diff --git a/chat/chat.c b/chat/chat.c
index 336c0f499..a8becafa4 100644
--- a/chat/chat.c
+++ b/chat/chat.c
@@ -178,12 +178,14 @@ struct termios saved_tty_parameters;
 
 char *abort_string[MAX_ABORTS], *fail_reason = (char *)0,
 	fail_buffer[50];
-int n_aborts = 0, abort_next = 0, timeout_next = 0, echo_next = 0;
+size_t n_aborts = 0;
+int abort_next = 0, timeout_next = 0, echo_next = 0;
 int clear_abort_next = 0;
 
 char *report_string[MAX_REPORTS] ;
 char  report_buffer[4096] ;
-int n_reports = 0, report_next = 0, report_gathering = 0 ; 
+size_t n_reports = 0;
+int report_next = 0, report_gathering = 0;
 int clear_report_next = 0;
 
 int say_next = 0, hup_next = 0;
@@ -606,15 +608,15 @@ void terminate(int status)
  * Allow the last of the report string to be gathered before we terminate.
  */
     if (report_gathering) {
-	int c, rep_len;
+	int c;
 
-	rep_len = strlen(report_buffer);
+	size_t rep_len = strlen(report_buffer);
 	while (rep_len + 1 < sizeof(report_buffer)) {
 	    alarm(1);
 	    c = get_char();
 	    alarm(0);
 	    if (c < 0 || iscntrl(c))
-		break;
+	    break;
 	    report_buffer[rep_len] = c;
 	    ++rep_len;
 	}
@@ -1342,7 +1344,8 @@ int echo_stderr(int n)
 int get_string(register char *string)
 {
     char temp[STR_LEN];
-    int c, printed = 0, len, minlen;
+    int c, printed = 0;
+    size_t len, minlen;
     register char *s = temp, *end = s + STR_LEN;
     char *s1, *logged = temp;
 
@@ -1372,11 +1375,11 @@ int get_string(register char *string)
     alarmed = 0;
 
     while ( ! alarmed && (c = get_char()) >= 0) {
-	int n, abort_len, report_len;
+	size_t n, abort_len, report_len;
 
 	if (echo) {
 	    if (echo_stderr(c) != 0) {
-		fatal(2, "Could not write to stderr, %m");
+	    fatal(2, "Could not write to stderr, %m");
 	    }
 	}
 	if (verbose && c == '\n') {
@@ -1421,8 +1424,8 @@ int get_string(register char *string)
 	}
 	else {
 	    if (!iscntrl (c)) {
-		int rep_len = strlen (report_buffer);
-		if ((rep_len + 1) < sizeof(report_buffer)) {
+		size_t rep_len = strlen (report_buffer);
+		if (rep_len < sizeof(report_buffer) - 1) {
 		    report_buffer[rep_len]     = c;
 		    report_buffer[rep_len + 1] = '\0';
 		}
diff --git a/pppd/auth.c b/pppd/auth.c
index ecd30badc..035f67f30 100644
--- a/pppd/auth.c
+++ b/pppd/auth.c
@@ -501,7 +501,7 @@ static int
 setupapfile(char **argv)
 {
     FILE *ufile;
-    int l;
+    size_t l;
     uid_t euid;
     char u[MAXNAMELEN], p[MAXSECRETLEN];
     char *fname;
@@ -593,7 +593,7 @@ static int
 set_noauth_addr(char **argv)
 {
     char *addr = *argv;
-    int l = strlen(addr) + 1;
+    size_t l = strlen(addr) + 1;
     struct wordlist *wp;
 
     wp = (struct wordlist *) malloc(sizeof(struct wordlist) + l);
@@ -614,7 +614,7 @@ static int
 set_permitted_number(char **argv)
 {
     char *number = *argv;
-    int l = strlen(number) + 1;
+    size_t l = strlen(number) + 1;
     struct wordlist *wp;
 
     wp = (struct wordlist *) malloc(sizeof(struct wordlist) + l);
@@ -1831,7 +1831,8 @@ get_secret(int unit, char *client, char *server,
 	   char *secret, int *secret_len, int am_server)
 {
     FILE *f;
-    int ret, len;
+    int ret;
+    size_t len;
     char *filename;
     struct wordlist *addrs, *opts;
     char secbuf[MAXWORDLEN];
@@ -2154,22 +2155,24 @@ int
 auth_number(void)
 {
     struct wordlist *wp = permitted_numbers;
-    int l;
+    size_t l;
 
