From 036049a13f4013ba9ce2fc1c9c2d0012f5ebc6d4 Mon Sep 17 00:00:00 2001
From: Martin Michelsen <fuzziqersoftware+g@gmail.com>
Date: Wed, 14 Jun 2023 22:41:01 -0700
Subject: [PATCH] add encrypt-trivial-data

---
 README.md   |  2 +-
 src/Main.cc | 20 ++++++++++++++------
 2 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/README.md b/README.md
index e7f90059..d368616b 100644
--- a/README.md
+++ b/README.md
@@ -387,7 +387,7 @@ newserv has many CLI options, which can be used to access functionality other th
 * Compress or decompress data in the PRS and BC0 formats (`compress-prs`, `compress-bc0`, `decompress-prs`, `decompress-bc0`)
 * Compute the decompressed size of compressed PRS data without decompressing it (`prs-size`)
 * Encrypt or decrypt data using any PSO version's network encryption scheme (`encrypt-data`, `decrypt-data`)
-* Encrypt or decrypt data using Episode 3's trivial scheme (`decrypt-trivial-data`)
+* Encrypt or decrypt data using Episode 3's trivial scheme (`encrypt-trivial-data`, `decrypt-trivial-data`)
 * Encrypt or decrypt PSO GC save data (.gci files) (`encrypt-gci-save`, `decrypt-gci-save`)
 * Find the likely round1 or round2 seed for a corrupt save file (`salvage-gci`)
 * Run a brute-force search for a decryption seed (`find-decryption-seed`)
diff --git a/src/Main.cc b/src/Main.cc
index 93a498d0..c822d416 100644
--- a/src/Main.cc
+++ b/src/Main.cc
@@ -118,11 +118,12 @@ The actions are:\n\
     For non-BB ciphers, the --big-endian option applies the cipher masks as\n\
     big-endian instead of little-endian, which is necessary for some GameCube\n\
     file formats.\n\
-  decrypt-trivial-data [--seed=SEED] [INPUT-FILENAME [OUTPUT-FILENAME]]\n\
-    Decrypt (or encrypt; the algorithm is symmetric) data using the Episode 3\n\
-    trivial algorithm. If SEED is given, it should be specified as one hex\n\
-    byte. If SEED is not given, newserv will try all possible seeds and return\n\
-    the one that results in the greatest number of zero bytes in the output.\n\
+  encrypt-trivial-data [--seed=BASIS] [INPUT-FILENAME [OUTPUT-FILENAME]]\n\
+  decrypt-trivial-data [--seed=BASIS] [INPUT-FILENAME [OUTPUT-FILENAME]]\n\
+    Encrypt or decrypt data using the Episode 3 trivial algorithm. If BASIS is\n\
+    given, it should be specified as one hex byte. If BASIS is not given,\n\
+    newserv will try all possible values and return the one that results in the\n\
+    greatest number of zero bytes in the output.\n\
   encrypt-gci-save CRYPT-OPTION INPUT-FILENAME [OUTPUT-FILENAME]\n\
   decrypt-gci-save CRYPT-OPTION INPUT-FILENAME [OUTPUT-FILENAME]\n\
     Encrypt or decrypt a character or Guild Card file. If encrypting, the\n\
@@ -210,6 +211,7 @@ enum class Behavior {
   PRS_DISASSEMBLE,
   ENCRYPT_DATA,
   DECRYPT_DATA,
+  ENCRYPT_TRIVIAL_DATA,
   DECRYPT_TRIVIAL_DATA,
   ENCRYPT_GCI_SAVE,
   DECRYPT_GCI_SAVE,
@@ -241,6 +243,7 @@ static bool behavior_takes_input_filename(Behavior b) {
       (b == Behavior::PRS_DISASSEMBLE) ||
       (b == Behavior::ENCRYPT_DATA) ||
       (b == Behavior::DECRYPT_DATA) ||
+      (b == Behavior::ENCRYPT_TRIVIAL_DATA) ||
       (b == Behavior::DECRYPT_TRIVIAL_DATA) ||
       (b == Behavior::DECRYPT_GCI_SAVE) ||
       (b == Behavior::SALVAGE_GCI) ||
@@ -265,6 +268,7 @@ static bool behavior_takes_output_filename(Behavior b) {
       (b == Behavior::DECOMPRESS_BC0) ||
       (b == Behavior::ENCRYPT_DATA) ||
       (b == Behavior::DECRYPT_DATA) ||
+      (b == Behavior::ENCRYPT_TRIVIAL_DATA) ||
       (b == Behavior::DECRYPT_TRIVIAL_DATA) ||
       (b == Behavior::DECRYPT_GCI_SAVE) ||
       (b == Behavior::ENCRYPT_GCI_SAVE) ||
@@ -395,6 +399,8 @@ int main(int argc, char** argv) {
           behavior = Behavior::ENCRYPT_DATA;
         } else if (!strcmp(argv[x], "decrypt-data")) {
           behavior = Behavior::DECRYPT_DATA;
+        } else if (!strcmp(argv[x], "encrypt-trivial-data")) {
+          behavior = Behavior::ENCRYPT_TRIVIAL_DATA;
         } else if (!strcmp(argv[x], "decrypt-trivial-data")) {
           behavior = Behavior::DECRYPT_TRIVIAL_DATA;
         } else if (!strcmp(argv[x], "decrypt-gci-save")) {
@@ -637,6 +643,7 @@ int main(int argc, char** argv) {
       break;
     }
 
+    case Behavior::ENCRYPT_TRIVIAL_DATA:
     case Behavior::DECRYPT_TRIVIAL_DATA: {
       string data = read_input_data();
       uint8_t basis;
@@ -657,7 +664,8 @@ int main(int argc, char** argv) {
             best_seed_score = score;
           }
         }
-        fprintf(stderr, "Basis appears to be %02hhX\n", best_seed);
+        fprintf(stderr, "Basis appears to be %02hhX (%zu zero bytes in output)\n",
+            best_seed, best_seed_score);
         basis = best_seed;
       } else {
         basis = stoul(seed, nullptr, 16);