openssl/crypto/dh/dh_pmeth.c
Pauli ada66e78ef Deprecate the low level Diffie-Hellman functions.
Use of the low level DH functions has been informally discouraged for a
long time.  We now formally deprecate them.

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/11024)
2020-02-20 19:04:57 +10:00

564 lines
13 KiB
C

/*
* Copyright 2006-2018 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 & DSA low level APIs are deprecated for public use, but still ok for
* internal use.
*/
#include "internal/deprecated.h"
#include <stdio.h>
#include "internal/cryptlib.h"
#include <openssl/asn1t.h>
#include <openssl/x509.h>
#include <openssl/evp.h>
#include "dh_local.h"
#include <openssl/bn.h>
#include <openssl/dsa.h>
#include <openssl/objects.h>
#include "crypto/evp.h"
/* DH pkey context structure */
typedef struct {
/* Parameter gen parameters */
int prime_len;
int generator;
int paramgen_type;
int subprime_len;
int pad;
/* message digest used for parameter generation */
const EVP_MD *md;
int rfc5114_param;
int param_nid;
/* Keygen callback info */
int gentmp[2];
/* KDF (if any) to use for DH */
char kdf_type;
/* OID to use for KDF */
ASN1_OBJECT *kdf_oid;
/* Message digest to use for key derivation */
const EVP_MD *kdf_md;
/* User key material */
unsigned char *kdf_ukm;
size_t kdf_ukmlen;
/* KDF output length */
size_t kdf_outlen;
} DH_PKEY_CTX;
static int pkey_dh_init(EVP_PKEY_CTX *ctx)
{
DH_PKEY_CTX *dctx;
if ((dctx = OPENSSL_zalloc(sizeof(*dctx))) == NULL) {
DHerr(DH_F_PKEY_DH_INIT, ERR_R_MALLOC_FAILURE);
return 0;
}
dctx->prime_len = 2048;
dctx->subprime_len = -1;
dctx->generator = 2;
dctx->kdf_type = EVP_PKEY_DH_KDF_NONE;
ctx->data = dctx;
ctx->keygen_info = dctx->gentmp;
ctx->keygen_info_count = 2;
return 1;
}
static void pkey_dh_cleanup(EVP_PKEY_CTX *ctx)
{
DH_PKEY_CTX *dctx = ctx->data;
if (dctx != NULL) {
OPENSSL_free(dctx->kdf_ukm);
ASN1_OBJECT_free(dctx->kdf_oid);
OPENSSL_free(dctx);
}
}
static int pkey_dh_copy(EVP_PKEY_CTX *dst, const EVP_PKEY_CTX *src)
{
DH_PKEY_CTX *dctx, *sctx;
if (!pkey_dh_init(dst))
return 0;
sctx = src->data;
dctx = dst->data;
dctx->prime_len = sctx->prime_len;
dctx->subprime_len = sctx->subprime_len;
dctx->generator = sctx->generator;
dctx->paramgen_type = sctx->paramgen_type;
dctx->pad = sctx->pad;
dctx->md = sctx->md;
dctx->rfc5114_param = sctx->rfc5114_param;
dctx->param_nid = sctx->param_nid;
dctx->kdf_type = sctx->kdf_type;
dctx->kdf_oid = OBJ_dup(sctx->kdf_oid);
if (dctx->kdf_oid == NULL)
return 0;
dctx->kdf_md = sctx->kdf_md;
if (sctx->kdf_ukm != NULL) {
dctx->kdf_ukm = OPENSSL_memdup(sctx->kdf_ukm, sctx->kdf_ukmlen);
if (dctx->kdf_ukm == NULL)
return 0;
dctx->kdf_ukmlen = sctx->kdf_ukmlen;
}