     /* Allow all if no authorization list. */
     if (!wp)
 	return 1;
 
     /* Allow if we have a match in the authorization list. */
-    while (wp) {
+    do {
 	/* trailing '*' wildcard */
 	l = strlen(wp->word);
+	if (l == 0)
+	    return 1;
 	if ((wp->word)[l - 1] == '*')
 	    l--;
 	if (!strncasecmp(wp->word, remote_number, l))
 	    return 1;
 	wp = wp->next;
-    }
+    } while (wp);
 
     return 0;
 }
diff --git a/pppd/chap.c b/pppd/chap.c
index d0009e8ba..7b99fd3bf 100644
--- a/pppd/chap.c
+++ b/pppd/chap.c
@@ -310,7 +310,7 @@ chap_client_timeout(void *arg)
 static void
 chap_generate_challenge(struct chap_server_state *ss)
 {
-	int clen = 1, nlen, len;
+	size_t clen = 1, nlen, len;
 	unsigned char *p;
 
 	p = ss->challenge;
@@ -327,8 +327,8 @@ chap_generate_challenge(struct chap_server_state *ss)
 	p = ss->challenge + PPP_HDRLEN;
 	p[0] = CHAP_CHALLENGE;
 	p[1] = ++ss->id;
-	p[2] = len >> 8;
-	p[3] = len;
+	p[2] = (len >> 8) & 0xFF;
+	p[3] = len & 0xFF;
 }
 
 /*
diff --git a/pppd/main.c b/pppd/main.c
index 8310c9871..a6a712790 100644
--- a/pppd/main.c
+++ b/pppd/main.c
@@ -1863,13 +1863,13 @@ update_script_environment(void)
     struct userenv *uep;
 
     for (uep = userenv_list; uep != NULL; uep = uep->ue_next) {
-	int i;
-	char *p, *newstring;
-	int nlen = strlen(uep->ue_name);
+    size_t i;
+    char *p, *newstring;
+    size_t nlen = strlen(uep->ue_name);
 
-	for (i = 0; (p = script_env[i]) != NULL; i++) {
-	    if (strncmp(p, uep->ue_name, nlen) == 0 && p[nlen] == '=')
-		break;
+    for (i = 0; (p = script_env[i]) != NULL; i++) {
+    if (strncmp(p, uep->ue_name, nlen) == 0 && p[nlen] == '=')
+        break;
 	}
 	if (uep->ue_isset) {
 	    nlen += strlen(uep->ue_value) + 2;
@@ -2164,7 +2164,7 @@ ppp_script_setenv(char *var, char *value, int iskey)
 {
     size_t varl = strlen(var);
     size_t vl = varl + strlen(value) + 2;
-    int i;
+    size_t i;
     char *p, *newstring;
 
     newstring = (char *) malloc(vl+1);
@@ -2223,14 +2223,14 @@ ppp_script_setenv(char *var, char *value, int iskey)
 void
 ppp_script_unsetenv(char *var)
 {
-    int vl = strlen(var);
+    size_t vl = strlen(var);
     int i;
     char *p;
 
