*
* Author: Pekka Riikonen <priikone@poseidon.pspt.fi>
*
- * Copyright (C) 1997 - 2000 Pekka Riikonen
+ * 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
* Public key exponent:
* e relatively prime to (p-1) * (q-1)
* Private key exponent:
- * d = e ^ -1 mod ((p-1) * (q-1))
+ * 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.
+ * 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.
*
* 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.
+
+ o Sat Mar 16 18:27:19 EET 2002 Pekka
+
+ Use the SilcRng sent as argument to SILC_PKCS_API_INIT in prime
+ generation.
+
+ o Sat Sep 26 19:59:48 EEST 2002 Pekka
+
+ Fixed double free in public key setting. Use a bit larger e as
+ starting point in key generation.
+
+*/
#include "silcincludes.h"
+#include "rsa_internal.h"
#include "rsa.h"
/*
SILC_PKCS_API_INIT(rsa)
{
- unsigned int prime_bits = keylen / 2;
- SilcInt p, q;
+ SilcUInt32 prime_bits = keylen / 2;
+ SilcMPInt p, q;
+ bool found = FALSE;
printf("Generating RSA Public and Private keys, might take a while...\n");
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;
+ while (!found) {
+ printf("Finding p: ");
+ silc_math_gen_prime(&p, prime_bits, TRUE, rng);
+
+ printf("\nFinding q: ");
+ silc_math_gen_prime(&q, prime_bits, TRUE, rng);
+
+ if ((silc_mp_cmp(&p, &q)) == 0)
+ printf("\nFound equal primes, not good, retrying...\n");
+ else
+ found = TRUE;
}
/* If p is smaller than q, switch them */
if ((silc_mp_cmp(&p, &q)) > 0) {
- SilcInt hlp;
+ SilcMPInt hlp;
silc_mp_init(&hlp);
silc_mp_set(&hlp, &p);
silc_mp_set(&p, &q);
silc_mp_set(&q, &hlp);
- silc_mp_clear(&hlp);
+ silc_mp_uninit(&hlp);
}
/* Generate the actual keys */
rsa_generate_keys((RsaKey *)context, keylen, &p, &q);
- silc_mp_clear(&p);
- silc_mp_clear(&q);
+ silc_mp_uninit(&p);
+ silc_mp_uninit(&q);
- printf("\nKeys generated succesfully.\n");
+ printf("\nKeys generated successfully.\n");
return TRUE;
}
{
RsaKey *key = (RsaKey *)context;
unsigned char *e, *n, *ret;
- unsigned short e_len, n_len;
- unsigned char tmp[2];
+ SilcUInt32 e_len, n_len;
+ unsigned char tmp[4];
- e_len = silc_mp_sizeinbase(&key->e, 16);
- n_len = silc_mp_sizeinbase(&key->n, 16);
- e = silc_calloc(e_len + 1, sizeof(unsigned char));
- n = silc_calloc(n_len + 1, sizeof(unsigned char));
- silc_mp_get_str(e, 16, &key->e);
- silc_mp_get_str(n, 16, &key->n);
+ e = silc_mp_mp2bin(&key->e, 0, &e_len);
+ n = silc_mp_mp2bin(&key->n, (key->bits + 7) / 8, &n_len);
- *ret_len = e_len + 2 + n_len + 2;
+ *ret_len = e_len + 4 + n_len + 4;
ret = silc_calloc(*ret_len, sizeof(unsigned char));
/* Put the length of the e. */
- tmp[0] = e_len >> 8;
