Add CMS ECC support.

This brings in EC code from OpenSSL 1.1.1b, with style(9) and whitespace
cleanups. All of this code is currently under OPENSSL_NO_CMS hence is a
no-op.

ok inoguchi@

1 files changed, 370 insertions, 2 deletions

diff --git a/lib/libcrypto/ec/ec_ameth.c b/lib/libcrypto/ec/ec_ameth.c
index 04c068200f7..a7e80c73d7b 100644
--- a/lib/libcrypto/ec/ec_ameth.c
+++ b/lib/libcrypto/ec/ec_ameth.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ec_ameth.c,v 1.25 2018/08/24 20:22:15 tb Exp $ */
+/* $OpenBSD: ec_ameth.c,v 1.26 2019/09/08 17:00:05 jsing Exp $ */
 /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
  * project 2006.
  */
@@ -65,9 +65,15 @@
 #include <openssl/err.h>
 #include <openssl/x509.h>
 
-
 #include "asn1_locl.h"
 
+#ifndef OPENSSL_NO_CMS
+#include <openssl/cms.h>
+
+static int ecdh_cms_decrypt(CMS_RecipientInfo *ri);
+static int ecdh_cms_encrypt(CMS_RecipientInfo *ri);
+#endif
+
 static int 
 eckey_param2type(int *pptype, void **ppval, EC_KEY * ec_key)
 {
@@ -573,6 +579,36 @@ ec_pkey_ctrl(EVP_PKEY * pkey, int op, long arg1, void *arg2)
 		}
 		return 1;
 
+#ifndef OPENSSL_NO_CMS
+	case ASN1_PKEY_CTRL_CMS_SIGN:
+		if (arg1 == 0) {
+			X509_ALGOR *alg1, *alg2;
+			int snid, hnid;
+
+			CMS_SignerInfo_get0_algs(arg2, NULL, NULL, &alg1, &alg2);
+			if (alg1 == NULL || alg1->algorithm == NULL)
+				return -1;
+			hnid = OBJ_obj2nid(alg1->algorithm);
+			if (hnid == NID_undef)
+				return -1;
+			if (!OBJ_find_sigid_by_algs(&snid, hnid, EVP_PKEY_id(pkey)))
+				return -1;
+			X509_ALGOR_set0(alg2, OBJ_nid2obj(snid), V_ASN1_UNDEF, 0);
+		}
+		return 1;
+
+	case ASN1_PKEY_CTRL_CMS_ENVELOPE:
+		if (arg1 == 0)
+			return ecdh_cms_encrypt(arg2);
+		else if (arg1 == 1)
+			return ecdh_cms_decrypt(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:
 		*(int *) arg2 = NID_sha1;
 		return 2;
@@ -584,6 +620,338 @@ ec_pkey_ctrl(EVP_PKEY * pkey, int op, long arg1, void *arg2)
 
