acsm-calibre-plugin/calibre-plugin/keyextract/main.c

128 lines
4.1 KiB
C

#include <stdio.h>
#include <cpuid.h>
#include <intsafe.h>
// Size for buffers that will hold unknown-size data
#define BUFSIZE 1024
union CPUIDVendor {
unsigned int reg[3];
char vendor[13];
};
struct EncEntropy {
unsigned int serial;
char vendor[12];
char signature[3];
char user[13];
};
int main() {
// Get disk serial
DWORD serial;
if (GetVolumeInformation("c:\\\\", NULL, 0, &serial, NULL, NULL, NULL, 0) == 0) {
DWORD err = GetLastError();
fprintf(stderr, "Error with GetVolumeInformation: %ld\n", err);
return err;
}
DWORD be_serial = htonl(serial);
fprintf(stderr, "Disk serial (hex): %08lx\n", serial);
unsigned int eax, ebx, ecx, edx;
// Get CPUID vendor string
union CPUIDVendor cpu_vendor;
if (__get_cpuid(0, &eax, &cpu_vendor.reg[0], &cpu_vendor.reg[2], &cpu_vendor.reg[1]) == 0) {
fprintf(stderr, "Error: cpuid(0) not supported");
return 1;
}
cpu_vendor.vendor[12] = '\0';
fprintf(stderr, "CPUID Vendor: %s\n", cpu_vendor.vendor);
// Get CPUID "signature" (eax of CPUID(1))
unsigned int signature;
if (__get_cpuid(1, &signature, &ebx, &ecx, &edx) == 0) {
fprintf(stderr, "Error: cpuid(1) not supported");
return 1;
}
unsigned int be_signature = htonl(signature);
fprintf(stderr, "CPUID Signature (hex): %08x\n", signature);
// Get windows user
wchar_t wideuser[BUFSIZE];
// RegGetValueW/GetUserNameW only sets bytes as needed for length of username, but we need null bytes to fill the rest
memset(&wideuser, 0, sizeof(wideuser));
DWORD wideuser_size = BUFSIZE;
LSTATUS user_retval = RegGetValueW(HKEY_CURRENT_USER, L"Software\\Adobe\\Adept\\Device", L"username", RRF_RT_REG_SZ, NULL, &wideuser, &wideuser_size);
if (user_retval != ERROR_SUCCESS) {
fprintf(stderr, "Error with RegGetValue: %ld\n", user_retval);
fprintf(stderr, "wideuser_size: %ld\n", wideuser_size);
fprintf(stderr, "Falling back to GetUserNameW\n");
if (GetUserNameW(wideuser, &wideuser_size) == 0) {
DWORD err = GetLastError();
fprintf(stderr, "Error with GetUserName: %ld\n", err);
fprintf(stderr, "wideuser_size: %ld\n", wideuser_size);
return err;
}
}
fprintf(stderr, "Username: %ls\n", wideuser);
// Copy every second byte of the wide string, to make an ascii-ish/non-long string
// As adobe does
// Only the first 13 chars are used, so only copy those
char user[13];
for (unsigned int i = 0; i < 13; i++) {
user[i] = ((char *)wideuser)[i*2];
}
// Get Encrypted adobe key
BYTE key[BUFSIZE];
memset(&key, 0, sizeof(key));
DWORD key_size = BUFSIZE;
LSTATUS key_retval = RegGetValue(HKEY_CURRENT_USER, "Software\\Adobe\\Adept\\Device", "key", RRF_RT_REG_BINARY, NULL, &key, &key_size);
if (key_retval != ERROR_SUCCESS) {
fprintf(stderr, "Error with RegGetValue: %ld\n", key_retval);
fprintf(stderr, "key_size: %ld\n", key_size);
return key_retval;
}
fprintf(stderr, "Encrypted key (hex): ");
for (size_t i = 0; i < key_size; i++ )
{
fprintf(stderr, "%02x", key[i]);
}
fprintf(stderr, "\n");
// Assemble "entropy" (passphrase) for key
struct EncEntropy entropy;
memcpy(&entropy.serial, &be_serial, sizeof(entropy.serial));
memcpy(&entropy.vendor, &cpu_vendor.vendor, sizeof(entropy.vendor));
memcpy(&entropy.signature, ((char*)(&be_signature))+1, sizeof(entropy.signature)); // Only the last 3 bytes are needed, hence the +1 ptr
memcpy(&entropy.user, &user, sizeof(entropy.user));
// Print entropy byte by byte in hex
fprintf(stderr, "Entropy: ");
for (size_t i = 0; i < sizeof(entropy); i++ )
{
fprintf(stderr, "%02x", ((unsigned char*)&entropy)[i]);
}
fprintf(stderr, "\n");
// Run decryption API
DATA_BLOB ciphertext_data, entropy_data, plaintext_data;
ciphertext_data.pbData = key;
ciphertext_data.cbData = key_size;
entropy_data.pbData = (BYTE*)(&entropy);
entropy_data.cbData = sizeof(entropy);
if (CryptUnprotectData(&ciphertext_data, NULL, &entropy_data, NULL, NULL, 0, &plaintext_data) != TRUE) {
DWORD err = GetLastError();
fprintf(stderr, "Error with CryptUnprotectData: %ld\n", err);
return err;
}
fprintf(stderr, "Decrypted key length: %lu\n", plaintext_data.cbData);
// Print decrypted key to stdout
for (unsigned int i = 0; i < 16; i++) {
printf("%02x", plaintext_data.pbData[i]);
}
}