|
|
|
@@ -0,0 +1,394 @@
|
|
|
|
|
/*
|
|
|
|
|
* Copyright (C) 2012 Martin Willi
|
|
|
|
|
* Copyright (C) 2012 revosec AG
|
|
|
|
|
* Copyright (C) 2012 Tobias Brunner
|
|
|
|
|
* Copyright (C) 2002-2008 Andreas Steffen
|
|
|
|
|
* Copyright (C) 2005 Jan Hutter, Martin Willi
|
|
|
|
|
* Hochschule fuer Technik Rapperswil, Switzerland
|
|
|
|
|
*
|
|
|
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
|
|
|
* under the terms of the GNU General Public License as published by the
|
|
|
|
|
* Free Software Foundation; either version 2 of the License, or (at your
|
|
|
|
|
* option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
|
|
|
|
|
*
|
|
|
|
|
* This program is distributed in the hope that it will be useful, but
|
|
|
|
|
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
|
|
|
|
|
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
|
|
|
|
* for more details.
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
#include "pkcs7_enveloped_data.h"
|
|
|
|
|
|
|
|
|
|
#include <asn1/asn1.h>
|
|
|
|
|
#include <asn1/asn1_parser.h>
|
|
|
|
|
#include <asn1/oid.h>
|
|
|
|
|
#include <credentials/certificates/x509.h>
|
|
|
|
|
#include <utils/debug.h>
|
|
|
|
|
|
|
|
|
|
typedef struct private_pkcs7_enveloped_data_t private_pkcs7_enveloped_data_t;
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* Private data of a PKCS#7 signed-data container.
|
|
|
|
|
*/
|
|
|
|
|
struct private_pkcs7_enveloped_data_t {
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* Implements pkcs7_t.
|
|
|
|
|
*/
|
|
|
|
|
pkcs7_t public;
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* Decrypted content
|
|
|
|
|
*/
|
|
|
|
|
chunk_t content;
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* Encrypted and encoded PKCS#7 enveloped-data
|
|
|
|
|
*/
|
|
|
|
|
chunk_t encoding;
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* ASN.1 definition of the PKCS#7 envelopedData type
|
|
|
|
|
*/
|
|
|
|
|
static const asn1Object_t envelopedDataObjects[] = {
|
|
|
|
|
{ 0, "envelopedData", ASN1_SEQUENCE, ASN1_NONE }, /* 0 */
|
|
|
|
|
{ 1, "version", ASN1_INTEGER, ASN1_BODY }, /* 1 */
|
|
|
|
|
{ 1, "recipientInfos", ASN1_SET, ASN1_LOOP }, /* 2 */
|
|
|
|
|
{ 2, "recipientInfo", ASN1_SEQUENCE, ASN1_BODY }, /* 3 */
|
|
|
|
|
{ 3, "version", ASN1_INTEGER, ASN1_BODY }, /* 4 */
|
|
|
|
|
{ 3, "issuerAndSerialNumber", ASN1_SEQUENCE, ASN1_BODY }, /* 5 */
|
|
|
|
|
{ 4, "issuer", ASN1_SEQUENCE, ASN1_OBJ }, /* 6 */
|
|
|
|
|
{ 4, "serial", ASN1_INTEGER, ASN1_BODY }, /* 7 */
|
|
|
|
|
{ 3, "encryptionAlgorithm", ASN1_EOC, ASN1_RAW }, /* 8 */
|
|
|
|
|
