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Diffstat (limited to 'security/nss/lib/freebl/verified/specs/Spec.Chacha20.fst')
| -rw-r--r-- | security/nss/lib/freebl/verified/specs/Spec.Chacha20.fst | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/security/nss/lib/freebl/verified/specs/Spec.Chacha20.fst b/security/nss/lib/freebl/verified/specs/Spec.Chacha20.fst new file mode 100644 index 000000000..0bdc69725 --- /dev/null +++ b/security/nss/lib/freebl/verified/specs/Spec.Chacha20.fst @@ -0,0 +1,169 @@ +/* Copyright 2016-2017 INRIA and Microsoft Corporation + * + * 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. + */ + +module Spec.Chacha20 + +module ST = FStar.HyperStack.ST + +open FStar.Mul +open FStar.Seq +open FStar.UInt32 +open FStar.Endianness +open Spec.Lib +open Spec.Chacha20.Lemmas +open Seq.Create + +#set-options "--max_fuel 0 --z3rlimit 100" + +(* Constants *) +let keylen = 32 (* in bytes *) +let blocklen = 64 (* in bytes *) +let noncelen = 12 (* in bytes *) + +type key = lbytes keylen +type block = lbytes blocklen +type nonce = lbytes noncelen +type counter = UInt.uint_t 32 + +// using @ as a functional substitute for ; +// internally, blocks are represented as 16 x 4-byte integers +type state = m:seq UInt32.t {length m = 16} +type idx = n:nat{n < 16} +type shuffle = state -> Tot state + +let line (a:idx) (b:idx) (d:idx) (s:t{0 < v s /\ v s < 32}) (m:state) : Tot state = + let m = m.[a] <- (m.[a] +%^ m.[b]) in + let m = m.[d] <- ((m.[d] ^^ m.[a]) <<< s) in m + +let quarter_round a b c d : shuffle = + line a b d 16ul @ + line c d b 12ul @ + line a b d 8ul @ + line c d b 7ul + +let column_round : shuffle = + quarter_round 0 4 8 12 @ + quarter_round 1 5 9 13 @ + quarter_round 2 6 10 14 @ + quarter_round 3 7 11 15 + +let diagonal_round : shuffle = + quarter_round 0 5 10 15 @ + quarter_round 1 6 11 12 @ + quarter_round 2 7 8 13 @ + quarter_round 3 4 9 14 + +let double_round: shuffle = + column_round @ diagonal_round (* 2 rounds *) + +let rounds : shuffle = + iter 10 double_round (* 20 rounds *) + +let chacha20_core (s:state) : Tot state = + let s' = rounds s in + Spec.Loops.seq_map2 (fun x y -> x +%^ y) s' s + +(* state initialization *) +let c0 = 0x61707865ul +let c1 = 0x3320646eul +let c2 = 0x79622d32ul +let c3 = 0x6b206574ul + +let setup (k:key) (n:nonce) (c:counter): Tot state = + create_4 c0 c1 c2 c3 @| + uint32s_from_le 8 k @| + create_1 (UInt32.uint_to_t c) @| + uint32s_from_le 3 n + +let chacha20_block (k:key) (n:nonce) (c:counter): Tot block = + let st = setup k n c in + let st' = chacha20_core st in + uint32s_to_le 16 st' + +let chacha20_ctx: Spec.CTR.block_cipher_ctx = + let open Spec.CTR in + { + keylen = keylen; + blocklen = blocklen; + noncelen = noncelen; + counterbits = 32; + incr = 1 + } + +let chacha20_cipher: Spec.CTR.block_cipher chacha20_ctx = chacha20_block + +let chacha20_encrypt_bytes