| /* |
| * Copyright 2019-2022 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 |
| */ |
| |
| /* |
| * DH low level APIs are deprecated for public use, but still ok for |
| * internal use. |
| */ |
| #include "internal/deprecated.h" |
| |
| #include <string.h> |
| #include <openssl/crypto.h> |
| #include <openssl/core_dispatch.h> |
| #include <openssl/core_names.h> |
| #include <openssl/dh.h> |
| #include <openssl/err.h> |
| #include <openssl/proverr.h> |
| #include <openssl/params.h> |
| #include "prov/providercommon.h" |
| #include "prov/implementations.h" |
| #include "prov/provider_ctx.h" |
| #include "prov/securitycheck.h" |
| #include "crypto/dh.h" |
| |
| static OSSL_FUNC_keyexch_newctx_fn dh_newctx; |
| static OSSL_FUNC_keyexch_init_fn dh_init; |
| static OSSL_FUNC_keyexch_set_peer_fn dh_set_peer; |
| static OSSL_FUNC_keyexch_derive_fn dh_derive; |
| static OSSL_FUNC_keyexch_freectx_fn dh_freectx; |
| static OSSL_FUNC_keyexch_dupctx_fn dh_dupctx; |
| static OSSL_FUNC_keyexch_set_ctx_params_fn dh_set_ctx_params; |
| static OSSL_FUNC_keyexch_settable_ctx_params_fn dh_settable_ctx_params; |
| static OSSL_FUNC_keyexch_get_ctx_params_fn dh_get_ctx_params; |
| static OSSL_FUNC_keyexch_gettable_ctx_params_fn dh_gettable_ctx_params; |
| |
| /* |
| * This type is only really used to handle some legacy related functionality. |
| * If you need to use other KDF's (such as SSKDF) just use PROV_DH_KDF_NONE |
| * here and then create and run a KDF after the key is derived. |
| * Note that X942 has 2 variants of key derivation: |
| * (1) DH_KDF_X9_42_ASN1 - which contains an ANS1 encoded object that has |
| * the counter embedded in it. |
| * (2) DH_KDF_X941_CONCAT - which is the same as ECDH_X963_KDF (which can be |
| * done by creating a "X963KDF". |
| */ |
| enum kdf_type { |
| PROV_DH_KDF_NONE = 0, |
| PROV_DH_KDF_X9_42_ASN1 |
| }; |
| |
| /* |
| * What's passed as an actual key is defined by the KEYMGMT interface. |
| * We happen to know that our KEYMGMT simply passes DH structures, so |
| * we use that here too. |
| */ |
| |
| typedef struct { |
| OSSL_LIB_CTX *libctx; |
| DH *dh; |
| DH *dhpeer; |
| unsigned int pad : 1; |
| |
| /* DH KDF */ |
| /* KDF (if any) to use for DH */ |
| enum kdf_type kdf_type; |
| /* Message digest to use for key derivation */ |
| EVP_MD *kdf_md; |
| /* User key material */ |
| unsigned char *kdf_ukm; |
| size_t kdf_ukmlen; |
| /* KDF output length */ |
| size_t kdf_outlen; |
| char *kdf_cekalg; |
| } PROV_DH_CTX; |
| |
| static void *dh_newctx(void *provctx) |
| { |
| PROV_DH_CTX *pdhctx; |
| |
| if (!ossl_prov_is_running()) |
| return NULL; |
| |
| pdhctx = OPENSSL_zalloc(sizeof(PROV_DH_CTX)); |
| if (pdhctx == NULL) |
| return NULL; |
| pdhctx->libctx = PROV_LIBCTX_OF(provctx); |
| pdhctx->kdf_type = PROV_DH_KDF_NONE; |
| return pdhctx; |
| } |
| |
| static int dh_init(void *vpdhctx, void *vdh, const OSSL_PARAM params[]) |
| { |
