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Diffstat (limited to 'include/crypto/secret.h')
| -rw-r--r-- | include/crypto/secret.h | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/include/crypto/secret.h b/include/crypto/secret.h new file mode 100644 index 0000000000..913519ae27 --- /dev/null +++ b/include/crypto/secret.h @@ -0,0 +1,148 @@ +/* + * QEMU crypto secret support + * + * Copyright (c) 2015 Red Hat, Inc. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library 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 + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, see <http://www.gnu.org/licenses/>. + * + */ + +#ifndef QCRYPTO_SECRET_H__ +#define QCRYPTO_SECRET_H__ + +#include "qemu-common.h" +#include "qapi/error.h" +#include "qom/object.h" + +#define TYPE_QCRYPTO_SECRET "secret" +#define QCRYPTO_SECRET(obj) \ + OBJECT_CHECK(QCryptoSecret, (obj), TYPE_QCRYPTO_SECRET) + +typedef struct QCryptoSecret QCryptoSecret; +typedef struct QCryptoSecretClass QCryptoSecretClass; + +/** + * QCryptoSecret: + * + * The QCryptoSecret object provides storage of secrets, + * which may be user passwords, encryption keys or any + * other kind of sensitive data that is represented as + * a sequence of bytes. + * + * The sensitive data associated with the secret can + * be provided directly via the 'data' property, or + * indirectly via the 'file' property. In the latter + * case there is support for file descriptor passing + * via the usual /dev/fdset/NN syntax that QEMU uses. + * + * The data for a secret can be provided in two formats, + * either as a UTF-8 string (the default), or as base64 + * encoded 8-bit binary data. The latter is appropriate + * for raw encryption keys, while the former is appropriate + * for user entered passwords. + * + * The data may be optionally encrypted with AES-256-CBC, + * and the decryption key provided by another + * QCryptoSecret instance identified by the 'keyid' + * property. When passing sensitive data directly + * via the 'data' property it is strongly recommended + * to use the AES encryption facility to prevent the + * sensitive data being exposed in the process listing + * or system log files. + * + * Providing data directly, insecurely (suitable for + * ad hoc developer testing only) + * + * $QEMU -object secret,id=sec0,data=letmein + * + * Providing data indirectly: + * + * # printf "letmein" > password.txt + * # $QEMU \ + * -object secret,id=sec0,file=password.txt + * + * Using a master encryption key with data. + * + * The master key needs to be created as 32 secure + * random bytes (optionally base64 encoded) + * + * # openssl rand -base64 32 > key.b64 + * # KEY=$(base64 -d key.b64 | hexdump -v -e '/1 "%02X"') + * + * Each secret to be encrypted needs to have a random + * initialization vector generated. These do not need + * to be kept secret + * + * # openssl rand -base64 16 > iv.b64 + * # IV=$(base64 -d iv.b64 | hexdump -v -e '/1 "%02X"') + * + * A secret to be defined can now be encrypted + * + * # SECRET=$(printf "letmein" | + * openssl enc -aes-256-cbc -a -K $KEY -iv $IV) + * + * When launching QEMU, create a master secret pointing + * to key.b64 and specify that to be used to decrypt + * the user password + * + * # $QEMU \ + * -object secret,id=secmaster0,format=base64,file=key.b64 \ + * -object secret,id=sec0,keyid=secmaster0,format=base64,\ + * data=$SECRET,iv=$(<iv.b64) + * + * When encrypting, the data can still be provided via an + * external file, in which case it is possible to use either + * raw binary data, or base64 encoded. This example uses + * raw format + * + * # printf "letmein" | + * openssl enc -aes-256-cbc -K $KEY -iv $IV -o pw.aes + * # $QEMU \ + * -object secret,id=secmaster0,format=base64,file=key.b64 \ + * -object secret,id=sec0,keyid=secmaster0,\ + * file=pw.aes,iv=$(<iv.b64) + * + * Note that the ciphertext can be in either raw or base64 + * format, as indicated by the 'format' parameter, but the + * plaintext resulting from decryption is expected to always + * be in raw format. + */ + +struct QCryptoSecret { + Object parent_obj; + uint8_t *rawdata; + size_t rawlen; + QCryptoSecretFormat format; + char *data; + char *file; + char *keyid; + char *iv; +}; + + +struct QCryptoSecretClass { + ObjectClass parent_class; +}; + + +extern int qcrypto_secret_lookup(const char *secretid, + uint8_t **data, + size_t *datalen, + Error **errp); +extern char *qcrypto_secret_lookup_as_utf8(const char *secretid, + Error **errp); +extern char *qcrypto_secret_lookup_as_base64(const char *secretid, + Error **errp); + +#endif /* QCRYPTO_SECRET_H__ */ |