2 * Copyright 2020 The OpenSSL Project Authors. All Rights Reserved.
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
11 * RSA low level APIs are deprecated for public use, but still ok for
14 #include "internal/deprecated.h"
16 #include "e_os.h" /* strcasecmp */
17 #include <openssl/crypto.h>
18 #include <openssl/evp.h>
19 #include <openssl/core_dispatch.h>
20 #include <openssl/core_names.h>
21 #include <openssl/rsa.h>
22 #include <openssl/params.h>
23 #include <openssl/err.h>
24 #include <crypto/rsa.h>
25 #include <openssl/proverr.h>
26 #include "prov/provider_ctx.h"
27 #include "prov/implementations.h"
28 #include "prov/securitycheck.h"
30 static OSSL_FUNC_kem_newctx_fn rsakem_newctx;
31 static OSSL_FUNC_kem_encapsulate_init_fn rsakem_encapsulate_init;
32 static OSSL_FUNC_kem_encapsulate_fn rsakem_generate;
33 static OSSL_FUNC_kem_decapsulate_init_fn rsakem_decapsulate_init;
34 static OSSL_FUNC_kem_decapsulate_fn rsakem_recover;
35 static OSSL_FUNC_kem_freectx_fn rsakem_freectx;
36 static OSSL_FUNC_kem_dupctx_fn rsakem_dupctx;
37 static OSSL_FUNC_kem_get_ctx_params_fn rsakem_get_ctx_params;
38 static OSSL_FUNC_kem_gettable_ctx_params_fn rsakem_gettable_ctx_params;
39 static OSSL_FUNC_kem_set_ctx_params_fn rsakem_set_ctx_params;
40 static OSSL_FUNC_kem_settable_ctx_params_fn rsakem_settable_ctx_params;
43 * Only the KEM for RSASVE as defined in SP800-56b r2 is implemented
46 #define KEM_OP_UNDEFINED -1
47 #define KEM_OP_RSASVE 0
50 * What's passed as an actual key is defined by the KEYMGMT interface.
51 * We happen to know that our KEYMGMT simply passes RSA structures, so
52 * we use that here too.
60 static const OSSL_ITEM rsakem_opname_id_map[] = {
61 { KEM_OP_RSASVE, OSSL_KEM_PARAM_OPERATION_RSASVE },
64 static int name2id(const char *name, const OSSL_ITEM *map, size_t sz)
71 for (i = 0; i < sz; ++i) {
72 if (strcasecmp(map[i].ptr, name) == 0)
78 static int rsakem_opname2id(const char *name)
80 return name2id(name, rsakem_opname_id_map, OSSL_NELEM(rsakem_opname_id_map));
83 static void *rsakem_newctx(void *provctx)
85 PROV_RSA_CTX *prsactx = OPENSSL_zalloc(sizeof(PROV_RSA_CTX));
89 prsactx->libctx = PROV_LIBCTX_OF(provctx);
90 prsactx->op = KEM_OP_UNDEFINED;
95 static void rsakem_freectx(void *vprsactx)
97 PROV_RSA_CTX *prsactx = (PROV_RSA_CTX *)vprsactx;
99 RSA_free(prsactx->rsa);
100 OPENSSL_free(prsactx);
103 static void *rsakem_dupctx(void *vprsactx)
105 PROV_RSA_CTX *srcctx = (PROV_RSA_CTX *)vprsactx;
106 PROV_RSA_CTX *dstctx;
108 dstctx = OPENSSL_zalloc(sizeof(*srcctx));
113 if (dstctx->rsa != NULL && !RSA_up_ref(dstctx->rsa)) {
114 OPENSSL_free(dstctx);
120 static int rsakem_init(void *vprsactx, void *vrsa, int operation)
122 PROV_RSA_CTX *prsactx = (PROV_RSA_CTX *)vprsactx;
124 if (prsactx == NULL || vrsa == NULL || !RSA_up_ref(vrsa))
126 RSA_free(prsactx->rsa);
129 if (!ossl_rsa_check_key(vrsa, operation == EVP_PKEY_OP_ENCAPSULATE)) {
130 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
136 static int rsakem_encapsulate_init(void *vprsactx, void *vrsa)
138 return rsakem_init(vprsactx, vrsa, EVP_PKEY_OP_ENCAPSULATE);
141 static int rsakem_decapsulate_init(void *vprsactx, void *vrsa)
143 return rsakem_init(vprsactx, vrsa, EVP_PKEY_OP_DECAPSULATE);
146 static int rsakem_get_ctx_params(void *vprsactx, OSSL_PARAM *params)
148 PROV_RSA_CTX *ctx = (PROV_RSA_CTX *)vprsactx;
150 if (ctx == NULL || params == NULL)
155 static const OSSL_PARAM known_gettable_rsakem_ctx_params[] = {
159 static const OSSL_PARAM *rsakem_gettable_ctx_params(ossl_unused void *provctx)
161 return known_gettable_rsakem_ctx_params;
164 static int rsakem_set_ctx_params(void *vprsactx, const OSSL_PARAM params[])
166 PROV_RSA_CTX *prsactx = (PROV_RSA_CTX *)vprsactx;
170 if (prsactx == NULL || params == NULL)
173 p = OSSL_PARAM_locate_const(params, OSSL_KEM_PARAM_OPERATION);
175 if (p->data_type != OSSL_PARAM_UTF8_STRING)
177 op = rsakem_opname2id(p->data);
185 static const OSSL_PARAM known_settable_rsakem_ctx_params[] = {
186 OSSL_PARAM_utf8_string(OSSL_KEM_PARAM_OPERATION, NULL, 0),
190 static const OSSL_PARAM *rsakem_settable_ctx_params(ossl_unused void *provctx)
192 return known_settable_rsakem_ctx_params;
197 * 7.2.1.2 RSASVE Generate Operation (RSASVE.GENERATE).
