Add support for ECDH KARI.

Add support for ECDH in enveloped data. The CMS ctrls for the EC ASN1
method decode/encode the appropriate parameters from the CMS ASN1 data
and send appropriate data to the EC public key method.
This commit is contained in:
Dr. Stephen Henson 2013-07-17 15:13:37 +01:00
parent 25af7a5dbc
commit 88e20b8584
4 changed files with 402 additions and 2 deletions

View file

@ -1204,6 +1204,7 @@ void ERR_load_EC_strings(void);
#define EC_R_INVALID_COMPRESSED_POINT 110
#define EC_R_INVALID_COMPRESSION_BIT 109
#define EC_R_INVALID_CURVE 141
#define EC_R_INVALID_DIGEST 151
#define EC_R_INVALID_DIGEST_TYPE 138
#define EC_R_INVALID_ENCODING 102
#define EC_R_INVALID_FIELD 103

View file

@ -63,8 +63,12 @@
#ifndef OPENSSL_NO_CMS
#include <openssl/cms.h>
#endif
#include <openssl/asn1t.h>
#include "asn1_locl.h"
static int ecdh_cms_decrypt(CMS_RecipientInfo *ri);
static int ecdh_cms_encrypt(CMS_RecipientInfo *ri);
static int eckey_param2type(int *pptype, void **ppval, EC_KEY *ec_key)
{
const EC_GROUP *group;
@ -612,6 +616,17 @@ static int ec_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
X509_ALGOR_set0(alg2, OBJ_nid2obj(snid), V_ASN1_UNDEF, 0);
}
return 1;
case ASN1_PKEY_CTRL_CMS_ENVELOPE:
if (arg1 == 1)
return ecdh_cms_decrypt(arg2);
else if (arg1 == 0)
return ecdh_cms_encrypt(arg2);
return -2;
case ASN1_PKEY_CTRL_CMS_RI_TYPE:
*(int *)arg2 = CMS_RECIPINFO_AGREE;
return 1;
#endif
case ASN1_PKEY_CTRL_DEFAULT_MD_NID:
@ -658,3 +673,365 @@ const EVP_PKEY_ASN1_METHOD eckey_asn1_meth =
old_ec_priv_decode,
old_ec_priv_encode
};
#ifndef OPENSSL_NO_CMS
static int ecdh_cms_set_peerkey(EVP_PKEY_CTX *pctx,
X509_ALGOR *alg, ASN1_BIT_STRING *pubkey)
{
ASN1_OBJECT *aoid;
int atype;
void *aval;
int rv = 0;
EVP_PKEY *pkpeer = NULL;
EC_KEY *ecpeer = NULL;
const unsigned char *p;
int plen;
X509_ALGOR_get0(&aoid, &atype, &aval, alg);
if (OBJ_obj2nid(aoid) != NID_X9_62_id_ecPublicKey)
goto err;
/* If absent parameters get group from main key */
if (atype == V_ASN1_UNDEF || atype == V_ASN1_NULL)
{
const EC_GROUP *grp;
EVP_PKEY *pk;
pk = EVP_PKEY_CTX_get0_pkey(pctx);
if (!pk)
goto err;
grp = EC_KEY_get0_group(pk->pkey.ec);
ecpeer = EC_KEY_new();
if (!ecpeer)
goto err;
if (!EC_KEY_set_group(ecpeer, grp))
goto err;
}
else
{
ecpeer = eckey_type2param(atype, aval);
if (!ecpeer)
goto err;
}
/* We have parameters now set public key */
plen = ASN1_STRING_length(pubkey);