     if (script_env == 0)
-	return;
+    return;
     for (i = 0; (p = script_env[i]) != 0; ++i) {
-	if (strncmp(p, var, vl) == 0 && p[vl] == '=') {
+    if (strncmp(p, var, vl) == 0 && p[vl] == '=') {
 #ifdef PPP_WITH_TDB
 	    if (p[-1] && pppdb != NULL)
 		delete_db_key(p);
diff --git a/pppd/multilink.c b/pppd/multilink.c
index b44d2bbe5..92675ad4e 100644
--- a/pppd/multilink.c
+++ b/pppd/multilink.c
@@ -348,7 +348,7 @@ static void remove_bundle_link(void)
 	TDB_DATA key, rec;
 	char entry[32];
 	char *p, *q;
-	int l;
+	size_t l;
 
 	key.dptr = blinks_id;
 	key.dsize = strlen(blinks_id);
@@ -540,7 +540,7 @@ str_to_epdisc(struct epdisc *ep, char *str)
 	char *p, *endp;
 
 	for (i = EPD_NULL; i <= EPD_PHONENUM; ++i) {
-		int sl = strlen(endp_class_names[i]);
+		size_t sl = strlen(endp_class_names[i]);
 		if (strncasecmp(str, endp_class_names[i], sl) == 0) {
 			str += sl;
 			break;
diff --git a/pppd/options.c b/pppd/options.c
index 227e615c9..f3e062886 100644
--- a/pppd/options.c
+++ b/pppd/options.c
@@ -1614,7 +1614,8 @@ static int
 callfile(char **argv)
 {
     char *fname, *arg, *p;
-    int l, ok;
+    size_t l;
+    int ok;
 
     arg = *argv;
     ok = 1;
@@ -1769,7 +1770,7 @@ loadplugin(char **argv)
 
     if (strchr(arg, '/') == 0) {
 	const char *base = PPP_PATH_PLUGIN;
-	int l = strlen(base) + strlen(arg) + 2;
+	size_t l = strlen(base) + strlen(arg) + 2;
 	path = malloc(l);
 	if (path == 0)
 	    novm("plugin file path");
@@ -1832,9 +1833,8 @@ user_setenv(char **argv)
 	return 0;
     }
     for (uep = userenv_list; uep != NULL; uep = uep->ue_next) {
-	int nlen = strlen(uep->ue_name);
-	if (nlen == (eqp - arg) &&
-	    strncmp(arg, uep->ue_name, nlen) == 0)
+    size_t nlen = strlen(uep->ue_name);
+    if (nlen == (eqp - arg) && strncmp(arg, uep->ue_name, nlen) == 0)
 	    break;
     }
     /* Ignore attempts by unprivileged users to override privileged sources */
diff --git a/pppd/plugins/pppoatm/atm.h b/pppd/plugins/pppoatm/atm.h
index 3b15dda97..5f869fd1d 100644
--- a/pppd/plugins/pppoatm/atm.h
+++ b/pppd/plugins/pppoatm/atm.h
@@ -103,6 +103,6 @@ int sap2text(char *buffer,int length,const struct atm_sap *sap,int flags);
 int sap_equal(const struct atm_sap *a,const struct atm_sap *b,int flags,...);
 
 int __t2q_get_rate(const char **text,int up);
-int __atmlib_fetch(const char **pos,...); /* internal use only */
+size_t __atmlib_fetch(const char **pos,...); /* internal use only */
 
 #endif
diff --git a/pppd/plugins/pppoatm/misc.c b/pppd/plugins/pppoatm/misc.c
index 5e6975f3a..46f65bc14 100644
--- a/pppd/plugins/pppoatm/misc.c
+++ b/pppd/plugins/pppoatm/misc.c
@@ -17,27 +17,27 @@
 #include <atmsap.h>
 
