1 files changed, 74 insertions, 0 deletions
diff --git a/misclibs/signature_digest.c b/misclibs/signature_digest.c
new file mode 100644
index 00000000..d8d425ba
--- /dev/null
+++ b/misclibs/signature_digest.c
@@ -0,0 +1,74 @@
+/* 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.
+ */
+
+#include "signature_digest.h"
+#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 "cryptolib.h"
+#include "utility.h"
+
+uint8_t* PrependDigestInfo(int algorithm, uint8_t* digest) {
+  const int digest_size = hash_size_map[algorithm];
+  const int digestinfo_size = digestinfo_size_map[algorithm];
+  const uint8_t* digestinfo = hash_digestinfo_map[algorithm];
+  uint8_t* p = Malloc(digestinfo_size + digest_size);
+  Memcpy(p, digestinfo, digestinfo_size);
+  Memcpy(p + digestinfo_size, digest, digest_size);
+  return p;
+}
+
+uint8_t* SignatureDigest(const uint8_t* buf, uint64_t len, int algorithm) {
+  uint8_t* info_digest  = NULL;
+  uint8_t* digest = NULL;
+
+  if (algorithm >= kNumAlgorithms) {
+    fprintf(stderr, "SignatureDigest() called with invalid algorithm!\n");
+  } else if ((digest = DigestBuf(buf, len, algorithm))) {
+    info_digest = PrependDigestInfo(algorithm, digest);
+  }
+  Free(digest);
+  return info_digest;
+}
+
+uint8_t* SignatureBuf(const uint8_t* buf, uint64_t len, const char* key_file,
+                      int algorithm) {
+  FILE* key_fp = NULL;
+  RSA* key = NULL;
+  uint8_t* signature = NULL;
+  uint8_t* signature_digest = SignatureDigest(buf, len, algorithm);
+  int signature_digest_len = (hash_size_map[algorithm] +
+                              digestinfo_size_map[algorithm]);
+  key_fp  = fopen(key_file, "r");
+  if (!key_fp) {
+    fprintf(stderr, "SignatureBuf(): Couldn't open key file: %s\n", key_file);
+    Free(signature_digest);
+    return NULL;
+  }
+  if ((key = PEM_read_RSAPrivateKey(key_fp, NULL, NULL, NULL)))
+    signature = (uint8_t*) Malloc(siglen_map[algorithm]);
+  else
+    fprintf(stderr, "SignatureBuf(): Couldn't read private key from file: %s\n",
+            key_file);
+  if (signature) {
+    if (-1 == RSA_private_encrypt(signature_digest_len,  /* Input length. */
+                                  signature_digest,  /* Input data. */
+                                  signature,  /* Output signature. */
+                                  key,  /* Key to use. */
+                                  RSA_PKCS1_PADDING))  /* Padding to use. */
+      fprintf(stderr, "SignatureBuf(): RSA_private_encrypt() failed.\n");
+  }
+  fclose(key_fp);
+  if (key)
+    RSA_free(key);
+  Free(signature_digest);
+  return signature;
+}