key nonce counter m = + Spec.CTR.counter_mode chacha20_ctx chacha20_cipher key nonce counter m + + +unfold let test_plaintext = [ + 0x4cuy; 0x61uy; 0x64uy; 0x69uy; 0x65uy; 0x73uy; 0x20uy; 0x61uy; + 0x6euy; 0x64uy; 0x20uy; 0x47uy; 0x65uy; 0x6euy; 0x74uy; 0x6cuy; + 0x65uy; 0x6duy; 0x65uy; 0x6euy; 0x20uy; 0x6fuy; 0x66uy; 0x20uy; + 0x74uy; 0x68uy; 0x65uy; 0x20uy; 0x63uy; 0x6cuy; 0x61uy; 0x73uy; + 0x73uy; 0x20uy; 0x6fuy; 0x66uy; 0x20uy; 0x27uy; 0x39uy; 0x39uy; + 0x3auy; 0x20uy; 0x49uy; 0x66uy; 0x20uy; 0x49uy; 0x20uy; 0x63uy; + 0x6fuy; 0x75uy; 0x6cuy; 0x64uy; 0x20uy; 0x6fuy; 0x66uy; 0x66uy; + 0x65uy; 0x72uy; 0x20uy; 0x79uy; 0x6fuy; 0x75uy; 0x20uy; 0x6fuy; + 0x6euy; 0x6cuy; 0x79uy; 0x20uy; 0x6fuy; 0x6euy; 0x65uy; 0x20uy; + 0x74uy; 0x69uy; 0x70uy; 0x20uy; 0x66uy; 0x6fuy; 0x72uy; 0x20uy; + 0x74uy; 0x68uy; 0x65uy; 0x20uy; 0x66uy; 0x75uy; 0x74uy; 0x75uy; + 0x72uy; 0x65uy; 0x2cuy; 0x20uy; 0x73uy; 0x75uy; 0x6euy; 0x73uy; + 0x63uy; 0x72uy; 0x65uy; 0x65uy; 0x6euy; 0x20uy; 0x77uy; 0x6fuy; + 0x75uy; 0x6cuy; 0x64uy; 0x20uy; 0x62uy; 0x65uy; 0x20uy; 0x69uy; + 0x74uy; 0x2euy +] + +unfold let test_ciphertext = [ + 0x6euy; 0x2euy; 0x35uy; 0x9auy; 0x25uy; 0x68uy; 0xf9uy; 0x80uy; + 0x41uy; 0xbauy; 0x07uy; 0x28uy; 0xdduy; 0x0duy; 0x69uy; 0x81uy; + 0xe9uy; 0x7euy; 0x7auy; 0xecuy; 0x1duy; 0x43uy; 0x60uy; 0xc2uy; + 0x0auy; 0x27uy; 0xafuy; 0xccuy; 0xfduy; 0x9fuy; 0xaeuy; 0x0buy; + 0xf9uy; 0x1buy; 0x65uy; 0xc5uy; 0x52uy; 0x47uy; 0x33uy; 0xabuy; + 0x8fuy; 0x59uy; 0x3duy; 0xabuy; 0xcduy; 0x62uy; 0xb3uy; 0x57uy; + 0x16uy; 0x39uy; 0xd6uy; 0x24uy; 0xe6uy; 0x51uy; 0x52uy; 0xabuy; + 0x8fuy; 0x53uy; 0x0cuy; 0x35uy; 0x9fuy; 0x08uy; 0x61uy; 0xd8uy; + 0x07uy; 0xcauy; 0x0duy; 0xbfuy; 0x50uy; 0x0duy; 0x6auy; 0x61uy; + 0x56uy; 0xa3uy; 0x8euy; 0x08uy; 0x8auy; 0x22uy; 0xb6uy; 0x5euy; + 0x52uy; 0xbcuy; 0x51uy; 0x4duy; 0x16uy; 0xccuy; 0xf8uy; 0x06uy; + 0x81uy; 0x8cuy; 0xe9uy; 0x1auy; 0xb7uy; 0x79uy; 0x37uy; 0x36uy; + 0x5auy; 0xf9uy; 0x0buy; 0xbfuy; 0x74uy; 0xa3uy; 0x5buy; 0xe6uy; + 0xb4uy; 0x0buy; 0x8euy; 0xeduy; 0xf2uy; 0x78uy; 0x5euy; 0x42uy; + 0x87uy; 0x4duy +] + +unfold let test_key = [ + 0uy; 1uy; 2uy; 3uy; 4uy; 5uy; 6uy; 7uy; + 8uy; 9uy; 10uy; 11uy; 12uy; 13uy; 14uy; 15uy; + 16uy; 17uy; 18uy; 19uy; 20uy; 21uy; 22uy; 23uy; + 24uy; 25uy; 26uy; 27uy; 28uy; 29uy; 30uy; 31uy + ] +unfold let test_nonce = [ + 0uy; 0uy; 0uy; 0uy; 0uy; 0uy; 0uy; 0x4auy; 0uy; 0uy; 0uy; 0uy + ] + +unfold let test_counter = 1 + +let test() = + assert_norm(List.Tot.length test_plaintext = 114); + assert_norm(List.Tot.length test_ciphertext = 114); + assert_norm(List.Tot.length test_key = 32); + assert_norm(List.Tot.length test_nonce = 12); + let test_plaintext = createL test_plaintext in + let test_ciphertext = createL test_ciphertext in + let test_key = createL test_key in + let test_nonce = createL test_nonce in + chacha20_encrypt_bytes test_key test_nonce test_counter test_plaintext + = test_ciphertext |