--- /dev/null
+/*
+ * Copyright 2020 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the Apache License 2.0 (the "License"). You may not use
+ * this file except in compliance with the License. You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
+ */
+
+/*
+ * RSA low level APIs are deprecated for public use, but still ok for
+ * internal use.
+ */
+#include "internal/deprecated.h"
+
+#include "e_os.h" /* strcasecmp */
+#include <openssl/crypto.h>
+#include <openssl/evp.h>
+#include <openssl/core_dispatch.h>
+#include <openssl/core_names.h>
+#include <openssl/rsa.h>
+#include <openssl/params.h>
+#include <openssl/err.h>
+#include <crypto/rsa.h>
+#include "prov/providercommonerr.h"
+#include "prov/provider_ctx.h"
+#include "prov/implementations.h"
+
+static OSSL_FUNC_kem_newctx_fn rsakem_newctx;
+static OSSL_FUNC_kem_encapsulate_init_fn rsakem_init;
+static OSSL_FUNC_kem_encapsulate_fn rsakem_generate;
+static OSSL_FUNC_kem_decapsulate_init_fn rsakem_init;
+static OSSL_FUNC_kem_decapsulate_fn rsakem_recover;
+static OSSL_FUNC_kem_freectx_fn rsakem_freectx;
+static OSSL_FUNC_kem_dupctx_fn rsakem_dupctx;
+static OSSL_FUNC_kem_get_ctx_params_fn rsakem_get_ctx_params;
+static OSSL_FUNC_kem_gettable_ctx_params_fn rsakem_gettable_ctx_params;
+static OSSL_FUNC_kem_set_ctx_params_fn rsakem_set_ctx_params;
+static OSSL_FUNC_kem_settable_ctx_params_fn rsakem_settable_ctx_params;
+
+/*
+ * Only the KEM for RSASVE as defined in SP800-56b r2 is implemented
+ * currently.
+ */
+#define KEM_OP_UNDEFINED -1
+#define KEM_OP_RSASVE 0
+
+/*
+ * What's passed as an actual key is defined by the KEYMGMT interface.
+ * We happen to know that our KEYMGMT simply passes RSA structures, so
+ * we use that here too.
+ */
+typedef struct {
+ OPENSSL_CTX *libctx;
+ RSA *rsa;
+ int op;
+} PROV_RSA_CTX;
+
+static const OSSL_ITEM rsakem_opname_id_map[] = {
+ { KEM_OP_RSASVE, OSSL_KEM_PARAM_OPERATION_RSASVE },
+};
+
+static int name2id(const char *name, const OSSL_ITEM *map, size_t sz)
+{
+ size_t i;
+
+ if (name == NULL)
+ return -1;
+
+ for (i = 0; i < sz; ++i) {
+ if (strcasecmp(map[i].ptr, name) == 0)
+ return map[i].id;
+ }
+ return -1;
+}
+
+static int rsakem_opname2id(const char *name)
+{
+ return name2id(name, rsakem_opname_id_map, OSSL_NELEM(rsakem_opname_id_map));
+}
+
+static void *rsakem_newctx(void *provctx)
+{
+ PROV_RSA_CTX *prsactx = OPENSSL_zalloc(sizeof(PROV_RSA_CTX));
+
+ if (prsactx == NULL)
+ return NULL;
+ prsactx->libctx = PROV_LIBRARY_CONTEXT_OF(provctx);
+ prsactx->op = KEM_OP_UNDEFINED;
+
+ return prsactx;
+}
+
+static void rsakem_freectx(void *vprsactx)
+{
+ PROV_RSA_CTX *prsactx = (PROV_RSA_CTX *)vprsactx;
+
+ RSA_free(prsactx->rsa);
+ OPENSSL_free(prsactx);
+}
+
+static void *rsakem_dupctx(void *vprsactx)
+{
+ PROV_RSA_CTX *srcctx = (PROV_RSA_CTX *)vprsactx;
