41 lines
1.4 KiB
TypeScript
41 lines
1.4 KiB
TypeScript
import { bytesToHex, randomBytes } from '@noble/hashes/utils'
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import { secp256k1 } from '@noble/curves/secp256k1'
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import { cbc } from '@noble/ciphers/aes'
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import { base64 } from '@scure/base'
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import { utf8Decoder, utf8Encoder } from './utils.ts'
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export async function encrypt(secretKey: string | Uint8Array, pubkey: string, text: string): Promise<string> {
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const privkey: string = secretKey instanceof Uint8Array ? bytesToHex(secretKey) : secretKey
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const key = secp256k1.getSharedSecret(privkey, '02' + pubkey)
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const normalizedKey = getNormalizedX(key)
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let iv = Uint8Array.from(randomBytes(16))
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let plaintext = utf8Encoder.encode(text)
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let ciphertext = cbc(normalizedKey, iv).encrypt(plaintext)
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let ctb64 = base64.encode(new Uint8Array(ciphertext))
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let ivb64 = base64.encode(new Uint8Array(iv.buffer))
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return `${ctb64}?iv=${ivb64}`
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}
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export async function decrypt(secretKey: string | Uint8Array, pubkey: string, data: string): Promise<string> {
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const privkey: string = secretKey instanceof Uint8Array ? bytesToHex(secretKey) : secretKey
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let [ctb64, ivb64] = data.split('?iv=')
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let key = secp256k1.getSharedSecret(privkey, '02' + pubkey)
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let normalizedKey = getNormalizedX(key)
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let iv = base64.decode(ivb64)
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let ciphertext = base64.decode(ctb64)
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let plaintext = cbc(normalizedKey, iv).decrypt(ciphertext)
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return utf8Decoder.decode(plaintext)
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}
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function getNormalizedX(key: Uint8Array): Uint8Array {
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return key.slice(1, 33)
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}
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