Re: AW: AW: AW: AW: AW: RSA_public_decrypt problem

[Marek Marcola]

Hello,
> N:
> 008796FB4EAAB5FCC21619608ECB34D4BD82D062BF136A54E7E0BF6B2991C2F0F93A161930D650AF939C8282431D291D0E6E9F69A09AF091345D60439569C5CB5ECA566740B6A69FE4BBF2DB9CC03786AEDF8F9522EB7F6096A1B900140E6AA7AF55198B87E68A69546631E9EF90666984123F5364BE2EA6E067BBAA8831A34B15
> 
> E: 
> 0040000081
After modifying sample program "decryption" with your public key
seems to work good.

Best regards,
-- 
Marek Marcola <[EMAIL PROTECTED]>

#include <stdio.h>
#include <string.h>

#include <openssl/ssl.h>
#include <openssl/rsa.h>
#include <openssl/err.h>
#include <openssl/rand.h>
#include <openssl/bn.h>

int print_hex(unsigned char *buf, int len)
{
	int i;
	int n;

	printf(" ");

	for (i = 0, n = 0; i < len; i++) {
		if (n > 7) {
			printf("\n ");
			n = 0;
		}
		printf("0x%02x ", buf[i]);
		n++;
	}
	printf("\n");

	return (0);
}

int log_ssl(void)
{
	char buf[256];
	u_long err;

	while ((err = ERR_get_error()) != 0) {
		ERR_error_string_n(err, buf, sizeof(buf));
		printf("*** %s\n", buf);
	}

	return (0);
}

int main()
{
	RSA *rsa_pub;

	unsigned char enc_bin[1024];
	int enc_len;
	unsigned char dec_bin[1024];
	int dec_len;

	char N[] = { "008796FB4EAAB5FCC21619608ECB34D4BD82D062BF136A54E7E0BF6B2991C2F0F93A161930D650AF939C8282431D291D0E6E9F69A09AF091345D60439569C5CB5ECA566740B6A69FE4BBF2DB9CC03786AEDF8F9522EB7F6096A1B900140E6AA7AF55198B87E68A69546631E9EF90666984123F5364BE2EA6E067BBAA8831A34B15" };
	char E[] = { "0040000081" };

	char msg[] = { "xyz" };

	SSL_load_error_strings();
	SSLeay_add_ssl_algorithms();

	RAND_load_file("/dev/urandom", 1024);

	if ((rsa_pub = RSA_new()) == NULL) {
		goto err;
	}

	/* load public key */
	printf("public key parameters:\n");

	if (!BN_hex2bn(&rsa_pub->n, N)) {
		goto err;
	}
	printf(" N: %s\n", N);
	printf(" n: %s\n", BN_bn2hex(rsa_pub->n));

	if (!BN_hex2bn(&rsa_pub->e, E)) {
		goto err;
	}
	printf(" E: %s\n", E);
	printf(" e: %s\n", BN_bn2hex(rsa_pub->e));

	printf("public key size : %d bits\n", RSA_size(rsa_pub) * 8);

	/* prepare "encrypted" data */
	enc_len = RSA_size(rsa_pub);
	memset(enc_bin, 1, enc_len);

    /* decrypt */
    if ((dec_len = RSA_public_decrypt(enc_len, enc_bin, dec_bin, rsa_pub,
                                      RSA_NO_PADDING)) < 0) {
        goto err;
    }

    printf("decrypted data:\n");
    print_hex(dec_bin, dec_len);

	return (0);

  err:
	log_ssl();
	return (1);
}