windows-gnu"
-version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
-
-[[package]]
 name = "windows-link"
 version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
···
 
 [[package]]
 name = "windows-sys"
-version = "0.59.0"
+version = "0.52.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1e38bc4d79ed67fd075bcc251a1c39b32a1776bbe92e5bef1f0bf1f8c531853b"
+checksum = "282be5f36a8ce781fad8c8ae18fa3f9beff57ec1b52cb3de0789201425d9a33d"
 dependencies = [
- "windows-targets 0.52.6",
+ "windows-targets",
 ]
 
 [[package]]
 name = "windows-sys"
-version = "0.60.2"
+version = "0.59.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f2f500e4d28234f72040990ec9d39e3a6b950f9f22d3dba18416c35882612bcb"
+checksum = "1e38bc4d79ed67fd075bcc251a1c39b32a1776bbe92e5bef1f0bf1f8c531853b"
 dependencies = [
- "windows-targets 0.53.5",
+ "windows-targets",
 ]
 
 [[package]]
···
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9b724f72796e036ab90c1021d4780d4d3d648aca59e491e6b98e725b84e99973"
 dependencies = [
- "windows_aarch64_gnullvm 0.52.6",
- "windows_aarch64_msvc 0.52.6",
- "windows_i686_gnu 0.52.6",
- "windows_i686_gnullvm 0.52.6",
- "windows_i686_msvc 0.52.6",
- "windows_x86_64_gnu 0.52.6",
- "windows_x86_64_gnullvm 0.52.6",
- "windows_x86_64_msvc 0.52.6",
-]
-
-[[package]]
-name = "windows-targets"
-version = "0.53.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4945f9f551b88e0d65f3db0bc25c33b8acea4d9e41163edf90dcd0b19f9069f3"
-dependencies = [
- "windows-link",
- "windows_aarch64_gnullvm 0.53.1",
- "windows_aarch64_msvc 0.53.1",
- "windows_i686_gnu 0.53.1",
- "windows_i686_gnullvm 0.53.1",
- "windows_i686_msvc 0.53.1",
- "windows_x86_64_gnu 0.53.1",
- "windows_x86_64_gnullvm 0.53.1",
- "windows_x86_64_msvc 0.53.1",
+ "windows_aarch64_gnullvm",
+ "windows_aarch64_msvc",
+ "windows_i686_gnu",
+ "windows_i686_gnullvm",
+ "windows_i686_msvc",
+ "windows_x86_64_gnu",
+ "windows_x86_64_gnullvm",
+ "windows_x86_64_msvc",
 ]
 
 [[package]]
···
 checksum = "32a4622180e7a0ec044bb555404c800bc9fd9ec262ec147edd5989ccd0c02cd3"
 
 [[package]]
-name = "windows_aarch64_gnullvm"
-version = "0.53.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a9d8416fa8b42f5c947f8482c43e7d89e73a173cead56d044f6a56104a6d1b53"
-
-[[package]]
 name = "windows_aarch64_msvc"
 version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "09ec2a7bb152e2252b53fa7803150007879548bc709c039df7627cabbd05d469"
 
 [[package]]
-name = "windows_aarch64_msvc"
-version = "0.53.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b9d782e804c2f632e395708e99a94275910eb9100b2114651e04744e9b125006"
-
-[[package]]
 name = "windows_i686_gnu"
 version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8e9b5ad5ab802e97eb8e295ac6720e509ee4c243f69d781394014ebfe8bbfa0b"
 
 [[package]]
-name = "windows_i686_gnu"
-version = "0.53.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "960e6da069d81e09becb0ca57a65220ddff016ff2d6af6a223cf372a506593a3"
-
-[[package]]
 name = "windows_i686_gnullvm"
 version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0eee52d38c090b3caa76c563b86c3a4bd71ef1a819287c19d586d7334ae8ed66"
-
-[[package]]
-name = "windows_i686_gnullvm"
-version = "0.53.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fa7359d10048f68ab8b09fa71c3daccfb0e9b559aed648a8f95469c27057180c"
 
 [[package]]
 name = "windows_i686_msvc"
···
 checksum = "240948bc05c5e7c6dabba28bf89d89ffce3e303022809e73deaefe4f6ec56c66"
 
 [[package]]
-name = "windows_i686_msvc"
-version = "0.53.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1e7ac75179f18232fe9c285163565a57ef8d3c89254a30685b57d83a38d326c2"
-
-[[package]]
 name = "windows_x86_64_gnu"
 version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "147a5c80aabfbf0c7d901cb5895d1de30ef2907eb21fbbab29ca94c5b08b1a78"
 