| PROV_DH_CTX *pdhctx = (PROV_DH_CTX *)vpdhctx; |
| |
| if (!ossl_prov_is_running() |
| || pdhctx == NULL |
| || vdh == NULL |
| || !DH_up_ref(vdh)) |
| return 0; |
| DH_free(pdhctx->dh); |
| pdhctx->dh = vdh; |
| pdhctx->kdf_type = PROV_DH_KDF_NONE; |
| return dh_set_ctx_params(pdhctx, params) |
| && ossl_dh_check_key(pdhctx->libctx, vdh); |
| } |
| |
| /* The 2 parties must share the same domain parameters */ |
| static int dh_match_params(DH *priv, DH *peer) |
| { |
| int ret; |
| FFC_PARAMS *dhparams_priv = ossl_dh_get0_params(priv); |
| FFC_PARAMS *dhparams_peer = ossl_dh_get0_params(peer); |
| |
| ret = dhparams_priv != NULL |
| && dhparams_peer != NULL |
| && ossl_ffc_params_cmp(dhparams_priv, dhparams_peer, 1); |
| if (!ret) |
| ERR_raise(ERR_LIB_PROV, PROV_R_MISMATCHING_DOMAIN_PARAMETERS); |
| return ret; |
| } |
| |
| static int dh_set_peer(void *vpdhctx, void *vdh) |
| { |
| PROV_DH_CTX *pdhctx = (PROV_DH_CTX *)vpdhctx; |
| |
| if (!ossl_prov_is_running() |
| || pdhctx == NULL |
| || vdh == NULL |
| || !dh_match_params(vdh, pdhctx->dh) |
| || !DH_up_ref(vdh)) |
| return 0; |
| DH_free(pdhctx->dhpeer); |
| pdhctx->dhpeer = vdh; |
| return 1; |
| } |
| |
| static int dh_plain_derive(void *vpdhctx, |
| unsigned char *secret, size_t *secretlen, |
| size_t outlen, unsigned int pad) |
| { |
| PROV_DH_CTX *pdhctx = (PROV_DH_CTX *)vpdhctx; |
| int ret; |
| size_t dhsize; |
| const BIGNUM *pub_key = NULL; |
| |
| if (pdhctx->dh == NULL || pdhctx->dhpeer == NULL) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_KEY); |
| return 0; |
| } |
| |
| dhsize = (size_t)DH_size(pdhctx->dh); |
| if (secret == NULL) { |
| *secretlen = dhsize; |
| return 1; |
| } |
| if (outlen < dhsize) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_OUTPUT_BUFFER_TOO_SMALL); |
| return 0; |
| } |
| |
| DH_get0_key(pdhctx->dhpeer, &pub_key, NULL); |
| if (pad) |
| ret = DH_compute_key_padded(secret, pub_key, pdhctx->dh); |
| else |
| ret = DH_compute_key(secret, pub_key, pdhctx->dh); |
| if (ret <= 0) |
| return 0; |
| |
| *secretlen = ret; |
| return 1; |
| } |
| |
| static int dh_X9_42_kdf_derive(void *vpdhctx, unsigned char *secret, |
| size_t *secretlen, size_t outlen) |
| { |
| PROV_DH_CTX *pdhctx = (PROV_DH_CTX *)vpdhctx; |
| unsigned char *stmp = NULL; |
| size_t stmplen; |
| int ret = 0; |
| |
| if (secret == NULL) { |
| *secretlen = pdhctx->kdf_outlen; |
| return 1; |
| } |
| |
| if (pdhctx->kdf_outlen > outlen) { |
| ERR_raise(ERR_LIB_PROV, PROV_R_OUTPUT_BUFFER_TOO_SMALL); |
| return 0; |
| } |
| if (!dh_plain_derive(pdhctx, NULL, &stmplen, 0, 1)) |
| return 0; |
| if ((stmp = OPENSSL_secure_malloc(stmplen)) == NULL) { |
| ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE); |
| return 0; |
| } |
| if (!dh_plain_derive(pdhctx, stmp, &stmplen, stmplen, 1)) |
| goto err; |
| |
| /* Do KDF stuff */ |
| if (pdhctx->kdf_type == PROV_DH_KDF_X9_42_ASN1) { |
