nim-libp2p/libp2p/multibase.nim

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## Nim-Libp2p
## Copyright (c) 2018 Status Research & Development GmbH
## Licensed under either of
## * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
## * MIT license ([LICENSE-MIT](LICENSE-MIT))
## at your option.
## This file may not be copied, modified, or distributed except according to
## those terms.
## This module implements MultiBase.
##
## TODO:
## 1. base32z
import tables
import base32, base58, base64
type
MultibaseStatus* {.pure.} = enum
Error, Success, Overrun, Incorrect, BadCodec, NotSupported
MultiBase* = object
MBCodeSize = proc(length: int): int {.nimcall.}
MBCodec = object
code: char
name: string
encr: proc(inbytes: openarray[byte],
outbytes: var openarray[char],
outlen: var int): MultibaseStatus {.nimcall.}
decr: proc(inbytes: openarray[char],
outbytes: var openarray[byte],
outlen: var int): MultibaseStatus {.nimcall.}
encl: MBCodeSize
decl: MBCodeSize
2019-06-10 20:33:36 +00:00
MultiBaseError* = object of CatchableError
proc idd(inbytes: openarray[char], outbytes: var openarray[byte],
outlen: var int): MultibaseStatus =
let length = len(inbytes)
if length > len(outbytes):
outlen = length
result = MultibaseStatus.Overrun
else:
copyMem(addr outbytes[0], unsafeAddr inbytes[0], length)
outlen = length
result = MultibaseStatus.Success
proc ide(inbytes: openarray[byte],
outbytes: var openarray[char],
outlen: var int): MultibaseStatus =
let length = len(inbytes)
if length > len(outbytes):
outlen = length
result = MultibaseStatus.Overrun
else:
copyMem(addr outbytes[0], unsafeAddr inbytes[0], length)
outlen = length
result = MultibaseStatus.Success
proc idel(length: int): int = length
proc iddl(length: int): int = length
proc b16d(inbytes: openarray[char],
outbytes: var openarray[byte],
outlen: var int): MultibaseStatus =
discard
proc b16e(inbytes: openarray[byte],
outbytes: var openarray[char],
outlen: var int): MultibaseStatus =
discard
proc b16ud(inbytes: openarray[char],
outbytes: var openarray[byte],
outlen: var int): MultibaseStatus =
discard
proc b16ue(inbytes: openarray[byte],
outbytes: var openarray[char],
outlen: var int): MultibaseStatus =
discard
proc b16el(length: int): int = length shl 1
proc b16dl(length: int): int = (length + 1) div 2
proc b32ce(r: Base32Status): MultibaseStatus {.inline.} =
result = MultibaseStatus.Error
if r == Base32Status.Incorrect:
result = MultibaseStatus.Incorrect
elif r == Base32Status.Overrun:
result = MultibaseStatus.Overrun
elif r == Base32Status.Success:
result = MultibaseStatus.Success
proc b58ce(r: Base58Status): MultibaseStatus {.inline.} =
result = MultibaseStatus.Error
if r == Base58Status.Incorrect:
result = MultibaseStatus.Incorrect
elif r == Base58Status.Overrun:
result = MultibaseStatus.Overrun
elif r == Base58Status.Success:
result = MultibaseStatus.Success
proc b64ce(r: Base64Status): MultibaseStatus {.inline.} =
result = MultiBaseStatus.Error
if r == Base64Status.Incorrect:
result = MultibaseStatus.Incorrect
elif r == Base64Status.Overrun:
result = MultiBaseStatus.Overrun
elif r == Base64Status.Success:
result = MultibaseStatus.Success
proc b32hd(inbytes: openarray[char],
outbytes: var openarray[byte],
outlen: var int): MultibaseStatus =
result = b32ce(HexBase32Lower.decode(inbytes, outbytes, outlen))
proc b32he(inbytes: openarray[byte],
outbytes: var openarray[char],
outlen: var int): MultibaseStatus =
result = b32ce(HexBase32Lower.encode(inbytes, outbytes, outlen))
proc b32hud(inbytes: openarray[char],
outbytes: var openarray[byte],
outlen: var int): MultibaseStatus =
result = b32ce(HexBase32Upper.decode(inbytes, outbytes, outlen))
proc b32hue(inbytes: openarray[byte],
outbytes: var openarray[char],
outlen: var int): MultibaseStatus =
result = b32ce(HexBase32Upper.encode(inbytes, outbytes, outlen))
proc b32hpd(inbytes: openarray[char],
