-/*
- * rsa.c RSA Public and Private key generation functions,
- * RSA encrypt and decrypt functions.
- *
- * Author: Pekka Riikonen <priikone@poseidon.pspt.fi>
- *
- * Copyright (C) 1997 - 2001 Pekka Riikonen
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * Created: Sat Mar 1 13:26:45 1997 pekka
- *
- * RSA public key cryptographic algorithm used in this distribution is:
- *
- * Key generation:
- * p, q primes
- * p != q
- * n = p * q modulus
- *
- * Public key exponent:
- * e relatively prime to (p-1) * (q-1)
- * Private key exponent:
- * d = e ^ -1 mod lcm(((p-1) * (q-1)))
- *
- * Encryption:
- * c = m ^ e mod n
- * Decryption:
- * m = c ^ d mod n
- *
- * This code is based on SSH's (Secure Shell), PGP's (Pretty Good Privacy)
- * and RSAREF Toolkit's RSA source codes. They all were a big help for me.
- *
- * I also suggest reading Bruce Schneier's; Applied Cryptography, Second
- * Edition, John Wiley & Sons, Inc. 1996. This book deals about RSA and
- * everything else too about cryptography.
- *
- */
-/* $Id$ */
-
-/*
- ChangeLog
-
- o Mon Feb 12 11:20:32 EET 2001 Pekka
-
- Changed RSA private exponent generation to what PKCS #1 suggests. We
- try to find the smallest possible d by doing modinv(e, lcm(phi)) instead
- of modinv(e, phi). Note: this is not security fix but optimization.
-
- o Tue Feb 20 13:58:58 EET 2001 Pekka
-
- Set key->bits in rsa_generate_key. It is the modulus length in bits.
- The `tmplen' in encrypt, decrypt, sign and verify PKCS API functions
- is now calculated by (key->bits + 7) / 8. It is the length of one block.
-
-*/
-
-#include "silcincludes.h"
-#include "rsa.h"
-
/*
- * SILC PKCS API for RSA
- */
-
-/* Generates RSA key pair. */
-
-SILC_PKCS_API_INIT(rsa)
-{
- uint32 prime_bits = keylen / 2;
- SilcMPInt p, q;
-
- printf("Generating RSA Public and Private keys, might take a while...\n");
-
- silc_mp_init(&p);
- silc_mp_init(&q);
-
- /* Find p and q */
- retry_primes:
- printf("Finding p: ");
- silc_math_gen_prime(&p, prime_bits, TRUE);
-
- printf("\nFinding q: ");
- silc_math_gen_prime(&q, prime_bits, TRUE);
-
- if ((silc_mp_cmp(&p, &q)) == 0) {
- printf("\nFound equal primes, not good, retrying...\n");
- goto retry_primes;
- }
-
- /* If p is smaller than q, switch them */
- if ((silc_mp_cmp(&p, &q)) > 0) {
- SilcMPInt hlp;
- silc_mp_init(&hlp);
-
- silc_mp_set(&hlp, &p);
- silc_mp_set(&p, &q);
- silc_mp_set(&q, &hlp);
-
- silc_mp_uninit(&hlp);
- }
-
- /* Generate the actual keys */
- rsa_generate_keys((RsaKey *)context, keylen, &p, &q);
-
- silc_mp_uninit(&p);
- silc_mp_uninit(&q);
-
- printf("\nKeys generated succesfully.\n");
-
- return TRUE;
-}
-
-SILC_PKCS_API_CLEAR_KEYS(rsa)
-{
- rsa_clear_keys((RsaKey *)context);
-}
-
-/* Returns SILC style encoded RSA public key. */
-
-SILC_PKCS_API_GET_PUBLIC_KEY(rsa)
-{
- RsaKey *key = (RsaKey *)context;
- unsigned char *e, *n, *ret;
- uint32 e_len, n_len;
- unsigned char tmp[4];
-
- e = silc_mp_mp2bin(&key->e, 0, &e_len);