dctx->kdf_outlen = sctx->kdf_outlen;
return 1;
}
static int pkey_dh_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
{
DH_PKEY_CTX *dctx = ctx->data;
switch (type) {
case EVP_PKEY_CTRL_DH_PARAMGEN_PRIME_LEN:
if (p1 < 256)
return -2;
dctx->prime_len = p1;
return 1;
case EVP_PKEY_CTRL_DH_PARAMGEN_SUBPRIME_LEN:
if (dctx->paramgen_type == DH_PARAMGEN_TYPE_GENERATOR)
return -2;
dctx->subprime_len = p1;
return 1;
case EVP_PKEY_CTRL_DH_PAD:
dctx->pad = p1;
return 1;
case EVP_PKEY_CTRL_DH_PARAMGEN_GENERATOR:
if (dctx->paramgen_type != DH_PARAMGEN_TYPE_GENERATOR)
return -2;
dctx->generator = p1;
return 1;
case EVP_PKEY_CTRL_DH_PARAMGEN_TYPE:
#ifdef OPENSSL_NO_DSA
if (p1 != DH_PARAMGEN_TYPE_GENERATOR)
return -2;
#else
if (p1 < 0 || p1 > 2)
return -2;
#endif
dctx->paramgen_type = p1;
return 1;
case EVP_PKEY_CTRL_DH_RFC5114:
if (p1 < 1 || p1 > 3 || dctx->param_nid != NID_undef)
return -2;
dctx->rfc5114_param = p1;
return 1;
case EVP_PKEY_CTRL_DH_NID:
if (p1 <= 0 || dctx->rfc5114_param != 0)
return -2;
dctx->param_nid = p1;
return 1;
case EVP_PKEY_CTRL_PEER_KEY:
/* Default behaviour is OK */
return 1;
case EVP_PKEY_CTRL_DH_KDF_TYPE:
if (p1 == -2)
return dctx->kdf_type;
#ifdef OPENSSL_NO_CMS
if (p1 != EVP_PKEY_DH_KDF_NONE)
#else
if (p1 != EVP_PKEY_DH_KDF_NONE && p1 != EVP_PKEY_DH_KDF_X9_42)
#endif
return -2;
dctx->kdf_type = p1;
return 1;
case EVP_PKEY_CTRL_DH_KDF_MD:
dctx->kdf_md = p2;
return 1;
case EVP_PKEY_CTRL_GET_DH_KDF_MD:
*(const EVP_MD **)p2 = dctx->kdf_md;
return 1;
case EVP_PKEY_CTRL_DH_KDF_OUTLEN:
if (p1 <= 0)
return -2;
dctx->kdf_outlen = (size_t)p1;
return 1;
case EVP_PKEY_CTRL_GET_DH_KDF_OUTLEN:
*(int *)p2 = dctx->kdf_outlen;
return 1;
case EVP_PKEY_CTRL_DH_KDF_UKM:
OPENSSL_free(dctx->kdf_ukm);
dctx->kdf_ukm = p2;
if (p2)
dctx->kdf_ukmlen = p1;
else
dctx->kdf_ukmlen = 0;
return 1;
case EVP_PKEY_CTRL_GET_DH_KDF_UKM:
*(unsigned char **)p2 = dctx->kdf_ukm;
return dctx->kdf_ukmlen;
case EVP_PKEY_CTRL_DH_KDF_OID:
ASN1_OBJECT_free(dctx->kdf_oid);
dctx->kdf_oid = p2;
return 1;
case EVP_PKEY_CTRL_GET_DH_KDF_OID:
*(ASN1_OBJECT **)p2 = dctx->kdf_oid;
return 1;
default:
return -2;
}
}
static int pkey_dh_ctrl_str(EVP_PKEY_CTX *ctx,
const char *type, const char *value)
{
if (strcmp(type, "dh_paramgen_prime_len") == 0) {
int len;
len = atoi(value);
return EVP_PKEY_CTX_set_dh_paramgen_prime_len(ctx, len);
}
if (strcmp(type, "dh_rfc5114") == 0) {
DH_PKEY_CTX *dctx = ctx->data;
int len;
len = atoi(value);
if (len < 0 || len > 3)
return -2;
dctx->rfc5114_param = len;
return 1;
}
if (strcmp(type, "dh_param") == 0) {
DH_PKEY_CTX *dctx = ctx->data;
int nid = OBJ_sn2nid(value);
if (nid == NID_undef) {
DHerr(DH_F_PKEY_DH_CTRL_STR, DH_R_INVALID_PARAMETER_NAME);