+ PROV_RSA_CTX *dstctx;
+
+ dstctx = OPENSSL_zalloc(sizeof(*srcctx));
+ if (dstctx == NULL)
+ return NULL;
+
+ *dstctx = *srcctx;
+ if (dstctx->rsa != NULL && !RSA_up_ref(dstctx->rsa)) {
+ OPENSSL_free(dstctx);
+ return NULL;
+ }
+ return dstctx;
+}
+
+static int rsakem_init(void *vprsactx, void *vrsa)
+{
+ PROV_RSA_CTX *prsactx = (PROV_RSA_CTX *)vprsactx;
+
+ if (prsactx == NULL || vrsa == NULL || !RSA_up_ref(vrsa))
+ return 0;
+ RSA_free(prsactx->rsa);
+ prsactx->rsa = vrsa;
+ /* TODO(3.0) Add a RSA keylength check here for fips */
+ return 1;
+}
+
+static int rsakem_get_ctx_params(void *vprsactx, OSSL_PARAM *params)
+{
+ PROV_RSA_CTX *ctx = (PROV_RSA_CTX *)vprsactx;
+
+ if (ctx == NULL || params == NULL)
+ return 0;
+ return 1;
+}
+
+static const OSSL_PARAM known_gettable_rsakem_ctx_params[] = {
+ OSSL_PARAM_END
+};
+
+static const OSSL_PARAM *rsakem_gettable_ctx_params(ossl_unused void *provctx)
+{
+ return known_gettable_rsakem_ctx_params;
+}
+
+static int rsakem_set_ctx_params(void *vprsactx, const OSSL_PARAM params[])
+{
+ PROV_RSA_CTX *prsactx = (PROV_RSA_CTX *)vprsactx;
+ const OSSL_PARAM *p;
+ int op;
+
+ if (prsactx == NULL || params == NULL)
+ return 0;
+
+ p = OSSL_PARAM_locate_const(params, OSSL_KEM_PARAM_OPERATION);
+ if (p != NULL) {
+ if (p->data_type != OSSL_PARAM_UTF8_STRING)
+ return 0;
+ op = rsakem_opname2id(p->data);
+ if (op < 0)
+ return 0;
+ prsactx->op = op;
+ }
+ return 1;
+}
+
+static const OSSL_PARAM known_settable_rsakem_ctx_params[] = {
+ OSSL_PARAM_utf8_string(OSSL_KEM_PARAM_OPERATION, NULL, 0),
+ OSSL_PARAM_END
+};
+
+static const OSSL_PARAM *rsakem_settable_ctx_params(ossl_unused void *provctx)
+{
+ return known_settable_rsakem_ctx_params;
+}
+
+/*
+ * NIST.SP.800-56Br2
+ * 7.2.1.2 RSASVE Generate Operation (RSASVE.GENERATE).
+ *
+ * Generate a random in the range 1 < z < (n – 1)
+ */
+static int rsasve_gen_rand_bytes(RSA *rsa_pub,
+ unsigned char *out, int outlen)
+{
+ int ret = 0;
+ BN_CTX *bnctx;
+ BIGNUM *z, *nminus3;
+
+ bnctx = BN_CTX_secure_new_ex(rsa_get0_libctx(rsa_pub));
+ if (bnctx == NULL)
+ return 0;
+
+ /*
+ * Generate a random in the range 1 < z < (n – 1).
+ * Since BN_priv_rand_range_ex() returns a value in range 0 <= r < max
+ * We can achieve this by adding 2.. but then we need to subtract 3 from
+ * the upper bound i.e: 2 + (0 <= r < (n - 3))
+ */
+ BN_CTX_start(bnctx);
+ nminus3 = BN_CTX_get(bnctx);
+ z = BN_CTX_get(bnctx);
+ ret = (z != NULL
+ && (BN_copy(nminus3, RSA_get0_n(rsa_pub)) != NULL)
+ && BN_sub_word(nminus3, 3)
+ && BN_priv_rand_range_ex(z, nminus3, bnctx)
+ && BN_add_word(z, 2)
+ && (BN_bn2binpad(z, out, outlen) == outlen));
+ BN_CTX_end(bnctx);
+ BN_CTX_free(bnctx);
+ return ret;
+}
+
+/*
+ * NIST.SP.800-56Br2
+ * 7.2.1.2 RSASVE Generate Operation (RSASVE.GENERATE).