- n = silc_mp_mp2bin(&key->n, key->bits / 8, &n_len);
-
- *ret_len = e_len + 4 + n_len + 4;
- ret = silc_calloc(*ret_len, sizeof(unsigned char));
-
- /* Put the length of the e. */
- SILC_PUT32_MSB(e_len, tmp);
- memcpy(ret, tmp, 4);
-
- /* Put the e. */
- memcpy(ret + 4, e, e_len);
-
- /* Put the length of the n. */
- SILC_PUT32_MSB(n_len, tmp);
- memcpy(ret + 4 + e_len, tmp, 4);
-
- /* Put the n. */
- memcpy(ret + 4 + e_len + 4, n, n_len);
-
- memset(e, 0, e_len);
- memset(n, 0, n_len);
- silc_free(e);
- silc_free(n);
-
- return ret;
-}
-
-/* Returns SILC style encoded RSA private key. Public key is always
- returned in private key as well. Public keys are often derived
- directly from private key. */
-
-SILC_PKCS_API_GET_PRIVATE_KEY(rsa)
-{
- RsaKey *key = (RsaKey *)context;
- unsigned char *e, *n, *d, *ret;
- uint32 e_len, n_len, d_len;
- unsigned char tmp[4];
-
- e = silc_mp_mp2bin(&key->e, 0, &e_len);
- n = silc_mp_mp2bin(&key->n, key->bits / 8, &n_len);
- d = silc_mp_mp2bin(&key->d, 0, &d_len);
-
- *ret_len = e_len + 4 + n_len + 4 + d_len + 4;
- ret = silc_calloc(*ret_len, sizeof(unsigned char));
-
- /* Put the length of the e. */
- SILC_PUT32_MSB(e_len, tmp);
- memcpy(ret, tmp, 4);
-
- /* Put the e. */
- memcpy(ret + 4, e, e_len);
-
- /* Put the length of the n. */
- SILC_PUT32_MSB(n_len, tmp);
- memcpy(ret + 4 + e_len, tmp, 4);
-
- /* Put the n. */
- memcpy(ret + 4 + e_len + 4, n, n_len);
-
- /* Put the length of the d. */
- SILC_PUT32_MSB(d_len, tmp);
- memcpy(ret + 4 + e_len + 4 + n_len, tmp, 4);
-
- /* Put the n. */
- memcpy(ret + 4 + e_len + 4 + n_len + 4, d, d_len);
-
- memset(e, 0, e_len);
- memset(n, 0, n_len);
- memset(d, 0, d_len);
- silc_free(e);
- silc_free(n);
- silc_free(d);
-
- return ret;
-}
-
-/* Set public key */
-
-SILC_PKCS_API_SET_PUBLIC_KEY(rsa)
-{
- RsaKey *key = (RsaKey *)context;
- unsigned char tmp[4];
- uint32 e_len, n_len;
-
- silc_mp_init(&key->e);
- silc_mp_init(&key->n);
-
- memcpy(tmp, key_data, 4);
- SILC_GET32_MSB(e_len, tmp);
- if (e_len > key_len) {
- silc_mp_uninit(&key->e);
- silc_mp_uninit(&key->n);
- return 0;
- }
-
- silc_mp_bin2mp(key_data + 4, e_len, &key->e);
-
- memcpy(tmp, key_data + 4 + e_len, 4);
- SILC_GET32_MSB(n_len, tmp);
- if (e_len + n_len > key_len) {
- silc_mp_uninit(&key->e);
- silc_mp_uninit(&key->n);
- return 0;
- }
-
- silc_mp_bin2mp(key_data + 4 + e_len + 4, n_len, &key->n);
-
- key->bits = n_len * 8;
-
- return key->bits;
-}
-
-/* Set private key. This derives the public key from the private
- key and sets the public key as well. Public key should not be set
- already and should not be set after setting private key. */
-
-SILC_PKCS_API_SET_PRIVATE_KEY(rsa)
-{
- RsaKey *key = (RsaKey *)context;
- unsigned char tmp[4];
- uint32 e_len, n_len, d_len;
-
- silc_mp_init(&key->e);
- silc_mp_init(&key->n);
- silc_mp_init(&key->d);
-
- memcpy(tmp, key_data, 4);
- SILC_GET32_MSB(e_len, tmp);
- if (e_len > key_len) {
- silc_mp_uninit(&key->e);
- silc_mp_uninit(&key->n);
- return FALSE;
- }
