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strongswan/src/libstrongswan/crypto/pkcs7.c

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/*
* 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 <stdlib.h>
#include <string.h>
#include <time.h>
#include <library.h>
#include <debug.h>
#include <asn1/oid.h>
#include <asn1/asn1.h>
#include <asn1/asn1_parser.h>
#include <credentials/certificates/x509.h>
#include <credentials/keys/public_key.h>
#include <crypto/pkcs9.h>
#include <crypto/hashers/hasher.h>
#include <crypto/crypters/crypter.h>
#include <utils/linked_list.h>
#include "pkcs7.h"
typedef struct private_pkcs7_t private_pkcs7_t;
/**
* Private data of a pkcs7_t object.
*/
struct private_pkcs7_t {
/**
* Public interface for this certificate.
*/
pkcs7_t public;
/**
* contentInfo type
*/
int type;
/**
* ASN.1 encoded content
*/
chunk_t content;
/**
* ASN.1 parsing start level
*/
u_int level;
/**
* retrieved data
*/
chunk_t data;
/**
* ASN.1 encoded attributes
*/
pkcs9_t *attributes;
/**
* Linked list of X.509 certificates
*/
linked_list_t *certs;
};
METHOD(pkcs7_t, is_data, bool,
private_pkcs7_t *this)
{
return this->type == OID_PKCS7_DATA;
}
METHOD(pkcs7_t, is_signedData, bool,
private_pkcs7_t *this)
{
return this->type == OID_PKCS7_SIGNED_DATA;
}
METHOD(pkcs7_t, is_envelopedData, bool,
private_pkcs7_t *this)
{
return this->type == OID_PKCS7_ENVELOPED_DATA;
}
/**
* 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
/**
* Parse PKCS#7 contentInfo object
*/
static bool parse_contentInfo(private_pkcs7_t *this)
{
asn1_parser_t *parser;
chunk_t object;
int objectID;
bool success = FALSE;
if (!this->data.ptr)
{
return FALSE;
}
parser = asn1_parser_create(contentInfoObjects, this->data);
parser->set_top_level(parser, this->level);
while (parser->iterate(parser, &objectID, &object))
{
if (objectID == PKCS7_INFO_TYPE)
{
this->type = asn1_known_oid(object);
if (this->type < OID_PKCS7_DATA ||
this->type > OID_PKCS7_ENCRYPTED_DATA)
{
DBG1(DBG_LIB, "unknown pkcs7 content type");
goto end;
}
}
else if (objectID == PKCS7_INFO_CONTENT && object.len > 0)
{
chunk_free(&this->content);
this->content = chunk_clone(object);
}
}
success = parser->success(parser);
if (success)
{
this->level += 2;
chunk_free(&this->data);
}
end:
parser->destroy(parser);
return success;
}
/**
* Check whether to abort the requested parsing
*/
static bool abort_parsing(private_pkcs7_t *this, int type)
{
if (this->type != type)
{
DBG1(DBG_LIB, "pkcs7 content to be parsed is not of type '%s'",
oid_names[type].name);
return TRUE;
}
return FALSE;
}
METHOD(pkcs7_t, parse_data, bool,
private_pkcs7_t *this)
{
chunk_t data;
if (!parse_contentInfo(this) ||
abort_parsing(this, OID_PKCS7_DATA))
{
return FALSE;
}
data = this->content;
if (data.len == 0)
{
this->data = chunk_empty;
return TRUE;
}
if (asn1_parse_simple_object(&data, ASN1_OCTET_STRING,
this->level, "data"))
{
this->data = chunk_clone(data);
return TRUE;
}
return FALSE;
}
/**
* 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
METHOD(pkcs7_t, parse_signedData, bool,
private_pkcs7_t *this, certificate_t *cacert)
{
asn1_parser_t *parser;
chunk_t object;
int objectID, version;
int digest_alg = OID_UNKNOWN;
int enc_alg = OID_UNKNOWN;
int signerInfos = 0;
bool success = FALSE;
chunk_t encrypted_digest = chunk_empty;
