bitwarden_crypto/keys/
asymmetric_crypto_key.rs

1use std::pin::Pin;
2
3use rsa::{pkcs8::DecodePublicKey, RsaPrivateKey, RsaPublicKey};
4use serde_repr::{Deserialize_repr, Serialize_repr};
5
6use super::key_encryptable::CryptoKey;
7use crate::{
8    error::{CryptoError, Result},
9    Pkcs8PrivateKeyBytes, SpkiPublicKeyBytes,
10};
11
12/// Algorithm / public key encryption scheme used for encryption/decryption.
13#[derive(Serialize_repr, Deserialize_repr)]
14#[repr(u8)]
15pub enum PublicKeyEncryptionAlgorithm {
16    /// RSA with OAEP padding and SHA-1 hashing.
17    RsaOaepSha1 = 0,
18}
19
20#[derive(Clone, PartialEq)]
21pub(crate) enum RawPublicKey {
22    RsaOaepSha1(RsaPublicKey),
23}
24
25/// Public key of a key pair used in a public key encryption scheme. It is used for
26/// encrypting data.
27#[derive(Clone, PartialEq)]
28pub struct AsymmetricPublicCryptoKey {
29    inner: RawPublicKey,
30}
31
32impl AsymmetricPublicCryptoKey {
33    pub(crate) fn inner(&self) -> &RawPublicKey {
34        &self.inner
35    }
36
37    /// Build a public key from the SubjectPublicKeyInfo DER.
38    pub fn from_der(der: &SpkiPublicKeyBytes) -> Result<Self> {
39        Ok(AsymmetricPublicCryptoKey {
40            inner: RawPublicKey::RsaOaepSha1(
41                RsaPublicKey::from_public_key_der(der.as_ref())
42                    .map_err(|_| CryptoError::InvalidKey)?,
43            ),
44        })
45    }
46
47    /// Makes a SubjectPublicKeyInfo DER serialized version of the public key.
48    pub fn to_der(&self) -> Result<SpkiPublicKeyBytes> {
49        use rsa::pkcs8::EncodePublicKey;
50        match &self.inner {
51            RawPublicKey::RsaOaepSha1(public_key) => Ok(public_key
52                .to_public_key_der()
53                .map_err(|_| CryptoError::InvalidKey)?
54                .as_bytes()
55                .to_owned()
56                .into()),
57        }
58    }
59}
60
61#[derive(Clone)]
62pub(crate) enum RawPrivateKey {
63    // RsaPrivateKey is not a Copy type so this isn't completely necessary, but
64    // to keep the compiler from making stack copies when moving this struct around,
65    // we use a Box to keep the values on the heap. We also pin the box to make sure
66    // that the contents can't be pulled out of the box and moved
67    RsaOaepSha1(Pin<Box<RsaPrivateKey>>),
68}
69
70/// Private key of a key pair used in a public key encryption scheme. It is used for
71/// decrypting data that was encrypted with the corresponding public key.
72#[derive(Clone)]
73pub struct AsymmetricCryptoKey {
74    inner: RawPrivateKey,
75}
76
77// Note that RsaPrivateKey already implements ZeroizeOnDrop, so we don't need to do anything
78// We add this assertion to make sure that this is still true in the future
79const _: () = {
80    fn assert_zeroize_on_drop<T: zeroize::ZeroizeOnDrop>() {}
81    fn assert_all() {
82        assert_zeroize_on_drop::<RsaPrivateKey>();
83    }
84};
85impl zeroize::ZeroizeOnDrop for AsymmetricCryptoKey {}
86impl CryptoKey for AsymmetricCryptoKey {}
87
88impl AsymmetricCryptoKey {
89    /// Generate a random AsymmetricCryptoKey (RSA-2048).
