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examples/peterglen/test_asym.c

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/* =====[ test_asym.c ]=========================================================
Description: Encryption excamples. Feasability study for diba
[Digital Bank].
Revisions:
REV DATE BY DESCRIPTION
---- ----------- ---------- ------------------------------
0.00 jul.14.2017 Peter Glen Initial version.
======================================================================= */
#include <signal.h>
#include "gcrypt.h"
#include "gcry.h"
#include "zmalloc.h"
#include "getpass.h"
#include "gsexp.h"
static int dump = 0;
static int verbose = 0;
static int test = 0;
static int ppub = 0;
static int nocrypt = 0;
static char infile[MAX_PATH] = {'\0'};
static char outfile[MAX_PATH] = {'\0'};
static char keyfile[MAX_PATH] = {'\0'};
static char thispass[MAX_PATH] = {'\0'};
char usestr[] = "test_asym [options] keyfile";
opts opts_data[] = {
'i', "infile", NULL, infile, 0, 0, NULL,
"-i <filename> --infile <filename> - input file name",
'o', "outfile", NULL, outfile, 0, 0, NULL,
"-o <filename> --outfile <filename> - output file name",
'p', "pass", NULL, thispass, 0, 0, NULL,
"-p --pass - pass in for key (testing only)",
'k', "keyfile", NULL, keyfile, 0, 0, NULL,
"-k <filename> --keyfile <filename> - key file name",
'v', "verbose", NULL, NULL, 0, 0, &verbose,
"-v --verbose - Verbosity on",
'd', "dump", NULL, NULL, 0, 0, &dump,
"-d --dump - Dump buffers",
't', "test", NULL, NULL, 0, 0, &test,
"-t --test - test on",
'n', "nocrypt", NULL, NULL, 0, 0, &nocrypt,
"-n --nocrypt - do not decypt private key",
'x', "printpub", NULL, NULL, 0, 0, &ppub,
"-x --printpub - print public key",
0, NULL, NULL, NULL, 0, 0, NULL, NULL,
};
static void myfunc(int sig)
{
printf("\nSignal %d (segment violation)\n", sig);
exit(111);
}
int main(int argc, char** argv)
{
signal(SIGSEGV, myfunc);
char *err_str;
int nn = parse_commad_line(argv, opts_data, &err_str);
if (err_str)
{
printf(err_str);
usage(usestr, opts_data); exit(2);
}
if (argc - nn != 2 && strlen(keyfile) == 0) {
printf("Missing argument for ascrypt.");
usage(usestr, opts_data); exit(2);
}
//printf("thispass '%s'\n", thispass);
//zverbose(TRUE);
//gcry_set_allocation_handler(zalloc, NULL, NULL, zrealloc, zfree);
gcrypt_init();
gcry_error_t err;
char* fname = argv[1 + nn];
FILE* lockf = fopen(fname, "rb");
if (!lockf) {
xerr2("fopen() on '%s' failed.", fname);
}
/* Read and decrypt the key pair from disk. */
unsigned int flen = getfsize(lockf);
zline2(__LINE__, __FILE__);
char* fbuf = zalloc(flen + 1);
if (!fbuf) {
xerr("malloc: could not allocate rsa buffer");
}
if (fread(fbuf, flen, 1, lockf) != 1) {
xerr("fread() on composit key failed");
}
fclose(lockf);
//fbuf[flen] = '\0';
zcheck(fbuf, __LINE__);
if(dump)
dump_mem(fbuf, flen);
zline2(__LINE__, __FILE__);
int rsa_len = flen;
char *rsa_buf = decode_priv_key(fbuf, &rsa_len, &err_str);
zfree(fbuf);
if (!rsa_buf) {
//printf("%s\n", err_str);
xerr2("Decode key failed. %s", err_str);
}
//if(dump)
