openssl/crypto/ec/ecx_meth.c
Matt Caswell 13735cfef6 Integrate X448 and Ed448 into libcrypto
This adds all of the relevant EVP plumbing required to make
X448 and Ed448 work.

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Kurt Roeckx <kurt@roeckx.be>
(Merged from https://github.com/openssl/openssl/pull/5481)
2018-03-02 10:14:31 +00:00

732 lines
18 KiB
C

/*
* Copyright 2006-2016 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (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
*/
#include <stdio.h>
#include "internal/cryptlib.h"
#include <openssl/x509.h>
#include <openssl/ec.h>
#include <openssl/rand.h>
#include "internal/asn1_int.h"
#include "internal/evp_int.h"
#include "ec_lcl.h"
#define X25519_BITS 253
#define X25519_SECURITY_BITS 128
#define ED25519_SIGSIZE 64
#define X448_BITS 448
#define ED448_BITS 456
#define X448_SECURITY_BITS 224
#define ED448_SIGSIZE 114
#define ISX448(id) ((id) == EVP_PKEY_X448)
#define IS25519(id) ((id) == EVP_PKEY_X25519 || (id) == EVP_PKEY_ED25519)
#define KEYLENID(id) (IS25519(id) ? X25519_KEYLEN \
: ((id) == EVP_PKEY_X448 ? X448_KEYLEN \
: ED448_KEYLEN))
#define KEYLEN(p) KEYLENID((p)->ameth->pkey_id)
typedef enum {
KEY_OP_PUBLIC,
KEY_OP_PRIVATE,
KEY_OP_KEYGEN
} ecx_key_op_t;
/* Setup EVP_PKEY using public, private or generation */
static int ecx_key_op(EVP_PKEY *pkey, int id, const X509_ALGOR *palg,
const unsigned char *p, int plen, ecx_key_op_t op)
{
ECX_KEY *key = NULL;
unsigned char *privkey, *pubkey;
if (op != KEY_OP_KEYGEN) {
if (palg != NULL) {
int ptype;
/* Algorithm parameters must be absent */
X509_ALGOR_get0(NULL, &ptype, NULL, palg);
if (ptype != V_ASN1_UNDEF) {
ECerr(EC_F_ECX_KEY_OP, EC_R_INVALID_ENCODING);
return 0;
}
}
if (p == NULL || plen != KEYLENID(id)) {
ECerr(EC_F_ECX_KEY_OP, EC_R_INVALID_ENCODING);
return 0;
}
}
key = OPENSSL_zalloc(sizeof(*key));
if (key == NULL) {
ECerr(EC_F_ECX_KEY_OP, ERR_R_MALLOC_FAILURE);
return 0;
}
pubkey = key->pubkey;
if (op == KEY_OP_PUBLIC) {
memcpy(pubkey, p, plen);
} else {
privkey = key->privkey = OPENSSL_secure_malloc(KEYLENID(id));
if (privkey == NULL) {
ECerr(EC_F_ECX_KEY_OP, ERR_R_MALLOC_FAILURE);
goto err;
}
if (op == KEY_OP_KEYGEN) {
if (RAND_priv_bytes(privkey, KEYLENID(id)) <= 0) {
OPENSSL_secure_free(privkey);
key->privkey = NULL;
goto err;
}
if (id == EVP_PKEY_X25519) {
privkey[0] &= 248;
privkey[X25519_KEYLEN - 1] &= 127;
privkey[X25519_KEYLEN - 1] |= 64;
} else if (id == EVP_PKEY_X448) {
privkey[0] &= 252;
privkey[X448_KEYLEN - 1] |= 128;
}
} else {
memcpy(privkey, p, KEYLENID(id));
}
switch (id) {