p = ASN1_STRING_data(pubkey);
if (!p || !plen)
goto err;
if (!o2i_ECPublicKey(&ecpeer, &p, plen))
goto err;
pkpeer = EVP_PKEY_new();
if (!pkpeer)
goto err;
EVP_PKEY_set1_EC_KEY(pkpeer, ecpeer);
if (EVP_PKEY_derive_set_peer(pctx, pkpeer) > 0)
rv = 1;
err:
if (ecpeer)
EC_KEY_free(ecpeer);
if (pkpeer)
EVP_PKEY_free(pkpeer);
return rv;
}
/* Set KDF parameters based on KDF NID */
static int ecdh_cms_set_kdf_param(EVP_PKEY_CTX *pctx, int eckdf_nid)
{
int kdf_nid, kdfmd_nid, cofactor;
const EVP_MD *kdf_md;
if (eckdf_nid == NID_undef)
return 0;
/* Lookup KDF type, cofactor mode and digest */
if (!OBJ_find_sigid_algs(eckdf_nid, &kdfmd_nid, &kdf_nid))
return 0;
if (kdf_nid == NID_dh_std_kdf)
cofactor = 0;
else if (kdf_nid == NID_dh_cofactor_kdf)
cofactor = 1;
else return 0;
if (EVP_PKEY_CTX_set_ecdh_cofactor_mode(pctx, cofactor) <= 0)
return 0;
if (EVP_PKEY_CTX_set_ecdh_kdf_type(pctx, EVP_PKEY_ECDH_KDF_X9_62) <= 0)
return 0;
kdf_md = EVP_get_digestbynid(kdfmd_nid);
if (!kdf_md)
return 0;
if (EVP_PKEY_CTX_set_ecdh_kdf_md(pctx, kdf_md) <= 0)
return 0;
return 1;
}
/* Utilities to encode the ECC_CMS_SharedInfo structure used during key
* derivation.
*/
typedef struct {
X509_ALGOR *keyInfo;
ASN1_OCTET_STRING *entityUInfo;
ASN1_OCTET_STRING *suppPubInfo;
} ECC_CMS_SharedInfo;
ASN1_SEQUENCE(ECC_CMS_SharedInfo) = {
ASN1_SIMPLE(ECC_CMS_SharedInfo, keyInfo, X509_ALGOR),
ASN1_EXP_OPT(ECC_CMS_SharedInfo, entityUInfo, ASN1_OCTET_STRING, 0),
ASN1_EXP_OPT(ECC_CMS_SharedInfo, suppPubInfo, ASN1_OCTET_STRING, 2),
} ASN1_SEQUENCE_END(ECC_CMS_SharedInfo)
static int ecdh_cms_set_ukm(EVP_PKEY_CTX *pctx,
X509_ALGOR *kekalg,
ASN1_OCTET_STRING *ukm,
int keylen)
{
union {
ECC_CMS_SharedInfo *pecsi;
ASN1_VALUE *a;
} intsi = {NULL};
unsigned char *der = NULL;
int plen;
ASN1_OCTET_STRING oklen;
unsigned char kl[4];
ECC_CMS_SharedInfo ecsi;
keylen <<= 3;
kl[0] = (keylen >> 24) & 0xff;
kl[1] = (keylen >> 16) & 0xff;
kl[2] = (keylen >> 8) & 0xff;
kl[3] = keylen & 0xff;
oklen.length = 4;
oklen.data = kl;
oklen.type = V_ASN1_OCTET_STRING;
oklen.flags = 0;
ecsi.keyInfo = kekalg;
ecsi.entityUInfo = ukm;
ecsi.suppPubInfo = &oklen;
intsi.pecsi = &ecsi;
plen = ASN1_item_i2d(intsi.a, &der, ASN1_ITEM_rptr(ECC_CMS_SharedInfo));
if (!der || !plen)
goto err;
if (EVP_PKEY_CTX_set0_ecdh_kdf_ukm(pctx, der, plen) <= 0)
goto err;
return 1;
err:
if (der)
OPENSSL_free(der);
return 0;
}
static int ecdh_cms_set_shared_info(EVP_PKEY_CTX *pctx, CMS_RecipientInfo *ri)