// dump_mem(rsa_buf, rsa_len);
zline2(__LINE__, __FILE__);
/* Grab a key pair password and create an AES context with it. */
if(thispass[0] == '\0' && !nocrypt)
{
getpassx passx;
passx.prompt = "Enter keypair pass:";
passx.pass = thispass;
passx.maxlen = MAXPASSLEN;
passx.minlen = 3;
passx.weak = TRUE;
passx.nodouble = TRUE;
passx.strength = 4;
int ret = getpass2(&passx);
if(ret < 0)
xerr("Error on password entry.");
}
//printf("thispass '%s'\n", thispass);
gcry_cipher_hd_t aes_hd;
get_aes_ctx(&aes_hd, thispass, strlen(thispass));
zline2(__LINE__, __FILE__);
if(!nocrypt)
{
// Decrypt buffer
err = gcry_cipher_decrypt(aes_hd, (unsigned char*) rsa_buf,
rsa_len, NULL, 0);
if (err) {
xerr("gcrypt: failed to decrypt key pair");
}
}
if(dump)
dump_mem(rsa_buf, rsa_len);
zline2(__LINE__, __FILE__);
/* Load the key pair components into sexps. */
gcry_sexp_t rsa_keypair;
err = gcry_sexp_new(&rsa_keypair, rsa_buf, rsa_len, 0);
if(err)
{
//printerr(err, NULL);
xerr2("gcrypt: failed to load key. (pass?)");
}
zline2(__LINE__, __FILE__);
gcry_sexp_t pubk = gcry_sexp_find_token(rsa_keypair, "public-key", 0);
if(pubk == NULL)
xerr2("gcrypt: no public key present");
//print_sexp(pubk);
gcry_sexp_t privk = gcry_sexp_find_token(rsa_keypair, "private-key", 0);
if(privk == NULL)
xerr2("gcrypt: no private key present");
//print_sexp(privk);
zline2(__LINE__, __FILE__);
printf("Key length pub: %d priv: %d\n",
gcry_pk_get_nbits(pubk), gcry_pk_get_nbits(privk));
int cycle = gcry_pk_get_nbits(privk)/8;
const unsigned char* ss = (const unsigned char*)
"Hello world. Hello world. Hello world. Hello world. Hello world. Hello world."
//"Hello world. Hello world. Hello world. Hello world. Hello world. Hello world. Hello world."
"Hello world. Hello world. Hello world. Hello world. Hello world. Hello world. Hello world.";
printf("Original message -> %d bytes \n'%s'\n", strlen(ss), (char*) ss);
zline2(__LINE__, __FILE__);
gcry_sexp_t ciph;
int ret = pk_encrypt_buffer(ss, strlen(ss), pubk, &ciph);
//print_sexp(ciph);
decode_sexp(ciph, "a");
zline2(__LINE__, __FILE__);
/* Decrypt the message. */
gcry_sexp_t plain;
zline2(__LINE__, __FILE__);
err = gcry_pk_decrypt(&plain, ciph, privk);
if (err) {
xerr("gcrypt: decryption failed");
}
zline2(__LINE__, __FILE__);
/* Pretty-print the results. */
gcry_mpi_t out_msg = gcry_sexp_nth_mpi(plain, 0, GCRYMPI_FMT_USG);
zline2(__LINE__, __FILE__);
int written = 0;
unsigned char *buffm;
err = gcry_mpi_aprint(GCRYMPI_FMT_USG, &buffm, &written, out_msg);
if (err) {
xerr("failed to stringify mpi");
}
printf("Decrypted message -> (%d bytes)\n'%s'\n", strlen(buffm), (char*) buffm);
if(strcmp(buffm, ss) == 0)
{
printf("Buffers compare OK\n");
}
else
{
printf("Buffers DO NOT compare.\n");
}
/* Release contexts. */
gcry_mpi_release(out_msg);
gcry_sexp_release(rsa_keypair);
gcry_sexp_release(pubk);
gcry_sexp_release(privk);
gcry_sexp_release(ciph);
gcry_sexp_release(plain);
gcry_cipher_close(aes_hd);
zline2(__LINE__, __FILE__);
zfree(rsa_buf);
zline2(__LINE__, __FILE__);
gcry_free(buffm);
zleak();
return 0;
}