| if (!ossl_dh_kdf_X9_42_asn1(secret, pdhctx->kdf_outlen, |
| stmp, stmplen, |
| pdhctx->kdf_cekalg, |
| pdhctx->kdf_ukm, |
| pdhctx->kdf_ukmlen, |
| pdhctx->kdf_md, |
| pdhctx->libctx, NULL)) |
| goto err; |
| } |
| *secretlen = pdhctx->kdf_outlen; |
| ret = 1; |
| err: |
| OPENSSL_secure_clear_free(stmp, stmplen); |
| return ret; |
| } |
| |
| static int dh_derive(void *vpdhctx, unsigned char *secret, |
| size_t *psecretlen, size_t outlen) |
| { |
| PROV_DH_CTX *pdhctx = (PROV_DH_CTX *)vpdhctx; |
| |
| if (!ossl_prov_is_running()) |
| return 0; |
| |
| switch (pdhctx->kdf_type) { |
| case PROV_DH_KDF_NONE: |
| return dh_plain_derive(pdhctx, secret, psecretlen, outlen, |
| pdhctx->pad); |
| case PROV_DH_KDF_X9_42_ASN1: |
| return dh_X9_42_kdf_derive(pdhctx, secret, psecretlen, outlen); |
| default: |
| break; |
| } |
| return 0; |
| } |
| |
| static void dh_freectx(void *vpdhctx) |
| { |
| PROV_DH_CTX *pdhctx = (PROV_DH_CTX *)vpdhctx; |
| |
| OPENSSL_free(pdhctx->kdf_cekalg); |
| DH_free(pdhctx->dh); |
| DH_free(pdhctx->dhpeer); |
| EVP_MD_free(pdhctx->kdf_md); |
| OPENSSL_clear_free(pdhctx->kdf_ukm, pdhctx->kdf_ukmlen); |
| |
| OPENSSL_free(pdhctx); |
| } |
| |
| static void *dh_dupctx(void *vpdhctx) |
| { |
| PROV_DH_CTX *srcctx = (PROV_DH_CTX *)vpdhctx; |
| PROV_DH_CTX *dstctx; |
| |
| if (!ossl_prov_is_running()) |
| return NULL; |
| |
| dstctx = OPENSSL_zalloc(sizeof(*srcctx)); |
| if (dstctx == NULL) |
| return NULL; |
| |
| *dstctx = *srcctx; |
| dstctx->dh = NULL; |
| dstctx->dhpeer = NULL; |
| dstctx->kdf_md = NULL; |
| dstctx->kdf_ukm = NULL; |
| dstctx->kdf_cekalg = NULL; |
| |
| if (srcctx->dh != NULL && !DH_up_ref(srcctx->dh)) |
| goto err; |
| else |
| dstctx->dh = srcctx->dh; |
| |
| if (srcctx->dhpeer != NULL && !DH_up_ref(srcctx->dhpeer)) |
| goto err; |
| else |
| dstctx->dhpeer = srcctx->dhpeer; |
| |
| if (srcctx->kdf_md != NULL && !EVP_MD_up_ref(srcctx->kdf_md)) |
| goto err; |
| else |
| dstctx->kdf_md = srcctx->kdf_md; |
| |
| /* Duplicate UKM data if present */ |
| if (srcctx->kdf_ukm != NULL && srcctx->kdf_ukmlen > 0) { |
| dstctx->kdf_ukm = OPENSSL_memdup(srcctx->kdf_ukm, |
| srcctx->kdf_ukmlen); |
| if (dstctx->kdf_ukm == NULL) |
| goto err; |
| } |
| |
| if (srcctx->kdf_cekalg != NULL) { |
| dstctx->kdf_cekalg = OPENSSL_strdup(srcctx->kdf_cekalg); |
| if (dstctx->kdf_cekalg == NULL) |
| goto err; |
| } |
| |
| return dstctx; |
| err: |
| dh_freectx(dstctx); |
| return NULL; |
| } |
| |
| static int dh_set_ctx_params(void *vpdhctx, const OSSL_PARAM params[]) |
| { |
| PROV_DH_CTX *pdhctx = (PROV_DH_CTX *)vpdhctx; |
| const OSSL_PARAM *p; |
| unsigned int pad; |
| char name[80] = { '\0' }; /* should be big enough */ |
| char *str = NULL; |
| |
| if (pdhctx == NULL) |
| return 0; |
| if (params == NULL) |
| return 1; |
| |
| p = OSSL_PARAM_locate_const(params, OSSL_EXCHANGE_PARAM_KDF_TYPE); |
| if (p != NULL) { |
| str = name; |
| if (!OSSL_PARAM_get_utf8_string(p, &str, sizeof(name))) |
