END_TEST
/*******************************************************************************
* known_oid
*/
START_TEST(test_asn1_known_oid)
{
typedef struct {
int n;
chunk_t oid;
} testdata_t;
testdata_t test[] = {
{ OID_UNKNOWN, chunk_empty },
{ OID_UNKNOWN, chunk_from_chars(0x55, 0x04, 0x02) },
{ OID_COUNTRY, chunk_from_chars(0x55, 0x04, 0x06) },
{ OID_STRONGSWAN, chunk_from_chars(0x2b, 0x06, 0x01, 0x04, 0x01,
0x82, 0xa0, 0x2a, 0x01) }
};
int i;
for (i = 0; i < countof(test); i++)
{
ck_assert(asn1_known_oid(test[i].oid) == test[i].n);
}
}
/**
* Parse X.501 attributes
*/
bool parse_attributes(chunk_t blob, scep_attributes_t *attrs)
{
asn1_parser_t *parser;
chunk_t object;
int oid = OID_UNKNOWN;
int objectID;
bool success = FALSE;
parser = asn1_parser_create(attributesObjects, blob);
DBG(DBG_CONTROL | DBG_PARSING,
DBG_log("parsing attributes")
)
while (parser->iterate(parser, &objectID, &object))
{
switch (objectID)
{
case ATTRIBUTE_OBJ_TYPE:
oid = asn1_known_oid(object);
break;
case ATTRIBUTE_OBJ_VALUE:
if (!extract_attribute(oid, object, parser->get_level(parser), attrs))
{
goto end;
}
}
}
success = parser->success(parser);
end:
parser->destroy(parser);
return success;
}
/**
* 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 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;
}
/**
* Encode the public key as Base64 encoded SSH key blob
*/
static bool build_public_key(chunk_t *encoding, va_list args)
{
bio_writer_t *writer;
chunk_t n, e;
if (cred_encoding_args(args, CRED_PART_RSA_MODULUS, &n,
CRED_PART_RSA_PUB_EXP, &e, CRED_PART_END))
{
writer = bio_writer_create(0);
writer->write_data32(writer, chunk_from_str("ssh-rsa"));
writer->write_data32(writer, e);
writer->write_data32(writer, n);
*encoding = chunk_to_base64(writer->get_buf(writer), NULL);
writer->destroy(writer);
return TRUE;
}
else if (cred_encoding_args(args, CRED_PART_EDDSA_PUB_ASN1_DER, &n,
CRED_PART_END))
{
chunk_t alg;
char *prefix;
int oid;
/* parse subjectPublicKeyInfo */
if (asn1_unwrap(&n, &n) != ASN1_SEQUENCE)
{
return FALSE;
}
oid = asn1_parse_algorithmIdentifier(n, 1, NULL);
switch (oid)
{
case OID_ED25519:
prefix = "ssh-ed25519";
break;
case OID_ED448:
prefix = "ssh-ed448";
break;
default:
return FALSE;
}
if (asn1_unwrap(&n, &alg) != ASN1_SEQUENCE ||
asn1_unwrap(&n, &n) != ASN1_BIT_STRING || !n.len)
{
return FALSE;
}
writer = bio_writer_create(0);
writer->write_data32(writer, chunk_from_str(prefix));
writer->write_data32(writer, chunk_skip(n, 1));
*encoding = chunk_to_base64(writer->get_buf(writer), NULL);
writer->destroy(writer);
return TRUE;
}
else if (cred_encoding_args(args, CRED_PART_ECDSA_PUB_ASN1_DER, &n,
CRED_PART_END))
{
chunk_t params, alg, q;
int oid;
/* parse subjectPublicKeyInfo */
if (asn1_unwrap(&n, &n) != ASN1_SEQUENCE)
{
return FALSE;
}
oid = asn1_parse_algorithmIdentifier(n, 1, ¶ms);
if (oid != OID_EC_PUBLICKEY ||
asn1_unwrap(¶ms, ¶ms) != ASN1_OID)
{
return FALSE;
}
oid = asn1_known_oid(params);
if (oid == OID_UNKNOWN)
{
return FALSE;
}
if (asn1_unwrap(&n, &alg) != ASN1_SEQUENCE ||
asn1_unwrap(&n, &q) != ASN1_BIT_STRING)
{
return FALSE;
}
writer = bio_writer_create(0);
write_ec_identifier(writer, ECDSA_PREFIX, oid, params);
write_ec_identifier(writer, "", oid, params);
q = chunk_skip_zero(q);
writer->write_data32(writer, q);
*encoding = chunk_to_base64(writer->get_buf(writer), NULL);
writer->destroy(writer);
return TRUE;
}
return FALSE;
}