 [[package]]
-name = "windows_x86_64_gnu"
-version = "0.53.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9c3842cdd74a865a8066ab39c8a7a473c0778a3f29370b5fd6b4b9aa7df4a499"
-
-[[package]]
 name = "windows_x86_64_gnullvm"
 version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "24d5b23dc417412679681396f2b49f3de8c1473deb516bd34410872eff51ed0d"
 
 [[package]]
-name = "windows_x86_64_gnullvm"
-version = "0.53.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0ffa179e2d07eee8ad8f57493436566c7cc30ac536a3379fdf008f47f6bb7ae1"
-
-[[package]]
 name = "windows_x86_64_msvc"
 version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "589f6da84c646204747d1270a2a5661ea66ed1cced2631d546fdfb155959f9ec"
 
 [[package]]
-name = "windows_x86_64_msvc"
-version = "0.53.1"
+name = "winnow"
+version = "0.7.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d6bbff5f0aada427a1e5a6da5f1f98158182f26556f345ac9e04d36d0ebed650"
+checksum = "df79d97927682d2fd8adb29682d1140b343be4ac0f08fd68b7765d9c059d3945"
 
 [[package]]
 name = "winnow"
-version = "0.7.14"
+version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5a5364e9d77fcdeeaa6062ced926ee3381faa2ee02d3eb83a5c27a8825540829"
+checksum = "a90e88e4667264a994d34e6d1ab2d26d398dcdca8b7f52bec8668957517fc7d8"
 dependencies = [
  "memchr",
 ]
···
  "unicode-xid",
  "wasmparser",
 ]
+
+[[package]]
+name = "zeroize"
+version = "1.8.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b97154e67e32c85465826e8bcc1c59429aaaf107c1e4a9e53c8d8ccd5eff88d0"
 
 [[package]]
 name = "zmij"

Cargo.toml

···
     "sachy-battery",
     "sachy-bthome",
     "sachy-config",
+    "sachy-crypto",
     "sachy-esphome",
     "sachy-fmt",
     "sachy-fnv",
···
 embassy-sync = { version = "0.7" }
 embassy-net = { version = "0.7" }
 defmt = { version = "1" }
+
+[patch.crates-io]
+dhkem = { git = "https://github.com/RustCrypto/KEMs", rev = "2d277162e0c5ed1c53bb315d0c0dace394cba70a" }

sachy-crypto/Cargo.toml

···
+[package]
+name = "sachy-crypto"
+authors.workspace = true
+edition.workspace = true
+repository.workspace = true
+license.workspace = true
+version.workspace = true
+rust-version.workspace = true
+
+[dependencies]
+chacha20poly1305 = { version = "=0.11.0-rc.3", default-features = false, features = ["getrandom", "alloc"] }
+k256 = { version = "=0.14.0-rc.8", default-features = false, features = ["ecdh", "getrandom"] }
+sha2 = { version = "=0.11.0-rc.5", default-features = false, features = [] }
+dhkem = { version = "0.1.0-rc.0", features = ["getrandom", "k256"] }
+elliptic-curve = { version = "0.14.0-rc.28", default-features = false, features = ["ecdh"] }

sachy-crypto/README.md

···
+# Sachy's Crypto
+
+A custom rolled encryption scheme that more or less implements HPKE.
+
+☢️ **WARNING: DO NOT USE IN PRODUCTION. THIS CRATE IS FOR LEARNING/PERSONAL USAGE. AAAAAAAAAA** ☢️

