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Allows bruteforce of keys that already in gpg keyring but have been forgotten to passpharse #2

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6 changes: 4 additions & 2 deletions Makefile
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Original file line number Diff line number Diff line change
@@ -1,12 +1,14 @@
GPGMELIBS := $(shell pkg-config --libs gpgme)

bruteforce-gpg: src/main.c bruteforce_gpg.o log.o agent.o
gcc -pthread -l gpgme -o bruteforce-gpg src/main.c bruteforce_gpg.o log.o agent.o
gcc -o bruteforce-gpg src/main.c bruteforce_gpg.o log.o agent.o -pthread $(GPGMELIBS)
bruteforce_gpg.o: src/bruteforce_gpg.c src/bruteforce_gpg.h
gcc -c src/bruteforce_gpg.c -o bruteforce_gpg.o
agent.o: src/agent.c src/agent.h
gcc -c src/agent.c -o agent.o
log.o: src/log.c src/log.h
gcc -c src/log.c -o log.o
clean:
rm --force bruteforce-gpg bruteforce_gpg.o log.o
rm --force bruteforce-gpg *.o
install:
install bruteforce-gpg /usr/local/bin/
8 changes: 4 additions & 4 deletions README.md
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Original file line number Diff line number Diff line change
Expand Up @@ -11,16 +11,16 @@ bruteforce-gpg [-h] [-v] [-t NUM_THREADS] -f WORDLIST GPG_SECRET_KEY
## Setup
### 1. Install Dependencies

This tool depends on the [libgpgme](https://www.gnupg.org/software/gpgme/index.html) library.
This tool depends on the [libgpgme](https://www.gnupg.org/software/gpgme/index.html) library and [pkg-config](http://pkg-config.freedesktop.org) tool.

On Kali
```bash
$ sudo apt install libgpgme-dev
$ sudo apt install libgpgme-dev pkg-config
```

On Arch Linux
```bash
$ sudo pacman -S gpgme
$ sudo pacman -S gpgme pkg-config
```

### 2. Download
Expand All @@ -41,7 +41,7 @@ $ make
`bruteforce-gpg` will be installed in the `/usr/local/bin/` directory, so you may want to ensure it is included in your `PATH` environment variable.

```bash
make install
# make install
```

## Examples
Expand Down
43 changes: 37 additions & 6 deletions src/bruteforce_gpg.c
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Original file line number Diff line number Diff line change
@@ -1,9 +1,11 @@
#include <stdbool.h>

#include "bruteforce_gpg.h"
#include "log.h"

static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;

char *bruteforce_gpg_load_secret_key(char *secret_key_filename, char **fingerprint) {
char *bruteforce_gpg_import_secret_key(char *secret_key_filename, char **fingerprint) {
gpgme_ctx_t context;
gpgme_error_t err;
gpgme_data_t secret_key_data;
Expand Down Expand Up @@ -76,12 +78,45 @@ char *bruteforce_gpg_load_secret_key(char *secret_key_filename, char **fingerpri
*fingerprint = strndup(result->imports->fpr, 40);
else
strncpy(*fingerprint, result->imports->fpr, 40);

gpgme_data_release(secret_key_data);
gpgme_release(context);
return *fingerprint;
}

bool bruteforce_gpg_delete_secret_key(char const *fingerprint)
{
gpgme_ctx_t context;
gpgme_error_t err;
gpgme_key_t key;
bool ret = true;

err = gpgme_new(&context);
if (gpgme_err_code(err) != GPG_ERR_NO_ERROR) {
fprintf(stderr, "Context creation failed: %s\n", gpgme_strerror(err));
return false;
}

err = gpgme_get_key(context, fingerprint, &key, true); // secret: true
if (gpgme_err_code(err) != GPG_ERR_NO_ERROR) {
fprintf(stderr, "Failed to get secret key: %s\n", gpgme_strerror(err));
ret = false;
goto release_context;
}

err = gpgme_op_delete_ext(context, key, GPGME_DELETE_ALLOW_SECRET | GPGME_DELETE_FORCE);
if (gpgme_err_code(err) != GPG_ERR_NO_ERROR) {
fprintf(stderr, "Failed to delete key: %s\n", gpgme_strerror(err));
ret = false;
goto release_context;
}

release_context:
gpgme_release(context);
return ret;
}


gpgme_error_t bruteforce_gpg_read_passphrases_from_file(void *hook, const char *uid_hint, const char *passphrase_info, int prev_was_bad, int fd) {
struct callback_data *data = (struct callback_data *) hook;

Expand Down Expand Up @@ -196,7 +231,6 @@ void *bruteforce_gpg_crack_passphrase(void *args) {
/* Set key as signing key */
err = gpgme_signers_add(context, secret_key);
if (gpgme_err_code(err) != GPG_ERR_NO_ERROR) {
gpgme_op_delete_ext(context, secret_key, GPGME_DELETE_ALLOW_SECRET | GPGME_DELETE_FORCE);
gpgme_release(context);
free(data);
gpgme_strerror_r(err, err_buf, ERR_BUF_LEN);
Expand All @@ -211,7 +245,6 @@ void *bruteforce_gpg_crack_passphrase(void *args) {
err = gpgme_data_new_from_mem(&signing_data, "test", 4, 0);
if (gpgme_err_code(err) != GPG_ERR_NO_ERROR) {
gpgme_signers_clear(context);
gpgme_op_delete_ext(context, secret_key, GPGME_DELETE_ALLOW_SECRET | GPGME_DELETE_FORCE);
free(data);
gpgme_release(context);
gpgme_strerror_r(err, err_buf, ERR_BUF_LEN);
Expand All @@ -226,7 +259,6 @@ void *bruteforce_gpg_crack_passphrase(void *args) {
if (gpgme_err_code(err) != GPG_ERR_NO_ERROR) {
gpgme_data_release(signing_data);
gpgme_signers_clear(context);
gpgme_op_delete_ext(context, secret_key, GPGME_DELETE_ALLOW_SECRET | GPGME_DELETE_FORCE);
free(data);
gpgme_release(context);
gpgme_strerror_r(err, err_buf, ERR_BUF_LEN);
Expand Down Expand Up @@ -267,7 +299,6 @@ void *bruteforce_gpg_crack_passphrase(void *args) {

