Add more error checking in auth

[blerg.git] / common / auth.c

diff --git a/common/auth.c b/common/auth.c
index a4a40cd..9053a26 100644 (file)
--- a/common/auth.c
+++ b/common/auth.c
@@ -69,7 +69,7 @@ int auth_get_password_version(const char *username) {
        char filename[FILENAME_MAX];
        int fd;
        char str[4];
-       int len;
+       int len = 0;
 
        snprintf(filename, FILENAME_MAX, "%s/%s/password_version", blergconf.data_path, username);
        if (access(filename, F_OK) != 0) {
@@ -77,9 +77,18 @@ int auth_get_password_version(const char *username) {
        }
 
        fd = open(filename, O_RDONLY);
+       if (fd == -1)
+               return -1;
        len = read(fd, str, 4);
        close(fd);
+
+       if (len < -1) {
+               perror("auth_get_password_version");
+               return -1;
+       }
+
        str[len] = 0;
+
        /* strtol returns zero if there isn't a number */
        return strtol(str, NULL, 10);
 }
@@ -87,25 +96,38 @@ int auth_get_password_version(const char *username) {
 int auth_get_password(const char *username, char *password) {
        char filename[FILENAME_MAX];
        int fd;
+       int read_size;
        int len = 0;
 
        if (!valid_name(username))
                return 0;
 
-       snprintf(filename, FILENAME_MAX, "%s/%s/password", blergconf.data_path, username);
-       fd = open(filename, O_RDONLY);
-       if (fd == -1)
-               return 0;
        switch(auth_get_password_version(username)) {
        case 0:
-               len = read(fd, password, MD5_DIGEST_SIZE);
+               read_size = MD5_DIGEST_SIZE;
                break;
        case 1:
-               len = read(fd, password, SCRYPT_OUTPUT_SIZE);
+               read_size = SCRYPT_OUTPUT_SIZE;
                break;
+       default:
+               return 0;
        }
+
+       snprintf(filename, FILENAME_MAX, "%s/%s/password", blergconf.data_path, username);
+       fd = open(filename, O_RDONLY);
+       if (fd == -1)
+               return 0;
+       len = read(fd, password, read_size);
        close(fd);
 
+       if (len < 0) {
+               perror("auth_get_password");
+               return 0;
+       } else if (len < read_size) {
+               fprintf(stderr, "Short read getting password\n");
+               return 0;
+       }
+
        password[len] = 0;
 
        return 1;
@@ -113,7 +135,8 @@ int auth_get_password(const char *username, char *password) {
 
 int auth_get_salt(const char *username, uint8_t *salt) {
        char filename[FILENAME_MAX];
-       int fd, len;
+       int fd;
+       int len = 0;
 
        if (!valid_name(username))
                return 0;
@@ -125,6 +148,14 @@ int auth_get_salt(const char *username, uint8_t *salt) {
        len = read(fd, salt, SCRYPT_SALT_SIZE);
        close(fd);
 
+       if (len < 0) {
+               perror("auth_get_salt");
+               return 0;
+       } else if (len < SCRYPT_SALT_SIZE) {
+               fprintf(stderr, "Short read getting salt\n");
+               return 0;
+       }
+
        return 1;
 }