Add support for Component ID (container label)

Signed-off-by: Dave Heller <hellerda@us.ibm.com>

1 files changed, 41 insertions, 2 deletions

diff --git a/container.c b/container.c
index 1f180a5..ceaa979 100644
--- a/container.c
+++ b/container.c
@@ -76,6 +76,11 @@ void debug_print(char *lead, unsigned char *buffer, size_t buflen)
 		hex_print(lead, buffer, buflen);
 }
 
+/**
+ * Validate hexadecimal ASCII input of a given length.
+ * - len is the byte len of the resulting value, not the len of the hexascii.
+ * - len = 0 means validate input of arbitrary length.
+*/
 int isValidHex(char *input, int len) {
 	int r;
 	size_t maxlen = 512; // sane limit
@@ -88,9 +93,9 @@ int isValidHex(char *input, int len) {
 		die(EX_DATAERR, "input exceeded max length: %lu", maxlen);
 
 	if (len > 0)
-		sprintf(multiplier, "{%d}", len * 2);
+		sprintf(multiplier, "{%d}", len * 2); // allow this (byte) len only
 	else
-		sprintf(multiplier, "+");
+		sprintf(multiplier, "+"); // unlimited
 
 	sprintf(pattern, "^(0x|0X)?[a-fA-F0-9]%s$", multiplier);
 
@@ -103,3 +108,37 @@ int isValidHex(char *input, int len) {
 	regfree(&regexpr);
 	return result;
 }
+
+/**
+ * Validate ASCII input up to a given length.
+ * - len is the expected len of the ascii input.
+ * - len = 0 means validate input of arbitrary length.
+ * - NOTE: not all ascii chars are allowed here.
+ */
+int isValidAscii(char *input, int len) {
+	int r;
+	size_t maxlen = 256; // sane limit
+	regex_t regexpr;
+	char pattern[48];
+	char multiplier[8];
+	bool result = false;
+
+	if (strnlen(input, maxlen) >= maxlen)
+		die(EX_DATAERR, "input exceeded max length: %lu", maxlen);
+
+	if (len > 0)
+		sprintf(multiplier, "{,%d}", len);  // allow *up to* this len
+	else
+		sprintf(multiplier, "+"); // unlimited
+
+	sprintf(pattern, "^[a-zA-Z0-9_+-]%s$", multiplier);
+
+	if ((r = regcomp(&regexpr, pattern, REG_EXTENDED | REG_NOSUB)))
+		die(EX_SOFTWARE, "%s", "failure to compile regex");
+
+	if (!(r = regexec(&regexpr, input, 0, NULL, 0)))
+		result = true;
+
+	regfree(&regexpr);
+	return result;
+}