90    pub fn make(algorithm: PublicKeyEncryptionAlgorithm) -> Self {
91        Self::make_internal(algorithm, &mut rand::thread_rng())
92    }
93
94    fn make_internal<R: rand::CryptoRng + rand::RngCore>(
95        algorithm: PublicKeyEncryptionAlgorithm,
96        rng: &mut R,
97    ) -> Self {
98        match algorithm {
99            PublicKeyEncryptionAlgorithm::RsaOaepSha1 => Self {
100                inner: RawPrivateKey::RsaOaepSha1(Box::pin(
101                    RsaPrivateKey::new(rng, 2048).expect("failed to generate a key"),
102                )),
103            },
104        }
105    }
106
107    #[allow(missing_docs)]
108    pub fn from_pem(pem: &str) -> Result<Self> {
109        use rsa::pkcs8::DecodePrivateKey;
110        Ok(Self {
111            inner: RawPrivateKey::RsaOaepSha1(Box::pin(
112                RsaPrivateKey::from_pkcs8_pem(pem).map_err(|_| CryptoError::InvalidKey)?,
113            )),
114        })
115    }
116
117    #[allow(missing_docs)]
118    pub fn from_der(der: &Pkcs8PrivateKeyBytes) -> Result<Self> {
119        use rsa::pkcs8::DecodePrivateKey;
120        Ok(Self {
121            inner: RawPrivateKey::RsaOaepSha1(Box::pin(
122                RsaPrivateKey::from_pkcs8_der(der.as_ref()).map_err(|_| CryptoError::InvalidKey)?,
123            )),
124        })
125    }
126
127    #[allow(missing_docs)]
128    pub fn to_der(&self) -> Result<Pkcs8PrivateKeyBytes> {
129        match &self.inner {
130            RawPrivateKey::RsaOaepSha1(private_key) => {
131                use rsa::pkcs8::EncodePrivateKey;
132                Ok(private_key
133                    .to_pkcs8_der()
134                    .map_err(|_| CryptoError::InvalidKey)?
135                    .as_bytes()
136                    .to_owned()
137                    .into())
138            }
139        }
140    }
141
142    /// Derives the public key corresponding to this private key. This is deterministic
143    /// and always derives the same public key.
144    pub fn to_public_key(&self) -> AsymmetricPublicCryptoKey {
145        match &self.inner {
146            RawPrivateKey::RsaOaepSha1(private_key) => AsymmetricPublicCryptoKey {
147                inner: RawPublicKey::RsaOaepSha1(private_key.to_public_key()),
148            },
149        }
150    }
151
152    pub(crate) fn inner(&self) -> &RawPrivateKey {
153        &self.inner
154    }
155}
156
157// We manually implement these to make sure we don't print any sensitive data
158impl std::fmt::Debug for AsymmetricCryptoKey {
159    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
160        f.debug_struct("AsymmetricCryptoKey").finish()
161    }
162}
163
164#[cfg(test)]
165mod tests {
166    use base64::{engine::general_purpose::STANDARD, Engine};
167
168    use crate::{
169        content_format::{Bytes, Pkcs8PrivateKeyDerContentFormat},
170        AsymmetricCryptoKey, AsymmetricPublicCryptoKey, Pkcs8PrivateKeyBytes, SpkiPublicKeyBytes,
171        SymmetricCryptoKey, UnsignedSharedKey,
172    };
173
174    #[test]
175    fn test_asymmetric_crypto_key() {