outbytes: var openarray[byte],
outlen: var int): MultibaseStatus =
result = b32ce(HexBase32LowerPad.decode(inbytes, outbytes, outlen))
proc b32hpe(inbytes: openarray[byte],
outbytes: var openarray[char],
outlen: var int): MultibaseStatus =
result = b32ce(HexBase32LowerPad.encode(inbytes, outbytes, outlen))
proc b32hpud(inbytes: openarray[char],
outbytes: var openarray[byte],
outlen: var int): MultibaseStatus =
result = b32ce(HexBase32UpperPad.decode(inbytes, outbytes, outlen))
proc b32hpue(inbytes: openarray[byte],
outbytes: var openarray[char],
outlen: var int): MultibaseStatus =
result = b32ce(HexBase32UpperPad.encode(inbytes, outbytes, outlen))
proc b32d(inbytes: openarray[char],
outbytes: var openarray[byte],
outlen: var int): MultibaseStatus =
result = b32ce(Base32Lower.decode(inbytes, outbytes, outlen))
proc b32e(inbytes: openarray[byte],
outbytes: var openarray[char],
outlen: var int): MultibaseStatus =
result = b32ce(Base32Lower.encode(inbytes, outbytes, outlen))
proc b32ud(inbytes: openarray[char],
outbytes: var openarray[byte],
outlen: var int): MultibaseStatus =
result = b32ce(Base32Upper.decode(inbytes, outbytes, outlen))
proc b32ue(inbytes: openarray[byte],
outbytes: var openarray[char],
outlen: var int): MultibaseStatus =
result = b32ce(Base32Upper.encode(inbytes, outbytes, outlen))
proc b32pd(inbytes: openarray[char],
outbytes: var openarray[byte],
outlen: var int): MultibaseStatus =
result = b32ce(Base32LowerPad.decode(inbytes, outbytes, outlen))
proc b32pe(inbytes: openarray[byte],
outbytes: var openarray[char],
outlen: var int): MultibaseStatus =
result = b32ce(Base32LowerPad.encode(inbytes, outbytes, outlen))
proc b32pud(inbytes: openarray[char],
outbytes: var openarray[byte],
outlen: var int): MultibaseStatus =
result = b32ce(Base32UpperPad.decode(inbytes, outbytes, outlen))
proc b32pue(inbytes: openarray[byte],
outbytes: var openarray[char],
outlen: var int): MultibaseStatus =
result = b32ce(Base32UpperPad.encode(inbytes, outbytes, outlen))
proc b32el(length: int): int = Base32Lower.encodedLength(length)
proc b32dl(length: int): int = Base32Lower.decodedLength(length)
proc b32pel(length: int): int = Base32LowerPad.encodedLength(length)
proc b32pdl(length: int): int = Base32LowerPad.decodedLength(length)
proc b58fd(inbytes: openarray[char],
outbytes: var openarray[byte],
outlen: var int): MultibaseStatus =
result = b58ce(FLCBase58.decode(inbytes, outbytes, outlen))
proc b58fe(inbytes: openarray[byte],
outbytes: var openarray[char],
outlen: var int): MultibaseStatus =
result = b58ce(FLCBase58.encode(inbytes, outbytes, outlen))
proc b58bd(inbytes: openarray[char],
outbytes: var openarray[byte],
outlen: var int): MultibaseStatus =
result = b58ce(BTCBase58.decode(inbytes, outbytes, outlen))
proc b58be(inbytes: openarray[byte],
outbytes: var openarray[char],
outlen: var int): MultibaseStatus =
result = b58ce(BTCBase58.encode(inbytes, outbytes, outlen))
proc b58el(length: int): int = Base58.encodedLength(length)
proc b58dl(length: int): int = Base58.decodedLength(length)
proc b64el(length: int): int = Base64.encodedLength(length)
proc b64dl(length: int): int = Base64.decodedLength(length)
proc b64pel(length: int): int = Base64Pad.encodedLength(length)
proc b64pdl(length: int): int = Base64Pad.decodedLength(length)
proc b64e(inbytes: openarray[byte],
outbytes: var openarray[char],
outlen: var int): MultibaseStatus =
result = b64ce(Base64.encode(inbytes, outbytes, outlen))
proc b64d(inbytes: openarray[char],
outbytes: var openarray[byte],
outlen: var int): MultibaseStatus =
result = b64ce(Base64.decode(inbytes, outbytes, outlen))
proc b64pe(inbytes: openarray[byte],
outbytes: var openarray[char],
outlen: var int): MultibaseStatus =
result = b64ce(Base64Pad.encode(inbytes, outbytes, outlen))
proc b64pd(inbytes: openarray[char],
outbytes: var openarray[byte],