{ 3, "encryptedKey", ASN1_OCTET_STRING, ASN1_BODY }, /* 9 */
|
|
|
|
|
{ 1, "end loop", ASN1_EOC, ASN1_END }, /* 10 */
|
|
|
|
|
{ 1, "encryptedContentInfo", ASN1_SEQUENCE, ASN1_OBJ }, /* 11 */
|
|
|
|
|
{ 2, "contentType", ASN1_OID, ASN1_BODY }, /* 12 */
|
|
|
|
|
{ 2, "contentEncryptionAlgorithm", ASN1_EOC, ASN1_RAW }, /* 13 */
|
|
|
|
|
{ 2, "encryptedContent", ASN1_CONTEXT_S_0, ASN1_BODY }, /* 14 */
|
|
|
|
|
{ 0, "exit", ASN1_EOC, ASN1_EXIT }
|
|
|
|
|
};
|
|
|
|
|
#define PKCS7_VERSION 1
|
|
|
|
|
#define PKCS7_RECIPIENT_INFO_VERSION 4
|
|
|
|
|
#define PKCS7_ISSUER 6
|
|
|
|
|
#define PKCS7_SERIAL_NUMBER 7
|
|
|
|
|
#define PKCS7_ENCRYPTION_ALG 8
|
|
|
|
|
#define PKCS7_ENCRYPTED_KEY 9
|
|
|
|
|
#define PKCS7_CONTENT_TYPE 12
|
|
|
|
|
#define PKCS7_CONTENT_ENC_ALGORITHM 13
|
|
|
|
|
#define PKCS7_ENCRYPTED_CONTENT 14
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* Find a private key for issuerAndSerialNumber
|
|
|
|
|
*/
|
|
|
|
|
static private_key_t *find_private(identification_t *issuer,
|
|
|
|
|
identification_t *serial)
|
|
|
|
|
{
|
|
|
|
|
enumerator_t *enumerator;
|
|
|
|
|
certificate_t *cert;
|
|
|
|
|
public_key_t *public;
|
|
|
|
|
private_key_t *private = NULL;
|
|
|
|
|
identification_t *id;
|
|
|
|
|
chunk_t fp;
|
|
|
|
|
|
|
|
|
|
enumerator = lib->credmgr->create_cert_enumerator(lib->credmgr,
|
|
|
|
|
CERT_X509, KEY_RSA, serial, FALSE);
|
|
|
|
|
while (enumerator->enumerate(enumerator, &cert))
|
|
|
|
|
{
|
|
|
|
|
if (issuer->equals(issuer, cert->get_issuer(cert)))
|
|
|
|
|
{
|
|
|
|
|
public = cert->get_public_key(cert);
|
|
|
|
|
if (public)
|
|
|
|
|
{
|
|
|
|
|
if (public->get_fingerprint(public, KEYID_PUBKEY_SHA1, &fp))
|
|
|
|
|
{
|
|
|
|
|
id = identification_create_from_encoding(ID_KEY_ID, fp);
|
|
|
|
|
private = lib->credmgr->get_private(lib->credmgr,
|
|
|
|
|
KEY_ANY, id, NULL);
|
|
|
|
|
id->destroy(id);
|
|
|
|
|
}
|
|
|
|
|
public->destroy(public);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
if (private)
|
|
|
|
|
{
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
enumerator->destroy(enumerator);
|
|
|
|
|
return private;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* Decrypt content using a private key from "issuer"
|
|
|
|
|
*/
|
|
|
|
|
static bool decrypt(private_key_t *private, chunk_t key, chunk_t iv, int oid,
|
|
|
|
|
chunk_t encrypted, chunk_t *plain)
|
|
|
|
|
{
|
|
|
|
|
encryption_algorithm_t alg;
|
|
|
|
|
chunk_t plain_key;
|
|
|
|
|
crypter_t *crypter;
|
|
|
|
|
size_t key_size;
|
|
|
|
|
|
|
|
|
|
alg = encryption_algorithm_from_oid(oid, &key_size);
|
|
|
|
|
if (alg == ENCR_UNDEFINED)
|
|
|
|
|
{
|
|