199 * Generate a random in the range 1 < z < (n – 1)
201 static int rsasve_gen_rand_bytes(RSA *rsa_pub,
202 unsigned char *out, int outlen)
208 bnctx = BN_CTX_secure_new_ex(ossl_rsa_get0_libctx(rsa_pub));
213 * Generate a random in the range 1 < z < (n – 1).
214 * Since BN_priv_rand_range_ex() returns a value in range 0 <= r < max
215 * We can achieve this by adding 2.. but then we need to subtract 3 from
216 * the upper bound i.e: 2 + (0 <= r < (n - 3))
219 nminus3 = BN_CTX_get(bnctx);
220 z = BN_CTX_get(bnctx);
222 && (BN_copy(nminus3, RSA_get0_n(rsa_pub)) != NULL)
223 && BN_sub_word(nminus3, 3)
224 && BN_priv_rand_range_ex(z, nminus3, bnctx)
226 && (BN_bn2binpad(z, out, outlen) == outlen));
234 * 7.2.1.2 RSASVE Generate Operation (RSASVE.GENERATE).
236 static int rsasve_generate(PROV_RSA_CTX *prsactx,
237 unsigned char *out, size_t *outlen,
238 unsigned char *secret, size_t *secretlen)
243 /* Step (1): nlen = Ceil(len(n)/8) */
244 nlen = RSA_size(prsactx->rsa);
248 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY);
251 if (outlen == NULL && secretlen == NULL)
255 if (secretlen != NULL)
260 * Step (2): Generate a random byte string z of nlen bytes where
263 if (!rsasve_gen_rand_bytes(prsactx->rsa, secret, nlen))
266 /* Step(3): out = RSAEP((n,e), z) */
267 ret = RSA_public_encrypt(nlen, secret, out, prsactx->rsa, RSA_NO_PADDING);
272 if (secretlen != NULL)
275 OPENSSL_cleanse(secret, nlen);
282 * 7.2.1.3 RSASVE Recovery Operation (RSASVE.RECOVER).
284 static int rsasve_recover(PROV_RSA_CTX *prsactx,
285 unsigned char *out, size_t *outlen,
286 const unsigned char *in, size_t inlen)
290 /* Step (1): get the byte length of n */
291 nlen = RSA_size(prsactx->rsa);
295 ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY);
302 /* Step (2): check the input ciphertext 'inlen' matches the nlen */
304 ERR_raise(ERR_LIB_PROV, PROV_R_BAD_LENGTH);
307 /* Step (3): out = RSADP((n,d), in) */
308 return (RSA_private_decrypt(inlen, in, out, prsactx->rsa, RSA_NO_PADDING) > 0);
311 static int rsakem_generate(void *vprsactx, unsigned char *out, size_t *outlen,
312 unsigned char *secret, size_t *secretlen)
314 PROV_RSA_CTX *prsactx = (PROV_RSA_CTX *)vprsactx;
316 switch (prsactx->op) {
318 return rsasve_generate(prsactx, out, outlen, secret, secretlen);
324 static int rsakem_recover(void *vprsactx, unsigned char *out, size_t *outlen,
325 const unsigned char *in, size_t inlen)
327 PROV_RSA_CTX *prsactx = (PROV_RSA_CTX *)vprsactx;
329 switch (prsactx->op) {
331 return rsasve_recover(prsactx, out, outlen, in, inlen);
337 const OSSL_DISPATCH ossl_rsa_asym_kem_functions[] = {
338 { OSSL_FUNC_KEM_NEWCTX, (void (*)(void))rsakem_newctx },
339 { OSSL_FUNC_KEM_ENCAPSULATE_INIT,
340 (void (*)(void))rsakem_encapsulate_init },
341 { OSSL_FUNC_KEM_ENCAPSULATE, (void (*)(void))rsakem_generate },
342 { OSSL_FUNC_KEM_DECAPSULATE_INIT,
343 (void (*)(void))rsakem_decapsulate_init },
344 { OSSL_FUNC_KEM_DECAPSULATE, (void (*)(void))rsakem_recover },
345 { OSSL_FUNC_KEM_FREECTX, (void (*)(void))rsakem_freectx },
346 { OSSL_FUNC_KEM_DUPCTX, (void (*)(void))rsakem_dupctx },
347 { OSSL_FUNC_KEM_GET_CTX_PARAMS,
348 (void (*)(void))rsakem_get_ctx_params },
349 { OSSL_FUNC_KEM_GETTABLE_CTX_PARAMS,
350 (void (*)(void))rsakem_gettable_ctx_params },
351 { OSSL_FUNC_KEM_SET_CTX_PARAMS,
352 (void (*)(void))rsakem_set_ctx_params },
353 { OSSL_FUNC_KEM_SETTABLE_CTX_PARAMS,
354 (void (*)(void))rsakem_settable_ctx_params },