756 lines
22 KiB
C
756 lines
22 KiB
C
/* Support of PKCS#7 data structures
|
|
* Copyright (C) 2005 Jan Hutter, Martin Willi
|
|
* Copyright (C) 2002-2009 Andreas Steffen
|
|
*
|
|
* HSR 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 <stdlib.h>
|
|
#include <string.h>
|
|
#include <time.h>
|
|
|
|
#include <library.h>
|
|
#include <debug.h>
|
|
#include <asn1/asn1.h>
|
|
#include <asn1/asn1_parser.h>
|
|
#include <asn1/oid.h>
|
|
#include <crypto/rngs/rng.h>
|
|
#include <crypto/crypters/crypter.h>
|
|
#include <credentials/certificates/x509.h>
|
|
|
|
#include "pkcs7.h"
|
|
|
|
const contentInfo_t empty_contentInfo = {
|
|
OID_UNKNOWN , /* type */
|
|
{ NULL, 0 } /* content */
|
|
};
|
|
|
|
/**
|
|
* ASN.1 definition of the PKCS#7 ContentInfo type
|
|
*/
|
|
static const asn1Object_t contentInfoObjects[] = {
|
|
{ 0, "contentInfo", ASN1_SEQUENCE, ASN1_NONE }, /* 0 */
|
|
{ 1, "contentType", ASN1_OID, ASN1_BODY }, /* 1 */
|
|
{ 1, "content", ASN1_CONTEXT_C_0, ASN1_OPT|ASN1_BODY }, /* 2 */
|
|
{ 1, "end opt", ASN1_EOC, ASN1_END }, /* 3 */
|
|
{ 0, "exit", ASN1_EOC, ASN1_EXIT }
|
|
};
|
|
#define PKCS7_INFO_TYPE 1
|
|
#define PKCS7_INFO_CONTENT 2
|
|
|
|
/**
|
|
* ASN.1 definition of the PKCS#7 signedData type
|
|
*/
|
|
static const asn1Object_t signedDataObjects[] = {
|
|
{ 0, "signedData", ASN1_SEQUENCE, ASN1_NONE }, /* 0 */
|
|
{ 1, "version", ASN1_INTEGER, ASN1_BODY }, /* 1 */
|
|
{ 1, "digestAlgorithms", ASN1_SET, ASN1_LOOP }, /* 2 */
|
|
{ 2, "algorithm", ASN1_EOC, ASN1_RAW }, /* 3 */
|
|
{ 1, "end loop", ASN1_EOC, ASN1_END }, /* 4 */
|
|
{ 1, "contentInfo", ASN1_EOC, ASN1_RAW }, /* 5 */
|
|
{ 1, "certificates", ASN1_CONTEXT_C_0, ASN1_OPT|ASN1_LOOP }, /* 6 */
|
|
{ 2, "certificate", ASN1_SEQUENCE, ASN1_OBJ }, /* 7 */
|
|
{ 1, "end opt or loop", ASN1_EOC, ASN1_END }, /* 8 */
|
|
{ 1, "crls", ASN1_CONTEXT_C_1, ASN1_OPT|ASN1_LOOP }, /* 9 */
|
|
{ 2, "crl", ASN1_SEQUENCE, ASN1_OBJ }, /* 10 */
|
|
{ 1, "end opt or loop", ASN1_EOC, ASN1_END }, /* 11 */
|
|
{ 1, "signerInfos", ASN1_SET, ASN1_LOOP }, /* 12 */
|
|
{ 2, "signerInfo", ASN1_SEQUENCE, ASN1_NONE }, /* 13 */
|
|
{ 3, "version", ASN1_INTEGER, ASN1_BODY }, /* 14 */
|
|
{ 3, "issuerAndSerialNumber", ASN1_SEQUENCE, ASN1_BODY }, /* 15 */
|
|
{ 4, "issuer", ASN1_SEQUENCE, ASN1_OBJ }, /* 16 */
|
|
{ 4, "serial", ASN1_INTEGER, ASN1_BODY }, /* 17 */
|
|
{ 3, "digestAlgorithm", ASN1_EOC, ASN1_RAW }, /* 18 */
|
|
{ 3, "authenticatedAttributes", ASN1_CONTEXT_C_0, ASN1_OPT|ASN1_OBJ }, /* 19 */
|
|
{ 3, "end opt", ASN1_EOC, ASN1_END }, /* 20 */
|
|
{ 3, "digestEncryptionAlgorithm", ASN1_EOC, ASN1_RAW }, /* 21 */
|
|
{ 3, "encryptedDigest", ASN1_OCTET_STRING, ASN1_BODY }, /* 22 */
|
|
{ 3, "unauthenticatedAttributes", ASN1_CONTEXT_C_1, ASN1_OPT }, /* 23 */