| return 0; |
| |
| if (name[0] == '\0') |
| pdhctx->kdf_type = PROV_DH_KDF_NONE; |
| else if (strcmp(name, OSSL_KDF_NAME_X942KDF_ASN1) == 0) |
| pdhctx->kdf_type = PROV_DH_KDF_X9_42_ASN1; |
| else |
| return 0; |
| } |
| p = OSSL_PARAM_locate_const(params, OSSL_EXCHANGE_PARAM_KDF_DIGEST); |
| if (p != NULL) { |
| char mdprops[80] = { '\0' }; /* should be big enough */ |
| |
| str = name; |
| if (!OSSL_PARAM_get_utf8_string(p, &str, sizeof(name))) |
| return 0; |
| |
| str = mdprops; |
| p = OSSL_PARAM_locate_const(params, |
| OSSL_EXCHANGE_PARAM_KDF_DIGEST_PROPS); |
| |
| if (p != NULL) { |
| if (!OSSL_PARAM_get_utf8_string(p, &str, sizeof(mdprops))) |
| return 0; |
| } |
| |
| EVP_MD_free(pdhctx->kdf_md); |
| pdhctx->kdf_md = EVP_MD_fetch(pdhctx->libctx, name, mdprops); |
| if (pdhctx->kdf_md == NULL) |
| return 0; |
| if (!ossl_digest_is_allowed(pdhctx->libctx, pdhctx->kdf_md)) { |
| EVP_MD_free(pdhctx->kdf_md); |
| pdhctx->kdf_md = NULL; |
| return 0; |
| } |
| } |
| |
| p = OSSL_PARAM_locate_const(params, OSSL_EXCHANGE_PARAM_KDF_OUTLEN); |
| if (p != NULL) { |
| size_t outlen; |
| |
| if (!OSSL_PARAM_get_size_t(p, &outlen)) |
| return 0; |
| pdhctx->kdf_outlen = outlen; |
| } |
| |
| p = OSSL_PARAM_locate_const(params, OSSL_EXCHANGE_PARAM_KDF_UKM); |
| if (p != NULL) { |
| void *tmp_ukm = NULL; |
| size_t tmp_ukmlen; |
| |
| OPENSSL_free(pdhctx->kdf_ukm); |
| pdhctx->kdf_ukm = NULL; |
| pdhctx->kdf_ukmlen = 0; |
| /* ukm is an optional field so it can be NULL */ |
| if (p->data != NULL && p->data_size != 0) { |
| if (!OSSL_PARAM_get_octet_string(p, &tmp_ukm, 0, &tmp_ukmlen)) |
| return 0; |
| pdhctx->kdf_ukm = tmp_ukm; |
| pdhctx->kdf_ukmlen = tmp_ukmlen; |
| } |
| } |
| |
| p = OSSL_PARAM_locate_const(params, OSSL_EXCHANGE_PARAM_PAD); |
| if (p != NULL) { |
| if (!OSSL_PARAM_get_uint(p, &pad)) |
| return 0; |
| pdhctx->pad = pad ? 1 : 0; |
| } |
| |
| p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_CEK_ALG); |
| if (p != NULL) { |
| str = name; |
| |
| OPENSSL_free(pdhctx->kdf_cekalg); |
| pdhctx->kdf_cekalg = NULL; |
| if (p->data != NULL && p->data_size != 0) { |
| if (!OSSL_PARAM_get_utf8_string(p, &str, sizeof(name))) |
| return 0; |
| pdhctx->kdf_cekalg = OPENSSL_strdup(name); |
| if (pdhctx->kdf_cekalg == NULL) |
| return 0; |
| } |
| } |
| return 1; |
| } |
| |
| static const OSSL_PARAM known_settable_ctx_params[] = { |
| OSSL_PARAM_int(OSSL_EXCHANGE_PARAM_PAD, NULL), |
| OSSL_PARAM_utf8_string(OSSL_EXCHANGE_PARAM_KDF_TYPE, NULL, 0), |
| OSSL_PARAM_utf8_string(OSSL_EXCHANGE_PARAM_KDF_DIGEST, NULL, 0), |
| OSSL_PARAM_utf8_string(OSSL_EXCHANGE_PARAM_KDF_DIGEST_PROPS, NULL, 0), |
| OSSL_PARAM_size_t(OSSL_EXCHANGE_PARAM_KDF_OUTLEN, NULL), |
| OSSL_PARAM_octet_string(OSSL_EXCHANGE_PARAM_KDF_UKM, NULL, 0), |
| OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_CEK_ALG, NULL, 0), |
| OSSL_PARAM_END |
| }; |
| |
