1 /*
2  * Copyright 2024-2025 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the Apache License 2.0 (the "License").  You may not use
5  * this file except in compliance with the License.  You can obtain a copy
6  * in the file LICENSE in the source distribution or at
7  * https://www.openssl.org/source/license.html
8  */
9 
10 #include <string.h>
11 #include <openssl/opensslconf.h>
12 #include <openssl/rand.h>
13 #include <openssl/core_names.h>
14 #ifndef OPENSSL_NO_STDIO
15 # include <stdio.h>
16 #endif
17 #include <crypto/ml_kem.h>
18 #include "testutil.h"
19 #include "testutil/output.h"
20 
21 static uint8_t ml_kem_private_entropy[] = {
22     /* Seed for genkey */
23     0x7c, 0x99, 0x35, 0xa0, 0xb0, 0x76, 0x94, 0xaa, 0x0c, 0x6d, 0x10, 0xe4,
24     0xdb, 0x6b, 0x1a, 0xdd, 0x2f, 0xd8, 0x1a, 0x25, 0xcc, 0xb1, 0x48, 0x03,
25     0x2d, 0xcd, 0x73, 0x99, 0x36, 0x73, 0x7f, 0x2d, 0x86, 0x26, 0xed, 0x79,
26     0xd4, 0x51, 0x14, 0x08, 0x00, 0xe0, 0x3b, 0x59, 0xb9, 0x56, 0xf8, 0x21,
27     0x0e, 0x55, 0x60, 0x67, 0x40, 0x7d, 0x13, 0xdc, 0x90, 0xfa, 0x9e, 0x8b,
28     0x87, 0x2b, 0xfb, 0x8f
29 };
30 static uint8_t ml_kem_public_entropy[] = {
31     /* Seed for encap */
32     0x14, 0x7c, 0x03, 0xf7, 0xa5, 0xbe, 0xbb, 0xa4, 0x06, 0xc8, 0xfa, 0xe1,
33     0x87, 0x4d, 0x7f, 0x13, 0xc8, 0x0e, 0xfe, 0x79, 0xa3, 0xa9, 0xa8, 0x74,
34     0xcc, 0x09, 0xfe, 0x76, 0xf6, 0x99, 0x76, 0x15,
35     /* Seed for decap on length error */
36     0x4e, 0x6f, 0x74, 0x20, 0x74, 0x68, 0x65, 0x20, 0x64, 0x72, 0x6f, 0x69,
37     0x64, 0x73, 0x20, 0x79, 0x6f, 0x75, 0x27, 0x72, 0x65, 0x20, 0x6c, 0x6f,
38     0x6f, 0x6b, 0x69, 0x6e, 0x67, 0x20, 0x66, 0x6f
39 };
40 static uint8_t ml_kem_expected_rho[3][ML_KEM_RANDOM_BYTES] = {
41     {
42         0x7e, 0xfb, 0x9e, 0x40, 0xc3, 0xbf, 0x0f, 0xf0, 0x43, 0x29, 0x86, 0xae,
43         0x4b, 0xc1, 0xa2, 0x42, 0xce, 0x99, 0x21, 0xaa, 0x9e, 0x22, 0x44, 0x88,
44         0x19, 0x58, 0x5d, 0xea, 0x30, 0x8e, 0xb0, 0x39
45     },
46     {
47         0x16, 0x2e, 0xc0, 0x98, 0xa9, 0x00, 0xb1, 0x2d, 0xd8, 0xfa, 0xbb, 0xfb,
48         0x3f, 0xe8, 0xcb, 0x1d, 0xc4, 0xe8, 0x31, 0x5f, 0x2a, 0xf0, 0xd3, 0x2f,
49         0x00, 0x17, 0xae, 0x13, 0x6e, 0x19, 0xf0, 0x28
50     },
51     {
52         0x29, 0xb4, 0xf9, 0xf8, 0xcf, 0xba, 0xdf, 0x2e, 0x41, 0x86, 0x9a, 0xbf,
53         0xba, 0xd1, 0x07, 0x38, 0xad, 0x04, 0xcc, 0x75, 0x2b, 0xc2, 0x0c, 0x39,
54         0x47, 0x46, 0x85, 0x0e, 0x0c, 0x48, 0x47, 0xdb
55     }
56 };
57 static uint8_t ml_kem_expected_ctext_sha256[3][32] = {
58     {
59         0xbc, 0x29, 0xd7, 0xdf, 0x8b, 0xc5, 0x46, 0x5d, 0x98, 0x06, 0x01, 0xd8,
60         0x00, 0x25, 0x97, 0x93, 0xe2, 0x60, 0x38, 0x25, 0xa5, 0x72, 0xda, 0x6c,
61         0xd1, 0x98, 0xa5, 0x12, 0xcc, 0x6d, 0x1a, 0x34
62     },
63     {
64         0x36, 0x82, 0x9a, 0x2f, 0x35, 0xcb, 0xf4, 0xde, 0xb6, 0x2c, 0x0a, 0x12,
65         0xa1, 0x5c, 0x22, 0xda, 0xe9, 0xf8, 0xd2, 0xc2, 0x52, 0x56, 0x6f, 0xc2,
66         0x4f, 0x88, 0xab, 0xe8, 0x05, 0xcb, 0x57, 0x5e
67     },
68     {
69         0x50, 0x81, 0x36, 0xa1, 0x3f, 0x8a, 0x79, 0x20, 0xe3, 0x43, 0x44, 0x98,
70         0xc6, 0x97, 0x5c, 0xbb, 0xab, 0x45, 0x7d, 0x80, 0x93, 0x09, 0xeb, 0x2f,
71         0x92, 0x45, 0x3e, 0x74, 0x09, 0x73, 0x82, 0x10
72     }
73 };
74 static uint8_t ml_kem_expected_shared_secret[3][32] = {
75     {
76         0x31, 0x98, 0x39, 0xe8, 0x2a, 0xb6, 0xb2, 0x22, 0xde, 0x7b, 0x61, 0x9e,
77         0x80, 0xda, 0x83, 0x91, 0x52, 0x2b, 0xbb, 0x37, 0x67, 0x70, 0x18, 0x49,
78         0x4a, 0x47, 0x42, 0xc5, 0x3f, 0x9a, 0xbf, 0xdf
79     },
80     {
81         0xe7, 0x18, 0x4a, 0x09, 0x75, 0xee, 0x34, 0x70, 0x87, 0x8d, 0x2d, 0x15,
82         0x9e, 0xc8, 0x31, 0x29, 0xc8, 0xae, 0xc2, 0x53, 0xd4, 0xee, 0x17, 0xb4,
83         0x81, 0x03, 0x11, 0xd1, 0x98, 0xcd, 0x03, 0x68