if (!parse_contentInfo(this) ||
abort_parsing(this, OID_PKCS7_SIGNED_DATA))
{
return FALSE;
}
parser = asn1_parser_create(signedDataObjects, this->content);
parser->set_top_level(parser, this->level);
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:
{
pkcs7_t *data = pkcs7_create_from_chunk(object, level+1);
if (!data || !data->parse_data(data))
{
DESTROY_IF(data);
goto end;
}
this->data = chunk_clone(data->get_data(data));
data->destroy(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)
{
this->certs->insert_last(this->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;
issuer = identification_create_from_encoding(ID_DER_ASN1_DN, object);
DBG2(DBG_LIB, " '%Y'", issuer);
issuer->destroy(issuer);
break;
}
case PKCS7_AUTH_ATTRIBUTES:
*object.ptr = ASN1_SET;
this->attributes = pkcs9_create_from_chunk(object, level+1);
*object.ptr = ASN1_CONTEXT_C_0;
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);
end:
parser->destroy(parser);
if (!success)
{
return FALSE;
}
/* check the signature only if a cacert is available */
if (cacert != NULL)
{
signature_scheme_t scheme;
public_key_t *key;
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 (this->attributes == 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,
this->attributes->get_encoding(this->attributes), encrypted_digest))
{
DBG2(DBG_LIB, "signature is valid");
}
else
{
DBG1(DBG_LIB, "invalid signature");
key->destroy(key);
return FALSE;
}
key->destroy(key);
if (this->data.ptr != NULL)
{
chunk_t messageDigest;
messageDigest = this->attributes->get_attribute(this->attributes,
OID_PKCS9_MESSAGE_DIGEST);
if (messageDigest.ptr == NULL)
{
DBG1(DBG_LIB, "messageDigest attribute not found");
return FALSE;
}
else
{
hash_algorithm_t algorithm;
hasher_t *hasher;
chunk_t hash;
bool valid;
algorithm = hasher_algorithm_from_oid(digest_alg);
hasher = lib->crypto->create_hasher(lib->crypto, algorithm);
if (!hasher || !hasher->allocate_hash(hasher, this->data, &hash))
{
DESTROY_IF(hasher);
DBG1(DBG_LIB, "hash algorithm %N not supported",
hash_algorithm_names, algorithm);
return FALSE;
}
hasher->destroy(hasher);
DBG3(DBG_LIB, "hash: %B", &hash);
valid = chunk_equals(messageDigest, hash);
free(hash.ptr);
if (valid)
{
DBG2(DBG_LIB, "messageDigest is valid");
}
else
{
DBG1(DBG_LIB, "invalid messageDigest");
return FALSE;
}
}
}
}
return TRUE;
}
/**
* 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
METHOD(pkcs7_t, parse_envelopedData, bool,
private_pkcs7_t *this, chunk_t serialNumber, private_key_t *key)
{
asn1_parser_t *parser;
chunk_t object;
int objectID, version;
bool success = FALSE;
chunk_t iv = chunk_empty;
chunk_t symmetric_key = chunk_empty;
chunk_t encrypted_content = chunk_empty;
crypter_t *crypter = NULL;
if (!parse_contentInfo(this) ||
abort_parsing(this, OID_PKCS7_ENVELOPED_DATA))
{
return FALSE;
}
parser = asn1_parser_create(envelopedDataObjects, this->content);
parser->set_top_level(parser, this->level);
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;
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:
{
int alg;
alg = asn1_parse_algorithmIdentifier(object, level, NULL);
if (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:
{
encryption_algorithm_t enc_alg;
size_t key_size;
int alg;
alg = asn1_parse_algorithmIdentifier(object, level, &iv);