|
|
{ 3, "end opt", ASN1_EOC, ASN1_END }, /* 24 */
|
|
{ 1, "end loop", ASN1_EOC, ASN1_END }, /* 25 */
|
|
{ 0, "exit", ASN1_EOC, ASN1_EXIT }
|
|
};
|
|
#define PKCS7_SIGNED_VERSION 1
|
|
#define PKCS7_DIGEST_ALG 3
|
|
#define PKCS7_SIGNED_CONTENT_INFO 5
|
|
#define PKCS7_SIGNED_CERT 7
|
|
#define PKCS7_SIGNER_INFO 13
|
|
#define PKCS7_SIGNER_INFO_VERSION 14
|
|
#define PKCS7_SIGNED_ISSUER 16
|
|
#define PKCS7_SIGNED_SERIAL_NUMBER 17
|
|
#define PKCS7_DIGEST_ALGORITHM 18
|
|
#define PKCS7_AUTH_ATTRIBUTES 19
|
|
#define PKCS7_DIGEST_ENC_ALGORITHM 21
|
|
#define PKCS7_ENCRYPTED_DIGEST 22
|
|
|
|
/**
|
|
* 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_ENVELOPED_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
|
|
#define PKCS7_ENVELOPED_ROOF 15
|
|
|
|
/**
|
|
* Parse PKCS#7 ContentInfo object
|
|
*/
|
|
bool pkcs7_parse_contentInfo(chunk_t blob, u_int level0, contentInfo_t *cInfo)
|
|
{
|
|
asn1_parser_t *parser;
|
|
chunk_t object;
|
|
int objectID;
|
|
bool success = FALSE;
|
|
|
|
parser = asn1_parser_create(contentInfoObjects, blob);
|
|
parser->set_top_level(parser, level0);
|
|
|
|
while (parser->iterate(parser, &objectID, &object))
|
|
{
|
|
if (objectID == PKCS7_INFO_TYPE)
|
|
{
|
|
cInfo->type = asn1_known_oid(object);
|
|
if (cInfo->type < OID_PKCS7_DATA
|
|
|| cInfo->type > OID_PKCS7_ENCRYPTED_DATA)
|
|
{
|
|
DBG1(DBG_LIB, "unknown pkcs7 content type");
|
|
goto end;
|
|
}
|
|
}
|
|
else if (objectID == PKCS7_INFO_CONTENT)
|
|
{
|
|
cInfo->content = object;
|
|
}
|
|
}
|
|
success = parser->success(parser);
|
|
|
|
end:
|
|
parser->destroy(parser);
|
|
return success;
|
|
}
|
|
|
|
/**
|
|
* Parse a PKCS#7 signedData object
|
|
*/
|
|
bool pkcs7_parse_signedData(chunk_t blob, contentInfo_t *data,
|
|
linked_list_t *certs,
|
|
chunk_t *attributes, certificate_t *cacert)
|
|
{
|
|
asn1_parser_t *parser;
|
|
chunk_t object;
|
|
int digest_alg = OID_UNKNOWN;
|
|
int enc_alg = OID_UNKNOWN;
|
|
int signerInfos = 0;
|
|
int version;
|
|
int objectID;
|
|
bool success = FALSE;
|
|
|
|
contentInfo_t cInfo = empty_contentInfo;
|
|
chunk_t encrypted_digest = chunk_empty;
|
|
|
|
if (!pkcs7_parse_contentInfo(blob, 0, &cInfo))
|
|
{
|
|
return FALSE;
|
|
}
|
|
if (cInfo.type != OID_PKCS7_SIGNED_DATA)
|
|
{
|
|
DBG1(DBG_LIB, "pkcs7 content type is not signedData");
|
|
return FALSE;
|
|
}
|
|
|
|
parser = asn1_parser_create(signedDataObjects, cInfo.content);
|
|
parser->set_top_level(parser, 2);
|
|
|
|
while (parser->iterate(parser, &objectID, &object))
|
|
{
|
|
u_int level = parser->get_level(parser);
|
|
|
|
switch (objectID)
|
|
{
|
|
case PKCS7_SIGNED_VERSION:
|
|
version = object.len ? (int)*object.ptr : 0;
|
|
DBG2(DBG_LIB, " v%d", version);