{
int rv = 0;
X509_ALGOR *alg, *kekalg = NULL;
ASN1_OCTET_STRING *ukm;
const unsigned char *p;
int plen, keylen;
const EVP_CIPHER *kekcipher;
EVP_CIPHER_CTX *kekctx;
if (!CMS_RecipientInfo_kari_get0_alg(ri, &alg, &ukm))
return 0;
if (!ecdh_cms_set_kdf_param(pctx, OBJ_obj2nid(alg->algorithm)))
{
ECerr(EC_F_ECDH_CMS_SET_SHARED_INFO, EC_R_KDF_PARAMETER_ERROR);
return 0;
}
if (alg->parameter->type != V_ASN1_SEQUENCE)
return 0;
p = alg->parameter->value.sequence->data;
plen = alg->parameter->value.sequence->length;
kekalg = d2i_X509_ALGOR(NULL, &p, plen);
if (!kekalg)
goto err;
kekctx = CMS_RecipientInfo_kari_get0_ctx(ri);
if (!kekctx)
goto err;
kekcipher = EVP_get_cipherbyobj(kekalg->algorithm);
if (!kekcipher || EVP_CIPHER_mode(kekcipher) != EVP_CIPH_WRAP_MODE)
goto err;
if (!EVP_EncryptInit_ex(kekctx, kekcipher, NULL, NULL, NULL))
goto err;
keylen = EVP_CIPHER_CTX_key_length(kekctx);
if (EVP_PKEY_CTX_set_ecdh_kdf_outlen(pctx, keylen) <= 0)
goto err;
if (!ecdh_cms_set_ukm(pctx, kekalg, ukm, keylen))
goto err;
rv = 1;
err:
if (kekalg)
X509_ALGOR_free(kekalg);
return rv;
}
static int ecdh_cms_decrypt(CMS_RecipientInfo *ri)
{
EVP_PKEY_CTX *pctx;
pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
if (!pctx)
return 0;
/* See if we need to set peer key */
if (!EVP_PKEY_CTX_get0_peerkey(pctx))
{
X509_ALGOR *alg;
ASN1_BIT_STRING *pubkey;
if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &alg, &pubkey,
NULL, NULL, NULL))
return 0;
if (!alg || !pubkey)
return 0;
if (!ecdh_cms_set_peerkey(pctx, alg, pubkey))
{
ECerr(EC_F_ECDH_CMS_DECRYPT, EC_R_PEER_KEY_ERROR);
return 0;
}
}
/* Set ECDH derivation parameters and initialise unwrap context */
if (!ecdh_cms_set_shared_info(pctx, ri))
{
ECerr(EC_F_ECDH_CMS_DECRYPT, EC_R_SHARED_INFO_ERROR);
return 0;
}
return 1;
}
static int ecdh_cms_encrypt(CMS_RecipientInfo *ri)
{
EVP_PKEY_CTX *pctx;
EVP_PKEY *pkey;
EVP_CIPHER_CTX *ctx;
int keylen;
X509_ALGOR *talg, *wrap_alg = NULL;
ASN1_OBJECT *aoid;
ASN1_BIT_STRING *pubkey;
ASN1_STRING *wrap_str;
ASN1_OCTET_STRING *ukm;
unsigned char *penc = NULL;
int penclen;
int rv = 0;
int ecdh_nid, kdf_type, kdf_nid, wrap_nid;
const EVP_MD *kdf_md;
pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
if (!pctx)
return 0;
/* Get ephemeral key */
pkey = EVP_PKEY_CTX_get0_pkey(pctx);
if (!CMS_RecipientInfo_kari_get0_orig_id(ri, &talg, &pubkey,
NULL, NULL, NULL))
goto err;