enc_alg = encryption_algorithm_from_oid(alg, &key_size);
if (enc_alg == ENCR_UNDEFINED)
{
DBG1(DBG_LIB, "unsupported content encryption algorithm");
goto end;
}
crypter = lib->crypto->create_crypter(lib->crypto, enc_alg,
key_size);
if (crypter == NULL)
{
DBG1(DBG_LIB, "crypter %N not available",
encryption_algorithm_names, enc_alg);
goto end;
}
if (symmetric_key.len != crypter->get_key_size(crypter))
{
DBG1(DBG_LIB, "symmetric key length %d is wrong",
symmetric_key.len);
goto end;
}
if (!asn1_parse_simple_object(&iv, ASN1_OCTET_STRING,
level + 1, "IV"))
{
DBG1(DBG_LIB, "IV could not be parsed");
goto end;
}
if (iv.len != crypter->get_iv_size(crypter))
{
DBG1(DBG_LIB, "IV length %d is wrong", iv.len);
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 */
if (!crypter->set_key(crypter, symmetric_key) ||
!crypter->decrypt(crypter, encrypted_content, iv, &this->data))
{
success = FALSE;
goto failed;
}
DBG4(DBG_LIB, "decrypted content with padding: %B", &this->data);
/* remove the padding */
{
u_char *pos = this->data.ptr + this->data.len - 1;
u_char pattern = *pos;
size_t padding = pattern;
if (padding > this->data.len)
{
DBG1(DBG_LIB, "padding greater than data length");
goto failed;
}
this->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)
{
chunk_free(&this->data);
}
return success;
}
METHOD(pkcs7_t, get_data, chunk_t,
private_pkcs7_t *this)
{
return this->data;
}
METHOD(pkcs7_t, get_contentInfo, chunk_t,
private_pkcs7_t *this)
{
chunk_t content_type;
/* create DER-encoded OID for pkcs7_contentInfo type */
switch(this->type)
{
case OID_PKCS7_DATA:
case OID_PKCS7_SIGNED_DATA:
case OID_PKCS7_ENVELOPED_DATA:
case OID_PKCS7_SIGNED_ENVELOPED_DATA:
case OID_PKCS7_DIGESTED_DATA:
case OID_PKCS7_ENCRYPTED_DATA:
content_type = asn1_build_known_oid(this->type);
break;
case OID_UNKNOWN:
default:
DBG1(DBG_LIB, "invalid pkcs7 contentInfo type");
return chunk_empty;
}
return this->content.ptr == NULL
? asn1_wrap(ASN1_SEQUENCE, "m", content_type)
: asn1_wrap(ASN1_SEQUENCE, "mm", content_type,
asn1_simple_object(ASN1_CONTEXT_C_0, this->content));
}
METHOD(pkcs7_t, create_certificate_enumerator, enumerator_t*,
private_pkcs7_t *this)
{
return this->certs->create_enumerator(this->certs);
}
METHOD(pkcs7_t, set_certificate, void,
private_pkcs7_t *this, certificate_t *cert)
{
if (cert)
{
this->certs->insert_last(this->certs, cert);
}
}
METHOD(pkcs7_t, set_attributes, void,
private_pkcs7_t *this, pkcs9_t *attributes)
{
this->attributes = attributes;
}
METHOD(pkcs7_t, get_attributes, pkcs9_t*,
private_pkcs7_t *this)
{
return this->attributes;
}
/**
* build a DER-encoded issuerAndSerialNumber object
*/
chunk_t pkcs7_build_issuerAndSerialNumber(certificate_t *cert)
{
identification_t *issuer = cert->get_issuer(cert);
chunk_t serial = chunk_empty;
if (cert->get_type(cert) == CERT_X509)
{
x509_t *x509 = (x509_t*)cert;
serial = x509->get_serial(x509);
}
return asn1_wrap(ASN1_SEQUENCE, "cm",
issuer->get_encoding(issuer),
asn1_integer("c", serial));
}
METHOD(pkcs7_t, build_envelopedData, bool,
private_pkcs7_t *this, certificate_t *cert, encryption_algorithm_t alg,
size_t key_size)
{
chunk_t iv, symmetricKey, protectedKey, in, out;
crypter_t *crypter;
int alg_oid;
/* select OID of symmetric encryption algorithm */
alg_oid = encryption_algorithm_to_oid(alg, key_size);
if (alg_oid == OID_UNKNOWN)