case EVP_PKEY_X25519:
X25519_public_from_private(pubkey, privkey);
break;
case EVP_PKEY_ED25519:
ED25519_public_from_private(pubkey, privkey);
break;
case EVP_PKEY_X448:
X448_public_from_private(pubkey, privkey);
break;
case EVP_PKEY_ED448:
ED448_public_from_private(pubkey, privkey);
break;
}
}
EVP_PKEY_assign(pkey, id, key);
return 1;
err:
OPENSSL_free(key);
return 0;
}
static int ecx_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)
{
const ECX_KEY *ecxkey = pkey->pkey.ecx;
unsigned char *penc;
if (ecxkey == NULL) {
ECerr(EC_F_ECX_PUB_ENCODE, EC_R_INVALID_KEY);
return 0;
}
penc = OPENSSL_memdup(ecxkey->pubkey, KEYLEN(pkey));
if (penc == NULL) {
ECerr(EC_F_ECX_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
return 0;
}
if (!X509_PUBKEY_set0_param(pk, OBJ_nid2obj(pkey->ameth->pkey_id),
V_ASN1_UNDEF, NULL, penc, KEYLEN(pkey))) {
OPENSSL_free(penc);
ECerr(EC_F_ECX_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
return 0;
}
return 1;
}
static int ecx_pub_decode(EVP_PKEY *pkey, X509_PUBKEY *pubkey)
{
const unsigned char *p;
int pklen;
X509_ALGOR *palg;
if (!X509_PUBKEY_get0_param(NULL, &p, &pklen, &palg, pubkey))
return 0;
return ecx_key_op(pkey, pkey->ameth->pkey_id, palg, p, pklen,
KEY_OP_PUBLIC);
}
static int ecx_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
{
const ECX_KEY *akey = a->pkey.ecx;
const ECX_KEY *bkey = b->pkey.ecx;
if (akey == NULL || bkey == NULL)
return -2;
return CRYPTO_memcmp(akey->pubkey, bkey->pubkey, KEYLEN(a)) == 0;
}
static int ecx_priv_decode(EVP_PKEY *pkey, const PKCS8_PRIV_KEY_INFO *p8)
{
const unsigned char *p;
int plen;
ASN1_OCTET_STRING *oct = NULL;
const X509_ALGOR *palg;
int rv;
if (!PKCS8_pkey_get0(NULL, &p, &plen, &palg, p8))
return 0;
oct = d2i_ASN1_OCTET_STRING(NULL, &p, plen);
if (oct == NULL) {
p = NULL;
plen = 0;
} else {
p = ASN1_STRING_get0_data(oct);
plen = ASN1_STRING_length(oct);
}
rv = ecx_key_op(pkey, pkey->ameth->pkey_id, palg, p, plen, KEY_OP_PRIVATE);
ASN1_OCTET_STRING_free(oct);
return rv;
}
static int ecx_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)
{
const ECX_KEY *ecxkey = pkey->pkey.ecx;
ASN1_OCTET_STRING oct;
unsigned char *penc = NULL;
int penclen;
if (ecxkey == NULL || ecxkey->privkey == NULL) {
ECerr(EC_F_ECX_PRIV_ENCODE, EC_R_INVALID_PRIVATE_KEY);
return 0;
}
oct.data = ecxkey->privkey;
oct.length = KEYLEN(pkey);
oct.flags = 0;
penclen = i2d_ASN1_OCTET_STRING(&oct, &penc);
if (penclen < 0) {
ECerr(EC_F_ECX_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
return 0;
}
if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(pkey->ameth->pkey_id), 0,