X509_ALGOR_get0(&aoid, NULL, NULL, talg);
/* Is everything uninitialised? */
if (aoid == OBJ_nid2obj(NID_undef))
{
EC_KEY *eckey = pkey->pkey.ec;
/* Set the key */
unsigned char *p;
penclen = i2o_ECPublicKey(eckey, NULL);
if (penclen <= 0)
goto err;
penc = OPENSSL_malloc(penclen);
if (!penc)
goto err;
p = penc;
penclen = i2o_ECPublicKey(eckey, &p);
if (penclen <= 0)
goto err;
ASN1_STRING_set0(pubkey, penc, penclen);
pubkey->flags&= ~(ASN1_STRING_FLAG_BITS_LEFT|0x07);
pubkey->flags|=ASN1_STRING_FLAG_BITS_LEFT;
penc = NULL;
X509_ALGOR_set0(talg, OBJ_nid2obj(NID_X9_62_id_ecPublicKey),
V_ASN1_UNDEF, NULL);
}
/* See if custom paraneters set */
kdf_type = EVP_PKEY_CTX_get_ecdh_kdf_type(pctx);
if (kdf_type <= 0)
goto err;
if (!EVP_PKEY_CTX_get_ecdh_kdf_md(pctx, &kdf_md))
goto err;
ecdh_nid = EVP_PKEY_CTX_get_ecdh_cofactor_mode(pctx);
if (ecdh_nid < 0)
goto err;
else if (ecdh_nid == 0)
ecdh_nid = NID_dh_std_kdf;
else if (ecdh_nid == 1)
ecdh_nid = NID_dh_cofactor_kdf;
if (kdf_type == EVP_PKEY_ECDH_KDF_NONE)
{
kdf_type = EVP_PKEY_ECDH_KDF_X9_62;
if (EVP_PKEY_CTX_set_ecdh_kdf_type(pctx, kdf_type) <= 0)
goto err;
}
else
/* Uknown KDF */
goto err;
if (kdf_md == NULL)
{
/* Fixme later for better MD */
kdf_md = EVP_sha1();
if (EVP_PKEY_CTX_set_ecdh_kdf_md(pctx, kdf_md) <= 0)
goto err;
}
if (!CMS_RecipientInfo_kari_get0_alg(ri, &talg, &ukm))
goto err;
/* Lookup NID for KDF+cofactor+digest */
if (!OBJ_find_sigid_by_algs(&kdf_nid, EVP_MD_type(kdf_md), ecdh_nid))
goto err;
/* Get wrap NID */
ctx = CMS_RecipientInfo_kari_get0_ctx(ri);
wrap_nid = EVP_CIPHER_CTX_type(ctx);
keylen = EVP_CIPHER_CTX_key_length(ctx);
/* Package wrap algorithm in an AlgorithmIdentifier */
wrap_alg = X509_ALGOR_new();
if (!wrap_alg)
goto err;
X509_ALGOR_set0(wrap_alg, OBJ_nid2obj(wrap_nid), V_ASN1_UNDEF, NULL);
if (EVP_PKEY_CTX_set_ecdh_kdf_outlen(pctx, keylen) <= 0)
goto err;
if (!ecdh_cms_set_ukm(pctx, wrap_alg, ukm, keylen))
goto err;
/* Now need to wrap encoding of wrap AlgorithmIdentifier into
* parameter of another AlgorithmIdentifier.
*/
penc = NULL;
penclen = i2d_X509_ALGOR(wrap_alg, &penc);
if (!penc || !penclen)
goto err;
wrap_str = ASN1_STRING_new();
if (!wrap_str)
goto err;
ASN1_STRING_set0(wrap_str, penc, penclen);
penc = NULL;
X509_ALGOR_set0(talg, OBJ_nid2obj(kdf_nid), V_ASN1_SEQUENCE, wrap_str);
rv = 1;
err:
if (penc)
OPENSSL_free(penc);
if (wrap_alg)
X509_ALGOR_free(wrap_alg);
return rv;
}
#endif