{
DBG1(DBG_LIB, " encryption algorithm %N not supported",
encryption_algorithm_names, alg);
return FALSE;
}
crypter = lib->crypto->create_crypter(lib->crypto, alg, key_size / 8);
if (crypter == NULL)
{
DBG1(DBG_LIB, " could not create crypter for algorithm %N",
encryption_algorithm_names, alg);
return FALSE;
}
/* generate a true random symmetric encryption key
* and a pseudo-random iv
*/
{
rng_t *rng;
rng = lib->crypto->create_rng(lib->crypto, RNG_TRUE);
if (!rng || !rng->allocate_bytes(rng, crypter->get_key_size(crypter),
&symmetricKey))
{
DBG1(DBG_LIB, " failed to allocate symmetric encryption key");
DESTROY_IF(rng);
return FALSE;
}
DBG4(DBG_LIB, " symmetric encryption key: %B", &symmetricKey);
rng->destroy(rng);
rng = lib->crypto->create_rng(lib->crypto, RNG_WEAK);
if (!rng || !rng->allocate_bytes(rng, crypter->get_iv_size(crypter),
&iv))
{
DBG1(DBG_LIB, " failed to allocate initialization vector");
DESTROY_IF(rng);
return FALSE;
}
DBG4(DBG_LIB, " initialization vector: %B", &iv);
rng->destroy(rng);
}
/* pad the data so that the total length becomes
* a multiple of the block size
*/
{
size_t block_size = crypter->get_block_size(crypter);
size_t padding = block_size - this->data.len % block_size;
in.len = this->data.len + padding;
in.ptr = malloc(in.len);
DBG2(DBG_LIB, " padding %d bytes of data to multiple block size of %d bytes",
(int)this->data.len, (int)in.len);
/* copy data */
memcpy(in.ptr, this->data.ptr, this->data.len);
/* append padding */
memset(in.ptr + this->data.len, padding, padding);
}
DBG3(DBG_LIB, " padded unencrypted data: %B", &in);
/* symmetric encryption of data object */
if (!crypter->set_key(crypter, symmetricKey) ||
!crypter->encrypt(crypter, in, iv, &out))
{
crypter->destroy(crypter);
chunk_clear(&in);
chunk_clear(&symmetricKey);
chunk_free(&iv);
return FALSE;
}
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 FALSE;
}
key->encrypt(key, ENCRYPT_RSA_PKCS1, symmetricKey, &protectedKey);
key->destroy(key);
chunk_clear(&symmetricKey);
}
/* build pkcs7 enveloped data object */
{
chunk_t contentEncryptionAlgorithm = asn1_wrap(ASN1_SEQUENCE, "mm",
asn1_build_known_oid(alg_oid),
asn1_wrap(ASN1_OCTET_STRING, "m", 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);
this->content = asn1_wrap(ASN1_SEQUENCE, "cmm",
ASN1_INTEGER_0,
asn1_wrap(ASN1_SET, "m", recipientInfo),
encryptedContentInfo);
chunk_free(&this->data);
this->type = OID_PKCS7_ENVELOPED_DATA;
this->data = get_contentInfo(this);
}
return TRUE;
}
METHOD(pkcs7_t, build_signedData, bool,
private_pkcs7_t *this, private_key_t *private_key, hash_algorithm_t alg)
{
chunk_t authenticatedAttributes = chunk_empty;
chunk_t encryptedDigest = chunk_empty;
chunk_t signerInfo, encoding = chunk_empty;
signature_scheme_t scheme;
int digest_oid;
certificate_t *cert;
if (this->certs->get_first(this->certs, (void**)&cert) != SUCCESS)
{
DBG1(DBG_LIB, " no pkcs7 signer certificate found");
return FALSE;
}
digest_oid = hasher_algorithm_to_oid(alg);
scheme = signature_scheme_from_oid(digest_oid);
if (this->attributes != NULL)
{
if (this->data.ptr != NULL)
{
chunk_t messageDigest, signingTime, attributes;
hasher_t *hasher;
time_t now;
hasher = lib->crypto->create_hasher(lib->crypto, alg);
if (!hasher ||
!hasher->allocate_hash(hasher, this->data, &messageDigest))
{