84     },
85     {
86         0x48, 0x9d, 0xd1, 0xe9, 0xc2, 0xbe, 0x4a, 0xf3, 0x48, 0x2b, 0xdb, 0x35,
87         0xbb, 0x26, 0xce, 0x76, 0x0e, 0x6e, 0x41, 0x4d, 0xa6, 0xec, 0xbe, 0x48,
88         0x99, 0x85, 0x74, 0x8a, 0x82, 0x5f, 0x1c, 0xd6
89     },
90 };
91 
92 
sanity_test(void)93 static int sanity_test(void)
94 {
95     static const int alg[3] = {
96         EVP_PKEY_ML_KEM_512,
97         EVP_PKEY_ML_KEM_768,
98         EVP_PKEY_ML_KEM_1024
99     };
100     EVP_RAND_CTX *privctx;
101     EVP_RAND_CTX *pubctx;
102     EVP_MD *sha256 = EVP_MD_fetch(NULL, "sha256", NULL);
103     uint8_t *decap_entropy;
104     int i, ret = 0;
105 
106     if (!TEST_ptr(sha256))
107         return 0;
108 
109     if (!TEST_ptr(privctx = RAND_get0_private(NULL))
110         || !TEST_ptr(pubctx = RAND_get0_public(NULL))) {
111         ret = -1;
112         goto err;
113     }
114 
115     decap_entropy = ml_kem_public_entropy + ML_KEM_RANDOM_BYTES;
116 
117     for (i = 0; i < (int) OSSL_NELEM(alg); ++i) {
118         OSSL_PARAM params[3];
119         uint8_t hash[32];
120         uint8_t shared_secret[ML_KEM_SHARED_SECRET_BYTES];
121         uint8_t shared_secret2[ML_KEM_SHARED_SECRET_BYTES];
122         uint8_t *encoded_public_key = NULL;
123         uint8_t *ciphertext = NULL;
124         ML_KEM_KEY *private_key = NULL;
125         ML_KEM_KEY *public_key = NULL;
126         int ret2 = -1;
127         unsigned char c;
128         unsigned int strength = 256;
129         const ML_KEM_VINFO *v;
130 
131         /* Configure the private RNG to output just the keygen seed */
132         params[0] =
133             OSSL_PARAM_construct_octet_string(OSSL_RAND_PARAM_TEST_ENTROPY,
134                                               ml_kem_private_entropy,
135                                               sizeof(ml_kem_private_entropy));
136         params[1] =
137             OSSL_PARAM_construct_uint(OSSL_RAND_PARAM_STRENGTH, &strength);
138         params[2] = OSSL_PARAM_construct_end();
139         if (!TEST_true(EVP_RAND_CTX_set_params(privctx, params))) {
140             ret = -1;
141             goto err;
142         }
143 
144         public_key = ossl_ml_kem_key_new(NULL, NULL, alg[i]);
145         private_key = ossl_ml_kem_key_new(NULL, NULL, alg[i]);
146         if (private_key == NULL || public_key == NULL
147             || (v = ossl_ml_kem_key_vinfo(public_key)) == NULL)
148             goto done;
149 
150         encoded_public_key = OPENSSL_malloc(v->pubkey_bytes);
151         ciphertext = OPENSSL_malloc(v->ctext_bytes);
152         if (encoded_public_key == NULL || ciphertext == NULL)
153             goto done;
154 
155         ret2 = -2;
156         /* Generate a private key */
157         if (!ossl_ml_kem_genkey(encoded_public_key, v->pubkey_bytes,
158                                 private_key))
159             goto done;
160 
161         /* Check that no more entropy is available! */
162         if (!TEST_int_le(RAND_priv_bytes(&c, 1), 0))
163             goto done;
164 
165         ret2 = -3;
166         /* Check that we got the expected 'rho' value in the ciphertext */
167         if (!TEST_mem_eq(encoded_public_key + v->vector_bytes,
168                          ML_KEM_RANDOM_BYTES,
169                          ml_kem_expected_rho[i],
170                          ML_KEM_RANDOM_BYTES))
171             goto done;
172 
173         ret2 = -4;
174         /* Create the expected associated public key */
175         if (!ossl_ml_kem_parse_public_key(encoded_public_key, v->pubkey_bytes,
176                                           public_key))
177             goto done;
178 
179         /* Configure the public RNG to output the encap and decap seeds */
180         params[0] =
