sick

commit 80b802dd8d9344594c3bfdeb703abb2509de8d35
parent 94ec40e42c2f1515fd496fd9ee10ec60c4a0cd63
Author: z3bra <willyatmailoodotorg>
Date:   Tue May 10 21:01:28 +12000

Add a function to bufferize input stream

Diffstat:
sick.c
 | 
54
+++++++++++++++++++++++++++++++++++++++++++-----------
1 file changed, 43 insertions(+), 11 deletions(-)
diff --git a/sick.c b/sick.c
@@ -18,6 +18,7 @@ enum {
 };
 
 static void usage();
+static size_t bufferize(unsigned char **buf, FILE *fp);
 static int createkeypair(const char *);
 static int sign(FILE *fp, FILE *key);
 
@@ -30,6 +31,29 @@ usage()
 	exit(EXIT_FAILURE);
 }
 
+/*
+ * read chunks of data from a stream into a buffer, and return the size of the buffer
+ */
+static size_t
+bufferize(unsigned char **buf, FILE *fp)
+{
+	size_t n, len = 0;
+	char chunk[MAX_INPUT], *tmp;
+
+	while ((n = fread(chunk, 1, MAX_INPUT, fp)) > 0) {
+		if ((tmp = realloc(*buf, len + n)) == NULL) {
+			free(*buf);
+			*buf = NULL;
+			return 0;
+		}
+
+		*buf = (unsigned char *)tmp;
+		memcpy((*buf) + len, chunk, n);
+		len += n;
+	}
+
+	return len;
+}
 
 /*
  * Creates a set of ed25519 key pairs on disk.
@@ -85,23 +109,31 @@ createkeypair(const char *alias)
 int
 sign(FILE *fp, FILE *key)
 {
-	size_t len, siz = 0;
-	char tmp[64], *base64;
+	size_t len;
+	char *base64;
 	unsigned char sig[64], priv[64], *msg = NULL;
 
-	while((len = fread(tmp, 1, 64, fp)) > 0) {
-		siz += len;
-		msg = realloc(msg, siz);
-		memcpy(msg + siz - len, tmp, len);
-	}
+	if (!fread(priv, 1, 64, key))
+		return -1;
+
+	len = bufferize(&msg, fp);
+	if (len == 0)
+		return -1;
 
-	fread(priv, 1, 64, key);
-	ed25519_sign(sig, msg, siz, priv);
+	ed25519_sign(sig, msg, len, priv);
 
-	len = base64_encode(&base64, sig, 64);
-	fwrite(msg, 1, siz, stdout);
+	/* write buffer to stdout .. */
+	fwrite(msg, 1, len, stdout);
+	free(msg);
+
+	/* .. followed by the signature delimiter .. */
 	fwrite(SIGBEGIN, 1, sizeof(SIGBEGIN), stdout);
+
+	/* .. then the base64 encoded signature .. */
+	len = base64_encode(&base64, sig, 64);
 	base64_fold(stdout, base64, len, 0);
+
+	/* .. and the final signature delimiter! */
 	fwrite(SIGEND, 1, sizeof(SIGEND), stdout);
 
 	return 0;