+ */
+static int rsasve_generate(PROV_RSA_CTX *prsactx,
+ unsigned char *out, size_t *outlen,
+ unsigned char *secret, size_t *secretlen)
+{
+ int ret;
+ size_t nlen;
+
+ /* Step (1): nlen = Ceil(len(n)/8) */
+ nlen = RSA_size(prsactx->rsa);
+
+ if (out == NULL) {
+ if (nlen == 0) {
+ ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY);
+ return 0;
+ }
+ if (outlen == NULL && secretlen == NULL)
+ return 0;
+ if (outlen != NULL)
+ *outlen = nlen;
+ if (secretlen != NULL)
+ *secretlen = nlen;
+ return 1;
+ }
+ /*
+ * Step (2): Generate a random byte string z of nlen bytes where
+ * 1 < z < n - 1
+ */
+ if (!rsasve_gen_rand_bytes(prsactx->rsa, secret, nlen))
+ return 0;
+
+ /* Step(3): out = RSAEP((n,e), z) */
+ ret = RSA_public_encrypt(nlen, secret, out, prsactx->rsa, RSA_NO_PADDING);
+ if (ret) {
+ ret = 1;
+ if (outlen != NULL)
+ *outlen = nlen;
+ if (secretlen != NULL)
+ *secretlen = nlen;
+ } else {
+ OPENSSL_cleanse(secret, nlen);
+ }
+ return ret;
+}
+
+/*
+ * NIST.SP.800-56Br2
+ * 7.2.1.3 RSASVE Recovery Operation (RSASVE.RECOVER).
+ */
+static int rsasve_recover(PROV_RSA_CTX *prsactx,
+ unsigned char *out, size_t *outlen,
+ const unsigned char *in, size_t inlen)
+{
+ size_t nlen;
+
+ /* Step (1): get the byte length of n */
+ nlen = RSA_size(prsactx->rsa);
+
+ if (out == NULL) {
+ if (nlen == 0) {
+ ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY);
+ return 0;
+ }
+ *outlen = nlen;
+ return 1;
+ }
+
+ /* Step (2): check the input ciphertext 'inlen' matches the nlen */
+ if (inlen != nlen) {
+ ERR_raise(ERR_LIB_PROV, PROV_R_BAD_LENGTH);
+ return 0;
+ }
+ /* Step (3): out = RSADP((n,d), in) */
+ return (RSA_private_decrypt(inlen, in, out, prsactx->rsa, RSA_NO_PADDING) > 0);
+}
+
+static int rsakem_generate(void *vprsactx, unsigned char *out, size_t *outlen,
+ unsigned char *secret, size_t *secretlen)
+{
+ PROV_RSA_CTX *prsactx = (PROV_RSA_CTX *)vprsactx;
+
+ switch (prsactx->op) {
+ case KEM_OP_RSASVE:
+ return rsasve_generate(prsactx, out, outlen, secret, secretlen);
+ default:
+ return -2;
+ }
+}
+
+static int rsakem_recover(void *vprsactx, unsigned char *out, size_t *outlen,
+ const unsigned char *in, size_t inlen)
+{
+ PROV_RSA_CTX *prsactx = (PROV_RSA_CTX *)vprsactx;
+
+ switch (prsactx->op) {
+ case KEM_OP_RSASVE:
+ return rsasve_recover(prsactx, out, outlen, in, inlen);
+ default:
+ return -2;
+ }
+}
+
+const OSSL_DISPATCH rsa_asym_kem_functions[] = {
+ { OSSL_FUNC_KEM_NEWCTX, (void (*)(void))rsakem_newctx },
+ { OSSL_FUNC_KEM_ENCAPSULATE_INIT,
+ (void (*)(void))rsakem_init },
+ { OSSL_FUNC_KEM_ENCAPSULATE, (void (*)(void))rsakem_generate },
+ { OSSL_FUNC_KEM_DECAPSULATE_INIT,
+ (void (*)(void))rsakem_init },
+ { OSSL_FUNC_KEM_DECAPSULATE, (void (*)(void))rsakem_recover },
+ { OSSL_FUNC_KEM_FREECTX, (void (*)(void))rsakem_freectx },
+ { OSSL_FUNC_KEM_DUPCTX, (void (*)(void))rsakem_dupctx },
+ { OSSL_FUNC_KEM_GET_CTX_PARAMS,
+ (void (*)(void))rsakem_get_ctx_params },
+ { OSSL_FUNC_KEM_GETTABLE_CTX_PARAMS,
+ (void (*)(void))rsakem_gettable_ctx_params },
+ { OSSL_FUNC_KEM_SET_CTX_PARAMS,
+ (void (*)(void))rsakem_set_ctx_params },
+ { OSSL_FUNC_KEM_SETTABLE_CTX_PARAMS,
+ (void (*)(void))rsakem_settable_ctx_params },
+ { 0, NULL }
+};
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