sachy-crypto/src/lib.rs

···
+#![no_std]
+
+use core::ops::{AddAssign, BitXor};
+
+use chacha20poly1305::{
+    AeadInOut, ChaCha20Poly1305, KeyInit,
+    aead::{self, Buffer},
+};
+use dhkem::{
+    Encapsulate, Kem, Secp256k1DecapsulationKey, Secp256k1EncapsulationKey, Secp256k1Kem,
+    TryDecapsulate,
+    kem::{Ciphertext, SharedKey},
+};
+use elliptic_curve::sec1::{FromSec1Point, ToSec1Point};
+use k256::{Sec1Point, ecdh::SharedSecret, elliptic_curve::subtle::ConstantTimeEq};
+
+extern crate alloc;
+
+/// Error type.
+///
+/// This type is deliberately opaque as to avoid potential side-channel
+/// leakage (e.g. padding oracle).
+#[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
+pub struct ProtoError;
+
+impl core::fmt::Display for ProtoError {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        f.write_str("ProtoError")
+    }
+}
+
+impl core::error::Error for ProtoError {}
+
+impl From<chacha20poly1305::Error> for ProtoError {
+    fn from(_value: chacha20poly1305::Error) -> Self {
+        Self
+    }
+}
+
+pub struct ClientHandshake(Secp256k1DecapsulationKey);
+
+pub struct EncapsulatedPublicKey(Secp256k1EncapsulationKey);
+
+#[derive(Debug, PartialEq, Eq, Clone, Copy)]
+pub enum Role {
+    Client,
+    Server,
+}
+
+impl From<Role> for u8 {
+    fn from(value: Role) -> Self {
+        match value {
+            Role::Client => 0,
+            Role::Server => 1,
+        }
+    }
+}
+
+impl BitXor for Role {
+    type Output = u8;
+
+    fn bitxor(self, rhs: Self) -> u8 {
+        u8::from(self) ^ u8::from(rhs)
+    }
+}
+
+impl EncapsulatedPublicKey {
+    pub fn serialize(&self) -> Sec1Point {
+        self.0.to_sec1_point(true)
+    }
+
+    pub fn deserialize(buf: &[u8]) -> Result<Self, ProtoError> {
+        Ok(Self(
+            Secp256k1EncapsulationKey::from_sec1_bytes(buf).map_err(|_| ProtoError)?,
+        ))
+    }
+
+    pub fn encapsulate(&self) -> (Ciphertext<Secp256k1Kem>, SharedKey<Secp256k1Kem>) {
+        self.0.encapsulate()
+    }
+}
+
+impl ClientHandshake {
+    pub fn send() -> (EncapsulatedPublicKey, Self) {
+        let (decap, encap) = Secp256k1Kem::generate_keypair();
+
+        (EncapsulatedPublicKey(encap), Self(decap))
+    }
+
+    pub fn finish(self, ciphertext: &[u8], psk: &[u8; 32]) -> Result<TransportState, ProtoError> {
+        let shared = self
+            .0
+            .try_decapsulate_slice(ciphertext)
+            .map_err(|_| ProtoError)?;
+
+        TransportState::init(psk, shared, Role::Client)
+    }
+}
+
+pub struct ServerHandshake(SharedKey<Secp256k1Kem>);
+
+impl ServerHandshake {
+    pub fn receive(buf: &[u8]) -> Result<(Ciphertext<Secp256k1Kem>, Self), ProtoError> {
+        let encap = EncapsulatedPublicKey::deserialize(buf)?;
+
+        let (ciphertext, sk) = encap.encapsulate();
+
+        Ok((ciphertext, Self(sk)))
+    }
+
+    pub fn finish(self, psk: &[u8; 32]) -> Result<TransportState, ProtoError> {
+        TransportState::init(psk, self.0, Role::Server)
+    }
+}
+
+/// Low-level Transport implementation.
+///
+/// This trait provides a particular "flavor" of transport, as there are
+/// different ways the specifics of the construction can be implemented.
+pub trait TransportPrimitive<A>
+where
+    A: AeadInOut,
+{
+    /// Type used as the Trasnport counter.
+    type Counter: AddAssign + Copy + Default + Eq;
+
+    /// Value to use when incrementing the Transport counter (i.e. one)
+    const COUNTER_INCR: Self::Counter;
+
+    /// Maximum number of messages allowed to be sent via Transport
+    const COUNTER_MAX: Self::Counter;
+
+    /// Encrypt an AEAD message in-place at the given position in the Transport.
+    fn encrypt_in_place(
+        &self,
+        nonce: &aead::Nonce<A>,
+        associated_data: &[u8],
+        buffer: &mut dyn Buffer,
+    ) -> Result<(), ProtoError>;
+
+    /// Decrypt an AEAD message in-place at the given position in the Transport.
+    fn decrypt_in_place(
+        &self,
+        nonce: &aead::Nonce<A>,
+        associated_data: &[u8],
+        buffer: &mut dyn Buffer,
+    ) -> Result<(), ProtoError>;
+}
+
+pub struct SendingState<'a> {
+    transport: &'a TransportState,
+    counter: u64,
+}
+
+impl SendingState<'_> {
+    pub fn encrypt(&mut self, msg: &mut alloc::vec::Vec<u8>) -> Result<(), ProtoError> {
+        let counter = self.counter.to_be_bytes();