gpgme_data_release(signature);
gpgme_data_release(signing_data);
gpgme_op_delete_ext(context, secret_key, GPGME_DELETE_ALLOW_SECRET | GPGME_DELETE_FORCE);
gpgme_signers_clear(context);
free(data);
gpgme_release(context);
Expand Down
11 changes: 7 additions & 4 deletions src/bruteforce_gpg.h
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Original file line number Diff line number Diff line change
@@ -1,13 +1,15 @@
#include <gpgme.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <stdio.h>
#include <pthread.h>
#include <time.h>

#include <pthread.h>
#include <gpgme.h>

#include "log.h"

#define USAGE "%s [-h] [-v] [-t NUM_THREADS] -f WORDLIST GPG_SECRET_KEY\n"
#define USAGE "%s [-h] [-v] [-t NUM_THREADS] -f WORDLIST GPG_SECRET_KEYFILE | FINGERPRINT\n"
#define ERR_BUF_LEN 500

struct callback_data {
Expand All @@ -27,5 +29,6 @@ struct thread_args {
char *passphrase;
};

char *bruteforce_gpg_load_secret_key(char *secret_key_filename, char **fingerprint);
char *bruteforce_gpg_import_secret_key(char *secret_key_filename, char **fingerprint);
bool bruteforce_gpg_delete_secret_key(char const *fingerprint);
void *bruteforce_gpg_crack_passphrase(void *args);
34 changes: 24 additions & 10 deletions src/main.c
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Original file line number Diff line number Diff line change
@@ -1,4 +1,7 @@
#include <getopt.h>
#include <unistd.h>
#include <stdbool.h>

#include "bruteforce_gpg.h"
#include "log.h"
#include "agent.h"
Expand All @@ -14,12 +17,13 @@ int main(int argc, char *argv[argc])
{
int option;
long num_threads;
char *password_filename = NULL, *secret_key_filename, *endptr, *ttl = NULL;
char *password_filename = NULL, *secret_key, *endptr, *ttl = NULL;
pthread_t *workers;
gpgme_error_t err;
void *worker_err;
struct thread_args gpg_data;
time_t start_time;
bool import_keyfile = false;

num_threads = 1;
debug = opterr = 0;
Expand Down Expand Up @@ -60,11 +64,13 @@ int main(int argc, char *argv[argc])
fprintf(stderr, USAGE, argv[0]);
exit(1);
}
secret_key_filename = argv[optind];
secret_key = argv[optind];
import_keyfile = (access(secret_key, F_OK) == 0);

log_debug("wordlist: %s\nkey file: %s\n",
log_debug("wordlist: %s\n%s: %s\n",
password_filename,
secret_key_filename);
import_keyfile? "secret_key_filename": "fingerprint",
secret_key);

if (!(gpg_data.wordlist = fopen(password_filename, "r"))) {
fprintf(stderr,
Expand All @@ -85,21 +91,25 @@ int main(int argc, char *argv[argc])
gpgme_strerror(err));
exit(gpgme_err_code(err));
}

log_debug("%s engine supported!\n",
gpgme_get_protocol_name(GPGME_PROTOCOL_OPENPGP));

gpg_data.fingerprint = NULL;
if (!bruteforce_gpg_load_secret_key(secret_key_filename, &gpg_data.fingerprint))
exit(1);
if (import_keyfile) {
if (!bruteforce_gpg_import_secret_key(secret_key, &gpg_data.fingerprint))
exit(1);
} else {
gpg_data.fingerprint = strndup(secret_key, 40);
}

gpg_data.attempt = 0;
gpg_data.passphrase = NULL;
gpg_data.num_workers = 0;
workers = calloc(num_threads, sizeof(pthread_t));
gpg_data.workers = workers;


get_gpg_agent_cache_info(&ttl);
log_debug("Got existing gpg-agent default-cache-ttl: %s\n", ttl);
set_gpg_agent_cache_info("0");
Expand All @@ -118,7 +128,7 @@ int main(int argc, char *argv[argc])
for (int i = 0; i < num_threads; i++)
if (pthread_join(workers[i], &worker_err))
perror("Failed to join to worker thread");

if (gpg_data.passphrase) {
printf("\nFound passphrase: %s\n", gpg_data.passphrase);
}
Expand All @@ -128,11 +138,15 @@ int main(int argc, char *argv[argc])
}
printf("Duration: %lu seconds\n", gpg_data.end_time - start_time);

// delete imported_key
if (import_keyfile) {
bruteforce_gpg_delete_secret_key(gpg_data.fingerprint);
}
set_gpg_agent_cache_info(ttl);
log_debug("Reverted gpg-agent default-cache-ttl to %s\n", ttl);
free(ttl);
fclose(gpg_data.wordlist);
free(gpg_data.fingerprint);
free(workers);
return gpg_data.passphrase != NULL;
return gpg_data.passphrase == NULL; // 0: ok, 1: failure
}