- tmp[1] = e_len;
- memcpy(ret, tmp, 2);
+ SILC_PUT32_MSB(e_len, tmp);
+ memcpy(ret, tmp, 4);
/* Put the e. */
- memcpy(ret + 2, e, e_len);
+ memcpy(ret + 4, e, e_len);
/* Put the length of the n. */
- tmp[0] = n_len >> 8;
- tmp[1] = n_len;
- memcpy(ret + 2 + e_len, tmp, 2);
+ SILC_PUT32_MSB(n_len, tmp);
+ memcpy(ret + 4 + e_len, tmp, 4);
/* Put the n. */
- memcpy(ret + 2 + e_len + 2, n, n_len);
+ memcpy(ret + 4 + e_len + 4, n, n_len);
memset(e, 0, e_len);
memset(n, 0, n_len);
{
RsaKey *key = (RsaKey *)context;
unsigned char *e, *n, *d, *ret;
- unsigned short e_len, n_len, d_len;
- unsigned char tmp[2];
-
- e_len = silc_mp_sizeinbase(&key->e, 16);
- n_len = silc_mp_sizeinbase(&key->n, 16);
- d_len = silc_mp_sizeinbase(&key->d, 16);
- e = silc_calloc(e_len + 1, sizeof(unsigned char));
- n = silc_calloc(n_len + 1, sizeof(unsigned char));
- d = silc_calloc(d_len + 1, sizeof(unsigned char));
- silc_mp_get_str(e, 16, &key->e);
- silc_mp_get_str(n, 16, &key->n);
- silc_mp_get_str(d, 16, &key->d);
-
- *ret_len = e_len + 2 + n_len + 2 + d_len + 2;
+ SilcUInt32 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 + 7) / 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. */
- tmp[0] = e_len >> 8;
- tmp[1] = e_len;
- memcpy(ret, tmp, 2);
+ SILC_PUT32_MSB(e_len, tmp);
+ memcpy(ret, tmp, 4);
/* Put the e. */
- memcpy(ret + 2, e, e_len);
+ memcpy(ret + 4, e, e_len);
/* Put the length of the n. */
- tmp[0] = n_len >> 8;
- tmp[1] = n_len;
- memcpy(ret + 2 + e_len, tmp, 2);
+ SILC_PUT32_MSB(n_len, tmp);
+ memcpy(ret + 4 + e_len, tmp, 4);
/* Put the n. */
- memcpy(ret + 2 + e_len + 2, n, n_len);
+ memcpy(ret + 4 + e_len + 4, n, n_len);
/* Put the length of the d. */
- tmp[0] = d_len >> 8;
- tmp[1] = d_len;
- memcpy(ret + 2 + e_len + 2 + n_len, tmp, 2);
+ SILC_PUT32_MSB(d_len, tmp);
+ memcpy(ret + 4 + e_len + 4 + n_len, tmp, 4);
/* Put the n. */
- memcpy(ret + 2 + e_len + 2 + n_len + 2, d, d_len);
+ memcpy(ret + 4 + e_len + 4 + n_len + 4, d, d_len);
memset(e, 0, e_len);
memset(n, 0, n_len);
SILC_PKCS_API_SET_PUBLIC_KEY(rsa)
{
RsaKey *key = (RsaKey *)context;
- unsigned char *e, *n, tmp[2];
- unsigned short e_len, n_len;
+ unsigned char tmp[4];
+ SilcUInt32 e_len, n_len;
+
+ if (key->pub_set) {
+ silc_mp_uninit(&key->e);
+ silc_mp_uninit(&key->n);
+ key->pub_set = FALSE;
+ }
+
+ if (key_len < 4)
+ return 0;
silc_mp_init(&key->e);
silc_mp_init(&key->n);
- memcpy(tmp, key_data, 2);
- e_len = ((unsigned int)tmp[0] << 8) | ((unsigned int)tmp[1]);
- if (e_len > key_len) {
- silc_mp_clear(&key->e);
- silc_mp_clear(&key->n);
- return FALSE;
+ memcpy(tmp, key_data, 4);