return -2;
}
dctx->param_nid = nid;
return 1;
}
if (strcmp(type, "dh_paramgen_generator") == 0) {
int len;
len = atoi(value);
return EVP_PKEY_CTX_set_dh_paramgen_generator(ctx, len);
}
if (strcmp(type, "dh_paramgen_subprime_len") == 0) {
int len;
len = atoi(value);
return EVP_PKEY_CTX_set_dh_paramgen_subprime_len(ctx, len);
}
if (strcmp(type, "dh_paramgen_type") == 0) {
int typ;
typ = atoi(value);
return EVP_PKEY_CTX_set_dh_paramgen_type(ctx, typ);
}
if (strcmp(type, "dh_pad") == 0) {
int pad;
pad = atoi(value);
return EVP_PKEY_CTX_set_dh_pad(ctx, pad);
}
return -2;
}
static DH *ffc_params_generate(OPENSSL_CTX *libctx, DH_PKEY_CTX *dctx,
BN_GENCB *pcb)
{
DH *ret;
int rv = 0;
int res;
int prime_len = dctx->prime_len;
int subprime_len = dctx->subprime_len;
const EVP_MD *md = dctx->md;
if (dctx->paramgen_type > DH_PARAMGEN_TYPE_FIPS_186_4)
return NULL;
ret = DH_new();
if (ret == NULL)
return NULL;
if (subprime_len == -1) {
if (prime_len >= 2048)
subprime_len = 256;
else
subprime_len = 160;
}
if (md == NULL) {
if (prime_len >= 2048)
md = EVP_sha256();
else
md = EVP_sha1();
}
# ifndef FIPS_MODE
if (dctx->paramgen_type == DH_PARAMGEN_TYPE_FIPS_186_2)
rv = ffc_params_FIPS186_2_generate(libctx, &ret->params,
FFC_PARAM_TYPE_DH,
prime_len, subprime_len, md, &res,
pcb);
else
# endif
/* For FIPS we always use the DH_PARAMGEN_TYPE_FIPS_186_4 generator */
if (dctx->paramgen_type >= DH_PARAMGEN_TYPE_FIPS_186_2)
rv = ffc_params_FIPS186_4_generate(libctx, &ret->params,
FFC_PARAM_TYPE_DH,
prime_len, subprime_len, md, &res,
pcb);
if (rv <= 0) {
DH_free(ret);
return NULL;
}
return ret;
}
static int pkey_dh_paramgen(EVP_PKEY_CTX *ctx,
EVP_PKEY *pkey)
{
DH *dh = NULL;
DH_PKEY_CTX *dctx = ctx->data;
BN_GENCB *pcb = NULL;
int ret;
/*
* Look for a safe prime group for key establishment. Which uses
* either RFC_3526 (modp_XXXX) or RFC_7919 (ffdheXXXX).
*/
if (dctx->param_nid != NID_undef) {
if ((dh = DH_new_by_nid(dctx->param_nid)) == NULL)
return 0;
EVP_PKEY_assign(pkey, EVP_PKEY_DH, dh);
return 1;
}
#ifndef FIPS_MODE
if (dctx->rfc5114_param) {
switch (dctx->rfc5114_param) {
case 1:
dh = DH_get_1024_160();
break;
case 2:
dh = DH_get_2048_224();
break;
case 3:
dh = DH_get_2048_256();
break;
default:
return -2;
}
EVP_PKEY_assign(pkey, EVP_PKEY_DHX, dh);
return 1;
}
#endif /* FIPS_MODE */
if (ctx->pkey_gencb != NULL) {
pcb = BN_GENCB_new();
if (pcb == NULL)
return 0;
evp_pkey_set_cb_translate(pcb, ctx);
}
# ifdef FIPS_MODE
dctx->paramgen_type = DH_PARAMGEN_TYPE_FIPS_186_4;
# endif /* FIPS_MODE */
if (dctx->paramgen_type >= DH_PARAMGEN_TYPE_FIPS_186_2) {
dh = ffc_params_generate(NULL, dctx, pcb);
BN_GENCB_free(pcb);
if (dh == NULL)
return 0;
