mirror of https://github.com/waku-org/nwaku.git
95 lines
2.9 KiB
Nim
95 lines
2.9 KiB
Nim
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# Waku Noise Protocols for Waku Payload Encryption
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## See spec for more details:
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## https://github.com/vacp2p/rfc/tree/master/content/docs/rfcs/35
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##
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## Implementation partially inspired by noise-libp2p:
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## https://github.com/status-im/nim-libp2p/blob/master/libp2p/protocols/secure/noise.nim
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{.push raises: [Defect].}
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import std/[oids, options]
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import chronos
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import chronicles
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import bearssl
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import nimcrypto/[utils, sha2, hmac]
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import libp2p/stream/[connection]
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import libp2p/protobuf/minprotobuf
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import libp2p/utility
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import libp2p/errors
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import libp2p/crypto/[crypto, chacha20poly1305]
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logScope:
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topics = "wakunoise"
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const
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# EmptyKey is a special value which indicates a ChaChaPolyKey has not yet been initialized.
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EmptyKey = default(ChaChaPolyKey)
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type
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ChaChaPolyCiphertext* = object
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data: seq[byte]
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tag: ChaChaPolyTag
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ChaChaPolyCipherState* = object
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k*: ChaChaPolyKey
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nonce*: ChaChaPolyNonce
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ad*: seq[byte]
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NoiseError* = object of LPError
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NoiseDecryptTagError* = object of NoiseError
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#################################################################
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# Utilities
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# Generates random byte sequences of given size
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proc randomSeqByte*(rng: var BrHmacDrbgContext, size: uint32): seq[byte] =
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var output = newSeq[byte](size)
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brHmacDrbgGenerate(rng, output)
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return output
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#################################################################
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# ChaChaPoly Symmetric Cipher
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# ChaChaPoly encryption
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# It takes a Cipher State (with key, nonce, and associated data) and encrypts a plaintext
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proc encrypt*(
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state: ChaChaPolyCipherState,
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plaintext: openArray[byte]): ChaChaPolyCiphertext
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{.noinit, raises: [Defect].} =
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#TODO: add padding
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var ciphertext: ChaChaPolyCiphertext
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ciphertext.data.add plaintext
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ChaChaPoly.encrypt(state.k, state.nonce, ciphertext.tag, ciphertext.data, state.ad)
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return ciphertext
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# ChaChaPoly decryption
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# It takes a Cipher State (with key, nonce, and associated data) and decrypts a ciphertext
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proc decrypt*(
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state: ChaChaPolyCipherState,
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ciphertext: ChaChaPolyCiphertext): seq[byte]
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{.raises: [Defect, NoiseDecryptTagError].} =
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var
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tagIn = ciphertext.tag
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tagOut: ChaChaPolyTag
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var plaintext = ciphertext.data
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ChaChaPoly.decrypt(state.k, state.nonce, tagOut, plaintext, state.ad)
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#TODO: add unpadding
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trace "decrypt", tagIn = tagIn.shortLog, tagOut = tagOut.shortLog, nonce = state.nonce
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if tagIn != tagOut:
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debug "decrypt failed", plaintext = shortLog(plaintext)
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raise newException(NoiseDecryptTagError, "decrypt tag authentication failed.")
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return plaintext
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# Generates a random Cipher Test for testing encryption/decryption
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proc randomChaChaPolyCipherState*(rng: var BrHmacDrbgContext): ChaChaPolyCipherState =
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var randomCipherState: ChaChaPolyCipherState
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brHmacDrbgGenerate(rng, randomCipherState.k)
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brHmacDrbgGenerate(rng, randomCipherState.nonce)
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randomCipherState.ad = newSeq[byte](32)
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brHmacDrbgGenerate(rng, randomCipherState.ad)
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return randomCipherState
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