|
|
break;
|
|
case PKCS7_DIGEST_ALG:
|
|
digest_alg = asn1_parse_algorithmIdentifier(object, level, NULL);
|
|
break;
|
|
case PKCS7_SIGNED_CONTENT_INFO:
|
|
if (data != NULL)
|
|
{
|
|
pkcs7_parse_contentInfo(object, level, data);
|
|
}
|
|
break;
|
|
case PKCS7_SIGNED_CERT:
|
|
{
|
|
certificate_t *cert;
|
|
|
|
DBG2(DBG_LIB, " parsing pkcs7-wrapped certificate");
|
|
cert = lib->creds->create(lib->creds,
|
|
CRED_CERTIFICATE, CERT_X509,
|
|
BUILD_BLOB_ASN1_DER, object,
|
|
BUILD_END);
|
|
if (cert)
|
|
{
|
|
certs->insert_last(certs, cert);
|
|
}
|
|
}
|
|
break;
|
|
case PKCS7_SIGNER_INFO:
|
|
signerInfos++;
|
|
DBG2(DBG_LIB, " signer #%d", signerInfos);
|
|
break;
|
|
case PKCS7_SIGNER_INFO_VERSION:
|
|
version = object.len ? (int)*object.ptr : 0;
|
|
DBG2(DBG_LIB, " v%d", version);
|
|
break;
|
|
case PKCS7_SIGNED_ISSUER:
|
|
{
|
|
identification_t *issuer = identification_create_from_encoding(
|
|
ID_DER_ASN1_DN, object);
|
|
DBG2(DBG_LIB, " \"%Y\"", issuer);
|
|
issuer->destroy(issuer);
|
|
break;
|
|
}
|
|
case PKCS7_AUTH_ATTRIBUTES:
|
|
if (attributes != NULL)
|
|
{
|
|
*attributes = object;
|
|
*attributes->ptr = ASN1_SET;
|
|
}
|
|
break;
|
|
case PKCS7_DIGEST_ALGORITHM:
|
|
digest_alg = asn1_parse_algorithmIdentifier(object, level, NULL);
|
|
break;
|
|
case PKCS7_DIGEST_ENC_ALGORITHM:
|
|
enc_alg = asn1_parse_algorithmIdentifier(object, level, NULL);
|
|
break;
|
|
case PKCS7_ENCRYPTED_DIGEST:
|
|
encrypted_digest = object;
|
|
}
|
|
}
|
|
success = parser->success(parser);
|
|
parser->destroy(parser);
|
|
if (!success)
|
|
{
|
|
return FALSE;
|
|
}
|
|
|
|
/* check the signature only if a cacert is available */
|
|
if (cacert != NULL)
|
|
{
|
|
public_key_t *key;
|
|
signature_scheme_t scheme;
|
|
|
|
scheme = signature_scheme_from_oid(digest_alg);
|
|
if (scheme == SIGN_UNKNOWN)
|
|
{
|
|
DBG1(DBG_LIB, "unsupported signature scheme");
|
|
return FALSE;
|
|
}
|
|
if (signerInfos == 0)
|
|
{
|
|
DBG1(DBG_LIB, "no signerInfo object found");
|
|
return FALSE;
|
|
}
|
|
else if (signerInfos > 1)
|
|
{
|
|
DBG1(DBG_LIB, "more than one signerInfo object found");
|
|
return FALSE;
|
|
}
|
|
if (attributes->ptr == NULL)
|
|
{
|
|
DBG1(DBG_LIB, "no authenticatedAttributes object found");
|
|
return FALSE;
|
|
}
|
|
if (enc_alg != OID_RSA_ENCRYPTION)
|
|
{
|
|
DBG1(DBG_LIB, "only RSA digest encryption supported");
|
|
return FALSE;
|
|
}
|
|
|
|
/* verify the signature */
|
|
key = cacert->get_public_key(cacert);
|
|
if (key == NULL)
|
|
{
|
|
DBG1(DBG_LIB, "no public key found in CA certificate");
|
|
return FALSE;
|
|
}
|
|
if (key->verify(key, scheme, *attributes, encrypted_digest))
|
|
{
|
|
DBG2(DBG_LIB, "signature is valid");
|
|
}
|
|
else
|
|
{
|
|
DBG1(DBG_LIB, "invalid signature");