+
+        self.transport.encrypt_in_place(
+            &self.transport.mix_nonce(&counter, Role::Client),
+            &counter,
+            msg,
+        )?;
+
+        self.counter = self.counter.wrapping_add(TransportState::COUNTER_INCR);
+
+        // If we wrapped around and equal the finish value, we have maxed out the amount of
+        // messages we can send.
+        if self.counter.ct_eq(&TransportState::COUNTER_MAX).into() {
+            Err(ProtoError)
+        } else {
+            Ok(())
+        }
+    }
+}
+
+pub struct ReceivingState<'a> {
+    transport: &'a TransportState,
+    counter: u64,
+}
+
+impl ReceivingState<'_> {
+    pub fn decrypt(&mut self, msg: &mut alloc::vec::Vec<u8>) -> Result<(), ProtoError> {
+        let counter = self.counter.to_be_bytes();
+
+        self.transport.decrypt_in_place(
+            &self.transport.mix_nonce(&counter, Role::Server),
+            &counter,
+            msg,
+        )?;
+
+        self.counter = self.counter.wrapping_add(TransportState::COUNTER_INCR);
+
+        // If we wrapped around and equal the finish value, we have maxed out the amount of
+        // messages we can send.
+        if self.counter.ct_eq(&TransportState::COUNTER_MAX).into() {
+            Err(ProtoError)
+        } else {
+            Ok(())
+        }
+    }
+}
+
+impl TransportPrimitive<ChaCha20Poly1305> for TransportState {
+    type Counter = u64;
+
+    const COUNTER_INCR: Self::Counter = 1;
+
+    const COUNTER_MAX: Self::Counter = u64::MAX;
+
+    fn encrypt_in_place(
+        &self,
+        epstein: &aead::Nonce<ChaCha20Poly1305>,
+        associated_data: &[u8],
+        buffer: &mut dyn Buffer,
+    ) -> Result<(), ProtoError> {
+        self.aead
+            .encrypt_in_place(epstein, associated_data, buffer)?;
+        Ok(())
+    }
+
+    fn decrypt_in_place(
+        &self,
+        epstein: &aead::Nonce<ChaCha20Poly1305>,
+        associated_data: &[u8],
+        buffer: &mut dyn Buffer,
+    ) -> Result<(), ProtoError> {
+        self.aead
+            .decrypt_in_place(epstein, associated_data, buffer)?;
+        Ok(())
+    }
+}
+
+#[repr(align(4))]
+pub struct TransportState {
+    aead: ChaCha20Poly1305,
+    first: aead::Nonce<ChaCha20Poly1305>,
+    second: aead::Nonce<ChaCha20Poly1305>,
+    role: Role,
+}
+
+impl TransportState {
+    pub fn init(
+        psk: &[u8; 32],
+        shared: impl Into<SharedSecret>,
+        role: Role,
+    ) -> Result<Self, ProtoError> {
+        let noncer = shared.into();
+        let kdf = noncer.extract::<sha2::Sha256>(Some(psk));
+
+        let mut key = [0u8; 32];
+
+        let mut first = aead::Nonce::<ChaCha20Poly1305>::default();
+        let mut second = aead::Nonce::<ChaCha20Poly1305>::default();
+
+        kdf.expand(b"SachY-Crypt0", &mut key)
+            .map_err(|_| ProtoError)?;
+
+        kdf.expand(b"N*nceOne", &mut first)
+            .map_err(|_| ProtoError)?;
+        kdf.expand(b"N#nceTwo", &mut second)
+            .map_err(|_| ProtoError)?;
+
+        Ok(Self {
+            aead: ChaCha20Poly1305::new(&key.into()),
+            first,
+            second,
+            role,
+        })
+    }
+
+    pub fn split(&self) -> (SendingState<'_>, ReceivingState<'_>) {
+        (
+            SendingState {
+                transport: self,
+                counter: 0,
+            },
+            ReceivingState {
+                transport: self,
+                counter: 0,
+            },
+        )
+    }
+
+    fn mix_nonce(&self, position: &[u8; 8], send: Role) -> aead::Nonce<ChaCha20Poly1305> {
+        let mut trump = aead::Nonce::<ChaCha20Poly1305>::default();
+
+        let context_select = self.role ^ send;
+
+        // Role switch allows toggling which nonce to use for encrypting/decrypting
+        // Callee ROLE XOR Transport ROLE selects either one or other nonce context,
+        // (0) for first context, (1) for second context
+        // Sending:   Client ^ Client = 0 (select first)
+        // Receiving: Server ^ Server = 0 (select first)
+        // Sending:   Server ^ Client = 1 (select second)
+        // Receiving: Client ^ Server = 1 (select second)
+        let epstein = if context_select.ct_eq(&0).into() {
+            &self.first
+        } else {
+            &self.second
+        };
+
+        let (head, tail) = trump.split_at_mut(position.len());