V_ASN1_UNDEF, NULL, penc, penclen)) {
OPENSSL_clear_free(penc, penclen);
ECerr(EC_F_ECX_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);
return 0;
}
return 1;
}
static int ecx_size(const EVP_PKEY *pkey)
{
return KEYLEN(pkey);
}
static int ecx_bits(const EVP_PKEY *pkey)
{
if (IS25519(pkey->ameth->pkey_id)) {
return X25519_BITS;
} else if(ISX448(pkey->ameth->pkey_id)) {
return X448_BITS;
} else {
return ED448_BITS;
}
}
static int ecx_security_bits(const EVP_PKEY *pkey)
{
if (IS25519(pkey->ameth->pkey_id)) {
return X25519_SECURITY_BITS;
} else {
return X448_SECURITY_BITS;
}
}
static void ecx_free(EVP_PKEY *pkey)
{
if (pkey->pkey.ecx != NULL)
OPENSSL_secure_clear_free(pkey->pkey.ecx->privkey, KEYLEN(pkey));
OPENSSL_free(pkey->pkey.ecx);
}
/* "parameters" are always equal */
static int ecx_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
{
return 1;
}
static int ecx_key_print(BIO *bp, const EVP_PKEY *pkey, int indent,
ASN1_PCTX *ctx, ecx_key_op_t op)
{
const ECX_KEY *ecxkey = pkey->pkey.ecx;
const char *nm = OBJ_nid2ln(pkey->ameth->pkey_id);
if (op == KEY_OP_PRIVATE) {
if (ecxkey == NULL || ecxkey->privkey == NULL) {
if (BIO_printf(bp, "%*s<INVALID PRIVATE KEY>\n", indent, "") <= 0)
return 0;
return 1;
}
if (BIO_printf(bp, "%*s%s Private-Key:\n", indent, "", nm) <= 0)
return 0;
if (BIO_printf(bp, "%*spriv:\n", indent, "") <= 0)
return 0;
if (ASN1_buf_print(bp, ecxkey->privkey, KEYLEN(pkey),
indent + 4) == 0)
return 0;
} else {
if (ecxkey == NULL) {
if (BIO_printf(bp, "%*s<INVALID PUBLIC KEY>\n", indent, "") <= 0)
return 0;
return 1;
}
if (BIO_printf(bp, "%*s%s Public-Key:\n", indent, "", nm) <= 0)
return 0;
}
if (BIO_printf(bp, "%*spub:\n", indent, "") <= 0)
return 0;
if (ASN1_buf_print(bp, ecxkey->pubkey, KEYLEN(pkey),
indent + 4) == 0)
return 0;
return 1;
}
static int ecx_priv_print(BIO *bp, const EVP_PKEY *pkey, int indent,
ASN1_PCTX *ctx)
{
return ecx_key_print(bp, pkey, indent, ctx, KEY_OP_PRIVATE);
}
static int ecx_pub_print(BIO *bp, const EVP_PKEY *pkey, int indent,
ASN1_PCTX *ctx)
{
return ecx_key_print(bp, pkey, indent, ctx, KEY_OP_PUBLIC);
}
static int ecx_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
{
switch (op) {
case ASN1_PKEY_CTRL_SET1_TLS_ENCPT:
return ecx_key_op(pkey, pkey->ameth->pkey_id, NULL, arg2, arg1,
KEY_OP_PUBLIC);
case ASN1_PKEY_CTRL_GET1_TLS_ENCPT:
if (pkey->pkey.ecx != NULL) {
unsigned char **ppt = arg2;
*ppt = OPENSSL_memdup(pkey->pkey.ecx->pubkey, KEYLEN(pkey));
if (*ppt != NULL)
return KEYLEN(pkey);
}
return 0;
case ASN1_PKEY_CTRL_DEFAULT_MD_NID:
*(int *)arg2 = NID_sha256;
return 2;
default:
return -2;
}
}
const EVP_PKEY_ASN1_METHOD ecx25519_asn1_meth = {
EVP_PKEY_X25519,
EVP_PKEY_X25519,
0,
"X25519",
"OpenSSL X25519 algorithm",
ecx_pub_decode,
ecx_pub_encode,
ecx_pub_cmp,
ecx_pub_print,
ecx_priv_decode,
ecx_priv_encode,
ecx_priv_print,
ecx_size,
ecx_bits,
ecx_security_bits,
0, 0, 0, 0,
ecx_cmp_parameters,
0, 0,
ecx_free,
ecx_ctrl,
NULL,
NULL
};
const EVP_PKEY_ASN1_METHOD ecx448_asn1_meth = {
EVP_PKEY_X448,
EVP_PKEY_X448,
0,
"X448",
"OpenSSL X448 algorithm",
ecx_pub_decode,
ecx_pub_encode,
ecx_pub_cmp,
ecx_pub_print,
ecx_priv_decode,
ecx_priv_encode,
ecx_priv_print,
ecx_size,
ecx_bits,
ecx_security_bits,
0, 0, 0, 0,
ecx_cmp_parameters,
0, 0,
ecx_free,
ecx_ctrl,
NULL,
NULL
};
static int ecd_size25519(const EVP_PKEY *pkey)
{
return ED25519_SIGSIZE;
}
static int ecd_size448(const EVP_PKEY *pkey)
{
return ED448_SIGSIZE;
}
static int ecd_item_verify(EVP_MD_CTX *ctx, const ASN1_ITEM *it, void *asn,
X509_ALGOR *sigalg, ASN1_BIT_STRING *str,
EVP_PKEY *pkey)
{
const ASN1_OBJECT *obj;
int ptype;
int nid;
/* Sanity check: make sure it is ED25519/ED448 with absent parameters */
X509_ALGOR_get0(&obj, &ptype, NULL, sigalg);
nid = OBJ_obj2nid(obj);
if ((nid != NID_ED25519 && nid != NID_ED448) || ptype != V_ASN1_UNDEF) {
ECerr(EC_F_ECD_ITEM_VERIFY, EC_R_INVALID_ENCODING);
return 0;
}
if (!EVP_DigestVerifyInit(ctx, NULL, NULL, NULL, pkey))
return 0;
return 2;
}
static int ecd_item_sign25519(EVP_MD_CTX *ctx, const ASN1_ITEM *it, void *asn,
X509_ALGOR *alg1, X509_ALGOR *alg2,
ASN1_BIT_STRING *str)
{
/* Set algorithms identifiers */
X509_ALGOR_set0(alg1, OBJ_nid2obj(NID_ED25519), V_ASN1_UNDEF, NULL);
if (alg2)
X509_ALGOR_set0(alg2, OBJ_nid2obj(NID_ED25519), V_ASN1_UNDEF, NULL);
/* Algorithm idetifiers set: carry on as normal */
return 3;
}
static int ecd_sig_info_set25519(X509_SIG_INFO *siginf, const X509_ALGOR *alg,
const ASN1_STRING *sig)
{
X509_SIG_INFO_set(siginf, NID_undef, NID_ED25519, X25519_SECURITY_BITS,
X509_SIG_INFO_TLS);
return 1;
}
static int ecd_item_sign448(EVP_MD_CTX *ctx, const ASN1_ITEM *it, void *asn,
X509_ALGOR *alg1, X509_ALGOR *alg2,
ASN1_BIT_STRING *str)
{
/* Set algorithm identifier */
X509_ALGOR_set0(alg1, OBJ_nid2obj(NID_ED448), V_ASN1_UNDEF, NULL);
if (alg2 != NULL)
X509_ALGOR_set0(alg2, OBJ_nid2obj(NID_ED448), V_ASN1_UNDEF, NULL);
/* Algorithm identifier set: carry on as normal */
return 3;
}
static int ecd_sig_info_set448(X509_SIG_INFO *siginf, const X509_ALGOR *alg,
const ASN1_STRING *sig)
{
X509_SIG_INFO_set(siginf, NID_undef, NID_ED448, X448_SECURITY_BITS,