|
|
success = FALSE;
|
|
}
|
|
key->destroy(key);
|
|
}
|
|
return success;
|
|
}
|
|
|
|
/**
|
|
* Parse a PKCS#7 envelopedData object
|
|
*/
|
|
bool pkcs7_parse_envelopedData(chunk_t blob, chunk_t *data,
|
|
chunk_t serialNumber,
|
|
private_key_t *key)
|
|
{
|
|
asn1_parser_t *parser;
|
|
chunk_t object;
|
|
chunk_t iv = chunk_empty;
|
|
chunk_t symmetric_key = chunk_empty;
|
|
chunk_t encrypted_content = chunk_empty;
|
|
|
|
crypter_t *crypter = NULL;
|
|
|
|
int enc_alg = OID_UNKNOWN;
|
|
int content_enc_alg = OID_UNKNOWN;
|
|
int version;
|
|
int objectID;
|
|
bool success = FALSE;
|
|
|
|
contentInfo_t cInfo = empty_contentInfo;
|
|
*data = chunk_empty;
|
|
|
|
if (!pkcs7_parse_contentInfo(blob, 0, &cInfo))
|
|
{
|
|
goto failed;
|
|
}
|
|
if (cInfo.type != OID_PKCS7_ENVELOPED_DATA)
|
|
{
|
|
DBG1(DBG_LIB, "pkcs7 content type is not envelopedData");
|
|
goto failed;
|
|
}
|
|
|
|
parser = asn1_parser_create(envelopedDataObjects, cInfo.content);
|
|
parser->set_top_level(parser, 2);
|
|
|
|
while (parser->iterate(parser, &objectID, &object))
|
|
{
|
|
u_int level = parser->get_level(parser);
|
|
|
|
switch (objectID)
|
|
{
|
|
case PKCS7_ENVELOPED_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:
|
|
{
|
|
identification_t *issuer = identification_create_from_encoding(
|
|
ID_DER_ASN1_DN, object);
|
|
DBG2(DBG_LIB, " \"%Y\"", issuer);
|
|
issuer->destroy(issuer);
|
|
break;
|
|
}
|
|
case PKCS7_SERIAL_NUMBER:
|
|
if (!chunk_equals(serialNumber, object))
|
|
{
|
|
DBG1(DBG_LIB, "serial numbers do not match");
|
|
goto end;
|
|
}
|
|
break;
|
|
case PKCS7_ENCRYPTION_ALG:
|
|
enc_alg = asn1_parse_algorithmIdentifier(object, level, NULL);
|
|
if (enc_alg != OID_RSA_ENCRYPTION)
|
|
{
|
|
DBG1(DBG_LIB, "only rsa encryption supported");
|
|
goto end;
|
|
}
|
|
break;
|
|
case PKCS7_ENCRYPTED_KEY:
|
|
if (!key->decrypt(key, ENCRYPT_RSA_PKCS1, object, &symmetric_key))
|
|
{
|
|
DBG1(DBG_LIB, "symmetric key could not be decrypted with rsa");
|
|
goto end;
|
|
}
|
|
DBG4(DBG_LIB, "symmetric key %B", &symmetric_key);
|
|
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:
|
|
content_enc_alg = asn1_parse_algorithmIdentifier(object, level, &iv);
|
|
|
|
if (content_enc_alg == OID_UNKNOWN)
|
|
{
|
|
DBG1(DBG_LIB, "unknown content encryption algorithm");
|
|
goto end;
|
|
}
|
|
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_content = object;
|
|
break;
|
|
}
|
|
}
|
|
success = parser->success(parser);
|
|
|
|
end:
|
|
parser->destroy(parser);
|
|
if (!success)
|
|
{
|
|
goto failed;
|
|
}
|
|
success = FALSE;
|
|
|
|
/* decrypt the content */
|
|
{
|
|
encryption_algorithm_t alg;
|
|
size_t key_size;
|
|
crypter_t *crypter;
|
|
|
|