-
- silc_mp_bin2mp(key_data + 4, e_len, &key->e);
-
- memcpy(tmp, key_data + 4 + e_len, 4);
- SILC_GET32_MSB(n_len, tmp);
- if (e_len + n_len > key_len) {
- silc_mp_uninit(&key->e);
- silc_mp_uninit(&key->n);
- return FALSE;
- }
-
- silc_mp_bin2mp(key_data + 4 + e_len + 4, n_len, &key->n);
-
- memcpy(tmp, key_data + 4 + e_len + 4 + n_len, 4);
- SILC_GET32_MSB(d_len, tmp);
- if (e_len + n_len + d_len > key_len) {
- silc_mp_uninit(&key->e);
- silc_mp_uninit(&key->n);
- return FALSE;
- }
- silc_mp_bin2mp(key_data + 4 + e_len + 4 + n_len + 4, d_len, &key->d);
-
- key->bits = n_len * 8;
-
- return TRUE;
-}
-
-SILC_PKCS_API_CONTEXT_LEN(rsa)
-{
- return sizeof(RsaKey);
-}
-
-SILC_PKCS_API_ENCRYPT(rsa)
-{
- RsaKey *key = (RsaKey *)context;
- int i, tmplen;
- SilcMPInt mp_tmp;
- SilcMPInt mp_dst;
-
- silc_mp_init(&mp_tmp);
- silc_mp_init(&mp_dst);
- silc_mp_set_ui(&mp_tmp, 0);
- silc_mp_set_ui(&mp_dst, 0);
-
- /* Format the data into MP int */
- for (i = 0; i < src_len; i++) {
- silc_mp_mul_2exp(&mp_tmp, &mp_tmp, 8);
- silc_mp_add_ui(&mp_tmp, &mp_tmp, src[i]);
- }
+ rsa.c RSA Public and Private key generation functions,
+ RSA encrypt and decrypt functions.
- /* Encrypt */
- rsa_en_de_crypt(&mp_dst, &mp_tmp, &key->e, &key->n);
-
- tmplen = (key->bits + 7) / 8;
+ Author: Pekka Riikonen <priikone@silcnet.org>
- /* Format the MP int back into data */
- for (i = tmplen; i > 0; i--) {
- dst[i - 1] = (unsigned char)(silc_mp_get_ui(&mp_dst) & 0xff);
- silc_mp_div_2exp(&mp_dst, &mp_dst, 8);
- }
- *dst_len = tmplen;
+ Copyright (C) 1997 - 2007 Pekka Riikonen
- silc_mp_uninit(&mp_tmp);
- silc_mp_uninit(&mp_dst);
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; version 2 of the License.
- return TRUE;
-}
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
-SILC_PKCS_API_DECRYPT(rsa)
-{
- RsaKey *key = (RsaKey *)context;
- int i, tmplen;
- SilcMPInt mp_tmp;
- SilcMPInt mp_dst;
-
- silc_mp_init(&mp_tmp);
- silc_mp_init(&mp_dst);
- silc_mp_set_ui(&mp_tmp, 0);
- silc_mp_set_ui(&mp_dst, 0);
-
- /* Format the data into MP int */
- for (i = 0; i < src_len; i++) {
- silc_mp_mul_2exp(&mp_tmp, &mp_tmp, 8);
- silc_mp_add_ui(&mp_tmp, &mp_tmp, src[i]);
- }
+ Created: Sat Mar 1 13:26:45 1997 pekka
- /* Decrypt */
- rsa_en_de_crypt(&mp_dst, &mp_tmp, &key->d, &key->n);
+ RSA public key cryptographic algorithm used in this distribution is:
- tmplen = (key->bits + 7) / 8;
+ Key generation:
+ p, q primes
+ p != q
+ n = p * q modulus
- /* Format the MP int back into data */
- for (i = tmplen; i > 0; i--) {
- dst[i - 1] = (unsigned char)(silc_mp_get_ui(&mp_dst) & 0xff);
- silc_mp_div_2exp(&mp_dst, &mp_dst, 8);
- }
- *dst_len = tmplen;
+ Public key exponent:
+ e relatively prime to (p-1) * (q-1)
+ Private key exponent:
+ d = e ^ -1 mod lcm(((p-1) * (q-1)))
- silc_mp_uninit(&mp_tmp);
- silc_mp_uninit(&mp_dst);
+ Encryption:
+ c = m ^ e mod n
+ Decryption:
+ m = c ^ d mod n
- return TRUE;
-}
+ Supports CRT (Chinese Remainder Theorem) for private key operations.
