make IMAP parsing case insensitive

it's easy to overlook, but the spec demands this. we got away with it so
far, as everyone just uses UPPERCASE ... for the things we use so far.

src/common.h

@@ -189,6 +189,8 @@ void *memrchr( const void *s, int c, size_t n );
 size_t strnlen( const char *str, size_t maxlen );
 #endif
 
+void to_upper( char *str, uint len );
+
 int starts_with( const char *str, int strl, const char *cmp, uint cmpl );
 int starts_with_upper( const char *str, int strl, const char *cmp, uint cmpl );
 int equals( const char *str, int strl, const char *cmp, uint cmpl );

src/drv_imap.c

@@ -924,7 +924,7 @@ parse_imap_list( imap_store_t *ctx, char **sp, parse_list_state_t *sts )
 				if (sts->level && *s == ')')
 					break;
 			cur->len = (uint)(s - p);
-			if (equals( p, (int)cur->len, "NIL", 3 ))
+			if (equals_upper( p, (int)cur->len, "NIL", 3 ))
 				cur->val = NIL;
 			else
 				cur->val = nfstrndup( p, cur->len );
@@ -1086,12 +1086,13 @@ parse_fetched_flags( list_t *list, uchar *flags, uchar *status )
 		}
 		if (list->val[0] != '\\' && list->val[0] != '$')
 			continue;
-		if (equals( list->val, list->len, "\\Recent", 7 )) {
+		to_upper( list->val, list->len );
+		if (equals( list->val, list->len, "\\RECENT", 7 )) {
 			*status |= M_RECENT;
 			goto flagok;
 		}
 		for (uint i = 0; i < as(Flags); i++) {
-			if (!strcmp( Flags[i], list->val )) {
+			if (!strcasecmp( Flags[i], list->val )) {
 				*flags |= 1 << i;
 				goto flagok;
 			}
@@ -1169,9 +1170,10 @@ parse_fetch_rsp( imap_store_t *ctx, list_t *list )
 			error( "IMAP error: bogus item name in FETCH response\n" );
 			return LIST_BAD;
 		}
-		const char *name = tmp->val;
+		char *name = tmp->val;
 		uint namel = tmp->len;
 		tmp = tmp->next;
+		to_upper( name, namel );
 		if (equals( name, namel, "UID", 3 )) {
 			if (!is_atom( tmp ) || (uid = strtoul( tmp->val, &ep, 10 ), *ep)) {
 				error( "IMAP error: unable to parse UID\n" );
@@ -1282,6 +1284,7 @@ parse_capability( imap_store_t *ctx, char *cmd )
 	ctx->auth_mechs = NULL;
 	ctx->caps = 0x80000000;
 	while ((arg = next_arg( &cmd, &argl ))) {
+		to_upper( arg, argl );
 		if (starts_with( arg, argl, "AUTH=", 5 )) {
 			add_string_list_n( &ctx->auth_mechs, arg + 5, argl - 5 );
 		} else {
@@ -1308,6 +1311,7 @@ parse_response_code( imap_store_t *ctx, imap_cmd_t *cmd, char *s )
 		error( "IMAP error: malformed response code\n" );
 		return RESP_CANCEL;
 	}
+	to_upper( arg, argl );
 	if (equals( arg, argl, "UIDVALIDITY", 11 )) {
 		if (!(arg = next_arg( &s, &argl )) ||
 		    (ctx->uidvalidity = strtoul( arg, &earg, 10 ), *earg != ']'))
@@ -1374,7 +1378,7 @@ parse_response_code( imap_store_t *ctx, imap_cmd_t *cmd, char *s )
 				ret = RESP_CANCEL;
 				break;
 			}
-			if (equals( tmp->val, tmp->len, "\\*", 2 ) || equals( tmp->val, tmp->len, "$Forwarded", 10 )) {
+			if (equals( tmp->val, tmp->len, "\\*", 2 ) || equals_upper( tmp->val, tmp->len, "$FORWARDED", 10 )) {
 				ctx->has_forwarded = 1;
 				break;
 			}
@@ -1621,6 +1625,7 @@ imap_socket_read( void *aux )
 				break;
 			}
 
+			to_upper( arg, argl );
 			if (ctx->greeting == GreetingPending && equals( arg, argl, "PREAUTH", 7 )) {
 				parse_response_code( ctx, NULL, cmd );
 				ctx->greeting = GreetingPreauth;
@@ -1661,6 +1666,7 @@ imap_socket_read( void *aux )
 				resp = parse_list( ctx, cmd, parse_namespace_rsp, "NAMESPACE" );
 				goto listret;
 			} else if ((arg1 = next_arg( &cmd, &argl1 ))) {
+				to_upper( arg1, argl1 );
 				if (equals( arg1, argl1, "EXISTS", 6 )) {
 					ctx->total_msgs = atoi( arg );
 				} else if (equals( arg1, argl1, "EXPUNGE", 7 )) {
@@ -1736,13 +1742,14 @@ imap_socket_read( void *aux )
 				error( "IMAP error: malformed tagged response\n" );
 				break;
 			}
+			to_upper( arg, argl );
 			if (equals( arg, argl, "OK", 2 )) {
 				if (cmdp->param.to_trash)
 					ctx->trashnc = TrashKnown; /* Can't get NO [TRYCREATE] any more. */
 				resp = RESP_OK;
 			} else {
 				if (equals( arg, argl, "NO", 2 )) {
-					if (cmdp->param.create && cmd && starts_with( cmd, -1, "[TRYCREATE]", 11 )) { /* APPEND or UID COPY */
+					if (cmdp->param.create && cmd && starts_with_upper( cmd, -1, "[TRYCREATE]", 11 )) { /* APPEND or UID COPY */
 						imap_cmd_trycreate_t *cmd2 =
 							(imap_cmd_trycreate_t *)new_imap_cmd( sizeof(*cmd2) );
 						cmd2->orig_cmd = cmdp;

src/util.c

@@ -284,6 +284,13 @@ strnlen( const char *str, size_t maxlen )
 
 #endif
 
+void
+to_upper( char *str, uint len )
+{
+	for (uint i = 0; i < len; i++)
+		str[i] = toupper( str[i] );
+}
+
 int
 starts_with( const char *str, int strl, const char *cmp, uint cmpl )
 {