|
|
|
DBG1(DBG_LIB, "unsupported content encryption algorithm");
|
|
|
|
|
return FALSE;
|
|
|
|
|
}
|
|
|
|
|
if (!private->decrypt(private, ENCRYPT_RSA_PKCS1, key, &plain_key))
|
|
|
|
|
{
|
|
|
|
|
DBG1(DBG_LIB, "symmetric key could not be decrypted with rsa");
|
|
|
|
|
return FALSE;
|
|
|
|
|
}
|
|
|
|
|
crypter = lib->crypto->create_crypter(lib->crypto, alg, key_size / 8);
|
|
|
|
|
if (!crypter)
|
|
|
|
|
{
|
|
|
|
|
DBG1(DBG_LIB, "crypter %N-%d not available",
|
|
|
|
|
encryption_algorithm_names, alg, key_size);
|
|
|
|
|
free(plain_key.ptr);
|
|
|
|
|
return FALSE;
|
|
|
|
|
}
|
|
|
|
|
if (plain_key.len != crypter->get_key_size(crypter))
|
|
|
|
|
{
|
|
|
|
|
DBG1(DBG_LIB, "symmetric key length %d is wrong", plain_key.len);
|
|
|
|
|
free(plain_key.ptr);
|
|
|
|
|
crypter->destroy(crypter);
|
|
|
|
|
return FALSE;
|
|
|
|
|
}
|
|
|
|
|
if (iv.len != crypter->get_iv_size(crypter))
|
|
|
|
|
{
|
|
|
|
|
DBG1(DBG_LIB, "IV length %d is wrong", iv.len);
|
|
|
|
|
free(plain_key.ptr);
|
|
|
|
|
crypter->destroy(crypter);
|
|
|
|
|
return FALSE;
|
|
|
|
|
}
|
|
|
|
|
if (!crypter->set_key(crypter, plain_key) ||
|
|
|
|
|
!crypter->decrypt(crypter, encrypted, iv, plain))
|
|
|
|
|
{
|
|
|
|
|
free(plain_key.ptr);
|
|
|
|
|
crypter->destroy(crypter);
|
|
|
|
|
return FALSE;
|
|
|
|
|
}
|
|
|
|
|
DBG4(DBG_LIB, "decrypted content with padding: %B", plain);
|
|
|
|
|
free(plain_key.ptr);
|
|
|
|
|
crypter->destroy(crypter);
|
|
|
|
|
return TRUE;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* Remove the padding from plain data
|
|
|
|
|
*/
|
|
|
|
|
static bool remove_padding(private_pkcs7_enveloped_data_t *this)
|
|
|
|
|
{
|
|
|
|
|
u_char *pos = this->content.ptr + this->content.len - 1;
|
|
|
|
|
u_char pattern = *pos;
|
|
|
|
|
size_t padding = pattern;
|
|
|
|
|
|
|
|
|
|
if (padding > this->content.len)
|
|
|
|
|
{
|
|
|
|
|
DBG1(DBG_LIB, "padding greater than data length");
|
|
|
|
|
return FALSE;
|
|
|
|
|
}
|
|
|
|
|
this->content.len -= padding;
|
|
|
|
|
|
|
|
|
|
while (padding-- > 0)
|
|
|
|
|
{
|
|
|
|
|
if (*pos-- != pattern)
|
|
|
|
|
{
|
|
|
|
|
DBG1(DBG_LIB, "wrong padding pattern");
|
|
|
|
|
return FALSE;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
return TRUE;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* Parse and decrypt enveloped-data
|
|
|
|
|
*/
|
|
|
|
|
static bool parse(private_pkcs7_enveloped_data_t *this, chunk_t content)
|
|
|
|
|
{
|
|
|
|
|
asn1_parser_t *parser;
|
|
|
|
|
chunk_t object;
|
|
|
|
|
int objectID, version, alg = OID_UNKNOWN;
|
|
|
|
|
bool success = FALSE;
|
|
|
|
|
identification_t *issuer = NULL, *serial = NULL;