X509_SIG_INFO_TLS);
return 1;
}
const EVP_PKEY_ASN1_METHOD ed25519_asn1_meth = {
EVP_PKEY_ED25519,
EVP_PKEY_ED25519,
0,
"ED25519",
"OpenSSL ED25519 algorithm",
ecx_pub_decode,
ecx_pub_encode,
ecx_pub_cmp,
ecx_pub_print,
ecx_priv_decode,
ecx_priv_encode,
ecx_priv_print,
ecd_size25519,
ecx_bits,
ecx_security_bits,
0, 0, 0, 0,
ecx_cmp_parameters,
0, 0,
ecx_free,
0,
NULL,
NULL,
ecd_item_verify,
ecd_item_sign25519,
ecd_sig_info_set25519
};
const EVP_PKEY_ASN1_METHOD ed448_asn1_meth = {
EVP_PKEY_ED448,
EVP_PKEY_ED448,
0,
"ED448",
"OpenSSL ED448 algorithm",
ecx_pub_decode,
ecx_pub_encode,
ecx_pub_cmp,
ecx_pub_print,
ecx_priv_decode,
ecx_priv_encode,
ecx_priv_print,
ecd_size448,
ecx_bits,
ecx_security_bits,
0, 0, 0, 0,
ecx_cmp_parameters,
0, 0,
ecx_free,
0,
NULL,
NULL,
ecd_item_verify,
ecd_item_sign448,
ecd_sig_info_set448
};
static int pkey_ecx_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)
{
return ecx_key_op(pkey, ctx->pmeth->pkey_id, NULL, NULL, 0, KEY_OP_KEYGEN);
}
static int validate_ecx_derive(EVP_PKEY_CTX *ctx, unsigned char *key,
size_t *keylen,
const unsigned char **privkey,
const unsigned char **pubkey)
{
const ECX_KEY *ecxkey, *peerkey;
if (ctx->pkey == NULL || ctx->peerkey == NULL) {
ECerr(EC_F_VALIDATE_ECX_DERIVE, EC_R_KEYS_NOT_SET);
return 0;
}
ecxkey = ctx->pkey->pkey.ecx;
peerkey = ctx->peerkey->pkey.ecx;
if (ecxkey == NULL || ecxkey->privkey == NULL) {
ECerr(EC_F_VALIDATE_ECX_DERIVE, EC_R_INVALID_PRIVATE_KEY);
return 0;
}
if (peerkey == NULL) {
ECerr(EC_F_VALIDATE_ECX_DERIVE, EC_R_INVALID_PEER_KEY);
return 0;
}
*privkey = ecxkey->privkey;
*pubkey = peerkey->pubkey;
return 1;
}
static int pkey_ecx_derive25519(EVP_PKEY_CTX *ctx, unsigned char *key,
size_t *keylen)
{
const unsigned char *privkey, *pubkey;
if (!validate_ecx_derive(ctx, key, keylen, &privkey, &pubkey)
|| (key != NULL
&& X25519(key, privkey, pubkey) == 0))
return 0;
*keylen = X25519_KEYLEN;
return 1;
}
static int pkey_ecx_derive448(EVP_PKEY_CTX *ctx, unsigned char *key,
size_t *keylen)
{
const unsigned char *privkey, *pubkey;
if (!validate_ecx_derive(ctx, key, keylen, &privkey, &pubkey)
|| (key != NULL
&& X448(key, privkey, pubkey) == 0))
return 0;
*keylen = X448_KEYLEN;
return 1;
}
static int pkey_ecx_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
{
/* Only need to handle peer key for derivation */
if (type == EVP_PKEY_CTRL_PEER_KEY)
return 1;
return -2;
}
const EVP_PKEY_METHOD ecx25519_pkey_meth = {
EVP_PKEY_X25519,
0, 0, 0, 0, 0, 0, 0,
pkey_ecx_keygen,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
pkey_ecx_derive25519,