alg = encryption_algorithm_from_oid(content_enc_alg, &key_size);
|
|
if (alg == ENCR_UNDEFINED)
|
|
{
|
|
DBG1(DBG_LIB, "unsupported content encryption algorithm");
|
|
goto failed;
|
|
}
|
|
crypter = lib->crypto->create_crypter(lib->crypto, alg, key_size);
|
|
if (crypter == NULL)
|
|
{
|
|
DBG1(DBG_LIB, "crypter %N not available", encryption_algorithm_names, alg);
|
|
goto failed;
|
|
}
|
|
if (symmetric_key.len != crypter->get_key_size(crypter))
|
|
{
|
|
DBG1(DBG_LIB, "symmetric key length %d is wrong", symmetric_key.len);
|
|
goto failed;
|
|
}
|
|
if (iv.len != crypter->get_iv_size(crypter))
|
|
{
|
|
DBG1(DBG_LIB, "IV length %d is wrong", iv.len);
|
|
goto failed;
|
|
}
|
|
crypter->set_key(crypter, symmetric_key);
|
|
crypter->decrypt(crypter, encrypted_content, iv, data);
|
|
DBG4(DBG_LIB, "decrypted content with padding: %B", data);
|
|
}
|
|
|
|
/* remove the padding */
|
|
{
|
|
u_char *pos = data->ptr + data->len - 1;
|
|
u_char pattern = *pos;
|
|
size_t padding = pattern;
|
|
|
|
if (padding > data->len)
|
|
{
|
|
DBG1(DBG_LIB, "padding greater than data length");
|
|
goto failed;
|
|
}
|
|
data->len -= padding;
|
|
|
|
while (padding-- > 0)
|
|
{
|
|
if (*pos-- != pattern)
|
|
{
|
|
DBG1(DBG_LIB, "wrong padding pattern");
|
|
goto failed;
|
|
}
|
|
}
|
|
}
|
|
success = TRUE;
|
|
|
|
failed:
|
|
DESTROY_IF(crypter);
|
|
chunk_clear(&symmetric_key);
|
|
if (!success)
|
|
{
|
|
free(data->ptr);
|
|
}
|
|
return success;
|
|
}
|
|
|
|
/**
|
|
* @brief Builds a contentType attribute
|
|
*
|
|
* @return ASN.1 encoded contentType attribute
|
|
*/
|
|
chunk_t pkcs7_contentType_attribute(void)
|
|
{
|
|
return asn1_wrap(ASN1_SEQUENCE, "mm",
|
|
asn1_build_known_oid(OID_PKCS9_CONTENT_TYPE),
|
|
asn1_wrap(ASN1_SET, "m",
|
|
asn1_build_known_oid(OID_PKCS7_DATA)));
|
|
}
|
|
|
|
/**
|
|
* @brief Builds a messageDigest attribute
|
|
*
|
|
*
|
|
* @param[in] blob content to create digest of
|
|
* @param[in] digest_alg digest algorithm to be used
|
|
* @return ASN.1 encoded messageDigest attribute
|
|
*
|
|
*/
|
|
chunk_t pkcs7_messageDigest_attribute(chunk_t content, int digest_alg)
|
|
{
|
|
chunk_t digest;
|
|
hash_algorithm_t hash_alg;
|
|
hasher_t *hasher;
|
|
|
|
hash_alg = hasher_algorithm_from_oid(digest_alg);
|
|
hasher = lib->crypto->create_hasher(lib->crypto, hash_alg);
|
|
hasher->allocate_hash(hasher, content, &digest);
|
|
hasher->destroy(hasher);
|
|
|
|
return asn1_wrap(ASN1_SEQUENCE, "mm",
|
|
asn1_build_known_oid(OID_PKCS9_MESSAGE_DIGEST),
|
|
asn1_wrap(ASN1_SET, "m",
|
|
asn1_wrap(ASN1_OCTET_STRING, "m", digest)));
|
|
}
|
|
|
|
/**
|
|
* build a DER-encoded contentInfo object
|
|
*/
|
|
static chunk_t pkcs7_build_contentInfo(contentInfo_t *cInfo)
|
|
{
|
|
return (cInfo->content.ptr) ?
