Allow for line-feed terminated responses

Also, remove old flags from the the `flags' list in `libgeminiclient.3'

gemini-cat.1

@@ -1,4 +1,4 @@
-.Dd Apr 29, 2020
+.Dd May 5, 2020
 .Dt GEMINI-CAT 1
 .Os
 .Sh NAME
@@ -6,7 +6,7 @@
 .Nd concatnate responses from a Gemini URLs
 .Sh SYNOPSIS
 .Nm
-.Op Fl RSisw
+.Op Fl RSeisw
 .Op Fl c Ar cert-file
 .Op Fl k Ar key-file
 .Op Fl p Ar port
@@ -26,6 +26,8 @@ Strip out non-space control-characters before writing, the default for
 TTY outputs.
 .It Fl c Ar cert-file
 The certificate file to use for TLS.
+.It Fl e
+Enforce a strict interpretation of the Gemini specification.
 .It Fl i
 Interactive mode (allow prompts).
 .It Fl k Ar key-file

gemini-cat.c

@@ -44,7 +44,7 @@ main(int argc, char *argv[])
 	    != 0)
 		err(EX_NOPERM, "Failed pledge(2)");
 #endif
-	while ((c = getopt(argc, argv, "RSc:ik:p:r:st:w")) != -1)
+	while ((c = getopt(argc, argv, "RSc:eik:p:r:st:w")) != -1)
 		switch (c) {
 		case 'R':
 			rawout = 1;
@@ -55,6 +55,9 @@ main(int argc, char *argv[])
 		case 'c':
 			gemini.certfile = optarg;
 			break;
+		case 'e':
+			gemini.flags |= GEMINI_STRICT;
+			break;
 		case 'i':
 			prompt = 1;
 			break;
@@ -150,7 +153,7 @@ err:
 	gemini_fini(&gemini);
 	return (EX_SOFTWARE);
 usage:
-	(void)fprintf(stderr, "usage: gemini-cat [-RSisw] "
+	(void)fprintf(stderr, "usage: gemini-cat [-RSeisw] "
 	    "[-c cert-file] [-k key-file] [-p port]\n"
 	    "                  [-r max-redirects] [-t tofu-file] "
 	    "URL...\n");

libgeminiclient.3

@@ -140,18 +140,13 @@ Possible
 .Fa flags
 are as follows:
 .Bl -tag -width Ds -compact
-.It Dv GEMINI_PROMPT
-Prompt the user for input on status
-.Li 10 .
-.It Dv GEMINI_SECURE_PROMPT
-Prompt the user for input on status
-.Li 10 ,
-without echoing the input.
 .It Dv GEMINI_TOFU_WRITE
 Write any new certificate information to
 .Fa tofufile
 on
 .Dn gemini_close .
+.It Dv GEMINI_STRICT
+Enforce a strict interpretation of the Gemini protocol.
 .El
 .Pp
 All knows

libgeminiclient.c

@@ -325,31 +325,26 @@ gemini_read(struct gemini *g, void *b, size_t bs)
 			 * If the white-space had a reasonable maximum
 			 * then this would be easier.
 			 */
-			if (i == 0 && g->meta[g->metalen - 1] == '\r' &&
-			    cb[0] == '\n') {
-				i++;
-				g->meta[--g->metalen] = '\0';
-			} else if (i == 0 && cb[0] == '\r' &&
-			    cb[1] == '\n') {
-				i += 2;
-			} else {
-				for (j = i + (i == 0);
-				    j < r && (cb[j] != '\n' ||
-				    cb[j - 1] != '\r'); j++)
-					/* do nothing */;
-				j -= j < r;
-				if (g->metalen + j - i >
-				    GEMINI_META_MAX + j == r)
-					goto errinval;
-				(void)memcpy(g->meta + g->metalen,
-				    cb + i, j - i);
-				g->meta[g->metalen += j - i] = '\0';
-				if (j == r) {
-					i = j;
-					break;
-				}
-				i = j + 2;
+			for (j = i; j < r && cb[j] != '\n'; j++)
+				/* do nothing */;
+			if (g->metalen + j - i > sizeof(g->meta))
+				goto errinval;
+			(void)memcpy(g->meta + g->metalen, cb + i,
+			    j - i);
+			g->metalen += j - i;
+			if (cb[j] != '\n') {
+				i = j;
+				break;
 			}
+			if (g->metalen > 0 &&
+			    g->meta[g->metalen - 1] == '\r')
+				g->metalen--;
+			else if (g->flags & GEMINI_STRICT)
+				goto errinval;
+			if (g->metalen > GEMINI_META_MAX)
+				goto errinval;
+			g->meta[g->metalen] = '\0';
+			i = j + 1;
 			if (g->status / 10 != 3)
 				g->redirects = 0;
 			switch (g->status / 10) {

libgeminiclient.h

@@ -13,6 +13,7 @@
 #define GEMINI_REDIRECT_MAX 5
 
 #define GEMINI_TOFU_WRITE 0x01
+#define GEMINI_STRICT 0x02
 
 struct gemini_tofu {
 	struct gemini_tofu	*next;