DESTROY_IF(hasher);
DBG1(DBG_LIB, " hash algorithm %N not support",
hash_algorithm_names, alg);
return FALSE;
}
hasher->destroy(hasher);
this->attributes->set_attribute(this->attributes,
OID_PKCS9_MESSAGE_DIGEST,
messageDigest);
free(messageDigest.ptr);
/* take the current time as signingTime */
now = time(NULL);
signingTime = asn1_from_time(&now, ASN1_UTCTIME);
this->attributes->set_attribute_raw(this->attributes,
OID_PKCS9_SIGNING_TIME, signingTime);
this->attributes->set_attribute_raw(this->attributes,
OID_PKCS9_CONTENT_TYPE,
asn1_build_known_oid(OID_PKCS7_DATA));
attributes = this->attributes->get_encoding(this->attributes);
private_key->sign(private_key, scheme, attributes, &encryptedDigest);
authenticatedAttributes = chunk_clone(attributes);
*authenticatedAttributes.ptr = ASN1_CONTEXT_C_0;
}
}
else if (this->data.ptr != NULL)
{
private_key->sign(private_key, scheme, this->data, &encryptedDigest);
}
if (encryptedDigest.ptr)
{
encryptedDigest = asn1_wrap(ASN1_OCTET_STRING, "m", encryptedDigest);
}
signerInfo = asn1_wrap(ASN1_SEQUENCE, "cmmmmm",
ASN1_INTEGER_1,
pkcs7_build_issuerAndSerialNumber(cert),
asn1_algorithmIdentifier(digest_oid),
authenticatedAttributes,
asn1_algorithmIdentifier(OID_RSA_ENCRYPTION),
encryptedDigest);
if (this->data.ptr != NULL)
{
chunk_free(&this->content);
this->content = asn1_simple_object(ASN1_OCTET_STRING, this->data);
chunk_free(&this->data);
}
this->type = OID_PKCS7_DATA;
this->data = get_contentInfo(this);
chunk_free(&this->content);
cert->get_encoding(cert, CERT_ASN1_DER, &encoding);
this->content = asn1_wrap(ASN1_SEQUENCE, "cmcmm",
ASN1_INTEGER_1,
asn1_wrap(ASN1_SET, "m", asn1_algorithmIdentifier(digest_oid)),
this->data,
asn1_wrap(ASN1_CONTEXT_C_0, "m", encoding),
asn1_wrap(ASN1_SET, "m", signerInfo));
chunk_free(&this->data);
this->type = OID_PKCS7_SIGNED_DATA;
this->data = get_contentInfo(this);
return TRUE;
}
METHOD(pkcs7_t, destroy, void,
private_pkcs7_t *this)
{
DESTROY_IF(this->attributes);
this->certs->destroy_offset(this->certs, offsetof(certificate_t, destroy));
free(this->content.ptr);
free(this->data.ptr);
free(this);
}
/**
* Generic private constructor
*/
static private_pkcs7_t *pkcs7_create_empty(void)
{
private_pkcs7_t *this;
INIT(this,
.public = {
.is_data = _is_data,
.is_signedData = _is_signedData,
.is_envelopedData = _is_envelopedData,
.parse_data = _parse_data,
.parse_signedData = _parse_signedData,
.parse_envelopedData = _parse_envelopedData,
.get_data = _get_data,
.get_contentInfo = _get_contentInfo,
.create_certificate_enumerator = _create_certificate_enumerator,
.set_certificate = _set_certificate,
.set_attributes = _set_attributes,
.get_attributes = _get_attributes,
.build_envelopedData = _build_envelopedData,
.build_signedData = _build_signedData,
.destroy = _destroy,
},
.type = OID_UNKNOWN,
.certs = linked_list_create(),
);
return this;
}
/*
* Described in header.
*/
pkcs7_t *pkcs7_create_from_chunk(chunk_t chunk, u_int level)
{
private_pkcs7_t *this = pkcs7_create_empty();
this->level = level;
this->data = chunk_clone(chunk);
return &this->public;
}
/*
* Described in header.
*/
pkcs7_t *pkcs7_create_from_data(chunk_t data)
{
private_pkcs7_t *this = pkcs7_create_empty();
this->data = chunk_clone(data);
return &this->public;
}
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