-SILC_PKCS_API_SIGN(rsa)
-{
- RsaKey *key = (RsaKey *)context;
- int i, tmplen;
- SilcMPInt mp_tmp;
- SilcMPInt mp_dst;
-
- silc_mp_init(&mp_tmp);
- silc_mp_init(&mp_dst);
- silc_mp_set_ui(&mp_tmp, 0);
- silc_mp_set_ui(&mp_dst, 0);
-
- /* Format the data into MP int */
- for (i = 0; i < src_len; i++) {
- silc_mp_mul_2exp(&mp_tmp, &mp_tmp, 8);
- silc_mp_add_ui(&mp_tmp, &mp_tmp, src[i]);
- }
+ The SSH's (Secure Shell), PGP's (Pretty Good Privacy) and RSAREF
+ Toolkit were used as reference when coding this implementation. They
+ all were a big help for me.
- /* Sign */
- rsa_en_de_crypt(&mp_dst, &mp_tmp, &key->d, &key->n);
+ I also suggest reading Bruce Schneier's; Applied Cryptography, Second
+ Edition, John Wiley & Sons, Inc. 1996. This book deals about RSA and
+ everything else too about cryptography.
- tmplen = (key->bits + 7) / 8;
+*/
+/* $Id$ */
- /* Format the MP int back into data */
- for (i = tmplen; i > 0; i--) {
- dst[i - 1] = (unsigned char)(silc_mp_get_ui(&mp_dst) & 0xff);
- silc_mp_div_2exp(&mp_dst, &mp_dst, 8);
- }
- *dst_len = tmplen;
+/*
+ ChangeLog
- silc_mp_uninit(&mp_tmp);
- silc_mp_uninit(&mp_dst);
+ o Mon Feb 12 11:20:32 EET 2001 Pekka
- return TRUE;
-}
+ Changed RSA private exponent generation to what PKCS #1 suggests. We
+ try to find the smallest possible d by doing modinv(e, lcm(phi)) instead
+ of modinv(e, phi). Note: this is not security fix but optimization.
-SILC_PKCS_API_VERIFY(rsa)
-{
- RsaKey *key = (RsaKey *)context;
- int i, ret;
- SilcMPInt mp_tmp, mp_tmp2;
- SilcMPInt mp_dst;
-
- silc_mp_init(&mp_tmp);
- silc_mp_init(&mp_tmp2);
- silc_mp_init(&mp_dst);
- silc_mp_set_ui(&mp_tmp, 0);
- silc_mp_set_ui(&mp_tmp2, 0);
- silc_mp_set_ui(&mp_dst, 0);
-
- /* Format the signature into MP int */
- for (i = 0; i < signature_len; i++) {
- silc_mp_mul_2exp(&mp_tmp2, &mp_tmp2, 8);
- silc_mp_add_ui(&mp_tmp2, &mp_tmp2, signature[i]);
- }
+ o Tue Feb 20 13:58:58 EET 2001 Pekka
- /* Verify */
- rsa_en_de_crypt(&mp_dst, &mp_tmp2, &key->e, &key->n);
+ Set key->bits in rsa_generate_key. It is the modulus length in bits.
