aws_lc_rs/
ec.rs

1// Copyright 2015-2016 Brian Smith.
2// SPDX-License-Identifier: ISC
3// Modifications copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
4// SPDX-License-Identifier: Apache-2.0 OR ISC
5
6#[cfg(feature = "fips")]
7use crate::aws_lc::EC_KEY_check_fips;
8#[cfg(not(feature = "fips"))]
9use crate::aws_lc::EC_KEY_check_key;
10use crate::aws_lc::{
11    ECDSA_SIG_from_bytes, ECDSA_SIG_get0_r, ECDSA_SIG_get0_s, EC_GROUP_get_curve_name,
12    EC_KEY_get0_group, EC_group_p224, EC_group_p256, EC_group_p384, EC_group_p521,
13    EC_group_secp256k1, EVP_PKEY_CTX_set_ec_paramgen_curve_nid, EVP_PKEY_get0_EC_KEY,
14    NID_X9_62_prime256v1, NID_secp224r1, NID_secp256k1, NID_secp384r1, NID_secp521r1, EC_GROUP,
15    EC_KEY, EVP_PKEY, EVP_PKEY_EC,
16};
17use crate::ec::signature::AlgorithmID;
18use crate::error::{KeyRejected, Unspecified};
19#[cfg(feature = "fips")]
20use crate::fips::indicator_check;
21use crate::ptr::{ConstPointer, LcPtr};
22use crate::signature::Signature;
23use core::ffi::c_int;
24use std::ptr::null;
25
26pub(crate) mod encoding;
27pub(crate) mod key_pair;
28pub(crate) mod signature;
29
30const ELEM_MAX_BITS: usize = 521;
31pub(crate) const ELEM_MAX_BYTES: usize = (ELEM_MAX_BITS + 7) / 8;
32
33/// The maximum length, in bytes, of an encoded public key.
34pub(crate) const PUBLIC_KEY_MAX_LEN: usize = 1 + (2 * ELEM_MAX_BYTES);
35
36fn verify_ec_key_nid(
37    ec_key: &ConstPointer<EC_KEY>,
38    expected_curve_nid: i32,
39) -> Result<(), KeyRejected> {
40    let ec_group = ec_key
41        .project_const_lifetime(unsafe { |ec_key| EC_KEY_get0_group(ec_key.as_const_ptr()) })?;
42    let key_nid = unsafe { EC_GROUP_get_curve_name(ec_group.as_const_ptr()) };
43
44    if key_nid != expected_curve_nid {
45        return Err(KeyRejected::wrong_algorithm());
46    }
47    Ok(())
48}
49
50#[inline]
51#[cfg(not(feature = "fips"))]
52pub(crate) fn verify_evp_key_nid(
53    evp_pkey: &ConstPointer<EVP_PKEY>,
54    expected_curve_nid: i32,
55) -> Result<(), KeyRejected> {
56    let ec_key = evp_pkey.project_const_lifetime(unsafe {
57        |evp_pkey| EVP_PKEY_get0_EC_KEY(evp_pkey.as_const_ptr())
58    })?;
59    verify_ec_key_nid(&ec_key, expected_curve_nid)?;
60
61    Ok(())
62}
63
64#[inline]
65pub(crate) fn validate_ec_evp_key(
66    evp_pkey: &ConstPointer<EVP_PKEY>,
67    expected_curve_nid: i32,
68) -> Result<(), KeyRejected> {
69    let ec_key = evp_pkey.project_const_lifetime(unsafe {
70        |evp_pkey| EVP_PKEY_get0_EC_KEY(evp_pkey.as_const_ptr())
71    })?;
72    verify_ec_key_nid(&ec_key, expected_curve_nid)?;
73
74    #[cfg(not(feature = "fips"))]
75    if 1 != unsafe { EC_KEY_check_key(ec_key.as_const_ptr()) } {
76        return Err(KeyRejected::inconsistent_components());
77    }
78
79    #[cfg(feature = "fips")]
80    if 1 != indicator_check!(unsafe { EC_KEY_check_fips(ec_key.as_const_ptr()) }) {
81        return Err(KeyRejected::inconsistent_components());
82    }
83
84    Ok(())
85}
86
87#[inline]
88pub(crate) fn evp_key_generate(nid: c_int) -> Result<LcPtr<EVP_PKEY>, Unspecified> {
89    let params_fn = |ctx| {
90        if 1 == unsafe { EVP_PKEY_CTX_set_ec_paramgen_curve_nid(ctx, nid) } {
91            Ok(())
92        } else {
93            Err(())
94        }
95    };
96    LcPtr::<EVP_PKEY>::generate(EVP_PKEY_EC, Some(params_fn))
97}
98
99#[inline]
100#[allow(non_upper_case_globals)]
101pub(crate) fn ec_group_from_nid(nid: i32) -> Result<ConstPointer<'static, EC_GROUP>, Unspecified> {
102    Ok(unsafe {
103        ConstPointer::new_static(match nid {
104            NID_secp224r1 => EC_group_p224(),
105            NID_X9_62_prime256v1 => EC_group_p256(),
106            NID_secp384r1 => EC_group_p384(),
107            NID_secp521r1 => EC_group_p521(),
108            NID_secp256k1 => EC_group_secp256k1(),
109            _ => {
110                // OPENSSL_PUT_ERROR(EC, EC_R_UNKNOWN_GROUP);
111                null()
112            }
113        })?