|
|
asn1_wrap(ASN1_SEQUENCE, "mm",
|
|
asn1_build_known_oid(cInfo->type),
|
|
asn1_simple_object(ASN1_CONTEXT_C_0, cInfo->content)) :
|
|
asn1_build_known_oid(cInfo->type);
|
|
}
|
|
|
|
/**
|
|
* build issuerAndSerialNumber object
|
|
*/
|
|
chunk_t pkcs7_build_issuerAndSerialNumber(certificate_t *cert)
|
|
{
|
|
identification_t *issuer = cert->get_issuer(cert);
|
|
x509_t *x509 = (x509_t*)cert;
|
|
|
|
return asn1_wrap(ASN1_SEQUENCE, "cm",
|
|
issuer->get_encoding(issuer),
|
|
asn1_integer("c", x509->get_serial(x509)));
|
|
}
|
|
|
|
/**
|
|
* create a signed pkcs7 contentInfo object
|
|
*/
|
|
chunk_t pkcs7_build_signedData(chunk_t data, chunk_t attributes,
|
|
certificate_t *cert, int digest_alg,
|
|
private_key_t *key)
|
|
{
|
|
contentInfo_t pkcs7Data, signedData;
|
|
chunk_t authenticatedAttributes = chunk_empty;
|
|
chunk_t encryptedDigest = chunk_empty;
|
|
chunk_t signerInfo, cInfo, signature, encoding = chunk_empty;;
|
|
signature_scheme_t scheme = signature_scheme_from_oid(digest_alg);
|
|
|
|
if (attributes.ptr)
|
|
{
|
|
if (key->sign(key, scheme, attributes, &signature))
|
|
{
|
|
encryptedDigest = asn1_wrap(ASN1_OCTET_STRING, "m", signature);
|
|
authenticatedAttributes = chunk_clone(attributes);
|
|
*authenticatedAttributes.ptr = ASN1_CONTEXT_C_0;
|
|
}
|
|
}
|
|
else if (data.ptr)
|
|
{
|
|
if (key->sign(key, scheme, data, &signature))
|
|
{
|
|
encryptedDigest = asn1_wrap(ASN1_OCTET_STRING, "m", signature);
|
|
}
|
|
}
|
|
signerInfo = asn1_wrap(ASN1_SEQUENCE, "cmmmmm"
|
|
, ASN1_INTEGER_1
|
|
, pkcs7_build_issuerAndSerialNumber(cert)
|
|
, asn1_algorithmIdentifier(digest_alg)
|
|
, authenticatedAttributes
|
|
, asn1_algorithmIdentifier(OID_RSA_ENCRYPTION)
|
|
, encryptedDigest);
|
|
|
|
pkcs7Data.type = OID_PKCS7_DATA;
|
|
pkcs7Data.content = (data.ptr == NULL)? chunk_empty
|
|
: asn1_simple_object(ASN1_OCTET_STRING, data);
|
|
|
|
cert->get_encoding(cert, CERT_ASN1_DER, &encoding);
|
|
signedData.type = OID_PKCS7_SIGNED_DATA;
|
|
signedData.content = asn1_wrap(ASN1_SEQUENCE, "cmmmm"
|
|
, ASN1_INTEGER_1
|
|
, asn1_wrap(ASN1_SET, "m", asn1_algorithmIdentifier(digest_alg))
|
|
, pkcs7_build_contentInfo(&pkcs7Data)
|
|
, asn1_wrap(ASN1_CONTEXT_C_0, "m", encoding)
|
|
, asn1_wrap(ASN1_SET, "m", signerInfo));
|
|
|
|
cInfo = pkcs7_build_contentInfo(&signedData);
|
|
DBG3(DBG_LIB, "signedData %B", &cInfo);
|
|
|
|
free(pkcs7Data.content.ptr);
|
|
free(signedData.content.ptr);
|
|
return cInfo;
|
|
}
|
|
|
|
/**
|
|
* create a symmetrically encrypted pkcs7 contentInfo object
|
|
*/
|
|
chunk_t pkcs7_build_envelopedData(chunk_t data, certificate_t *cert, int enc_alg)
|
|
{
|
|
encryption_algorithm_t alg;
|
|
size_t alg_key_size;
|
|
chunk_t symmetricKey, protectedKey, iv, in, out;
|
|
crypter_t *crypter;
|
|
|
|
alg = encryption_algorithm_from_oid(enc_alg, &alg_key_size);
|
|
crypter = lib->crypto->create_crypter(lib->crypto, alg,
|
|
alg_key_size/BITS_PER_BYTE);
|
|
if (crypter == NULL)
|
|
{
|
|
DBG1(DBG_LIB, "crypter for %N not available", encryption_algorithm_names, alg);