 }
 
+#ifndef OPENSSL_NO_CMS
+
+static int
+ecdh_cms_set_peerkey(EVP_PKEY_CTX *pctx, X509_ALGOR *alg,
+    ASN1_BIT_STRING *pubkey)
+{
+	const ASN1_OBJECT *aoid;
+	int atype;
+	const 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 == NULL)
+			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_get0_data(pubkey);
+	if (!p || !plen)
+		goto err;
+	if (!o2i_ECPublicKey(&ecpeer, &p, plen))
+		goto err;
+	pkpeer = EVP_PKEY_new();
+	if (pkpeer == NULL)
+		goto err;
+	EVP_PKEY_set1_EC_KEY(pkpeer, ecpeer);
+	if (EVP_PKEY_derive_set_peer(pctx, pkpeer) > 0)
+		rv = 1;
+ err:
+	EC_KEY_free(ecpeer);
+	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_63) <= 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;
+}
+
+static int
+ecdh_cms_set_shared_info(EVP_PKEY_CTX *pctx, CMS_RecipientInfo *ri)
+{
+	X509_ALGOR *alg, *kekalg = NULL;
+	ASN1_OCTET_STRING *ukm;
+	const unsigned char *p;
+	unsigned char *der = NULL;
+	int plen, keylen;
+	const EVP_CIPHER *kekcipher;
+	EVP_CIPHER_CTX *kekctx;
+	int rv = 0;
+
+	if (!CMS_RecipientInfo_kari_get0_alg(ri, &alg, &ukm))
+		return 0;
+
+	if (!ecdh_cms_set_kdf_param(pctx, OBJ_obj2nid(alg->algorithm))) {
+		ECerror(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;
+	if (EVP_CIPHER_asn1_to_param(kekctx, kekalg->parameter) <= 0)
+		goto err;
+
+	keylen = EVP_CIPHER_CTX_key_length(kekctx);
+	if (EVP_PKEY_CTX_set_ecdh_kdf_outlen(pctx, keylen) <= 0)
+		goto err;
+
+	plen = CMS_SharedInfo_encode(&der, kekalg, ukm, keylen);
+	if (!plen)
+		goto err;
+
+	if (EVP_PKEY_CTX_set0_ecdh_kdf_ukm(pctx, der, plen) <= 0)
+		goto err;
+	der = NULL;
+
+	rv = 1;
+ err:
+	X509_ALGOR_free(kekalg);
+	free(der);
+	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)) {
+			ECerror(EC_R_PEER_KEY_ERROR);
+			return 0;
+		}
+	}
+
+	/* Set ECDH derivation parameters and initialise unwrap context */
+	if (!ecdh_cms_set_shared_info(pctx, ri)) {
+		ECerror(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;
+	const ASN1_OBJECT *aoid;
+	ASN1_BIT_STRING *pubkey;
+	ASN1_STRING *wrap_str;
+	ASN1_OCTET_STRING *ukm;
+	unsigned char *penc = NULL;
+	int penclen;
+	int ecdh_nid, kdf_type, kdf_nid, wrap_nid;
+	const EVP_MD *kdf_md;
+	int rv = 0;
+
+	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;
+		unsigned char *p;
+
+		/* Set the key */
+		penclen = i2o_ECPublicKey(eckey, NULL);
+		if (penclen <= 0)
+			goto err;
+		penc = malloc(penclen);
+		if (penc == NULL)
+			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 parameters 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_63;
+		if (EVP_PKEY_CTX_set_ecdh_kdf_type(pctx, kdf_type) <= 0)
+			goto err;
+	} else {
+		/* Unknown 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 == NULL)
+		goto err;
+	wrap_alg->algorithm = OBJ_nid2obj(wrap_nid);
+	wrap_alg->parameter = ASN1_TYPE_new();
+	if (wrap_alg->parameter == NULL)
+		goto err;
+	if (EVP_CIPHER_param_to_asn1(ctx, wrap_alg->parameter) <= 0)
+		goto err;
+	if (ASN1_TYPE_get(wrap_alg->parameter) == NID_undef) {
+		ASN1_TYPE_free(wrap_alg->parameter);
+		wrap_alg->parameter = NULL;
+	}
+
+	if (EVP_PKEY_CTX_set_ecdh_kdf_outlen(pctx, keylen) <= 0)
+		goto err;
+
+	penclen = CMS_SharedInfo_encode(&penc, wrap_alg, ukm, keylen);
+	if (!penclen)
+		goto err;
+
+	if (EVP_PKEY_CTX_set0_ecdh_kdf_ukm(pctx, penc, penclen) <= 0)
+		goto err;
+	penc = NULL;
+
+	/*
+	 * Now need to wrap encoding of wrap AlgorithmIdentifier into parameter
+	 * of another AlgorithmIdentifier.
+	 */
+	penclen = i2d_X509_ALGOR(wrap_alg, &penc);
+	if (!penc || !penclen)
+		goto err;
+	wrap_str = ASN1_STRING_new();
+	if (wrap_str == NULL)
+		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:
+	free(penc);
+	X509_ALGOR_free(wrap_alg);
+	return rv;
+}
+
+#endif
+
 const EVP_PKEY_ASN1_METHOD eckey_asn1_meth = {
 	.pkey_id = EVP_PKEY_EC,
 	.pkey_base_id = EVP_PKEY_EC,