+ The `tmplen' in encrypt, decrypt, sign and verify PKCS API functions
+ is now calculated by (key->bits + 7) / 8. It is the length of one block.
- /* Format the data into MP int */
- for (i = 0; i < data_len; i++) {
- silc_mp_mul_2exp(&mp_tmp, &mp_tmp, 8);
- silc_mp_add_ui(&mp_tmp, &mp_tmp, data[i]);
- }
+ o Sat Mar 16 18:27:19 EET 2002 Pekka
- ret = TRUE;
+ Use the SilcRng sent as argument to SILC_PKCS_API_INIT in prime
+ generation.
- /* Compare */
- if ((silc_mp_cmp(&mp_tmp, &mp_dst)) != 0)
- ret = FALSE;
+ o Sat Sep 26 19:59:48 EEST 2002 Pekka
- silc_mp_uninit(&mp_tmp);
- silc_mp_uninit(&mp_tmp2);
- silc_mp_uninit(&mp_dst);
+ Fixed double free in public key setting. Use a bit larger e as
+ starting point in key generation.
+*/
- return ret;
-}
+#include "silc.h"
+#include "rsa.h"
/* Generates RSA public and private keys. Primes p and q that are used
to compute the modulus n has to be generated before calling this. They
are then sent as argument for the function. */
-void rsa_generate_keys(RsaKey *key, uint32 bits,
- SilcMPInt *p, SilcMPInt *q)
+SilcBool silc_rsa_generate_keys(SilcUInt32 bits, SilcMPInt *p, SilcMPInt *q,
+ void **ret_public_key, void **ret_private_key)
{
+ RsaPublicKey *pubkey;
+ RsaPrivateKey *privkey;
SilcMPInt phi, hlp;
SilcMPInt div, lcm;
SilcMPInt pm1, qm1;
-
+
+ *ret_public_key = pubkey = silc_calloc(1, sizeof(*pubkey));
+ if (!pubkey)
+ return FALSE;
+
+ *ret_private_key = privkey = silc_calloc(1, sizeof(*privkey));
+ if (!privkey)
+ return FALSE;
+
/* Initialize variables */
- silc_mp_init(&key->p);
- silc_mp_init(&key->q);
- silc_mp_init(&key->n);
- silc_mp_init(&key->e);
- silc_mp_init(&key->d);
+ silc_mp_init(&privkey->n);
+ silc_mp_init(&privkey->e);
+ silc_mp_init(&privkey->d);
+ silc_mp_init(&privkey->dP);
+ silc_mp_init(&privkey->dQ);
+ silc_mp_init(&privkey->qP);
silc_mp_init(&phi);
silc_mp_init(&hlp);
silc_mp_init(&div);
silc_mp_init(&qm1);
/* Set modulus length */
- key->bits = bits;
+ privkey->bits = bits;
- /* Set the primes */
- silc_mp_set(&key->p, p);
- silc_mp_set(&key->q, q);
-
/* Compute modulus, n = p * q */
- silc_mp_mul(&key->n, &key->p, &key->q);
-
+ silc_mp_mul(&privkey->n, p, q);
+
/* phi = (p - 1) * (q - 1) */
- silc_mp_sub_ui(&pm1, &key->p, 1);
- silc_mp_sub_ui(&qm1, &key->q, 1);
+ silc_mp_sub_ui(&pm1, p, 1);
+ silc_mp_sub_ui(&qm1, q, 1);
silc_mp_mul(&phi, &pm1, &qm1);
-
+
/* Set e, the public exponent. We try to use same public exponent
- for all keys. Also, to make encryption faster we use small
+ for all keys. Also, to make encryption faster we use small
number. */
- silc_mp_set_ui(&key->e, 127);
+ silc_mp_set_ui(&privkey->e, 65533);