181             OSSL_PARAM_construct_octet_string(OSSL_RAND_PARAM_TEST_ENTROPY,
182                                               ml_kem_public_entropy,
183                                               sizeof(ml_kem_public_entropy));
184         if (!TEST_true(EVP_RAND_CTX_set_params(pubctx, params)))
185             goto done;
186 
187         /* encaps - decaps test: validate shared secret equality */
188         ret2 = -5;
189         if (!ossl_ml_kem_encap_rand(ciphertext, v->ctext_bytes,
190                                     shared_secret, sizeof(shared_secret),
191                                     public_key))
192             goto done;
193 
194         ret2 = -6;
195         /* Check the ciphertext hash */
196         if (!TEST_true(EVP_Digest(ciphertext, v->ctext_bytes,
197                                   hash, NULL, sha256, NULL))
198             || !TEST_mem_eq(hash, sizeof(hash),
199                             ml_kem_expected_ctext_sha256[i],
200                             sizeof(ml_kem_expected_ctext_sha256[i])))
201             goto done;
202 
203         /* Check for the expected shared secret */
204         if (!TEST_mem_eq(shared_secret, sizeof(shared_secret),
205                          ml_kem_expected_shared_secret[i],
206                          ML_KEM_SHARED_SECRET_BYTES))
207             goto done;
208 
209         /* Now decapsulate the ciphertext */
210         ret2 = -7;
211         if (!ossl_ml_kem_decap(shared_secret2, sizeof(shared_secret2),
212                                ciphertext, v->ctext_bytes, private_key))
213             goto done;
214 
215         /* Check for the same shared secret */
216         if (!TEST_mem_eq(shared_secret, sizeof(shared_secret),
217                          shared_secret2, sizeof(shared_secret2)))
218             goto done;
219 
220         ret2 = -8;
221         /* Now a quick negative test by zeroing the ciphertext */
222         memset(ciphertext, 0, v->ctext_bytes);
223         if (!TEST_true(ossl_ml_kem_decap(shared_secret2, sizeof(shared_secret2),
224                                          ciphertext, v->ctext_bytes,
225                                          private_key)))
226             goto done;
227 
228         /* Ensure we have a mismatch */
229         if (!TEST_mem_ne(shared_secret, sizeof(shared_secret),
230                          shared_secret2, sizeof(shared_secret2)))
231             goto done;
232 
233         ret2 = -9;
234         /*
235          * Change the ciphertext length, decap should fail, but and consume the
236          * last batch of entropy to return a fake shared secret, just in case.
237          */
238         if (!TEST_false(ossl_ml_kem_decap(shared_secret2, sizeof(shared_secret2),
239                                           ciphertext, v->ctext_bytes - 1,
240                                           private_key)))
241             goto done;
242 
243         if (!TEST_mem_eq(shared_secret2, sizeof(shared_secret2),
244                          decap_entropy, ML_KEM_SHARED_SECRET_BYTES))
245             goto done;
246 
247         /* Check that no more entropy is available! */
248         if (!TEST_int_le(RAND_bytes(&c, 1), 0))
249             goto done;
250 
251         ret2 = 0;
252 
253     done:
254         if (ret2 != 0)
255             ret = ret2;
256         ossl_ml_kem_key_free(private_key);
257         ossl_ml_kem_key_free(public_key);
258         OPENSSL_free(encoded_public_key);
259         OPENSSL_free(ciphertext);
260     }
261 
262 err:
263     EVP_MD_free(sha256);
264     return ret == 0;
265 }
266 
setup_tests(void)267 int setup_tests(void)
268 {
269     if (!TEST_true(RAND_set_DRBG_type(NULL, "TEST-RAND", "fips=no", NULL, NULL)))
270         return 0;
271 
272     ADD_TEST(sanity_test);
273     return 1;
274 }
275