1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
macro_rules! argon2_module (($pwhash_name:ident,
$pwhash_str_name:ident,
$pwhash_str_verify_name:ident,
$saltbytes:expr,
$hashedpasswordbytes:expr,
$strprefix:expr,
$opslimit_interative:expr,
$opslimit_moderate:expr,
$opslimit_sensitive:expr,
$memlimit_interative:expr,
$memlimit_moderate:expr,
$memlimit_sensitive:expr,
$variant:expr) => (
use libc::{c_int, c_ulonglong};
use randombytes::randombytes_into;
/// Number of bytes in a `Salt`.
pub const SALTBYTES: usize = $saltbytes;
/// Number of bytes in a `HashedPassword`.
pub const HASHEDPASSWORDBYTES: usize = $hashedpasswordbytes;
/// All `HashedPasswords` start with this string.
pub const STRPREFIX: &'static [u8] = $strprefix;
/// Safe base line for `OpsLimit` for interactive password hashing.
pub const OPSLIMIT_INTERACTIVE: OpsLimit = OpsLimit($opslimit_interative);
/// Safe base line for `MemLimit` for interactive password hashing.
pub const MEMLIMIT_INTERACTIVE: MemLimit = MemLimit($memlimit_interative);
/// `OpsLimit` for moderately sensitive data.
pub const OPSLIMIT_MODERATE: OpsLimit = OpsLimit($opslimit_moderate);
/// `MemLimit` for moderately sensitive data.
pub const MEMLIMIT_MODERATE: MemLimit = MemLimit($memlimit_moderate);
/// `OpsLimit` for highly sensitive data.
pub const OPSLIMIT_SENSITIVE: OpsLimit = OpsLimit($opslimit_sensitive);
/// `MemLimit` for highly sensitive data.
pub const MEMLIMIT_SENSITIVE: MemLimit = MemLimit($memlimit_sensitive);
/// Variant id for the Argon2i13 algorithm
pub const VARIANT: u32 = $variant;
/// `OpsLimit` represents the maximum number of computations to perform when
/// using the functions in this module.
///
/// A high `OpsLimit` will make the functions
/// require more CPU cycles
#[derive(Copy, Clone, Debug)]
pub struct OpsLimit(pub usize);
/// `MemLimit` represents the maximum amount of RAM that the functions in this
/// module will use, in bytes.
///
/// It is highly recommended to allow the functions to use
/// at least 16 megabytes.
#[derive(Copy, Clone, Debug)]
pub struct MemLimit(pub usize);
new_type! {
/// `Salt` used for password hashing
public Salt(SALTBYTES);
}
new_type! {
/// `HashedPassword`is a password verifier generated from a password
///
/// A `HashedPassword` is zero-terminated, includes only ASCII characters and can
/// be conveniently stored into SQL databases and other data stores. No
/// additional information has to be stored in order to verify the password.
public HashedPassword(HASHEDPASSWORDBYTES);
}
/// `gen_salt()` randomly generates a new `Salt` for key derivation
///
/// THREAD SAFETY: `gen_salt()` is thread-safe provided that you have called
/// `sodiumoxide::init()` once before using any other function from sodiumoxide.
pub fn gen_salt() -> Salt {
let mut salt = Salt([0; SALTBYTES]);
randombytes_into(&mut salt.0);
salt
}
/// The `derive_key()` function derives a key from a password and a `Salt`
///
/// The computed key is stored into key.
///
/// `opslimit` represents a maximum amount of computations to perform. Raising
/// this number will make the function require more CPU cycles to compute a key.
///
/// `memlimit` is the maximum amount of RAM that the function will use, in
/// bytes. It is highly recommended to allow the function to use at least 16
/// megabytes.
///
/// For interactive, online operations, `OPSLIMIT_INTERACTIVE` and
/// `MEMLIMIT_INTERACTIVE` provide a safe base line for these two
/// parameters. However, using higher values may improve security.
///
/// For highly sensitive data, `OPSLIMIT_SENSITIVE` and `MEMLIMIT_SENSITIVE` can
/// be used as an alternative. But with these parameters, deriving a key takes
/// more than 10 seconds on a 2.8 Ghz Core i7 CPU and requires up to 1 gigabyte
/// of dedicated RAM.
///
/// The salt should be unpredictable. `gen_salt()` is the easiest way to create a `Salt`.
///
/// Keep in mind that in order to produce the same key from the same password,
/// the same salt, and the same values for opslimit and memlimit have to be
/// used.
///
/// The function returns `Ok(key)` on success and `Err(())` if the computation didn't
/// complete, usually because the operating system refused to allocate the
/// amount of requested memory.
pub fn derive_key<'a>(
key: &'a mut [u8],
passwd: &[u8],
&Salt(ref sb): &Salt,
OpsLimit(opslimit): OpsLimit,
MemLimit(memlimit): MemLimit,
) -> Result<&'a [u8], ()> {
let res = unsafe {
$pwhash_name(
key.as_mut_ptr(),
key.len() as c_ulonglong,
passwd.as_ptr() as *const _,
passwd.len() as c_ulonglong,
sb as *const _,
opslimit as c_ulonglong,
memlimit,
VARIANT as c_int)
};
match res {
0 => Ok(key),
_ => Err(()),
}
}
/// The `pwhash()` returns a `HashedPassword` which
/// includes:
///
/// - the result of a memory-hard, CPU-intensive hash function applied to the password
/// `passwd`
/// - the automatically generated salt used for the
/// previous computation
/// - the other parameters required to verify the password: opslimit and memlimit
///
/// `OPSLIMIT_INTERACTIVE` and `MEMLIMIT_INTERACTIVE` are safe baseline
/// values to use for `opslimit` and `memlimit`.
///
/// The function returns `Ok(hashed_password)` on success and `Err(())` if it didn't complete
/// successfully
pub fn pwhash(
passwd: &[u8],
OpsLimit(opslimit): OpsLimit,
MemLimit(memlimit): MemLimit,
) -> Result<HashedPassword, ()> {
let mut out = HashedPassword([0; HASHEDPASSWORDBYTES]);
let res = unsafe {
$pwhash_str_name(
out.0.as_mut_ptr() as *mut _,
passwd.as_ptr() as *const _,
passwd.len() as c_ulonglong,
opslimit as c_ulonglong,
memlimit)
};
match res {
0 => Ok(out),
_ => Err(()),
}
}
/// `pwhash_verify()` verifies that the password `str_` is a valid password
/// verification string (as generated by `pwhash()`) for `passwd`
///
/// It returns `true` if the verification succeeds, and `false` on error.
pub fn pwhash_verify(hp: &HashedPassword, passwd: &[u8]) -> bool {
let res = unsafe {
$pwhash_str_verify_name(
hp.0.as_ptr() as *const _,
passwd.as_ptr() as *const _,
passwd.len() as c_ulonglong)
};
res == 0
}
));