genprotimg: introduce new tool for the creation of PV images

Protected VMs (PVM) are KVM VMs, where KVM can't access the VM's state
like guest memory and guest registers anymore. Instead the PVMs are
mostly managed by a new entity called Ultravisor (UV), which provides
an API, so KVM and the PV can request management actions.

PVMs are encrypted at rest and protected from hypervisor access while
running. They switch from a normal operation into protected mode, so
we can still use the standard boot process to load an encrypted image
and then move it into protected mode.

This commit adds the tool 'genprotimg'. It takes a kernel, key files,
optionally an initrd, optionally a file with the kernel command line,
and it generates a single, loadable image file. The image consists of
a concatenation of a plain text boot loader, the encrypted components
for kernel, initrd, and cmdline, and the integrity-protected PV
header, containing metadata necessary for running the guest in PV
mode.

It's possible to use this image file as a kernel for zipl or for a
direct kernel boot using QEMU.

Reviewed-by: Bjoern Walk <bwalk@linux.ibm.com>
Acked-by: Patrick Steuer <patrick.steuer@de.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Jan Höppner <hoeppner@linux.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>

genprotimg/src/utils/crypto.h

@@ -0,0 +1,104 @@
+/*
+ * General cryptography helper functions and definitions
+ *
+ * Copyright IBM Corp. 2020
+ *
+ * s390-tools is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
+#ifndef PV_UTILS_CRYPTO_H
+#define PV_UTILS_CRYPTO_H
+
+#include <glib.h>
+#include <openssl/bio.h>
+#include <openssl/bn.h>
+#include <openssl/ec.h>
+#include <openssl/ecdh.h>
+#include <openssl/evp.h>
+#include <openssl/rand.h>
+#include <openssl/sha.h>
+#include <openssl/x509.h>
+#include <stdint.h>
+
+#include "common.h"
+#include "include/pv_crypto_def.h"
+#include "lib/zt_common.h"
+
+#include "buffer.h"
+
+#define AES_256_GCM_IV_SIZE  12
+#define AES_256_GCM_TAG_SIZE 16
+
+#define AES_256_XTS_TWEAK_SIZE 16
+#define AES_256_XTS_KEY_SIZE   64
+
+enum PvCryptoMode {
+	PV_ENCRYPT,
+	PV_DECRYPT,
+};
+
+typedef GSList HostKeyList;
+
+/* Register auto cleanup functions */
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(BIGNUM, BN_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(BIO, BIO_free_all)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(BN_CTX, BN_CTX_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(EC_GROUP, EC_GROUP_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(EC_KEY, EC_KEY_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(EC_POINT, EC_POINT_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(EVP_CIPHER_CTX, EVP_CIPHER_CTX_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(EVP_MD_CTX, EVP_MD_CTX_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(EVP_PKEY, EVP_PKEY_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(EVP_PKEY_CTX, EVP_PKEY_CTX_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(X509, X509_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(X509_LOOKUP, X509_LOOKUP_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(X509_STORE, X509_STORE_free)
+WRAPPED_G_DEFINE_AUTOPTR_CLEANUP_FUNC(X509_STORE_CTX, X509_STORE_CTX_free)
+
+union cmp_index {
+	struct {
+		uint16_t idx;
+		guchar rand[6];
+	} __packed;
+	uint64_t data;
+};
+
+/* The tweak is always stored in big endian format */
+union tweak {
+	struct {
+		union cmp_index cmp_idx;
+		uint64_t page_idx; /* page index */
+	} __packed;
+	uint8_t data[AES_256_XTS_TWEAK_SIZE];
+};
+
+struct cipher_parms {
+	const EVP_CIPHER *cipher;
+	const Buffer *key;
+	const Buffer *iv_or_tweak;
+};
+
+EVP_PKEY *read_ec_pubkey_cert(X509_STORE *store, gint nid, const gchar *path,
+			      GError **err);
+Buffer *compute_exchange_key(EVP_PKEY *cust, EVP_PKEY *host, GError **err);
+Buffer *generate_aes_key(guint size, GError **err);
+Buffer *generate_aes_iv(guint size, GError **err);
+EVP_PKEY *generate_ec_key(gint nid, GError **err);
+gint generate_tweak(union tweak *tweak, uint16_t i, GError **err);
+union ecdh_pub_key *evp_pkey_to_ecdh_pub_key(EVP_PKEY *key, GError **err);
+EVP_MD_CTX *digest_ctx_new(const EVP_MD *md, GError **err);
+Buffer *digest_ctx_finalize(EVP_MD_CTX *ctx, GError **err);
+Buffer *sha256_buffer(const Buffer *buf, GError **err);
+int64_t gcm_encrypt(const Buffer *in, const Buffer *aad,
+		    const struct cipher_parms *parms, Buffer *out,
+		    Buffer *tag, GError **err);
+gint encrypt_file(const struct cipher_parms *parms, const gchar *in_path,
+		  const gchar *path_out, gsize *in_size, gsize *out_size,
+		  GError **err);
+Buffer *encrypt_buf(const struct cipher_parms *parms, const Buffer *in,
+		    GError **err);
+G_GNUC_UNUSED Buffer *decrypt_buf(const struct cipher_parms *parms,
+				  const Buffer *in, GError **err);
+
+#endif