From 1c7e19e9a43f65db1a7f672e06121a06342778b5 Mon Sep 17 00:00:00 2001
From: Samuel Fadel <samuel@nihil.ws>
Date: Wed, 12 Apr 2023 08:53:34 +0200
Subject: Rename/retype some args and variables, better intializations.

* lpass.c: Better variable names; fixed type of passlen in
calc_entropy; smaller variable names where it makes sense; initialize
more defensively with cheaper initializations.
---
 lpass.c | 41 +++++++++++++++++++++++------------------
 1 file changed, 23 insertions(+), 18 deletions(-)

(limited to 'lpass.c')

diff --git a/lpass.c b/lpass.c
index 6006a82..b7a752d 100644
--- a/lpass.c
+++ b/lpass.c
@@ -49,7 +49,7 @@ calc_entropy(const char *site,
              const char *login,
              uint64_t counter,
              const char *master_pass,
-             int passlen)
+             size_t passlen)
 {
     char salt[MAX_BUF + 1];
     int saltlen = snprintf(salt, MAX_BUF, "%s%s%lx", site, login, counter);
@@ -73,7 +73,7 @@ calc_entropy(const char *site,
 }
 
 static int
-consume_entropy(char *generated_pass, BIGNUM *entropy, const char *charset, size_t maxlen)
+consume_entropy(char *pass, BIGNUM *entropy, const char *charset, size_t maxlen)
 {
     int retval = 1;
     BN_CTX *ctx = BN_CTX_new();
@@ -89,7 +89,7 @@ consume_entropy(char *generated_pass, BIGNUM *entropy, const char *charset, size
         retval = 0;
         goto consume_entropy_cleanup;
     }
-    for (size_t passlen = strlen(generated_pass);
+    for (size_t passlen = strlen(pass);
          passlen < maxlen;
          passlen++) {
         BN_div(entropy, bn_remainder, entropy, bn_charsetlen, ctx);
@@ -105,7 +105,7 @@ consume_entropy(char *generated_pass, BIGNUM *entropy, const char *charset, size
             retval = 0;
             goto consume_entropy_cleanup;
         }
-        generated_pass[passlen] = charset[remainder];
+        pass[passlen] = charset[remainder];
     }
 consume_entropy_cleanup:
     BN_free(bn_remainder);
@@ -115,11 +115,11 @@ consume_entropy_cleanup:
 }
 
 static int
-insert_str_pseudo_randomly(char *generated_pass, BIGNUM *entropy, const char *s)
+insert_str_pseudo_randomly(char *pass, BIGNUM *entropy, const char *s)
 {
     int retval = 1;
     char buf[MAX_BUF + 1];
-    uint64_t passlen = (uint64_t) strlen(generated_pass);
+    uint64_t passlen = (uint64_t) strlen(pass);
     BN_CTX *ctx = BN_CTX_new();
     BIGNUM *bn_passlen = BN_new();
     BIGNUM *bn_remainder = BN_new();
@@ -147,16 +147,17 @@ insert_str_pseudo_randomly(char *generated_pass, BIGNUM *entropy, const char *s)
         }
 
         /*
-         * Idea here is to add the char `c` at position `remainder` in `generated_pass`.
-         * 1. Copy the part that would need to be shifted into `buf`.
+         * Idea here is to add the char `c` at position `remainder` in
+         * `pass`. 1. Copy the part that would need to be shifted into
+         * `buf`.
          */
         memset(buf, 0, sizeof(buf));
-        strncpy(buf, &generated_pass[remainder], passlen - remainder);
+        strncpy(buf, &pass[remainder], passlen - remainder);
         /*
-         * 2. Add new character, then copy `buf` back into `generated_pass`.
+         * 2. Add new character, then copy `buf` back into `pass`.
          */
-        generated_pass[remainder] = c;
-        strncpy(&generated_pass[remainder + 1], buf, passlen - remainder);
+        pass[remainder] = c;
+        strncpy(&pass[remainder + 1], buf, passlen - remainder);
         passlen++;
     }
 insert_str_pseudo_randomly_cleanup:
@@ -201,6 +202,7 @@ render_pass(BIGNUM *entropy, uint8_t allowed_charsets, char *out, size_t length)
 {
     char charset[MAX_BUF + 1];
     size_t num_charsets = build_charset(charset, allowed_charsets);
+    out[0] = '\0';
     if (consume_entropy(out, entropy, charset, length - num_charsets) == 0) {
         return 0;
     }
@@ -211,21 +213,25 @@ render_pass(BIGNUM *entropy, uint8_t allowed_charsets, char *out, size_t length)
      */
     char str_to_add[num_charsets + 1];
     memset(str_to_add, 0, sizeof(str_to_add));
-    size_t c = 0;
+    size_t count = 0;
     if (charsets_has_set(allowed_charsets, CHARSET_LOWER)
-        && consume_entropy(&str_to_add[c++], entropy, CHAR_SUBSET_LOWER, 1) == 0) {
+        && consume_entropy(&str_to_add[count], entropy, CHAR_SUBSET_LOWER, 1) == 0) {
+        count++;
         return 0;
     }
     if (charsets_has_set(allowed_charsets, CHARSET_UPPER)
-        && consume_entropy(&str_to_add[c++], entropy, CHAR_SUBSET_UPPER, 1) == 0) {
+        && consume_entropy(&str_to_add[count], entropy, CHAR_SUBSET_UPPER, 1) == 0) {
+        count++;
         return 0;
     }
     if (charsets_has_set(allowed_charsets, CHARSET_DIGITS)
-        && consume_entropy(&str_to_add[c++], entropy, CHAR_SUBSET_DIGITS, 1) == 0) {
+        && consume_entropy(&str_to_add[count], entropy, CHAR_SUBSET_DIGITS, 1) == 0) {
+        count++;
         return 0;
     }
     if (charsets_has_set(allowed_charsets, CHARSET_SYMBOLS)
-        && consume_entropy(&str_to_add[c++], entropy, CHAR_SUBSET_SYMBOLS, 1) == 0) {
+        && consume_entropy(&str_to_add[count], entropy, CHAR_SUBSET_SYMBOLS, 1) == 0) {
+        count++;
         return 0;
     }
     return insert_str_pseudo_randomly(out, entropy, str_to_add);
@@ -338,7 +344,6 @@ main(int argc, char *argv[])
     }
 
     char generated_pass[length + 1];
-    memset(generated_pass, 0, sizeof(generated_pass));
     if (render_pass(entropy, allowed_charsets, generated_pass, length) == 0) {
         BN_free(entropy);
         err("Failed to generate password");
-- 
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