Major refactoring of structures, with unit tests.

host/lib/host_key.c

+/* Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * Host functions for keys.
+ */
+
+/* TODO: change all 'return 0', 'return 1' into meaningful return codes */
+
+#define OPENSSL_NO_SHA
+#include <openssl/engine.h>
+#include <openssl/pem.h>
+#include <openssl/rsa.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "host_key.h"
+
+#include "cryptolib.h"
+#include "file_keys.h"
+#include "utility.h"
+#include "vboot_common.h"
+
+
+VbPrivateKey* PrivateKeyRead(const char* filename, uint64_t algorithm) {
+
+  VbPrivateKey* key;
+  RSA* rsa_key;
+  FILE* f;
+
+  if (algorithm >= kNumAlgorithms) {
+    debug("PrivateKeyRead() called with invalid algorithm!\n");
+    return NULL;
+  }
+
+  /* Read private key */
+  f = fopen(filename, "r");
+  if (!f) {
+    debug("PrivateKeyRead(): Couldn't open key file: %s\n", filename);
+    return NULL;
+  }
+  rsa_key = PEM_read_RSAPrivateKey(f, NULL, NULL, NULL);
+  fclose(f);
+  if (!rsa_key) {
+    debug("PrivateKeyRead(): Couldn't read private key from file: %s\n",
+          filename);
+    return NULL;
+  }
+
+  /* Store key and algorithm in our struct */
+  key = (VbPrivateKey*)Malloc(sizeof(VbPrivateKey));
+  if (!key) {
+    RSA_free(rsa_key);
+    return NULL;
+  }
+  key->rsa_private_key = rsa_key;
+  key->algorithm = algorithm;
+
+  /* Return the key */
+  return key;
+}
+
+
+void PrivateKeyFree(VbPrivateKey* key) {
+  if (!key)
+    return;
+  if (key->rsa_private_key)
+    RSA_free(key->rsa_private_key);
+  Free(key);
+}
+
+
+void PublicKeyInit(VbPublicKey* key, uint8_t* key_data, uint64_t key_size) {
+  key->key_offset = OffsetOf(key, key_data);
+  key->key_size = key_size;
+  key->algorithm = kNumAlgorithms; /* Key not present yet */
+  key->key_version = 0;
+}
+
+
+/* Allocate a new public key with space for a [key_size] byte key. */

[gauravsh, 2010/06/10 14:44:13]

nit: there's a possibility of confusion with what we mean by [key_size] byte
key. In this case, we are referring to the size of stored key on  disk. But this
might be also be interpreted to mean the strength of the key. I had to check the
source to make sure I was interpreting it right. 

I noticed this elsewhere too. It would be useful to clarify that we mean the
storage size of the key.

+VbPublicKey* PublicKeyAlloc(uint64_t key_size, uint64_t algorithm,
+                            uint64_t version) {
+  VbPublicKey* key = (VbPublicKey*)Malloc(sizeof(VbPublicKey) + key_size);
+  if (!key)
+    return NULL;
+
+  key->algorithm = algorithm;
+  key->key_version = version;
+  key->key_size = key_size;
+  key->key_offset = sizeof(VbPublicKey);
+  return key;
+}
+
+
+/* Copy a public key from [src] to [dest].
+ *
+ * Returns zero if success, non-zero if error. */
+int PublicKeyCopy(VbPublicKey* dest, const VbPublicKey* src) {
+  if (dest->key_size < src->key_size)

[gauravsh, 2010/06/10 14:44:13]

shouldn't we always return an error if dest key_size and src key_size are
different?

+    return 1;
+
+  dest->key_size = src->key_size;
+  dest->algorithm = src->algorithm;
+  dest->key_version = src->key_version;
+  Memcpy(GetPublicKeyData(dest), GetPublicKeyDataC(src), src->key_size);
+  return 0;
+}
+
+
+VbPublicKey* PublicKeyRead(const char* filename, uint64_t algorithm,
+                           uint64_t version) {
+
+  VbPublicKey* key;
+  uint8_t* key_data;
+  uint64_t key_size;
+
+  if (algorithm >= kNumAlgorithms) {
+    debug("PublicKeyRead() called with invalid algorithm!\n");
+    return NULL;
+  }
+  if (version > 0xFFFF) {
+    /* Currently, TPM only supports 16-bit version */
+    debug("PublicKeyRead() called with invalid version!\n");
+    return NULL;
+  }
+
+  key_data = BufferFromFile(filename, &key_size);
+  if (!key_data)
+    return NULL;
+
+  /* TODO: sanity-check key length based on algorithm */
+
+  key = PublicKeyAlloc(key_size, algorithm, version);
+  if (!key) {
+    Free(key_data);
+    return NULL;
+  }
+  Memcpy(GetPublicKeyData(key), key_data, key_size);
+
+  Free(key_data);
+  return key;
+}