176        let pem_key_str = "-----BEGIN PRIVATE KEY-----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203-----END PRIVATE KEY-----";
204
205        let der_key_vec = STANDARD.decode("MIIEwAIBADANBgkqhkiG9w0BAQEFAASCBKowggSmAgEAAoIBAQDiTQVuzhdygFz5qv14i+XFDGTnDravzUQT1hPKPGUZOUSZ1gwdNgkWqOIaOnR65BHEnL0sp4bnuiYcafeK2JAW5Sc8Z7IxBNSuAwhQmuKx3RochMIiuCkI2/p+JvUQoJu6FBNm8OoJ4CwmqqHGZESMfnpQDCuDrB3JdJEdXhtmnl0C48sGjOk3WaBMcgGqn8LbJDUlyu1zdqyvb0waJf0iV4PJm2fkUl7+57D/2TkpbCqURVnZK1FFIEg8mr6FzSN1F2pOfktkNYZwP7MSNR7o81CkRSCMr7EkIVa+MZYMBx106BMK7FXgWB7nbSpsWKxBk7ZDHkID2famrEcVtrzDAgMBAAECggEBAKwq9OssGGKgjhvUnyrLJHAZ0dqIMyzk+dotkLjX4gKiszJmyqiep6N5sStLNbsZMPtoU/RZMCW0VbJgXFhiEp2YkZU/Py5UAoqw++53J+kx0d/IkPphKbb3xUec0+1mg5O6GljDCQuiZXS1dIa/WfeZcezclW6Dz9WovY6ePjJ+8vEBR1icbNKzyeINd6MtPtpcgQPHtDwHvhPyUDbKDYGbLvjh9nui8h4+ZUlXKuVRjB0ChxiKV1xJRjkrEVoulOOicd5r597WfB2ghax3pvRZ4MdXemCXm3gQYqPVKachvGU+1cPQR/MBJZpxT+EZA97xwtFS3gqwbxJaNFcoE8ECgYEA9OaeYZhQPDo485tI1u/Z7L/3PNape9hBQIXoW7+MgcQ5NiWqYh8Jnj43EIYa0wM/ECQINr1Za8Q5e6KRJ30FcU+kfyjuQ0jeXdNELGU/fx5XXNg/vV8GevHwxRlwzqZTCg6UExUZzbYEQqd7l+wPyETGeua5xCEywA1nX/D101kCgYEA7I6aMFjhEjO71RmzNhqjKJt6DOghoOfQTjhaaanNEhLYSbenFz1mlb21mW67ulmz162saKdIYLxQNJIP8ZPmxh4ummOJI8w9ClHfo8WuCI2hCjJ19xbQJocSbTA5aJg6lA1IDVZMDbQwsnAByPRGpaLHBT/Q9ByeKvCMB+9amXsCgYEAx65yXSkP4sumPBrVHUub6MntERIGRxBgw/drKcPZEMWp0FiNwEuGUBxyUWrG3F69QK/gcqGZE6F/LSu0JvptQaKqgXQiMYJsrRvhbkFvsHpQyUcZUZL1ebFjm5HOxPAgrQaN/bEqxOwwNRjSUWEMzUImg3c06JIZCzbinvudtKECgYEAkY3JF/iIPI/yglP27lKDlCfeeHSYxI3+oTKRhzSAxx8rUGidenJAXeDGDauR/T7Wpt3pGNfddBBK9Z3uC4Iq3DqUCFE4f/taj7ADAJ1Q0Vh7/28/IJM77ojr8J1cpZwNZy2o6PPxhfkagaDjqEeN9Lrs5LD4nEvDkr5CG1vOjmMCgYEAvIBFKRm31NyF8jLiCVuPwC5PzrW5iThDmsWTaXFpB3esUsbICO2pEz872oeQS+Em4GO5vXUlpbbFPzupPFhA8iMJ8TAvemhvc7oM0OZqpU6p3K4seHf6BkwLxumoA3vDJfovu9RuXVcJVOnfDnqOsltgPomWZ7xVfMkm9niL2OA=").unwrap();
206
207        // Load the two different formats and check they are the same key
208        let pem_key = AsymmetricCryptoKey::from_pem(pem_key_str).unwrap();
209        let der_key = AsymmetricCryptoKey::from_der(
210            &Bytes::<Pkcs8PrivateKeyDerContentFormat>::from(der_key_vec.clone()),
211        )
212        .unwrap();
213        assert_eq!(pem_key.to_der().unwrap(), der_key.to_der().unwrap());
214
215        // Check that the keys can be converted back to DER
216        assert_eq!(der_key.to_der().unwrap().to_vec(), der_key_vec);
217        assert_eq!(pem_key.to_der().unwrap().to_vec(), der_key_vec);
218    }
219
220    #[test]
221    fn test_encrypt_public_decrypt_private() {
222        let private_key = STANDARD
223            .decode(concat!(
224                "MIIEvQIBADANBgkqhkiG9w0BAQEFAASCBKcwggSjAgEAAoIBAQCu9xd+vmkIPoqH",
225                "NejsFZzkd1xuCn1TqGTT7ANhAEnbI/yaVt3caI30kwUC2WIToFpNgu7Ej0x2TteY",
226                "OgrLrdcC4jy1SifmKYv/v3ZZxrd/eqttmH2k588panseRwHK3LVk7xA+URhQ/bjL",
227                "gPM59V0uR1l+z1fmooeJPFz5WSXNObc9Jqnh45FND+U/UYHXTLSomTn7jgZFxJBK",
228                "veS7q6Lat7wAnYZCF2dnPmhZoJv+SKPltA8HAGsgQGWBF1p5qxV1HrAUk8kBBnG2",
229                "paj0w8p5UM6RpDdCuvKH7j1LiuWffn3b9Z4dgzmE7jsMmvzoQtypzIKaSxhqzvFO",
