ADD A3 solution, miss report

03-Average3/A3.txt

@@ -0,0 +1,6 @@
+1. What is the algorithm used to check the validity of a password?
+
+2. This program relies on a specific trick. How does it work?
+
+3. Can you recover the secret password? You must send 1 the valid password by email to pascal+sre25@mod-p.ch before Apr. 28th, 2025, 12h00 CET to validate this lab and get 10 points.
+JFuzhFSI4YShfqE7

03-Average3/pw.c

@@ -0,0 +1,52 @@
+ #include <stdio.h>
+ #include <stdint.h>
+ #include <stdbool.h>
+ #include <string.h>
+ #include <sys/types.h>
+ #include <signal.h>
+ #include <sys/ptrace.h>
+
+ // uVar4 = 1396505404 = 0x533CFB3C
+ // uVar5 = 2294410125 = 0x88C1EB8D
+ // uVar6 = 2929865363 = 0xAEA23293
+
+uint8_t main(int argc, char** argv) {
+    char* list = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ+-";
+    uint32_t uVar4 = 1396505404;
+    uint32_t uVar5 = 929308192;
+    uint32_t uVar6 = 2929865363;
+    char password[17];
+    password[16] = '\0';
+    password[0] = list[uVar6 >> 0x1a];
+    password[1] = list[uVar6 >> 0x14 & 0x3f];
+    password[2] = list[uVar6 >> 0xe & 0x3f];
+     // [uVar6 >> 8 & 0x3f] ^ password[3] |
+    password[3] = list[uVar6 >> 8 & 0x3f];
+     // [uVar6 >> 2 & 0x3f] ^ password[4] |
+    password[4] = list[uVar6 >> 2 & 0x3f];
+     // [(uVar6 & 3) << 4 | uVar4 >> 0x1c] ^ password[5] |
+    password[5] = list[(uVar6 & 3) << 4 | uVar4 >> 0x1c];
+     // [uVar4 >> 0x16 & 0x3f] ^ password[6] |
+    password[6] = list[uVar4 >> 0x16 & 0x3f];
+     // [uVar4 >> 0x10 & 0x3f] ^ password[7] |
+    password[7] = list[uVar4 >> 0x10 & 0x3f];
+     // [uVar4 >> 10 & 0x3f] ^ password[8] |
+    password[8] = list[uVar4 >> 10 & 0x3f];
+     // [uVar4 >> 4 & 0x3f] ^ password[9] |
+    password[9] = list[uVar4 >> 4 & 0x3f];
+     // [uVar5 >> 0x1e | (uVar4 & 0xf) << 2] ^ password[10] |
+    password[10] = list[uVar5 >> 0x1e | (uVar4 & 0xf) << 2];
+     // [uVar5 >> 0x18 & 0x3f] ^ password[11] |
+    password[11] = list[uVar5 >> 0x18 & 0x3f];
+     // [uVar5 >> 0x12 & 0x3f] ^ password[12] |
+    password[12] = list[uVar5 >> 0x12 & 0x3f];
+     // [uVar5 >> 0xc & 0x3f] ^ password[13] |
+    password[13] = list[uVar5 >> 0xc & 0x3f];
+     // [uVar5 >> 6 & 0x3f] ^ password[14] |
+    password[14] = list[uVar5 >> 6 & 0x3f];
+     // [uVar5 & 0x3f] ^ password[15]
+    password[15] = list[uVar5 & 0x3f];
+
+    printf("%s\n", password);
+    return 0;
+}

SRE.rep/idata/~index.bak

@@ -1,10 +1,12 @@
 VERSION=1
 /
   00000001:A1:a801f6f89b95769364193802
+  00000006:A3:a801f56ab658487152928151
+  00000007:D1:c0a82d69e3b15562440310963
   00000000:E4:a801f6f84bf5726727918611
   00000002:HelloRust:c0a82f6ac5f11262297970056
   00000005:liba2.so:c0a82678bad57470710627698
 /E5.apk
   00000004:DebugProbesKt.bin:a947c5a05d160355288677079
-NEXT-ID:6
+NEXT-ID:8
 MD5:d41d8cd98f00b204e9800998ecf8427e

SRE.rep/idata/~index.dat

@@ -2,10 +2,11 @@ VERSION=1
 /
   00000001:A1:a801f6f89b95769364193802
   00000006:A3:a801f56ab658487152928151
+  00000007:D1:c0a82d69e3b15562440310963
   00000000:E4:a801f6f84bf5726727918611
   00000002:HelloRust:c0a82f6ac5f11262297970056
   00000005:liba2.so:c0a82678bad57470710627698
 /E5.apk
   00000004:DebugProbesKt.bin:a947c5a05d160355288677079
-NEXT-ID:7
+NEXT-ID:8
 MD5:d41d8cd98f00b204e9800998ecf8427e

SRE.rep/user/~index.bak

@@ -3,6 +3,7 @@ VERSION=1
   00000000:udf_a801f6f84bf5726727918611:a801f6f835112597744365961
   00000001:udf_a801f6f89b95769364193802:c0a82ee829520057231966697
   00000003:udf_a947c5a05d160355288677079:a947c5b473161854856522726
+  00000004:udf_c0a82678bad57470710627698:c0a82679e4158658428888916
   00000002:udf_c0a82f6ac5f11262297970056:a801f2faf4d101904923747351
-NEXT-ID:4
+NEXT-ID:5
 MD5:d41d8cd98f00b204e9800998ecf8427e

SRE.rep/user/~index.dat

@@ -1,9 +1,11 @@
 VERSION=1
 /
+  00000005:udf_a801f56ab658487152928151:c0a82d6804915544445885584
   00000000:udf_a801f6f84bf5726727918611:a801f6f835112597744365961
   00000001:udf_a801f6f89b95769364193802:c0a82ee829520057231966697
   00000003:udf_a947c5a05d160355288677079:a947c5b473161854856522726
   00000004:udf_c0a82678bad57470710627698:c0a82679e4158658428888916
+  00000006:udf_c0a82d69e3b15562440310963:c0a82d68fef15936786772401
   00000002:udf_c0a82f6ac5f11262297970056:a801f2faf4d101904923747351
-NEXT-ID:5
+NEXT-ID:7
 MD5:d41d8cd98f00b204e9800998ecf8427e

SRE.rep/user/~journal.bak

@@ -1,2 +1,4 @@
-IADD:00000004:/udf_c0a82678bad57470710627698
+IADD:00000005:/udf_a801f56ab658487152928151
-IDSET:/udf_c0a82678bad57470710627698:c0a82679e4158658428888916
+IDSET:/udf_a801f56ab658487152928151:c0a82d6804915544445885584
+IADD:00000006:/udf_c0a82d69e3b15562440310963
+IDSET:/udf_c0a82d69e3b15562440310963:c0a82d68fef15936786772401