v/vlib/crypto/bcrypt/bcrypt.v

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module bcrypt
import encoding.base64
import crypto.rand
import crypto.blowfish
pub const (
min_cost = 4
max_cost = 31
default_cost = 10
salt_length = 16
max_crypted_hash_size = 23
encoded_salt_size = 22
encoded_hash_size = 31
min_hash_size = 59
major_version = '2'
minor_version = 'a'
)
pub struct Hashed {
mut:
hash []byte
salt []byte
cost int
major string
minor string
}
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const magic_cipher_data = [byte(0x4f), 0x72, 0x70, 0x68, 0x65, 0x61, 0x6e, 0x42, 0x65, 0x68, 0x6f,
0x6c, 0x64, 0x65, 0x72, 0x53, 0x63, 0x72, 0x79, 0x44, 0x6f, 0x75, 0x62, 0x74]
pub fn generate_from_password(password []byte, cost int) ?string {
mut p := new_from_password(password, cost) or { return error('Error: $err') }
x := p.hash_byte()
return x.bytestr()
}
pub fn compare_hash_and_password(password []byte, hashed_password []byte) ? {
mut p := new_from_hash(hashed_password) or { return error('Error: $err') }
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p.salt << `=`
p.salt << `=`
other_hash := bcrypt(password, p.cost, p.salt) or { return error('err') }
mut other_p := Hashed{
hash: other_hash
salt: p.salt
cost: p.cost
major: p.major
minor: p.minor
}
if p.hash_byte() != other_p.hash_byte() {
return error('mismatched hash and password')
}
}
pub fn generate_salt() string {
randbytes := rand.read(bcrypt.salt_length) or { panic(err) }
return randbytes.bytestr()
}
fn new_from_password(password []byte, cost int) ?&Hashed {
mut cost_ := cost
if cost < bcrypt.min_cost {
cost_ = bcrypt.default_cost
}
mut p := &Hashed{}
p.major = bcrypt.major_version
p.minor = bcrypt.minor_version
if cost_ < bcrypt.min_cost || cost_ > bcrypt.max_cost {
return error('invalid cost')
}
p.cost = cost_
salt := generate_salt().bytes()
p.salt = base64.encode(salt).bytes()
hash := bcrypt(password, p.cost, p.salt) or { return err }
p.hash = hash
return p
}
fn new_from_hash(hashed_secret []byte) ?&Hashed {
mut tmp := hashed_secret.clone()
if tmp.len < bcrypt.min_hash_size {
return error('hash to short')
}
mut p := &Hashed{}
mut n := p.decode_version(tmp) or { return err }
tmp = tmp[n..].clone()
n = p.decode_cost(tmp) or { return err }
tmp = tmp[n..].clone()
p.salt = tmp[..bcrypt.encoded_salt_size].clone()
p.hash = tmp[bcrypt.encoded_salt_size..].clone()
return p
}
fn bcrypt(password []byte, cost int, salt []byte) ?[]byte {
mut cipher_data := []byte{len: 72 - bcrypt.magic_cipher_data.len, init: 0}
cipher_data << bcrypt.magic_cipher_data
mut bf := expensive_blowfish_setup(password, u32(cost), salt) or { return err }
for i := 0; i < 24; i += 8 {
for j := 0; j < 64; j++ {
bf.encrypt(mut cipher_data[i..i + 8], cipher_data[i..i + 8])
}
}
hsh := base64.encode(cipher_data[..bcrypt.max_crypted_hash_size])
return hsh.bytes()
}
fn expensive_blowfish_setup(key []byte, cost u32, salt []byte) ?&blowfish.Blowfish {
csalt := base64.decode(salt.bytestr())
mut bf := blowfish.new_salted_cipher(key, csalt) or { return err }
mut i := u64(0)
mut rounds := u64(0)
rounds = 1 << cost
for i = 0; i < rounds; i++ {
blowfish.expand_key(key, mut bf)
blowfish.expand_key(csalt, mut bf)
}
return &bf
}
fn (mut h Hashed) hash_byte() []byte {
mut arr := []byte{len: 65, init: 0}
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arr[0] = `$`
arr[1] = h.major[0]
mut n := 2
if h.minor != '0' {
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arr[2] = h.minor[0]
n = 3
}
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arr[n] = `$`
n++
copy(arr[n..], '${int(h.cost):02}'.bytes())
n += 2
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arr[n] = `$`
n++
copy(arr[n..], h.salt)
n += bcrypt.encoded_salt_size
copy(arr[n..], h.hash)
n += bcrypt.encoded_hash_size
res := arr[..n].clone()
return res
}
fn (mut h Hashed) decode_version(sbytes []byte) ?int {
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if sbytes[0] != `$` {
return error("bcrypt hashes must start with '$'")
}
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if sbytes[1] != bcrypt.major_version[0] {
return error('bcrypt algorithm version $bcrypt.major_version')
}
h.major = sbytes[1].ascii_str()
mut n := 3
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if sbytes[2] != `$` {
h.minor = sbytes[2].ascii_str()
n++
}
return n
}
fn (mut h Hashed) decode_cost(sbytes []byte) ?int {
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cost := sbytes[0..2].bytestr().int()
check_cost(cost) or { return err }
h.cost = cost
return 3
}
fn check_cost(cost int) ? {
if cost < bcrypt.min_cost || cost > bcrypt.max_cost {
return error('invalid cost')
}
}