230                "od9V8dJdAgMBAAECggEAGGIYjOIB1rOKkDHP4ljXutI0mCRPl3FMDemiBeppoIfZ",
231                "G/Q3qpAKmndDt0Quwh/yfcNdvZhf1kwCCTWri/uPz5fSUIyDV3TaTRu0ZWoHaBVj",
232                "Hxylg+4HRZUQj+Vi50/PWr/jQmAAVMcrMfcoTl82q2ynmP/R1vM3EsXOCjTliv5B",
233                "XlMPRjj/9PDBH0dnnVcAPDOpflzOTL2f4HTFEMlmg9/tZBnd96J/cmfhjAv9XpFL",
234                "FBAFZzs5pz0rwCNSR8QZNonnK7pngVUlGDLORK58y84tGmxZhGdne3CtCWey/sJ4",
235                "7QF0Pe8YqWBU56926IY6DcSVBuQGZ6vMCNlU7J8D2QKBgQDXyh3t2TicM/n1QBLk",
236                "zLoGmVUmxUGziHgl2dnJiGDtyOAU3+yCorPgFaCie29s5qm4b0YEGxUxPIrRrEro",
237                "h0FfKn9xmr8CdmTPTcjJW1+M7bxxq7oBoU/QzKXgIHlpeCjjnvPJt0PcNkNTjCXv",
238                "shsrINh2rENoe/x79eEfM/N5eQKBgQDPkYSmYyALoNq8zq0A4BdR+F5lb5Fj5jBH",
239                "Jk68l6Uti+0hRbJ2d1tQTLkU+eCPQLGBl6fuc1i4K5FV7v14jWtRPdD7wxrkRi3j",
240                "ilqQwLBOU6Bj3FK4DvlLF+iYTuBWj2/KcxflXECmsjitKHLK6H7kFEiuJql+NAHU",
241                "U9EFXepLBQKBgQDQ+HCnZ1bFHiiP8m7Zl9EGlvK5SwlnPV9s+F1KJ4IGhCNM09UM",
242                "ZVfgR9F5yCONyIrPiyK40ylgtwqQJlOcf281I8irUXpsfg7+Gou5Q31y0r9NLUpC",
243                "Td8niyePtqMdGjouxD2+OHXFCd+FRxFt4IMi7vnxYr0csAVAXkqWlw7PsQKBgH/G",
244                "/PnQm7GM3BrOwAGB8dksJDAddkshMScblezTDYP0V43b8firkTLliCo5iNum357/",
245                "VQmdSEhXyag07yR/Kklg3H2fpbZQ3X7tdMMXW3FcWagfwWw9C4oGtdDM/Z1Lv23J",
246                "XDR9je8QV4OBGul+Jl8RfYx3kG94ZIfo8Qt0vP5hAoGARjAzdCGYz42NwaUk8n94",
247                "W2RuKHtTV9vtjaAbfPFbZoGkT7sXNJVlrA0C+9f+H9rOTM3mX59KrjmLVzde4Vhs",
248                "avWMShuK4vpAiDQLU7GyABvi5CR6Ld+AT+LSzxHhVe0ASOQPNCA2SOz3RQvgPi7R",
249                "GDgRMUB6cL3IRVzcR0dC6cY=",
250            ))
251            .unwrap();
252
253        let public_key = STANDARD
254            .decode(concat!(
255                "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEArvcXfr5pCD6KhzXo7BWc",
256                "5Hdcbgp9U6hk0+wDYQBJ2yP8mlbd3GiN9JMFAtliE6BaTYLuxI9Mdk7XmDoKy63X",
257                "AuI8tUon5imL/792Wca3f3qrbZh9pOfPKWp7HkcByty1ZO8QPlEYUP24y4DzOfVd",
258                "LkdZfs9X5qKHiTxc+VklzTm3PSap4eORTQ/lP1GB10y0qJk5+44GRcSQSr3ku6ui",
259                "2re8AJ2GQhdnZz5oWaCb/kij5bQPBwBrIEBlgRdaeasVdR6wFJPJAQZxtqWo9MPK",
260                "eVDOkaQ3Qrryh+49S4rln3592/WeHYM5hO47DJr86ELcqcyCmksYas7xTqHfVfHS",
261                "XQIDAQAB",
262            ))
263            .unwrap();
264
265        let private_key = Pkcs8PrivateKeyBytes::from(private_key);
266        let private_key = AsymmetricCryptoKey::from_der(&private_key).unwrap();
267        let public_key =
268            AsymmetricPublicCryptoKey::from_der(&SpkiPublicKeyBytes::from(public_key)).unwrap();
269
270        let raw_key = SymmetricCryptoKey::make_aes256_cbc_hmac_key();
271        let encrypted = UnsignedSharedKey::encapsulate_key_unsigned(&raw_key, &public_key).unwrap();
272        let decrypted = encrypted.decapsulate_key_unsigned(&private_key).unwrap();
273
274        assert_eq!(raw_key, decrypted);
275    }
276}