114    })
115}
116
117#[inline]
118fn ecdsa_asn1_to_fixed(alg_id: &'static AlgorithmID, sig: &[u8]) -> Result<Signature, Unspecified> {
119    let expected_number_size = alg_id.private_key_size();
120
121    let ecdsa_sig = LcPtr::new(unsafe { ECDSA_SIG_from_bytes(sig.as_ptr(), sig.len()) })?;
122
123    let r_bn = ecdsa_sig.project_const_lifetime(unsafe {
124        |ecdsa_sig| ECDSA_SIG_get0_r(ecdsa_sig.as_const_ptr())
125    })?;
126    let r_buffer = r_bn.to_be_bytes();
127
128    let s_bn = ecdsa_sig.project_const_lifetime(unsafe {
129        |ecdsa_sig| ECDSA_SIG_get0_s(ecdsa_sig.as_const_ptr())
130    })?;
131    let s_buffer = s_bn.to_be_bytes();
132
133    Ok(Signature::new(|slice| {
134        let (r_start, r_end) = (expected_number_size - r_buffer.len(), expected_number_size);
135        let (s_start, s_end) = (
136            2 * expected_number_size - s_buffer.len(),
137            2 * expected_number_size,
138        );
139
140        slice[r_start..r_end].copy_from_slice(r_buffer.as_slice());
141        slice[s_start..s_end].copy_from_slice(s_buffer.as_slice());
142        2 * expected_number_size
143    }))
144}
145
146#[inline]
147pub(crate) const fn compressed_public_key_size_bytes(curve_field_bits: usize) -> usize {
148    1 + (curve_field_bits + 7) / 8
149}
150
151#[inline]
152pub(crate) const fn uncompressed_public_key_size_bytes(curve_field_bits: usize) -> usize {
153    1 + 2 * ((curve_field_bits + 7) / 8)
154}
155
156#[cfg(test)]
157mod tests {
158    use crate::encoding::{
159        AsBigEndian, AsDer, EcPublicKeyCompressedBin, EcPublicKeyUncompressedBin, PublicKeyX509Der,
160    };
161    use crate::signature::{
162        EcdsaKeyPair, KeyPair, UnparsedPublicKey, ECDSA_P256_SHA256_FIXED,
163        ECDSA_P256_SHA256_FIXED_SIGNING,
164    };
165    use crate::test::from_dirty_hex;
166    use crate::{signature, test};
167
168    #[test]
169    fn test_from_pkcs8() {
170        let input = from_dirty_hex(
171            r"308187020100301306072a8648ce3d020106082a8648ce3d030107046d306b0201010420090460075f15d
172            2a256248000fb02d83ad77593dde4ae59fc5e96142dffb2bd07a14403420004cf0d13a3a7577231ea1b66cf4
173            021cd54f21f4ac4f5f2fdd28e05bc7d2bd099d1374cd08d2ef654d6f04498db462f73e0282058dd661a4c9b0
174            437af3f7af6e724",
175        );
176
177        let result = EcdsaKeyPair::from_pkcs8(&ECDSA_P256_SHA256_FIXED_SIGNING, &input);
178        assert!(result.is_ok());
179        let key_pair = result.unwrap();
180        assert_eq!("EcdsaKeyPair { public_key: EcdsaPublicKey(\"04cf0d13a3a7577231ea1b66cf4021cd54f21f4ac4f5f2fdd28e05bc7d2bd099d1374cd08d2ef654d6f04498db462f73e0282058dd661a4c9b0437af3f7af6e724\") }",
181                   format!("{key_pair:?}"));
182        assert_eq!(
183            "EcdsaPrivateKey(ECDSA_P256)",
184            format!("{:?}", key_pair.private_key())
185        );
186        let pub_key = key_pair.public_key();
187        let der_pub_key: PublicKeyX509Der = pub_key.as_der().unwrap();