outlen: var int): MultibaseStatus =
result = b64ce(Base64Pad.decode(inbytes, outbytes, outlen))
proc b64ue(inbytes: openarray[byte],
outbytes: var openarray[char],
outlen: var int): MultibaseStatus =
result = b64ce(Base64Url.encode(inbytes, outbytes, outlen))
proc b64ud(inbytes: openarray[char],
outbytes: var openarray[byte],
outlen: var int): MultibaseStatus =
result = b64ce(Base64Url.decode(inbytes, outbytes, outlen))
proc b64upe(inbytes: openarray[byte],
outbytes: var openarray[char],
outlen: var int): MultibaseStatus =
result = b64ce(Base64UrlPad.encode(inbytes, outbytes, outlen))
proc b64upd(inbytes: openarray[char],
outbytes: var openarray[byte],
outlen: var int): MultibaseStatus =
result = b64ce(Base64UrlPad.decode(inbytes, outbytes, outlen))
const
MultibaseCodecs = [
MBCodec(name: "identity", code: chr(0x00),
decr: idd, encr: ide, decl: iddl, encl: idel
),
MBCodec(name: "base1", code: '1'),
MBCodec(name: "base2", code: '0'),
MBCodec(name: "base8", code: '7'),
MBCodec(name: "base10", code: '9'),
MBCodec(name: "base16", code: 'f',
decr: b16d, encr: b16e, decl: b16dl, encl: b16el
),
MBCodec(name: "base16upper", code: 'F',
decr: b16ud, encr: b16ue, decl: b16dl, encl: b16el
),
MBCodec(name: "base32hex", code: 'v',
decr: b32hd, encr: b32he, decl: b32dl, encl: b32el
),
MBCodec(name: "base32hexupper", code: 'V',
decr: b32hud, encr: b32hue, decl: b32dl, encl: b32el
),
MBCodec(name: "base32hexpad", code: 't',
decr: b32hpd, encr: b32hpe, decl: b32pdl, encl: b32pel
),
MBCodec(name: "base32hexpadupper", code: 'T',
decr: b32hpud, encr: b32hpue, decl: b32pdl, encl: b32pel
),
MBCodec(name: "base32", code: 'b',
decr: b32d, encr: b32e, decl: b32dl, encl: b32el
),
MBCodec(name: "base32upper", code: 'B',
decr: b32ud, encr: b32ue, decl: b32dl, encl: b32el
),
MBCodec(name: "base32pad", code: 'c',
decr: b32pd, encr: b32pe, decl: b32pdl, encl: b32pel
),
MBCodec(name: "base32padupper", code: 'C',
decr: b32pud, encr: b32pue, decl: b32pdl, encl: b32pel
),
MBCodec(name: "base32z", code: 'h'),
MBCodec(name: "base58flickr", code: 'Z',
decr: b58fd, encr: b58fe, decl: b58dl, encl: b58el
),
MBCodec(name: "base58btc", code: 'z',
decr: b58bd, encr: b58be, decl: b58dl, encl: b58el
),
MBCodec(name: "base64", code: 'm',
decr: b64d, encr: b64e, decl: b64dl, encl: b64el
),
MBCodec(name: "base64pad", code: 'M',
decr: b64pd, encr: b64pe, decl: b64pdl, encl: b64pel
),
MBCodec(name: "base64url", code: 'u',
decr: b64ud, encr: b64ue, decl: b64dl, encl: b64el
),
MBCodec(name: "base64urlpad", code: 'U',
decr: b64upd, encr: b64upe, decl: b64pdl, encl: b64pel
)
]
proc initMultiBaseCodeTable(): Table[char, MBCodec] {.compileTime.} =
result = initTable[char, MBCodec]()
for item in MultibaseCodecs:
result[item.code] = item
proc initMultiBaseNameTable(): Table[string, MBCodec] {.compileTime.} =
result = initTable[string, MBCodec]()
for item in MultibaseCodecs:
result[item.name] = item
const
CodeMultibases = initMultiBaseCodeTable()
NameMultibases = initMultiBaseNameTable()
proc encodedLength*(mbtype: typedesc[MultiBase], encoding: string,
length: int): int =
## Return estimated size of buffer to store MultiBase encoded value with
## encoding ``encoding`` of length ``length``.
##
## Procedure returns ``-1`` if ``encoding`` scheme is not supported or
## not present.
let mb = NameMultibases.getOrDefault(encoding)
if len(mb.name) == 0 or isNil(mb.encl):
result = -1
else:
if length == 0:
result = 1
else:
result = mb.encl(length) + 1
proc decodedLength*(mbtype: typedesc[MultiBase], encoding: char,
length: int): int =
## Return estimated size of buffer to store MultiBase decoded value with
## encoding character ``encoding`` of length ``length``.
let mb = CodeMultibases.getOrDefault(encoding)
if len(mb.name) == 0 or isNil(mb.decl) or length == 0:
result = -1
else:
if length == 1:
result = 0
else:
result = mb.decl(length - 1)