|
|
return chunk_empty;
|
|
}
|
|
|
|
/* generate a true random symmetric encryption key and a pseudo-random iv */
|
|
{
|
|
rng_t *rng;
|
|
|
|
rng = lib->crypto->create_rng(lib->crypto, RNG_TRUE);
|
|
rng->allocate_bytes(rng, crypter->get_key_size(crypter), &symmetricKey);
|
|
DBG4(DBG_LIB, "symmetric encryption key %B", &symmetricKey);
|
|
rng->destroy(rng);
|
|
|
|
rng = lib->crypto->create_rng(lib->crypto, RNG_WEAK);
|
|
rng->allocate_bytes(rng, crypter->get_iv_size(crypter), &iv);
|
|
DBG4(DBG_LIB, "initialization vector: %B", &iv);
|
|
rng->destroy(rng);
|
|
}
|
|
|
|
/* pad the data to a multiple of the block size */
|
|
{
|
|
size_t block_size = crypter->get_block_size(crypter);
|
|
size_t padding = block_size - data.len % block_size;
|
|
|
|
in.len = data.len + padding;
|
|
in.ptr = malloc(in.len);
|
|
|
|
DBG2(DBG_LIB, "padding %u bytes of data to multiple block size of %u bytes",
|
|
data.len, in.len);
|
|
|
|
/* copy data */
|
|
memcpy(in.ptr, data.ptr, data.len);
|
|
/* append padding */
|
|
memset(in.ptr + data.len, padding, padding);
|
|
}
|
|
DBG3(DBG_LIB, "padded unencrypted data %B", &in);
|
|
|
|
/* symmetric encryption of data object */
|
|
crypter->set_key(crypter, symmetricKey);
|
|
crypter->encrypt(crypter, in, iv, &out);
|
|
crypter->destroy(crypter);
|
|
chunk_clear(&in);
|
|
DBG3(DBG_LIB, "encrypted data %B", &out);
|
|
|
|
/* protect symmetric key by public key encryption */
|
|
{
|
|
public_key_t *key = cert->get_public_key(cert);
|
|
|
|
if (key == NULL)
|
|
{
|
|
DBG1(DBG_LIB, "public key not found in encryption certificate");
|
|
chunk_clear(&symmetricKey);
|
|
chunk_free(&iv);
|
|
chunk_free(&out);
|
|
return chunk_empty;
|
|
}
|
|
key->encrypt(key, ENCRYPT_RSA_PKCS1, symmetricKey, &protectedKey);
|
|
key->destroy(key);
|
|
}
|
|
|
|
/* build pkcs7 enveloped data object */
|
|
{
|
|
|
|
chunk_t contentEncryptionAlgorithm = asn1_wrap(ASN1_SEQUENCE, "mm"
|
|
, asn1_build_known_oid(enc_alg)
|
|
, asn1_simple_object(ASN1_OCTET_STRING, iv));
|
|
|
|
chunk_t encryptedContentInfo = asn1_wrap(ASN1_SEQUENCE, "mmm"
|
|
, asn1_build_known_oid(OID_PKCS7_DATA)
|
|
, contentEncryptionAlgorithm
|
|
, asn1_wrap(ASN1_CONTEXT_S_0, "m", out));
|
|
|
|
chunk_t encryptedKey = asn1_wrap(ASN1_OCTET_STRING, "m"
|
|
, protectedKey);
|
|
|
|
chunk_t recipientInfo = asn1_wrap(ASN1_SEQUENCE, "cmmm"
|
|
, ASN1_INTEGER_0
|
|
, pkcs7_build_issuerAndSerialNumber(cert)
|
|
, asn1_algorithmIdentifier(OID_RSA_ENCRYPTION)
|
|
, encryptedKey);
|
|
|
|
chunk_t cInfo;
|
|
contentInfo_t envelopedData;
|
|
|
|
envelopedData.type = OID_PKCS7_ENVELOPED_DATA;
|
|
envelopedData.content = asn1_wrap(ASN1_SEQUENCE, "cmm"
|
|
, ASN1_INTEGER_0
|
|
, asn1_wrap(ASN1_SET, "m", recipientInfo)
|
|
, encryptedContentInfo);
|
|
|
|
cInfo = pkcs7_build_contentInfo(&envelopedData);
|
|
DBG3(DBG_LIB, "envelopedData %B", &cInfo);
|
|
|
|
chunk_free(&envelopedData.content);
|
|
chunk_free(&iv);
|
|
chunk_clear(&symmetricKey);
|
|
return cInfo;
|
|
}
|
|
}
|