188
189        assert_eq!(
190            from_dirty_hex(
191                r"3059301306072a8648ce3d020106082a8648ce3d03010703420004cf0d13a3a7577231ea1b66cf402
192                1cd54f21f4ac4f5f2fdd28e05bc7d2bd099d1374cd08d2ef654d6f04498db462f73e0282058dd661a4c9
193                b0437af3f7af6e724",
194            )
195            .as_slice(),
196            der_pub_key.as_ref()
197        );
198    }
199
200    #[test]
201    fn test_ecdsa_asn1_verify() {
202        /*
203                Curve = P-256
204        Digest = SHA256
205        Msg = ""
206        Q = 0430345fd47ea21a11129be651b0884bfac698377611acc9f689458e13b9ed7d4b9d7599a68dcf125e7f31055ccb374cd04f6d6fd2b217438a63f6f667d50ef2f0
207        Sig = 30440220341f6779b75e98bb42e01095dd48356cbf9002dc704ac8bd2a8240b88d3796c60220555843b1b4e264fe6ffe6e2b705a376c05c09404303ffe5d2711f3e3b3a010a1
208        Result = P (0 )
209                 */
210
211        let alg = &signature::ECDSA_P256_SHA256_ASN1;
212        let msg = "";
213        let public_key = from_dirty_hex(
214            r"0430345fd47ea21a11129be651b0884bfac698377611acc9f689458e1
215        3b9ed7d4b9d7599a68dcf125e7f31055ccb374cd04f6d6fd2b217438a63f6f667d50ef2f0",
216        );
217        let sig = from_dirty_hex(
218            r"30440220341f6779b75e98bb42e01095dd48356cbf9002dc704ac8bd2a8240b8
219        8d3796c60220555843b1b4e264fe6ffe6e2b705a376c05c09404303ffe5d2711f3e3b3a010a1",
220        );
221        let unparsed_pub_key = signature::UnparsedPublicKey::new(alg, &public_key);
222
223        let actual_result = unparsed_pub_key.verify(msg.as_bytes(), &sig);
224        assert!(actual_result.is_ok(), "Key: {}", test::to_hex(public_key));
225    }
226
227    #[test]
228    fn public_key_formats() {
229        const MESSAGE: &[u8] = b"message to be signed";
230
231        let key_pair = EcdsaKeyPair::generate(&ECDSA_P256_SHA256_FIXED_SIGNING).unwrap();
232        let public_key = key_pair.public_key();
233        let as_ref_bytes = public_key.as_ref();
234        let compressed = AsBigEndian::<EcPublicKeyCompressedBin>::as_be_bytes(public_key).unwrap();
235        let uncompressed =
236            AsBigEndian::<EcPublicKeyUncompressedBin>::as_be_bytes(public_key).unwrap();
237        let pub_x509 = AsDer::<PublicKeyX509Der>::as_der(public_key).unwrap();
238        assert_eq!(as_ref_bytes, uncompressed.as_ref());
239        assert_ne!(compressed.as_ref()[0], 0x04);
240
241        let rng = crate::rand::SystemRandom::new();
242
243        let signature = key_pair.sign(&rng, MESSAGE).unwrap();
244
245        for pub_key_bytes in [
246            as_ref_bytes,
247            compressed.as_ref(),
248            uncompressed.as_ref(),
249            pub_x509.as_ref(),
250        ] {
251            UnparsedPublicKey::new(&ECDSA_P256_SHA256_FIXED, pub_key_bytes)
252                .verify(MESSAGE, signature.as_ref())
253                .unwrap();
254        }
255    }
256}