pkey_ecx_ctrl,
0
};
const EVP_PKEY_METHOD ecx448_pkey_meth = {
EVP_PKEY_X448,
0, 0, 0, 0, 0, 0, 0,
pkey_ecx_keygen,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
pkey_ecx_derive448,
pkey_ecx_ctrl,
0
};
static int pkey_ecd_digestsign25519(EVP_MD_CTX *ctx, unsigned char *sig,
size_t *siglen, const unsigned char *tbs,
size_t tbslen)
{
const ECX_KEY *edkey = EVP_MD_CTX_pkey_ctx(ctx)->pkey->pkey.ecx;
if (sig == NULL) {
*siglen = ED25519_SIGSIZE;
return 1;
}
if (*siglen < ED25519_SIGSIZE) {
ECerr(EC_F_PKEY_ECD_DIGESTSIGN25519, EC_R_BUFFER_TOO_SMALL);
return 0;
}
if (ED25519_sign(sig, tbs, tbslen, edkey->pubkey, edkey->privkey) == 0)
return 0;
*siglen = ED25519_SIGSIZE;
return 1;
}
static int pkey_ecd_digestsign448(EVP_MD_CTX *ctx, unsigned char *sig,
size_t *siglen, const unsigned char *tbs,
size_t tbslen)
{
const ECX_KEY *edkey = EVP_MD_CTX_pkey_ctx(ctx)->pkey->pkey.ecx;
if (sig == NULL) {
*siglen = ED448_SIGSIZE;
return 1;
}
if (*siglen < ED448_SIGSIZE) {
ECerr(EC_F_PKEY_ECD_DIGESTSIGN448, EC_R_BUFFER_TOO_SMALL);
return 0;
}
if (ED448_sign(sig, tbs, tbslen, edkey->pubkey, edkey->privkey, NULL,
0) == 0)
return 0;
*siglen = ED448_SIGSIZE;
return 1;
}
static int pkey_ecd_digestverify25519(EVP_MD_CTX *ctx, const unsigned char *sig,
size_t siglen, const unsigned char *tbs,
size_t tbslen)
{
const ECX_KEY *edkey = EVP_MD_CTX_pkey_ctx(ctx)->pkey->pkey.ecx;
if (siglen != ED25519_SIGSIZE)
return 0;
return ED25519_verify(tbs, tbslen, sig, edkey->pubkey);
}
static int pkey_ecd_digestverify448(EVP_MD_CTX *ctx, const unsigned char *sig,
size_t siglen, const unsigned char *tbs,
size_t tbslen)
{
const ECX_KEY *edkey = EVP_MD_CTX_pkey_ctx(ctx)->pkey->pkey.ecx;
if (siglen != ED448_SIGSIZE)
return 0;
return ED448_verify(tbs, tbslen, sig, edkey->pubkey, NULL, 0);
}
static int pkey_ecd_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
{
switch (type) {
case EVP_PKEY_CTRL_MD:
/* Only NULL allowed as digest */
if (p2 == NULL)
return 1;
ECerr(EC_F_PKEY_ECD_CTRL, EC_R_INVALID_DIGEST_TYPE);
return 0;
case EVP_PKEY_CTRL_DIGESTINIT:
return 1;
}
return -2;
}
const EVP_PKEY_METHOD ed25519_pkey_meth = {
EVP_PKEY_ED25519, EVP_PKEY_FLAG_SIGCTX_CUSTOM,
0, 0, 0, 0, 0, 0,
pkey_ecx_keygen,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
pkey_ecd_ctrl,
0,
pkey_ecd_digestsign25519,
pkey_ecd_digestverify25519
};
const EVP_PKEY_METHOD ed448_pkey_meth = {
EVP_PKEY_ED448, EVP_PKEY_FLAG_SIGCTX_CUSTOM,
0, 0, 0, 0, 0, 0,
pkey_ecx_keygen,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
pkey_ecd_ctrl,
0,
pkey_ecd_digestsign448,
pkey_ecd_digestverify448
};