diff options
Diffstat (limited to 'cqrlogo.c')
| -rw-r--r-- | cqrlogo.c | 96 |
1 files changed, 58 insertions, 38 deletions
@@ -18,7 +18,7 @@ #include "config.h" #define URLPATTERN "^[hH][tT][tT][pP][sS]\\?://%s/" -#define TEXTSTOLEN "This QR Code has been stolen from %s!" +#define TEXTSTOLEN "This QR Code has been stolen from http%s://%s/!" /* a bitmap */ struct bitmap_t { @@ -28,7 +28,7 @@ struct bitmap_t { }; /*** generate_png ***/ -int generate_png (struct bitmap_t *bitmap, char *http_referer) { +int generate_png (struct bitmap_t *bitmap, const char *uri) { png_structp png_ptr = NULL; png_infop info_ptr = NULL; png_byte ** row_pointers = NULL; @@ -66,7 +66,7 @@ int generate_png (struct bitmap_t *bitmap, char *http_referer) { text[2].compression = PNG_TEXT_COMPRESSION_zTXt; text[2].key = "referer"; - text[2].text = http_referer; + text[2].text = (char*)uri; png_set_text(png_ptr, info_ptr, text, 3); free(version); @@ -120,7 +120,7 @@ void bitmap_free(struct bitmap_t * bitmap) { } /*** encode_qrcode ***/ -struct bitmap_t * encode_qrcode (char *text, unsigned int scale, unsigned int border, unsigned int level) { +struct bitmap_t * encode_qrcode (const char *text, unsigned int scale, unsigned int border, unsigned int level) { QRcode *qrcode; struct bitmap_t *bitmap, *scaled; int i, j, k, l; @@ -191,17 +191,15 @@ int get_value(const char *query_string, const char *pattern, unsigned int *value /*** main ***/ int main(int argc, char **argv) { - char * http_referer, * server_name, * pattern; + const char * http_referer, * server_name, * query_string, * uri; + char * uri_server_name = NULL, * uri_png = NULL, * pattern = NULL, * stolen = NULL; regex_t preg; regmatch_t pmatch[1]; - int referer = 0; + unsigned int https = 0; struct bitmap_t * bitmap; unsigned int scale = QRCODE_SCALE, border = QRCODE_BORDER, level = QRCODE_LEVEL; - /* get query string for later use */ - char * query_string = getenv("QUERY_STRING"); - /* check if we have environment variables from CGI */ if ((server_name = getenv("SERVER_NAME")) == NULL) { fprintf(stderr, "This is a CGI executable. Running without a web service is not supported.\n" @@ -209,9 +207,31 @@ int main(int argc, char **argv) { "to send referer information.\n"); return EXIT_FAILURE; } - if ((http_referer = getenv("HTTP_REFERER")) == NULL) { - http_referer = server_name; - } else { + + /* check if we have https connection */ + if (getenv("HTTPS") != NULL) + https = 1; + + /* assemble uri for use when referer is missing or fails */ + uri_server_name = malloc(10 + strlen(server_name)); + sprintf(uri_server_name, "http%s://%s/", https ? "s" : "", server_name); + + /* get query string and read settings */ + if ((query_string = getenv("QUERY_STRING")) != NULL) { + /* do we have a special scale? */ + get_value(query_string, "scale", &scale, QRCODE_SCALE, 1, QRCODE_MAX_SCALE); + + /* width of the border? */ + get_value(query_string, "border", &border, QRCODE_BORDER, 0, QRCODE_MAX_BORDER); + + /* error correction level? */ + get_value(query_string, "level", &level, QRCODE_LEVEL, 0, QR_ECLEVEL_H); + } + + /* get http referer */ + if ((http_referer = getenv("HTTP_REFERER")) != NULL) { + uri = http_referer; + /* prepare pattern matching */ pattern = malloc(sizeof(URLPATTERN) + strlen(server_name)); sprintf(pattern, URLPATTERN, server_name); @@ -221,28 +241,24 @@ int main(int argc, char **argv) { } /* check if the QR-Code is for the correct server */ - if ((referer = regexec(&preg, http_referer, 1, pmatch, 0)) != 0) { - http_referer = malloc(sizeof(TEXTSTOLEN) + strlen(server_name)); - sprintf(http_referer, TEXTSTOLEN, server_name); + if (regexec(&preg, http_referer, 1, pmatch, 0) != 0) { + stolen = malloc(sizeof(TEXTSTOLEN) + strlen(server_name)); + sprintf(stolen, TEXTSTOLEN, https ? "s" : "", server_name); + uri = stolen; } regfree(&preg); free(pattern); + } else { + /* use uri assembled from server name */ + uri = uri_server_name; } - if (query_string ) { - /* do we have a special scale? */ - get_value(query_string, "scale", &scale, QRCODE_SCALE, 1, QRCODE_MAX_SCALE); - - /* width of the border? */ - get_value(query_string, "border", &border, QRCODE_BORDER, 0, QRCODE_MAX_BORDER); - - /* error correction level? */ - get_value(query_string, "level", &level, QRCODE_LEVEL, 0, QR_ECLEVEL_H); - } - - if ((bitmap = encode_qrcode(http_referer, scale, border, level)) == NULL) { - if ((bitmap = encode_qrcode(server_name, scale, border, level)) == NULL) { + /* encode the QR-Code */ + if ((bitmap = encode_qrcode(uri, scale, border, level)) == NULL) { + /* uri too long? retry with uri from server name */ + uri = uri_server_name; + if ((bitmap = encode_qrcode(uri, scale, border, level)) == NULL) { fprintf(stderr, "Could not generate QR-Code.\n"); return EXIT_FAILURE; } @@ -251,23 +267,27 @@ int main(int argc, char **argv) { /* print HTTP header */ printf("Content-Type: image/png\n\n"); - /* cut http_referer, text in png file may have a max length of 79 chars */ - if (strlen(http_referer) > 79) { - if (!referer) { - http_referer = strdup(http_referer); - referer++; - } - sprintf(http_referer + 76, "..."); + /* cut uri, text in png file may have a max length of 79 chars */ + if (strlen(uri) > 79) { + uri_png = strdup(uri); + sprintf(uri_png + 76, "..."); + uri = uri_png; } /* print PNG data */ - if (generate_png(bitmap, http_referer)) { + if (generate_png(bitmap, uri)) { fprintf(stderr, "Failed to generate PNG.\n"); return EXIT_FAILURE; } - if (referer) - free(http_referer); + + /* free memory we no longer need */ + if (uri_server_name) + free(uri_server_name); + if (stolen) + free(stolen); + if (uri_png) + free(uri_png); free(bitmap); return EXIT_SUCCESS; |