|
|
|
|
|
private_key_t *private = NULL;
|
|
|
|
|
chunk_t iv = chunk_empty, key = chunk_empty, encrypted = chunk_empty;
|
|
|
|
|
|
|
|
|
|
parser = asn1_parser_create(envelopedDataObjects, content);
|
|
|
|
|
parser->set_top_level(parser, 0);
|
|
|
|
|
|
|
|
|
|
while (parser->iterate(parser, &objectID, &object))
|
|
|
|
|
{
|
|
|
|
|
u_int level = parser->get_level(parser);
|
|
|
|
|
|
|
|
|
|
switch (objectID)
|
|
|
|
|
{
|
|
|
|
|
case PKCS7_VERSION:
|
|
|
|
|
version = object.len ? (int)*object.ptr : 0;
|
|
|
|
|
DBG2(DBG_LIB, " v%d", version);
|
|
|
|
|
if (version != 0)
|
|
|
|
|
{
|
|
|
|
|
DBG1(DBG_LIB, "envelopedData version is not 0");
|
|
|
|
|
goto end;
|
|
|
|
|
}
|
|
|
|
|
break;
|
|
|
|
|
case PKCS7_RECIPIENT_INFO_VERSION:
|
|
|
|
|
version = object.len ? (int)*object.ptr : 0;
|
|
|
|
|
DBG2(DBG_LIB, " v%d", version);
|
|
|
|
|
if (version != 0)
|
|
|
|
|
{
|
|
|
|
|
DBG1(DBG_LIB, "recipient info version is not 0");
|
|
|
|
|
goto end;
|
|
|
|
|
}
|
|
|
|
|
break;
|
|
|
|
|
case PKCS7_ISSUER:
|
|
|
|
|
if (!issuer)
|
|
|
|
|
{
|
|
|
|
|
issuer = identification_create_from_encoding(ID_DER_ASN1_DN,
|
|
|
|
|
object);
|
|
|
|
|
}
|
|
|
|
|
break;
|
|
|
|
|
case PKCS7_SERIAL_NUMBER:
|
|
|
|
|
if (!serial)
|
|
|
|
|
{
|
|
|
|
|
serial = identification_create_from_encoding(ID_KEY_ID,
|
|
|
|
|
object);
|
|
|
|
|
}
|
|
|
|
|
break;
|
|
|
|
|
case PKCS7_ENCRYPTION_ALG:
|
|
|
|
|
if (asn1_parse_algorithmIdentifier(object, level,
|
|
|
|
|
NULL) != OID_RSA_ENCRYPTION)
|
|
|
|
|
{
|
|
|
|
|
DBG1(DBG_LIB, "only rsa encryption supported");
|
|
|
|
|
goto end;
|
|
|
|
|
}
|
|
|
|
|
break;
|
|
|
|
|
case PKCS7_ENCRYPTED_KEY:
|
|
|
|
|
key = object;
|
|
|
|
|
break;
|
|
|
|
|
case PKCS7_CONTENT_TYPE:
|
|
|
|
|
if (asn1_known_oid(object) != OID_PKCS7_DATA)
|
|
|
|
|
{
|
|
|
|
|
DBG1(DBG_LIB, "encrypted content not of type pkcs7 data");
|
|
|
|
|
goto end;
|
|
|
|
|
}
|
|
|
|
|
break;
|
|
|
|
|
case PKCS7_CONTENT_ENC_ALGORITHM:
|
|
|
|
|
alg = asn1_parse_algorithmIdentifier(object, level, &iv);
|
|
|
|
|
if (!asn1_parse_simple_object(&iv, ASN1_OCTET_STRING,
|
|
|
|
|
level + 1, "IV"))
|
|
|
|
|
{
|
|
|
|
|
DBG1(DBG_LIB, "IV could not be parsed");
|
|
|
|
|
goto end;
|
|
|
|
|
}
|
|
|
|
|
break;
|
|
|
|
|
case PKCS7_ENCRYPTED_CONTENT:
|
|
|
|
|
encrypted = object;
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
success = parser->success(parser);
|
|
|
|
|
|
|
|
|
|
end:
|
|
|
|
|
parser->destroy(parser);
|
|
|
|
|
if (!success)
|
|
|
|
|
{
|
|
|
|
|
goto failed;
|
|
|
|
|
}
|
|
|
|
|
success = FALSE;
|
|
|
|
|
if (!issuer)
|
|
|
|
|
{
|
|
|