retry_e:
/* See if e is relatively prime to phi. gcd == greates common divisor,
if gcd equals 1 they are relatively prime. */
- silc_mp_gcd(&hlp, &key->e, &phi);
- if((silc_mp_cmp_ui(&hlp, 1)) > 0) {
- silc_mp_add_ui(&key->e, &key->e, 2);
+ silc_mp_gcd(&hlp, &privkey->e, &phi);
+ if ((silc_mp_cmp_ui(&hlp, 1)) > 0) {
+ silc_mp_add_ui(&privkey->e, &privkey->e, 2);
goto retry_e;
}
-
- /* Find d, the private exponent. */
+
+ /* Find d, the private exponent, e ^ -1 mod lcm(phi). */
silc_mp_gcd(&div, &pm1, &qm1);
silc_mp_div(&lcm, &phi, &div);
- silc_mp_modinv(&key->d, &key->e, &lcm);
-
+ silc_mp_modinv(&privkey->d, &privkey->e, &lcm);
+
+ /* Optimize d with CRT. */
+ silc_mp_mod(&privkey->dP, &privkey->d, &pm1);
+ silc_mp_mod(&privkey->dQ, &privkey->d, &qm1);
+ silc_mp_modinv(&privkey->qP, q, p);
+ silc_mp_set(&privkey->p, p);
+ silc_mp_set(&privkey->q, q);
+
silc_mp_uninit(&phi);
silc_mp_uninit(&hlp);
silc_mp_uninit(&div);
silc_mp_uninit(&lcm);
silc_mp_uninit(&pm1);
silc_mp_uninit(&qm1);
+
+ /* Set public key */
+ silc_mp_init(&pubkey->n);
+ silc_mp_init(&pubkey->e);
+ pubkey->bits = privkey->bits;
+ silc_mp_set(&pubkey->n, &privkey->n);
+ silc_mp_set(&pubkey->e, &privkey->e);
+
+ return TRUE;
}
-/* Clears whole key structure. */
+/* RSA public key operation */
-void rsa_clear_keys(RsaKey *key)
+SilcBool silc_rsa_public_operation(RsaPublicKey *key, SilcMPInt *src,
+ SilcMPInt *dst)
{
- key->bits = 0;
- silc_mp_uninit(&key->p);
- silc_mp_uninit(&key->q);
- silc_mp_uninit(&key->n);
- silc_mp_uninit(&key->e);
- silc_mp_uninit(&key->d);
+ /* dst = src ^ e mod n */
+ silc_mp_pow_mod(dst, src, &key->e, &key->n);
+ return TRUE;
}
-/* RSA encrypt/decrypt function. cm = ciphertext or plaintext,
- mc = plaintext or ciphertext, expo = public or private exponent,
- and modu = modulus.
-
- Encrypt: c = m ^ e mod n,
- Decrypt: m = c ^ d mod n
-*/
+/* RSA private key operation */
-void rsa_en_de_crypt(SilcMPInt *cm, SilcMPInt *mc,
- SilcMPInt *expo, SilcMPInt *modu)
+SilcBool silc_rsa_private_operation(RsaPrivateKey *key, SilcMPInt *src,
+ SilcMPInt *dst)
{
- silc_mp_pow_mod(cm, mc, expo, modu);
+ SilcMPInt tmp;
+
+ silc_mp_init(&tmp);
+
+ /* dst = (src ^ dP mod p) */
+ silc_mp_pow_mod(dst, src, &key->dP, &key->p);
+
+ /* tmp = (src ^ dQ mod q) */
+ silc_mp_pow_mod(&tmp, src, &key->dQ, &key->q);
+
+ /* dst = (dst - tmp) * qP mod p */
+ silc_mp_sub(dst, dst, &tmp);
+ silc_mp_mul(dst, dst, &key->qP);
+ silc_mp_mod(dst, dst, &key->p);
+
+ /* dst = (q * dst) + tmp */
+ silc_mp_mul(dst, dst, &key->q);
+ silc_mp_add(dst, dst, &tmp);
+
+ silc_mp_uninit(&tmp);
+
+ return TRUE;
}
projects / silc.git / blobdiff