proc encode*(mbtype: typedesc[MultiBase], encoding: string,
inbytes: openarray[byte], outbytes: var openarray[char],
outlen: var int): MultibaseStatus =
## Encode array ``inbytes`` using MultiBase encoding scheme ``encoding`` and
## store encoded value to ``outbytes``.
##
## If ``encoding`` is not supported ``MultiBaseStatus.NotSupported`` will be
## returned.
##
## If ``encoding`` is not correct string, then ``MultBaseStatus.BadCodec``
## will be returned.
##
## If length of ``outbytes`` is not enough to store encoded result, then
## ``MultiBaseStatus.Overrun`` error will be returned and ``outlen`` will be
## set to length required.
##
## On successfull encoding ``MultiBaseStatus.Success`` will be returned and
## ``outlen`` will be set to number of encoded octets (bytes).
let mb = NameMultibases.getOrDefault(encoding)
if len(mb.name) == 0:
return MultibaseStatus.BadCodec
if isNil(mb.encr) or isNil(mb.encl):
return MultibaseStatus.NotSupported
if len(outbytes) > 1:
result = mb.encr(inbytes, outbytes.toOpenArray(1, len(outbytes) - 1),
outlen)
if result == MultiBaseStatus.Overrun:
outlen += 1
elif result == MultiBaseStatus.Success:
outlen += 1
outbytes[0] = mb.code
else:
if len(inbytes) == 0 and len(outbytes) == 1:
result = MultiBaseStatus.Success
outlen = 1
outbytes[0] = mb.code
else:
result = MultiBaseStatus.Overrun
outlen = mb.encl(len(inbytes)) + 1
proc decode*(mbtype: typedesc[MultiBase], inbytes: openarray[char],
outbytes: var openarray[byte], outlen: var int): MultibaseStatus =
## Decode array ``inbytes`` using MultiBase encoding and store decoded value
## to ``outbytes``.
##
## If ``inbytes`` is not correct MultiBase string, then
## ``MultiBaseStatus.BadCodec`` if first character is wrong, or
## ``MultiBaseStatus.Incorrect`` if string has incorrect characters for
## such encoding.
##
## If length of ``outbytes`` is not enough to store decoded result, then
## ``MultiBaseStatus.Overrun`` error will be returned and ``outlen`` will be
## set to length required.
##
## On successfull decoding ``MultiBaseStatus.Success`` will be returned and
## ``outlen`` will be set to number of encoded octets (bytes).
let length = len(inbytes)
if length == 0:
return MultibaseStatus.Incorrect
let mb = CodeMultibases.getOrDefault(inbytes[0])
if len(mb.name) == 0:
return MultibaseStatus.BadCodec
if isNil(mb.decr) or isNil(mb.decl):
return MultibaseStatus.NotSupported
if length == 1:
outlen = 0
result = MultibaseStatus.Success
else:
result = mb.decr(inbytes.toOpenArray(1, length - 1), outbytes, outlen)
proc encode*(mbtype: typedesc[MultiBase], encoding: string,
inbytes: openarray[byte]): string =
## Encode array ``inbytes`` using MultiBase encoding scheme ``encoding`` and
## return encoded string.
let length = len(inbytes)
let mb = NameMultibases.getOrDefault(encoding)
if len(mb.name) == 0:
raise newException(MultiBaseError, "Encoding scheme is incorrect!")
if isNil(mb.encr) or isNil(mb.encl):
raise newException(MultiBaseError, "Encoding scheme is not supported!")
var buffer: string
if length > 0:
buffer = newString(mb.encl(length) + 1)
var outlen = 0
let res = mb.encr(inbytes, buffer.toOpenArray(1, len(buffer) - 1), outlen)
if res != MultiBaseStatus.Success:
raise newException(MultiBaseError, "Encoding error [" & $res & "]")
buffer.setLen(outlen + 1)
buffer[0] = mb.code
else:
buffer = newString(1)
buffer[0] = mb.code
result = buffer
proc decode*(mbtype: typedesc[MultiBase], inbytes: openarray[char]): seq[byte] =
## Decode MultiBase encoded array ``inbytes`` and return decoded sequence of
## bytes.
let length = len(inbytes)
if length == 0:
raise newException(MultiBaseError, "Could not decode zero-length string")
let mb = CodeMultibases.getOrDefault(inbytes[0])
if len(mb.name) == 0:
raise newException(MultiBaseError, "MultiBase scheme is incorrect!")
if isNil(mb.decr) or isNil(mb.decl):
raise newException(MultiBaseError, "MultiBase scheme is not supported!")
if length == 1:
result = newSeq[byte]()
else:
var buffer = newSeq[byte](mb.decl(length - 1))
var outlen = 0
let res = mb.decr(inbytes.toOpenArray(1, length - 1),
buffer, outlen)
if res != MultiBaseStatus.Success:
raise newException(MultiBaseError, "Decoding error [" & $res & "]")
result = buffer
result.setLen(outlen)