38 lines
1.3 KiB
JavaScript
38 lines
1.3 KiB
JavaScript
var assert = require('assert')
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var randombytes_buf = require('.').randombytes_buf
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var blake2b = require('blake2b')
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module.exports.crypto_kdf_PRIMITIVE = 'blake2b'
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module.exports.crypto_kdf_BYTES_MIN = 16
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module.exports.crypto_kdf_BYTES_MAX = 64
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module.exports.crypto_kdf_CONTEXTBYTES = 8
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module.exports.crypto_kdf_KEYBYTES = 64
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function STORE64_LE(dest, int) {
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var mul = 1
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var i = 0
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dest[0] = int & 0xFF
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while (++i < 8 && (mul *= 0x100)) {
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dest[i] = (int / mul) & 0xFF
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}
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}
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module.exports.crypto_kdf_derive_from_key = function crypto_kdf_derive_from_key (subkey, subkey_id, ctx, key) {
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assert(subkey.length >= module.exports.crypto_kdf_BYTES_MIN, 'subkey must be')
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assert(ctx.length >= module.exports.crypto_kdf_CONTEXTBYTES, 'context must be')
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var ctx_padded = new Uint8Array(blake2b.PERSONALBYTES)
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var salt = new Uint8Array(blake2b.SALTBYTES)
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ctx_padded.set(ctx, 0, module.exports.crypto_kdf_CONTEXTBYTES)
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STORE64_LE(salt, subkey_id)
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blake2b(subkey.slice(0, Math.min(subkey.length, module.exports.crypto_kdf_BYTES_MAX)), [], key, salt, ctx_padded, true)
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}
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module.exports.crypto_kdf_keygen = function crypto_kdf_keygen (out) {
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assert(out.length >= module.exports.crypto_kdf_KEYBYTES)
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randombytes_buf(out, module.exports.crypto_kdf_KEYBYTES)
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}
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