libify: Move library sources down into lib directory.

[notmuch] / lib / sha1.c

diff --git a/lib/sha1.c b/lib/sha1.c
new file mode 100644 (file)
index 0000000..ff4dd16
--- /dev/null
+++ b/lib/sha1.c
@@ -0,0 +1,115 @@
+/* sha1.c - Interfaces to SHA-1 hash for the notmuch mail system
+ *
+ * Copyright © 2009 Carl Worth
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see http://www.gnu.org/licenses/ .
+ *
+ * Author: Carl Worth <cworth@cworth.org>
+ */
+
+#include "notmuch-private.h"
+
+#include "libsha1.h"
+
+/* Just some simple interfaces on top of libsha1 so that we can leave
+ * libsha1 as untouched as possible. */
+
+static char *
+_hex_of_sha1_digest (const unsigned char digest[SHA1_DIGEST_SIZE])
+{
+    char *result, *r;
+    int i;
+
+    result = xcalloc (SHA1_DIGEST_SIZE * 2 + 1, 1);
+
+    for (r = result, i = 0;
+        i < SHA1_DIGEST_SIZE;
+        r += 2, i++)
+    {
+       sprintf (r, "%02x", digest[i]);
+    }
+
+    return result;
+}
+
+/* Create a hexadcimal string version of the SHA-1 digest of 'str'
+ * (including its null terminating character).
+ *
+ * This function returns a newly allocated string which the caller
+ * should free() when finished.
+ */
+char *
+notmuch_sha1_of_string (const char *str)
+{
+    sha1_ctx sha1;
+    unsigned char digest[SHA1_DIGEST_SIZE];
+
+    sha1_begin (&sha1);
+
+    sha1_hash ((unsigned char *) str, strlen (str) + 1, &sha1);
+
+    sha1_end (digest, &sha1);
+
+    return _hex_of_sha1_digest (digest);
+}
+
+/* Create a hexadecimal string version of the SHA-1 digest of the
+ * contents of the named file.
+ *
+ * This function returns a newly allocated string which the caller
+ * should free() when finished.
+ *
+ * If any error occurs while reading the file, (permission denied,
+ * file not found, etc.), this function returns NULL.
+ */
+char *
+notmuch_sha1_of_file (const char *filename)
+{
+    FILE *file;
+#define BLOCK_SIZE 4096
+    unsigned char block[BLOCK_SIZE];
+    size_t bytes_read;
+    sha1_ctx sha1;
+    unsigned char digest[SHA1_DIGEST_SIZE];
+    char *result;
+
+    file = fopen (filename, "r");
+    if (file == NULL)
+       return NULL;
+
+    sha1_begin (&sha1);
+
+    while (1) {
+       bytes_read = fread (block, 1, 4096, file);
+       if (bytes_read == 0) {
+           if (feof (file)) {
+               break;
+           } else if (ferror (file)) {
+               fclose (file);
+               return NULL;
+           }
+       } else {
+           sha1_hash (block, bytes_read, &sha1);
+       }
+    }
+
+    sha1_end (digest, &sha1);
+
+    result = _hex_of_sha1_digest (digest);
+
+    fclose (file);
+
+    return result;
+}
+