+ SILC_GET32_MSB(e_len, tmp);
+ if (!e_len || e_len + 4 > key_len) {
+ silc_mp_uninit(&key->e);
+ silc_mp_uninit(&key->n);
+ return 0;
}
- e = silc_calloc(e_len + 1, sizeof(unsigned char));
- memcpy(e, key_data + 2, e_len);
- silc_mp_set_str(&key->e, e, 16);
-
- memcpy(tmp, key_data + 2 + e_len, 2);
- n_len = ((unsigned int)tmp[0] << 8) | ((unsigned int)tmp[1]);
- if (e_len + n_len > key_len) {
- memset(e, 0, e_len);
- silc_free(e);
- silc_mp_clear(&key->e);
- silc_mp_clear(&key->n);
- return FALSE;
+ silc_mp_bin2mp(key_data + 4, e_len, &key->e);
+
+ if (key_len < 4 + e_len + 4) {
+ silc_mp_uninit(&key->e);
+ silc_mp_uninit(&key->n);
+ return 0;
}
- n = silc_calloc(n_len + 1, sizeof(unsigned char));
- memcpy(n, key_data + 2 + e_len + 2, n_len);
- silc_mp_set_str(&key->n, n, 16);
+ memcpy(tmp, key_data + 4 + e_len, 4);
+ SILC_GET32_MSB(n_len, tmp);
+ if (!n_len || e_len + 4 + n_len + 4 > key_len) {
+ silc_mp_uninit(&key->e);
+ silc_mp_uninit(&key->n);
+ return 0;
+ }
- memset(e, 0, e_len);
- memset(n, 0, n_len);
- silc_free(e);
- silc_free(n);
+ silc_mp_bin2mp(key_data + 4 + e_len + 4, n_len, &key->n);
- return TRUE;
+ key->bits = silc_mp_sizeinbase(&key->n, 2);
+ key->pub_set = TRUE;
+
+ return key->bits;
}
/* Set private key. This derives the public key from the private
SILC_PKCS_API_SET_PRIVATE_KEY(rsa)
{
RsaKey *key = (RsaKey *)context;
- unsigned char *e, *n, *d, tmp[2];
- unsigned short e_len, n_len, d_len;
+ unsigned char tmp[4];
+ SilcUInt32 e_len, n_len, d_len;
+
+ if (key->prv_set) {
+ silc_mp_uninit(&key->d);
+ key->prv_set = FALSE;
+ }
+
+ if (key->pub_set) {
+ silc_mp_uninit(&key->e);
+ silc_mp_uninit(&key->n);
+ key->pub_set = FALSE;
+ }
+
+ if (key_len < 4)
+ return FALSE;
silc_mp_init(&key->e);
silc_mp_init(&key->n);
silc_mp_init(&key->d);
- memcpy(tmp, key_data, 2);
- e_len = ((unsigned int)tmp[0] << 8) | ((unsigned int)tmp[1]);
- if (e_len > key_len) {
- silc_mp_clear(&key->e);
- silc_mp_clear(&key->n);
+ memcpy(tmp, key_data, 4);
+ SILC_GET32_MSB(e_len, tmp);
+ if (e_len + 4 > key_len) {
+ silc_mp_uninit(&key->e);
+ silc_mp_uninit(&key->n);
+ silc_mp_uninit(&key->d);
return FALSE;
}
- e = silc_calloc(e_len + 1, sizeof(unsigned char));
- memcpy(e, key_data + 2, e_len);
- silc_mp_set_str(&key->e, e, 16);
+ silc_mp_bin2mp(key_data + 4, e_len, &key->e);
- memcpy(tmp, key_data + 2 + e_len, 2);
- n_len = ((unsigned int)tmp[0] << 8) | ((unsigned int)tmp[1]);
- if (e_len + n_len > key_len) {
- memset(e, 0, e_len);
- silc_free(e);
- silc_mp_clear(&key->e);
- silc_mp_clear(&key->n);
+ if (key_len < e_len + 4 + 4) {
+ silc_mp_uninit(&key->e);
+ silc_mp_uninit(&key->n);
