emerald-vault-core 0.26.6

Ethereum secure account management core libary
Documentation 
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

/*
Copyright 2019 ETCDEV GmbH

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
//! # Keystore files pseudo-random functions

use super::Error;
use hmac::{Hmac, Mac};
use sha2::{Sha256, Sha512};
use std::fmt;
use std::str::FromStr;

/// `HMAC_SHA256` pseudo-random function name
pub const HMAC_SHA256_PRF_NAME: &str = "hmac-sha256";

/// `HMAC_SHA512` pseudo-random function name
pub const HMAC_SHA512_PRF_NAME: &str = "hmac-sha512";

/// Pseudo-Random Functions (PRFs)
#[derive(Serialize, Deserialize, Clone, Copy, Debug, PartialEq, Eq)]
pub enum Prf {
    /// HMAC-SHA-256 (specified in (RFC 4868)[https://tools.ietf.org/html/rfc4868])
    #[serde(rename = "hmac-sha256")]
    HmacSha256,

    /// HMAC-SHA-512 (specified in (RFC 4868)[https://tools.ietf.org/html/rfc4868])
    #[serde(rename = "hmac-sha512")]
    HmacSha512,
}

impl Prf {
    /// Calculate hashed message authentication code using SHA-256 digest
    pub fn hmac(&self, passphrase: &str) -> Hmac<Sha256> {
        Hmac::new_varkey(passphrase.as_bytes()).expect("HMAC accepts all key sizes")
    }

    /// Calculate hashed message authentication code using SHA-512 digest
    pub fn hmac512(&self, passphrase: &str) -> Hmac<Sha512> {
        Hmac::new_varkey(passphrase.as_bytes()).expect("HMAC accepts all key sizes")
    }
}

impl Default for Prf {
    fn default() -> Self {
        Prf::HmacSha256
    }
}

impl FromStr for Prf {
    type Err = Error;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        match s {
            _ if s == HMAC_SHA256_PRF_NAME => Ok(Prf::HmacSha256),
            _ if s == HMAC_SHA512_PRF_NAME => Ok(Prf::HmacSha512),
            _ => Err(Error::UnsupportedPrf(s.to_string())),
        }
    }
}

impl fmt::Display for Prf {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match *self {
            Prf::HmacSha256 => f.write_str(HMAC_SHA256_PRF_NAME),
            Prf::HmacSha512 => f.write_str(HMAC_SHA512_PRF_NAME),
        }
    }
}