1 /*
2  * Copyright 2020-2023 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 <openssl/core_dispatch.h>
11 #include "prov/seeding.h"
12 #include "prov/providercommon.h"
13 
14 static OSSL_FUNC_get_entropy_fn *c_get_entropy = NULL;
15 static OSSL_FUNC_get_user_entropy_fn *c_get_user_entropy = NULL;
16 static OSSL_FUNC_cleanup_entropy_fn *c_cleanup_entropy = NULL;
17 static OSSL_FUNC_cleanup_user_entropy_fn *c_cleanup_user_entropy = NULL;
18 static OSSL_FUNC_get_nonce_fn *c_get_nonce = NULL;
19 static OSSL_FUNC_get_user_nonce_fn *c_get_user_nonce = NULL;
20 static OSSL_FUNC_cleanup_nonce_fn *c_cleanup_nonce = NULL;
21 static OSSL_FUNC_cleanup_user_nonce_fn *c_cleanup_user_nonce = NULL;
22 
23 #ifdef FIPS_MODULE
24 /*
25  * The FIPS provider uses an internal library context which is what the
26  * passed provider context references.  Since the seed source is external
27  * to the FIPS provider, this is the wrong one.  We need to convert this
28  * to the correct core handle before up-calling libcrypto.
29  */
30 # define CORE_HANDLE(provctx) \
31     FIPS_get_core_handle(ossl_prov_ctx_get0_libctx(provctx))
32 #else
33 /*
34  * The non-FIPS path *should* be unused because the full DRBG chain including
35  * seed source is instantiated.  However, that might not apply for third
36  * party providers, so this is retained for compatibility.
37  */
38 # define CORE_HANDLE(provctx) ossl_prov_ctx_get0_handle(provctx)
39 #endif
40 
ossl_prov_seeding_from_dispatch(const OSSL_DISPATCH * fns)41 int ossl_prov_seeding_from_dispatch(const OSSL_DISPATCH *fns)
42 {
43     for (; fns->function_id != 0; fns++) {
44         /*
45          * We do not support the scenario of an application linked against
46          * multiple versions of libcrypto (e.g. one static and one dynamic), but
47          * sharing a single fips.so. We do a simple sanity check here.
48          */
49 #define set_func(c, f) \
50     do { if (c == NULL) c = f; else if (c != f) return 0; } while (0)
51         switch (fns->function_id) {
52         case OSSL_FUNC_GET_ENTROPY:
53             set_func(c_get_entropy, OSSL_FUNC_get_entropy(fns));
54             break;
55         case OSSL_FUNC_GET_USER_ENTROPY:
56             set_func(c_get_user_entropy, OSSL_FUNC_get_user_entropy(fns));
57             break;
58         case OSSL_FUNC_CLEANUP_ENTROPY:
59             set_func(c_cleanup_entropy, OSSL_FUNC_cleanup_entropy(fns));
60             break;
61         case OSSL_FUNC_CLEANUP_USER_ENTROPY:
62             set_func(c_cleanup_user_entropy, OSSL_FUNC_cleanup_user_entropy(fns));
63             break;
64         case OSSL_FUNC_GET_NONCE:
65             set_func(c_get_nonce, OSSL_FUNC_get_nonce(fns));
66             break;
67         case OSSL_FUNC_GET_USER_NONCE:
68             set_func(c_get_user_nonce, OSSL_FUNC_get_user_nonce(fns));
69             break;
70         case OSSL_FUNC_CLEANUP_NONCE:
71             set_func(c_cleanup_nonce, OSSL_FUNC_cleanup_nonce(fns));
72             break;
73         case OSSL_FUNC_CLEANUP_USER_NONCE:
74             set_func(c_cleanup_user_nonce, OSSL_FUNC_cleanup_user_nonce(fns));
75             break;
76         }
77 #undef set_func
78     }
79     return 1;
80 }
81 
ossl_prov_get_entropy(PROV_CTX * prov_ctx,unsigned char ** pout,int entropy,size_t min_len,size_t max_len)82 size_t ossl_prov_get_entropy(PROV_CTX *prov_ctx, unsigned char **pout,
83                              int entropy, size_t min_len, size_t max_len)
84 {
85     const OSSL_CORE_HANDLE *handle = CORE_HANDLE(prov_ctx);
86 
87     if (c_get_user_entropy != NULL)
88         return c_get_user_entropy(handle, pout, entropy, min_len, max_len);
89     if (c_get_entropy != NULL)
90         return c_get_entropy(handle, pout, entropy, min_len, max_len);
91     return 0;
92 }
93 
ossl_prov_cleanup_entropy(PROV_CTX * prov_ctx,unsigned char * buf,size_t len)94 void ossl_prov_cleanup_entropy(PROV_CTX *prov_ctx, unsigned char *buf,
95                                size_t len)
96 {
97     const OSSL_CORE_HANDLE *handle = CORE_HANDLE(prov_ctx);
98 
99     if (c_cleanup_user_entropy != NULL)
100         c_cleanup_user_entropy(handle, buf, len);
101     else if (c_cleanup_entropy != NULL)
102         c_cleanup_entropy(handle, buf, len);
103 }
104 
ossl_prov_get_nonce(PROV_CTX * prov_ctx,unsigned char ** pout,size_t min_len,size_t max_len,const void * salt,size_t salt_len)105 size_t ossl_prov_get_nonce(PROV_CTX *prov_ctx, unsigned char **pout,
106                            size_t min_len, size_t max_len,
107                            const void *salt, size_t salt_len)
108 {
109     const OSSL_CORE_HANDLE *handle = CORE_HANDLE(prov_ctx);
110 
111     if (c_get_user_nonce != NULL)
112         return c_get_user_nonce(handle, pout, min_len, max_len, salt, salt_len);
113     if (c_get_nonce != NULL)
114         return c_get_nonce(handle, pout, min_len, max_len, salt, salt_len);
115     return 0;
116 }
117 
ossl_prov_cleanup_nonce(PROV_CTX * prov_ctx,unsigned char * buf,size_t len)118 void ossl_prov_cleanup_nonce(PROV_CTX *prov_ctx, unsigned char *buf, size_t len)
119 {
120     const OSSL_CORE_HANDLE *handle = CORE_HANDLE(prov_ctx);
121 
122     if (c_cleanup_user_nonce != NULL)
123         c_cleanup_user_nonce(handle, buf, len);
124     else if (c_cleanup_nonce != NULL)
125         c_cleanup_nonce(handle, buf, len);
126 }
127