|
|
goto failed;
|
|
|
|
|
}
|
|
|
|
|
private = find_private(issuer, serial);
|
|
|
|
|
if (!private)
|
|
|
|
|
{
|
|
|
|
|
DBG1(DBG_LIB, "no private key found to decrypt pkcs7");
|
|
|
|
|
goto failed;
|
|
|
|
|
}
|
|
|
|
|
if (!decrypt(private, key, iv, alg, encrypted, &this->content))
|
|
|
|
|
{
|
|
|
|
|
goto failed;
|
|
|
|
|
}
|
|
|
|
|
if (!remove_padding(this))
|
|
|
|
|
{
|
|
|
|
|
goto failed;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
success = TRUE;
|
|
|
|
|
failed:
|
|
|
|
|
DESTROY_IF(issuer);
|
|
|
|
|
DESTROY_IF(serial);
|
|
|
|
|
DESTROY_IF(private);
|
|
|
|
|
return success;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
METHOD(container_t, get_type, container_type_t,
|
|
|
|
|
private_pkcs7_enveloped_data_t *this)
|
|
|
|
|
{
|
|
|
|
|
return CONTAINER_PKCS7_ENVELOPED_DATA;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
METHOD(container_t, create_signature_enumerator, enumerator_t*,
|
|
|
|
|
private_pkcs7_enveloped_data_t *this)
|
|
|
|
|
{
|
|
|
|
|
return enumerator_create_empty();
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
METHOD(container_t, get_data, bool,
|
|
|
|
|
private_pkcs7_enveloped_data_t *this, chunk_t *data)
|
|
|
|
|
{
|
|
|
|
|
if (this->content.len)
|
|
|
|
|
{
|
|
|
|
|
*data = chunk_clone(this->content);
|
|
|
|
|
return TRUE;
|
|
|
|
|
}
|
|
|
|
|
return FALSE;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
METHOD(container_t, get_encoding, bool,
|
|
|
|
|
private_pkcs7_enveloped_data_t *this, chunk_t *data)
|
|
|
|
|
{
|
|
|
|
|
*data = chunk_clone(this->encoding);
|
|
|
|
|
return TRUE;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
METHOD(container_t, destroy, void,
|
|
|
|
|
private_pkcs7_enveloped_data_t *this)
|
|
|
|
|
{
|
|
|
|
|
free(this->content.ptr);
|
|
|
|
|
free(this->encoding.ptr);
|
|
|
|
|
free(this);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* See header.
|
|
|
|
|
*/
|
|
|
|
|
pkcs7_t *pkcs7_enveloped_data_load(chunk_t encoding, chunk_t content)
|
|
|
|
|
{
|
|
|
|
|
private_pkcs7_enveloped_data_t *this;
|
|
|
|
|
|
|
|
|
|
INIT(this,
|
|
|
|
|
.public = {
|
|
|
|
|
.container = {
|
|
|
|
|
.get_type = _get_type,
|
|
|
|
|
.create_signature_enumerator = _create_signature_enumerator,
|
|
|
|
|
.get_data = _get_data,
|
|
|
|
|
.get_encoding = _get_encoding,
|
|
|
|
|
.destroy = _destroy,
|
|
|
|
|
},
|
|
|
|
|
},
|
|
|
|
|
.encoding = chunk_clone(encoding),
|
|
|
|
|
);
|
|
|
|
|
|
|
|
|
|
if (!parse(this, content))
|
|
|
|
|
{
|
|
|
|
|
destroy(this);
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return &this->public;
|
|
|
|
|
}
|
Martin Willi