+ silc_mp_uninit(&key->d);
return FALSE;
}
- n = silc_calloc(n_len + 1, sizeof(unsigned char));
- memcpy(n, key_data + 2 + e_len + 2, n_len);
- silc_mp_set_str(&key->n, n, 16);
-
- memcpy(tmp, key_data + 2 + e_len + 2 + n_len, 2);
- d_len = ((unsigned int)tmp[0] << 8) | ((unsigned int)tmp[1]);
- if (e_len + n_len + d_len > key_len) {
- memset(n, 0, n_len);
- silc_free(n);
- memset(e, 0, e_len);
- silc_free(e);
- silc_mp_clear(&key->e);
- silc_mp_clear(&key->n);
+ memcpy(tmp, key_data + 4 + e_len, 4);
+ SILC_GET32_MSB(n_len, tmp);
+ if (e_len + 4 + n_len + 4 > key_len) {
+ silc_mp_uninit(&key->e);
+ silc_mp_uninit(&key->n);
+ silc_mp_uninit(&key->d);
return FALSE;
}
- d = silc_calloc(d_len + 1, sizeof(unsigned char));
- memcpy(d, key_data + 2 + e_len + 2 + n_len + 2, d_len);
- silc_mp_set_str(&key->d, d, 16);
+ silc_mp_bin2mp(key_data + 4 + e_len + 4, n_len, &key->n);
- memset(e, 0, e_len);
- memset(n, 0, n_len);
- memset(d, 0, d_len);
- silc_free(e);
- silc_free(n);
- silc_free(d);
+ if (key_len < e_len + 4 + n_len + 4 + 4) {
+ silc_mp_uninit(&key->e);
+ silc_mp_uninit(&key->n);
+ silc_mp_uninit(&key->d);
+ return FALSE;
+ }
- return TRUE;
-}
+ memcpy(tmp, key_data + 4 + e_len + 4 + n_len, 4);
+ SILC_GET32_MSB(d_len, tmp);
+ if (e_len + 4 + n_len + 4 + d_len + 4 > key_len) {
+ silc_mp_uninit(&key->e);
+ silc_mp_uninit(&key->n);
+ silc_mp_uninit(&key->d);
+ return FALSE;
+ }
-SILC_PKCS_API_CONTEXT_LEN(rsa)
-{
- return sizeof(RsaKey);
-}
+ silc_mp_bin2mp(key_data + 4 + e_len + 4 + n_len + 4, d_len, &key->d);
-SILC_PKCS_API_DATA_CONTEXT_LEN(rsa)
-{
- return sizeof(RsaDataContext);
+ key->bits = silc_mp_sizeinbase(&key->n, 2);
+ key->prv_set = TRUE;
+ key->pub_set = TRUE;
+
+ return key->bits;
}
-SILC_PKCS_API_SET_ARG(rsa)
+SILC_PKCS_API_CONTEXT_LEN(rsa)
{
- RsaDataContext *data_ctx = (RsaDataContext *)data_context;
-
- switch(argnum) {
- case 1:
- data_ctx->src = val;
- return TRUE;
- break;
- case 2:
- data_ctx->dst = val;
- return TRUE;
- break;
- case 3:
- data_ctx->exp = val;
- return TRUE;
- break;
- case 4:
- data_ctx->mod = val;
- return TRUE;
- break;
- default:
- return FALSE;
- break;
- }
-
- return FALSE;
+ return sizeof(RsaKey);
}
SILC_PKCS_API_ENCRYPT(rsa)
{
RsaKey *key = (RsaKey *)context;
- int i, tmplen;
- SilcInt mp_tmp;
- SilcInt mp_dst;
+ int tmplen;
+ SilcMPInt mp_tmp;
+ SilcMPInt mp_dst;
- silc_mp_init_set_ui(&mp_tmp, 0);
- silc_mp_init_set_ui(&mp_dst, 0);
+ silc_mp_init(&mp_tmp);
+ silc_mp_init(&mp_dst);
/* 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]);
- }
-
- silc_mp_out_str(stderr, 16, &mp_tmp);
+ silc_mp_bin2mp(src, src_len, &mp_tmp);
