Fix problem with single quotes in args

Single quotes can't be represented in single quoted text, so quote them separately by double quotes. Better version.

1 files changed, 69 insertions, 27 deletions

diff --git a/src/firejail/main.c b/src/firejail/main.c
index 28351a2df..4f1c81e2b 100644
--- a/src/firejail/main.c
+++ b/src/firejail/main.c
@@ -2009,25 +2009,34 @@ int main(int argc, char **argv) {
                 int len = 0;
                 int argcnt = argc - prog_index;
                 int j;
-                char *arg, *arg_ptr, *token;
+                bool in_quotes = false;
 
                 for (i = 0; i < argcnt; i++) {
-                        arg = strdup(argv[i + prog_index]);
-                        arg_ptr = arg;
-                        for (token = strsep(&arg_ptr, "\'"); token != NULL; token = strsep(&arg_ptr, "\'")) {
-                                if (token[0] == '\0') {
-                                        len += 3;
+                        in_quotes = false;
+                        for (j = 0; j < strlen(argv[i + prog_index]); j++) {
+                                if (argv[i + prog_index][j] == '\'') {
+                                        if (in_quotes)
+                                                len++;
+                                        if (j > 0 && argv[i + prog_index][j-1] == '\'')
+                                                len++;
+                                        else
+                                                len += 3;
+                                        in_quotes = false;
                                 } else {
-                                        len += strlen(token) + 5;
+                                        if (!in_quotes)
+                                                len++;
+                                        len++;
+                                        in_quotes = true;
                                 }
                         }
-                        free(arg);
-                        len -= 2; // + ' ' - 3 char overrun
+                        if (in_quotes) {
+                                len++;
+                        }
+                        if (strlen(argv[i + prog_index]) == 0) {
+                                len += 2;
+                        }
+                        len++;
                 }
-                len += 3; // for overrun
-
-                if (arg_debug)
-                        printf("Predicted command length %d\n", len);
 
                 // build the string
                 cfg.command_line = malloc(len + 1); // + '\0'
@@ -2040,31 +2049,64 @@ int main(int argc, char **argv) {
                 char *ptr1 = cfg.command_line;
                 char *ptr2 = cfg.window_title;
                 for (i = 0; i < argcnt; i++) {
+
                         // enclose args by single quotes,
                         // and since single quote can't be represented in single quoted text
-                        // each occurence of it in arg should be enclosed by double quotes
-                        arg = strdup(argv[i + prog_index]);
-                        arg_ptr = arg;
-                        for (token = strsep(&arg_ptr, "\'"); token != NULL; token = strsep(&arg_ptr, "\'")) {
-                                if (token[0] == '\0') {
-                                        sprintf(ptr1, "\"\'\"");
-                                } else {
-                                        sprintf(ptr1, "\'%s\'\"\'\"", token);
+                        // each occurence of it should be enclosed by double quotes
+                        in_quotes = false;
+                        for (j = 0; j < strlen(argv[i + prog_index]); j++) {
+                                // single quote
+                                if (argv[i + prog_index][j] == '\'') {
+                                        if (in_quotes) {
+                                                // close quotes
+                                                ptr1[0] = '\'';
+                                                ptr1++;
+                                        }
+                                        // previous char was single quote too
+                                        if (j > 0 && argv[i + prog_index][j-1] == '\'') {
+                                                ptr1--;
+                                                sprintf(ptr1, "\'\"");
+                                        } 
+                                        // this first in series
+                                        else
+                                        {
+                                                sprintf(ptr1, "\"\'\"");
+                                        }
+                                        ptr1 += strlen(ptr1);
+                                        in_quotes = false;
                                 }
+                                // anything other
+                                else
+                                {
+                                        if (!in_quotes) {
+                                                // open quotes
+                                                ptr1[0] = '\'';
+                                                ptr1++;
+                                        }
+                                        ptr1[0] = argv[i + prog_index][j];
+                                        ptr1++;
+                                        in_quotes = true;
+                                }
+                        }
+                        // close quotes
+                        if (in_quotes) {
+                                ptr1[0] = '\'';
+                                ptr1++;
+                        }
+                        // handle empty argument case
+                        if (strlen(argv[i + prog_index]) == 0) {
+                                sprintf(ptr1, "\'\'");
                                 ptr1 += strlen(ptr1);
                         }
-                        free(arg);
-                        ptr1 -= 3;
-
+                        // add space
                         sprintf(ptr1, " ");
                         ptr1 += strlen(ptr1);
 
                         sprintf(ptr2, "%s ", argv[i + prog_index]);
                         ptr2 += strlen(ptr2);
                 }
-                ptr1[0]='\0'; // just to be sure
-                if (arg_debug)
-                        printf("Actual command length %zd\n", strlen(cfg.command_line));
+
+                assert(len == strlen(cfg.command_line));
         }
         
         assert(cfg.command_name);