| static const OSSL_PARAM *dh_settable_ctx_params(ossl_unused void *vpdhctx, |
| ossl_unused void *provctx) |
| { |
| return known_settable_ctx_params; |
| } |
| |
| static const OSSL_PARAM known_gettable_ctx_params[] = { |
| OSSL_PARAM_utf8_string(OSSL_EXCHANGE_PARAM_KDF_TYPE, NULL, 0), |
| OSSL_PARAM_utf8_string(OSSL_EXCHANGE_PARAM_KDF_DIGEST, NULL, 0), |
| OSSL_PARAM_size_t(OSSL_EXCHANGE_PARAM_KDF_OUTLEN, NULL), |
| OSSL_PARAM_DEFN(OSSL_EXCHANGE_PARAM_KDF_UKM, OSSL_PARAM_OCTET_PTR, |
| NULL, 0), |
| OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_CEK_ALG, NULL, 0), |
| OSSL_PARAM_END |
| }; |
| |
| static const OSSL_PARAM *dh_gettable_ctx_params(ossl_unused void *vpdhctx, |
| ossl_unused void *provctx) |
| { |
| return known_gettable_ctx_params; |
| } |
| |
| static int dh_get_ctx_params(void *vpdhctx, OSSL_PARAM params[]) |
| { |
| PROV_DH_CTX *pdhctx = (PROV_DH_CTX *)vpdhctx; |
| OSSL_PARAM *p; |
| |
| if (pdhctx == NULL) |
| return 0; |
| |
| p = OSSL_PARAM_locate(params, OSSL_EXCHANGE_PARAM_KDF_TYPE); |
| if (p != NULL) { |
| const char *kdf_type = NULL; |
| |
| switch (pdhctx->kdf_type) { |
| case PROV_DH_KDF_NONE: |
| kdf_type = ""; |
| break; |
| case PROV_DH_KDF_X9_42_ASN1: |
| kdf_type = OSSL_KDF_NAME_X942KDF_ASN1; |
| break; |
| default: |
| return 0; |
| } |
| |
| if (!OSSL_PARAM_set_utf8_string(p, kdf_type)) |
| return 0; |
| } |
| |
| p = OSSL_PARAM_locate(params, OSSL_EXCHANGE_PARAM_KDF_DIGEST); |
| if (p != NULL |
| && !OSSL_PARAM_set_utf8_string(p, pdhctx->kdf_md == NULL |
| ? "" |
| : EVP_MD_get0_name(pdhctx->kdf_md))) { |
| return 0; |
| } |
| |
| p = OSSL_PARAM_locate(params, OSSL_EXCHANGE_PARAM_KDF_OUTLEN); |
| if (p != NULL && !OSSL_PARAM_set_size_t(p, pdhctx->kdf_outlen)) |
| return 0; |
| |
| p = OSSL_PARAM_locate(params, OSSL_EXCHANGE_PARAM_KDF_UKM); |
| if (p != NULL |
| && !OSSL_PARAM_set_octet_ptr(p, pdhctx->kdf_ukm, pdhctx->kdf_ukmlen)) |
| return 0; |
| |
| p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_CEK_ALG); |
| if (p != NULL |
| && !OSSL_PARAM_set_utf8_string(p, pdhctx->kdf_cekalg == NULL |
| ? "" : pdhctx->kdf_cekalg)) |
| return 0; |
| |
| return 1; |
| } |
| |
| const OSSL_DISPATCH ossl_dh_keyexch_functions[] = { |
| { OSSL_FUNC_KEYEXCH_NEWCTX, (void (*)(void))dh_newctx }, |
| { OSSL_FUNC_KEYEXCH_INIT, (void (*)(void))dh_init }, |
| { OSSL_FUNC_KEYEXCH_DERIVE, (void (*)(void))dh_derive }, |
| { OSSL_FUNC_KEYEXCH_SET_PEER, (void (*)(void))dh_set_peer }, |
| { OSSL_FUNC_KEYEXCH_FREECTX, (void (*)(void))dh_freectx }, |
| { OSSL_FUNC_KEYEXCH_DUPCTX, (void (*)(void))dh_dupctx }, |
| { OSSL_FUNC_KEYEXCH_SET_CTX_PARAMS, (void (*)(void))dh_set_ctx_params }, |
| { OSSL_FUNC_KEYEXCH_SETTABLE_CTX_PARAMS, |
| (void (*)(void))dh_settable_ctx_params }, |
| { OSSL_FUNC_KEYEXCH_GET_CTX_PARAMS, (void (*)(void))dh_get_ctx_params }, |
| { OSSL_FUNC_KEYEXCH_GETTABLE_CTX_PARAMS, |
| (void (*)(void))dh_gettable_ctx_params }, |
| { 0, NULL } |
| }; |