EVP_PKEY_assign(pkey, EVP_PKEY_DHX, dh);
return 1;
}
dh = DH_new();
if (dh == NULL) {
BN_GENCB_free(pcb);
return 0;
}
ret = DH_generate_parameters_ex(dh,
dctx->prime_len, dctx->generator, pcb);
BN_GENCB_free(pcb);
if (ret)
EVP_PKEY_assign_DH(pkey, dh);
else
DH_free(dh);
return ret;
}
static int pkey_dh_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)
{
DH_PKEY_CTX *dctx = ctx->data;
DH *dh = NULL;
if (ctx->pkey == NULL && dctx->param_nid == NID_undef) {
DHerr(DH_F_PKEY_DH_KEYGEN, DH_R_NO_PARAMETERS_SET);
return 0;
}
if (dctx->param_nid != NID_undef)
dh = DH_new_by_nid(dctx->param_nid);
else
dh = DH_new();
if (dh == NULL)
return 0;
EVP_PKEY_assign(pkey, ctx->pmeth->pkey_id, dh);
/* Note: if error return, pkey is freed by parent routine */
if (ctx->pkey != NULL && !EVP_PKEY_copy_parameters(pkey, ctx->pkey))
return 0;
return DH_generate_key(pkey->pkey.dh);
}
static int pkey_dh_derive(EVP_PKEY_CTX *ctx, unsigned char *key,
size_t *keylen)
{
int ret;
DH *dh;
DH_PKEY_CTX *dctx = ctx->data;
BIGNUM *dhpub;
if (!ctx->pkey || !ctx->peerkey) {
DHerr(DH_F_PKEY_DH_DERIVE, DH_R_KEYS_NOT_SET);
return 0;
}
dh = ctx->pkey->pkey.dh;
dhpub = ctx->peerkey->pkey.dh->pub_key;
if (dctx->kdf_type == EVP_PKEY_DH_KDF_NONE) {
if (key == NULL) {
*keylen = DH_size(dh);
return 1;
}
if (dctx->pad)
ret = DH_compute_key_padded(key, dhpub, dh);
else
ret = DH_compute_key(key, dhpub, dh);
if (ret < 0)
return ret;
*keylen = ret;
return 1;
}
#ifndef OPENSSL_NO_CMS
else if (dctx->kdf_type == EVP_PKEY_DH_KDF_X9_42) {
unsigned char *Z = NULL;
size_t Zlen = 0;
if (!dctx->kdf_outlen || !dctx->kdf_oid)
return 0;
if (key == NULL) {
*keylen = dctx->kdf_outlen;
return 1;
}
if (*keylen != dctx->kdf_outlen)
return 0;
ret = 0;
Zlen = DH_size(dh);
Z = OPENSSL_malloc(Zlen);
if (Z == NULL) {
goto err;
}
if (DH_compute_key_padded(Z, dhpub, dh) <= 0)
goto err;
if (!DH_KDF_X9_42(key, *keylen, Z, Zlen, dctx->kdf_oid,
dctx->kdf_ukm, dctx->kdf_ukmlen, dctx->kdf_md))
goto err;
*keylen = dctx->kdf_outlen;
ret = 1;
err:
OPENSSL_clear_free(Z, Zlen);
return ret;
}
#endif
return 0;
}
static const EVP_PKEY_METHOD dh_pkey_meth = {
EVP_PKEY_DH,
0,
pkey_dh_init,
pkey_dh_copy,
pkey_dh_cleanup,
0,
pkey_dh_paramgen,
0,
pkey_dh_keygen,
0,
0,
0,
0,
0, 0,
0, 0, 0, 0,
0, 0,
0, 0,
0,
pkey_dh_derive,
pkey_dh_ctrl,
pkey_dh_ctrl_str
};
const EVP_PKEY_METHOD *dh_pkey_method(void)
{
return &dh_pkey_meth;
}
static const EVP_PKEY_METHOD dhx_pkey_meth = {
EVP_PKEY_DHX,
0,
pkey_dh_init,
pkey_dh_copy,
pkey_dh_cleanup,
0,
pkey_dh_paramgen,
0,
pkey_dh_keygen,
0,
0,
0,
0,
0, 0,
0, 0, 0, 0,
0, 0,
0, 0,
0,
pkey_dh_derive,
pkey_dh_ctrl,
pkey_dh_ctrl_str
};
const EVP_PKEY_METHOD *dhx_pkey_method(void)
{
return &dhx_pkey_meth;
}