+        let (first, second) = epstein.split_at(position.len());
+
+        // XOR the base nonce with position bytes, copying them to the output nonce
+        head.iter_mut()
+            .zip(first)
+            .zip(position)
+            .for_each(|((head, ep), pos)| *head = ep ^ pos);
+
+        // Copy rest of base nonce into output nonce
+        tail.iter_mut()
+            .zip(second)
+            .for_each(|(tail, ep)| *tail = *ep);
+
+        trump
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use alloc::vec;
+    use dhkem::Generate;
+    use elliptic_curve::array::Array;
+
+    use super::*;
+
+    #[test]
+    fn handshake_protocol_works() -> Result<(), ProtoError> {
+        let psk: [u8; 32] = [
+            31, 48, 29, 177, 88, 236, 186, 84, 65, 51, 214, 243, 174, 24, 45, 101, 229, 129, 62,
+            132, 45, 174, 183, 65, 89, 73, 107, 177, 77, 90, 164, 251,
+        ];
+
+        let (ek, client) = ClientHandshake::send();
+
+        // Pretend to send ek across the webz: client -> server
+        let (ciphertext, server) = ServerHandshake::receive(ek.serialize().as_bytes())?;
+
+        // Pretend to send ciphertext across the webz: server -> client
+        let alice = client.finish(&ciphertext, &psk)?;
+        let bob = server.finish(&psk)?;
+
+        let nonce = aead::Nonce::<ChaCha20Poly1305>::generate();
+
+        let mut buffer1 = vec![0u8; 64];
+        let mut buffer2 = vec![0u8; 64];
+
+        // Using the same nonce to check that the internal AEAD states match. Normally, client/server
+        // would work with unique derived nonces, because nonce reuse is BAD
+        alice.aead.encrypt_in_place(&nonce, &[], &mut buffer1)?;
+        bob.aead.encrypt_in_place(&nonce, &[], &mut buffer2)?;
+
+        // If the nonces match, then we can assume the rest of the internal state is the same too
+        // so the outputs should match each other
+        assert_eq!(&buffer1, &buffer2);
+
+        // Both Transports have derived base nonces for each context.
+        // First context nonces will not match Second context nonces.
+        assert_eq!(alice.first, bob.first);
+        assert_eq!(alice.second, bob.second);
+        assert_ne!(alice.first, alice.second);
+        assert_ne!(bob.first, bob.second);
+
+        Ok(())
+    }
+
+    #[test]
+    fn two_way_transport_sync_works() -> Result<(), ProtoError> {
+        let shared_secret = [
+            0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d,
+            0x8e, 0x8f, 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b,
+            0x9c, 0x9d, 0x9e, 0x9f,
+        ];
+
+        let psk: [u8; 32] = [
+            31, 48, 29, 177, 88, 236, 186, 84, 65, 51, 214, 243, 174, 24, 45, 101, 229, 129, 62,
+            132, 45, 174, 183, 65, 89, 73, 107, 177, 77, 90, 164, 251,
+        ];
+
+        let alice = TransportState::init(&psk, Array(shared_secret), Role::Client)?;
+        let bob = TransportState::init(&psk, Array(shared_secret), Role::Server)?;
+
+        let (mut alice_send, mut alice_recv) = alice.split();
+        let (mut bob_send, mut bob_recv) = bob.split();
+
+        let orig = b"Test Message, Please ignore.";
+
+        let mut msg = orig.to_vec();
+
+        // a -> b
+        alice_send.encrypt(&mut msg)?;
+
+        assert_ne!(orig.as_slice(), msg.as_slice());
+        let ct1 = msg.clone();
+
+        bob_recv.decrypt(&mut msg)?;
+
+        // a -> b
+        alice_send.encrypt(&mut msg)?;
+
+        assert_ne!(msg.as_slice(), ct1.as_slice());
+        let ct2 = msg.clone();
+
+        bob_recv.decrypt(&mut msg)?;
+
+        // b -> a
+        bob_send.encrypt(&mut msg)?;
+
+        // None of the ciphertexts should match each other
+        assert_ne!(msg.as_slice(), ct1.as_slice());
+        assert_ne!(msg.as_slice(), ct2.as_slice());
+        assert_ne!(ct1.as_slice(), ct2.as_slice());
+
+        alice_recv.decrypt(&mut msg)?;
+
+        assert_eq!(orig.as_slice(), msg.as_slice());
+
+        // Counters are tracked from sender to receiver
+        assert_eq!(alice_send.counter, bob_recv.counter);
+        assert_eq!(bob_send.counter, alice_recv.counter);
+
+        // Counters are not linked on the same side
+        assert_ne!(alice_send.counter, alice_recv.counter);
+        assert_ne!(bob_send.counter, bob_recv.counter);
+
+        Ok(())
+    }
+}