View file

@ -1,6 +1,6 @@
/* crypto/ec/ec_err.c */
/* ====================================================================
* Copyright (c) 1999-2011 The OpenSSL Project. All rights reserved.
* Copyright (c) 1999-2013 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@ -76,6 +76,8 @@ static ERR_STRING_DATA EC_str_functs[]=
{ERR_FUNC(EC_F_D2I_ECPKPARAMETERS), "d2i_ECPKParameters"},
{ERR_FUNC(EC_F_D2I_ECPRIVATEKEY), "d2i_ECPrivateKey"},
{ERR_FUNC(EC_F_DO_EC_KEY_PRINT), "DO_EC_KEY_PRINT"},
{ERR_FUNC(EC_F_ECDH_CMS_DECRYPT), "ECDH_CMS_DECRYPT"},
{ERR_FUNC(EC_F_ECDH_CMS_SET_SHARED_INFO), "ECDH_CMS_SET_SHARED_INFO"},
{ERR_FUNC(EC_F_ECKEY_PARAM2TYPE), "ECKEY_PARAM2TYPE"},
{ERR_FUNC(EC_F_ECKEY_PARAM_DECODE), "ECKEY_PARAM_DECODE"},
{ERR_FUNC(EC_F_ECKEY_PRIV_DECODE), "ECKEY_PRIV_DECODE"},
@ -229,6 +231,7 @@ static ERR_STRING_DATA EC_str_reasons[]=
{ERR_REASON(EC_R_INVALID_COMPRESSED_POINT),"invalid compressed point"},
{ERR_REASON(EC_R_INVALID_COMPRESSION_BIT),"invalid compression bit"},
{ERR_REASON(EC_R_INVALID_CURVE) ,"invalid curve"},
{ERR_REASON(EC_R_INVALID_DIGEST) ,"invalid digest"},
{ERR_REASON(EC_R_INVALID_DIGEST_TYPE) ,"invalid digest type"},
{ERR_REASON(EC_R_INVALID_ENCODING) ,"invalid encoding"},
{ERR_REASON(EC_R_INVALID_FIELD) ,"invalid field"},
@ -237,6 +240,7 @@ static ERR_STRING_DATA EC_str_reasons[]=
{ERR_REASON(EC_R_INVALID_PENTANOMIAL_BASIS),"invalid pentanomial basis"},
{ERR_REASON(EC_R_INVALID_PRIVATE_KEY) ,"invalid private key"},
{ERR_REASON(EC_R_INVALID_TRINOMIAL_BASIS),"invalid trinomial basis"},
{ERR_REASON(EC_R_KDF_PARAMETER_ERROR) ,"kdf parameter error"},
{ERR_REASON(EC_R_KEYS_NOT_SET) ,"keys not set"},
{ERR_REASON(EC_R_MISSING_PARAMETERS) ,"missing parameters"},
{ERR_REASON(EC_R_MISSING_PRIVATE_KEY) ,"missing private key"},
@ -247,9 +251,11 @@ static ERR_STRING_DATA EC_str_reasons[]=
{ERR_REASON(EC_R_NO_FIELD_MOD) ,"no field mod"},
{ERR_REASON(EC_R_NO_PARAMETERS_SET) ,"no parameters set"},
{ERR_REASON(EC_R_PASSED_NULL_PARAMETER) ,"passed null parameter"},
{ERR_REASON(EC_R_PEER_KEY_ERROR) ,"peer key error"},
{ERR_REASON(EC_R_PKPARAMETERS2GROUP_FAILURE),"pkparameters2group failure"},
{ERR_REASON(EC_R_POINT_AT_INFINITY) ,"point at infinity"},
{ERR_REASON(EC_R_POINT_IS_NOT_ON_CURVE) ,"point is not on curve"},
{ERR_REASON(EC_R_SHARED_INFO_ERROR) ,"shared info error"},
{ERR_REASON(EC_R_SLOT_FULL) ,"slot full"},
{ERR_REASON(EC_R_UNDEFINED_GENERATOR) ,"undefined generator"},
{ERR_REASON(EC_R_UNDEFINED_ORDER) ,"undefined order"},

View file

@ -319,7 +319,7 @@ static int pkey_ec_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
case EVP_PKEY_CTRL_EC_ECDH_COFACTOR:
if (p1 == -2)
{
if (dctx->co_key)
if (dctx->cofactor_mode != -1)
return dctx->cofactor_mode;
else
{
@ -459,6 +459,22 @@ static int pkey_ec_ctrl_str(EVP_PKEY_CTX *ctx,
return -2;
return EVP_PKEY_CTX_set_ec_param_enc(ctx, param_enc);
}
else if (!strcmp(type, "ecdh_kdf_md"))
{
const EVP_MD *md;
if (!(md = EVP_get_digestbyname(value)))
{
ECerr(EC_F_PKEY_EC_CTRL_STR, EC_R_INVALID_DIGEST);
return 0;
}
return EVP_PKEY_CTX_set_ecdh_kdf_md(ctx, md);
}
else if (!strcmp(type, "ecdh_cofactor_mode"))
{
int co_mode;
co_mode = atoi(value);
return EVP_PKEY_CTX_set_ecdh_cofactor_mode(ctx, co_mode);
}
return -2;
}