/* Encrypt */
rsa_en_de_crypt(&mp_dst, &mp_tmp, &key->e, &key->n);
- fprintf(stderr, "\n");
- silc_mp_out_str(stderr, 16, &mp_dst);
-
- tmplen = (1024 + 7) / 8;
+ tmplen = (key->bits + 7) / 8;
/* 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_fdiv_q_2exp(&mp_dst, &mp_dst, 8);
- }
+ silc_mp_mp2bin_noalloc(&mp_dst, dst, tmplen);
*dst_len = tmplen;
- silc_mp_clear(&mp_tmp);
- silc_mp_clear(&mp_dst);
+ silc_mp_uninit(&mp_tmp);
+ silc_mp_uninit(&mp_dst);
return TRUE;
}
SILC_PKCS_API_DECRYPT(rsa)
{
RsaKey *key = (RsaKey *)context;
- int i, tmplen;
- SilcInt mp_tmp;
- SilcInt mp_dst;
+ int tmplen;
+ SilcMPInt mp_tmp;
+ SilcMPInt mp_dst;
- silc_mp_init_set_ui(&mp_tmp, 0);
- silc_mp_init_set_ui(&mp_dst, 0);
+ silc_mp_init(&mp_tmp);
+ silc_mp_init(&mp_dst);
/* 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]);
- }
-
- silc_mp_out_str(stderr, 16, &mp_tmp);
+ silc_mp_bin2mp(src, src_len, &mp_tmp);
/* Decrypt */
rsa_en_de_crypt(&mp_dst, &mp_tmp, &key->d, &key->n);
- fprintf(stderr, "\n");
- silc_mp_out_str(stderr, 16, &mp_dst);
-
- tmplen = (1024 + 7) / 8;
+ tmplen = (key->bits + 7) / 8;
/* 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_fdiv_q_2exp(&mp_dst, &mp_dst, 8);
- }
+ silc_mp_mp2bin_noalloc(&mp_dst, dst, tmplen);
*dst_len = tmplen;
- silc_mp_clear(&mp_tmp);
- silc_mp_clear(&mp_dst);
+ silc_mp_uninit(&mp_tmp);
+ silc_mp_uninit(&mp_dst);
return TRUE;
}
SILC_PKCS_API_SIGN(rsa)
{
RsaKey *key = (RsaKey *)context;
- int i, tmplen;
- SilcInt mp_tmp;
- SilcInt mp_dst;
+ int tmplen;
+ SilcMPInt mp_tmp;
+ SilcMPInt mp_dst;
- silc_mp_init_set_ui(&mp_tmp, 0);
- silc_mp_init_set_ui(&mp_dst, 0);
+ silc_mp_init(&mp_tmp);
+ silc_mp_init(&mp_dst);
/* 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]);
- }
+ silc_mp_bin2mp(src, src_len, &mp_tmp);
/* Sign */
rsa_en_de_crypt(&mp_dst, &mp_tmp, &key->d, &key->n);
- tmplen = (1024 + 7) / 8;
+ tmplen = (key->bits + 7) / 8;
/* 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_fdiv_q_2exp(&mp_dst, &mp_dst, 8);
- }
+ silc_mp_mp2bin_noalloc(&mp_dst, dst, tmplen);
*dst_len = tmplen;
- silc_mp_clear(&mp_tmp);
- silc_mp_clear(&mp_dst);
+ silc_mp_uninit(&mp_tmp);
+ silc_mp_uninit(&mp_dst);
return TRUE;
}
SILC_PKCS_API_VERIFY(rsa)
{
RsaKey *key = (RsaKey *)context;
- int i, ret;
- SilcInt mp_tmp, mp_tmp2;
- SilcInt mp_dst;
+ int ret;
+ SilcMPInt mp_tmp, mp_tmp2;
+ SilcMPInt mp_dst;
- silc_mp_init_set_ui(&mp_tmp, 0);
- silc_mp_init_set_ui(&mp_tmp2, 0);
- silc_mp_init_set_ui(&mp_dst, 0);
+ silc_mp_init(&mp_tmp);
+ silc_mp_init(&mp_tmp2);
+ silc_mp_init(&mp_dst);
/* 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]);
