1feeda422e
Daniel Stenberg
2025-10-12
Subject
examples/synctime: fix null termination assumptions
Binary
No binary (build failed)
Architecture & Compiler Flags
—
Build Log
(log yok)
Commit Diff GitHub →
docs/examples/synctime.c+13 -9
| @@ -117,7 +117,6 @@ static SYSTEMTIME LOCALTime; | |
| #define HTTP_COMMAND_HEAD 0 | |
| #define HTTP_COMMAND_GET 1 | |
| - | |
| static size_t SyncTime_CURL_WriteOutput(void *ptr, size_t size, size_t nmemb, | |
| void *stream) | |
| { | |
| @@ -125,6 +124,7 @@ static size_t SyncTime_CURL_WriteOutput(void *ptr, size_t size, size_t nmemb, | |
| return nmemb * size; | |
| } | |
| + | /* Remember: do not assume headers are passed on null terminated! */ |
| static size_t SyncTime_CURL_WriteHeader(void *ptr, size_t size, size_t nmemb, | |
| void *stream) | |
| { | |
| @@ -135,18 +135,22 @@ static size_t SyncTime_CURL_WriteHeader(void *ptr, size_t size, size_t nmemb, | |
| if(ShowAllHeader == 1) | |
| fprintf(stderr, "%.*s", (int)nmemb, (char *)ptr); | |
| - | if(strncmp((char *)ptr, "Date:", 5) == 0) { |
| + | if((nmemb >= 5) && !strncmp((char *)ptr, "Date:", 5)) { |
| if(ShowAllHeader == 0) | |
| fprintf(stderr, "HTTP Server. %.*s", (int)nmemb, (char *)ptr); | |
| if(AutoSyncTime == 1) { | |
| - | int RetVal; |
| + | int RetVal = 0; |
| + | char *field = ptr; |
| *TmpStr1 = 0; | |
| *TmpStr2 = 0; | |
| - | RetVal = sscanf((char *)ptr, "Date: %25s %hu %25s %hu %hu:%hu:%hu", |
| - | TmpStr1, &SYSTime.wDay, TmpStr2, &SYSTime.wYear, |
| - | &SYSTime.wHour, &SYSTime.wMinute, |
| - | &SYSTime.wSecond); |
| + | if(nmemb && (field[nmemb] == '\n')) { |
| + | field[nmemb] = 0; /* null terminated */ |
| + | RetVal = sscanf(field, "Date: %25s %hu %25s %hu %hu:%hu:%hu", |
| + | TmpStr1, &SYSTime.wDay, TmpStr2, &SYSTime.wYear, |
| + | &SYSTime.wHour, &SYSTime.wMinute, |
| + | &SYSTime.wSecond); |
| + | } |
| if(RetVal == 7) { | |
| int i; | |
| @@ -165,7 +169,7 @@ static size_t SyncTime_CURL_WriteHeader(void *ptr, size_t size, size_t nmemb, | |
| } | |
| } | |
| - | if(strncmp((char *)ptr, "X-Cache: HIT", 12) == 0) { |
| + | if((nmemb >= 12) && !strncmp((char *)ptr, "X-Cache: HIT", 12)) { |
| fprintf(stderr, "ERROR: HTTP Server data is cached." | |
| " Server Date is no longer valid.\n"); | |
| AutoSyncTime = 0; | |
| @@ -251,7 +255,7 @@ int main(int argc, char *argv[]) | |
| conf_init(conf); | |
| if(argc > 1) { | |
| - | int OptionIndex = 0; |
| + | int OptionIndex = 1; |
| while(OptionIndex < argc) { | |
| if(strncmp(argv[OptionIndex], "--server=", 9) == 0) | |
| snprintf(conf->timeserver, MAX_STRING, "%s", &argv[OptionIndex][9]); | |