 
-int __atmlib_fetch(const char **pos,...)
+size_t __atmlib_fetch(const char **pos,...)
 {
     const char *value;
-    int ref_len,best_len,len;
-    int i,best;
+    size_t ref_len,best_len,len;
+    size_t i,best;
     va_list ap;
 
     va_start(ap,pos);
     ref_len = strlen(*pos);
     best_len = 0;
-    best = -1;
+    best = 0;
     for (i = 0; (value = va_arg(ap,const char *)); i++) {
-	len = strlen(value);
-	if (*value != '!' && len <= ref_len && len > best_len &&
-	  !strncasecmp(*pos,value,len)) {
-	    best = i;
-	    best_len = len;
-	}
+    len = strlen(value);
+    if (*value != '!' && len <= ref_len && len > best_len &&
+    !strncasecmp(*pos,value,len)) {
+    best = i;
+    best_len = len;
+    }
     }
     va_end(ap);
-    if (best > -1) (*pos) += best_len;
+    (*pos) += best_len;
     return best;
 }
 
diff --git a/pppd/plugins/pppoatm/text2qos.c b/pppd/plugins/pppoatm/text2qos.c
index 060407a02..85bdca5c8 100644
--- a/pppd/plugins/pppoatm/text2qos.c
+++ b/pppd/plugins/pppoatm/text2qos.c
@@ -129,10 +129,10 @@ int text2qos(const char *text,struct atm_qos *qos,int flags)
     traffic_class = ATM_NONE;
     aal = ATM_NO_AAL;
     do {
-	static const unsigned char aal_number[] = { ATM_AAL0, ATM_AAL5 };
-	int item;
+    static const unsigned char aal_number[] = { ATM_AAL0, ATM_AAL5 };
+    size_t item;
 
-	item = fetch(&text,"!none","ubr","cbr","vbr","abr","aal0","aal5",NULL);
+    item = fetch(&text,"!none","ubr","cbr","vbr","abr","aal0","aal5",NULL);
 	switch (item) {
 	    case 1:
 	    case 2:
diff --git a/pppd/plugins/pppoe/pppoe.h b/pppd/plugins/pppoe/pppoe.h
index 9360eddf8..8c8a1d38b 100644
--- a/pppd/plugins/pppoe/pppoe.h
+++ b/pppd/plugins/pppoe/pppoe.h
@@ -284,7 +284,7 @@ void pppoe_log_packet(const char *prefix, PPPoEPacket *packet);
 
 static inline int parseHostUniq(const char *uniq, PPPoETag *tag)
 {
-    unsigned i, len = strlen(uniq);
+    size_t i, len = strlen(uniq);
 
 #define hex(x) \
     (((x) <= '9') ? ((x) - '0') : \
diff --git a/pppd/tls.c b/pppd/tls.c
index 8328e207d..d63c20e42 100644
--- a/pppd/tls.c
+++ b/pppd/tls.c
@@ -186,12 +186,13 @@ static int tls_verify_callback(int ok, X509_STORE_CTX *ctx)
 
         /* Match the suffix of common name */
         if (!strcmp(TLS_VERIFY_SUFFIX, tls_verify_method)) {
-            int len = strlen(ptr1);
-            int off = strlen(cn_str) - len;
+            size_t len1, len2;
             ptr2 = cn_str;
-            if (off > 0) {
-                ptr2 = cn_str + off;
-            }
+
+            len1 = strlen(ptr1);
+            len2 = strlen(ptr2);
+            if (len2 > len1)
+                ptr2 += len2 - len1;
         }
 
         if (strcmp(ptr1, ptr2)) {
diff --git a/pppd/utils.c b/pppd/utils.c
index bf9923ce3..5504bb3b0 100644
--- a/pppd/utils.c
+++ b/pppd/utils.c
@@ -615,12 +615,10 @@ log_write(int level, char *buf)
 {
     syslog(level, "%s", buf);
     if (log_to_fd >= 0 && (level != LOG_DEBUG || debug)) {
-	int n = strlen(buf);
-
-	if (n > 0 && buf[n-1] == '\n')
+    size_t n = strlen(buf);
+    if (n > 0 && buf[n - 1] == '\n')
 	    --n;
-	if (write(log_to_fd, buf, n) != n
-	    || write(log_to_fd, "\n", 1) != 1)
+    if (write(log_to_fd, buf, n) != n || write(log_to_fd, "\n", 1) != 1)
 	    log_to_fd = -1;
     }
 }