- }
+ silc_mp_bin2mp(signature, signature_len, &mp_tmp2);
/* Verify */
rsa_en_de_crypt(&mp_dst, &mp_tmp2, &key->e, &key->n);
/* 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]);
- }
+ silc_mp_bin2mp(data, data_len, &mp_tmp);
ret = TRUE;
if ((silc_mp_cmp(&mp_tmp, &mp_dst)) != 0)
ret = FALSE;
- silc_mp_clear(&mp_tmp);
- silc_mp_clear(&mp_tmp2);
- silc_mp_clear(&mp_dst);
+ silc_mp_uninit(&mp_tmp);
+ silc_mp_uninit(&mp_tmp2);
+ silc_mp_uninit(&mp_dst);
return ret;
}
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, unsigned int bits,
- SilcInt *p, SilcInt *q)
+void rsa_generate_keys(RsaKey *key, SilcUInt32 bits,
+ SilcMPInt *p, SilcMPInt *q)
{
- SilcInt phi, hlp;
- SilcInt dq;
- SilcInt pm1, qm1;
+ SilcMPInt phi, hlp;
+ SilcMPInt div, lcm;
+ SilcMPInt pm1, qm1;
/* 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(&phi);
silc_mp_init(&hlp);
- silc_mp_init(&dq);
+ silc_mp_init(&div);
+ silc_mp_init(&lcm);
silc_mp_init(&pm1);
silc_mp_init(&qm1);
- /* Set the primes */
- silc_mp_set(&key->p, p);
- silc_mp_set(&key->q, q);
-
+ /* Set modulus length */
+ key->bits = bits;
+
/* Compute modulus, n = p * q */
- silc_mp_mul(&key->n, &key->p, &key->q);
+ silc_mp_mul(&key->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
number. */
- silc_mp_set_ui(&key->e, 127);
+ silc_mp_set_ui(&key->e, 65533);
retry_e:
/* See if e is relatively prime to phi. gcd == greates common divisor,
if gcd equals 1 they are relatively prime. */
goto retry_e;
}
- /* Find d, the private exponent. First we do phi / 2, to get it a
- bit smaller */
- silc_mp_div_ui(&dq, &phi, 2);
- silc_mp_modinv(&key->d, &key->e, &dq);
+ /* 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_clear(&phi);
- silc_mp_clear(&hlp);
- silc_mp_clear(&dq);
- silc_mp_clear(&pm1);
- silc_mp_clear(&qm1);
+ silc_mp_uninit(&phi);
+ silc_mp_uninit(&hlp);
+ silc_mp_uninit(&div);
+ silc_mp_uninit(&lcm);
+ silc_mp_uninit(&pm1);
+ silc_mp_uninit(&qm1);
}
/* Clears whole key structure. */
void rsa_clear_keys(RsaKey *key)
{
key->bits = 0;
- silc_mp_clear(&key->p);
- silc_mp_clear(&key->q);
- silc_mp_clear(&key->n);
- silc_mp_clear(&key->e);
- silc_mp_clear(&key->d);
+ if (key->pub_set) {
+ silc_mp_uninit(&key->n);
+ silc_mp_uninit(&key->e);
+ }
+ if (key->prv_set)
+ silc_mp_uninit(&key->d);
}
/* RSA encrypt/decrypt function. cm = ciphertext or plaintext,
Decrypt: m = c ^ d mod n
*/
-void rsa_en_de_crypt(SilcInt *cm, SilcInt *mc,
- SilcInt *expo, SilcInt *modu)
+void rsa_en_de_crypt(SilcMPInt *cm, SilcMPInt *mc,
+ SilcMPInt *expo, SilcMPInt *modu)
{
- silc_mp_powm(cm, mc, expo, modu);
+ silc_mp_pow_mod(cm, mc, expo, modu);
}