+/*
+ rsagen.c -- RSA key generation and export
+ Copyright (C) 2008 Guus Sliepen <guus@tinc-vpn.org>
+
+ 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.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+ $Id$
+*/
+
+#include "system.h"
+
+#include <gcrypt.h>
+
+#include "rsagen.h"
+
+#if 0
+// Base64 encoding table
+
+static const char b64e[64] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+// PEM encoding
+
+static bool pem_encode(FILE *fp, const char *header, uint8_t *buf, size_t size) {
+ bool decode = false;
+ char line[1024];
+ uint32_t word = 0;
+ int shift = 0;
+ size_t i, j = 0;
+
+ fprintf(fp, "-----BEGIN %s-----\n", header);
+
+ for(i = 0; i < size; i += 3) {
+ if(i <= size - 3) {
+ word = buf[i] << 16 | buf[i + 1] << 8 | buf[i + 2];
+ } else {
+ word = buf[i] << 16;
+ if(i == size - 2)
+ word |= buf[i + 1] << 8;
+ }
+
+ line[j++] = b64e[(word >> 18) ];
+ line[j++] = b64e[(word >> 12) & 0x3f];
+ line[j++] = b64e[(word >> 6) & 0x3f];
+ line[j++] = b64e[(word ) & 0x3f];
+
+ if(j >= 64) {
+ line[j++] = '\n';
+ line[j] = 0;
+ fputs(line, fp);
+ j = 0;
+ }
+ }
+
+ if(size % 3 > 0) {
+ if(size % 3 > 1)
+ line[j++] = '=';
+ line[j++] = '=';
+ }
+
+ if(j) {
+ line[j++] = '\n';
+ line[j] = 0;
+ fputs(line, fp);
+ }
+
+ fprintf(fp, "-----END %s-----\n", header);
+
+ return true;
+}
+
+
+// BER encoding functions
+
+static bool ber_write_id(uint8_t **p, size_t *buflen, int id) {
+ if(*buflen <= 0)
+ return false;
+
+ if(id >= 0x1f) {
+ while(id) {
+ if(*buflen <= 0)
+ return false;
+
+ (*buflen)--;
+ **p = id & 0x7f;
+ id >>= 7;
+ if(id)
+ **p |= 0x80;
+ (*p)++;
+ }
+ } else {
+ (*buflen)--;
+ *(*p)++ = id;
+ }
+
+ return true;
+}
+
+static bool ber_write_len(uint8_t **p, size_t *buflen, size_t len) {
+ do {
+ if(*buflen <= 0)
+ return false;
+
+ (*buflen)--;
+ **p = len & 0x7f;
+ len >>= 7;
+ if(len)
+ **p |= 0x80;
+ (*p)++;
+ } while(len);
+
+ return true;
+}
+
+static bool ber_write_sequence(uint8_t **p, size_t *buflen, uint8_t *seqbuf, size_t seqlen) {
+ if(!ber_write_id(p, buflen, 0x10) || !ber_write_len(p, buflen, seqlen) || *buflen < seqlen)
+ return false;
+
+ memcpy(*p, seqbuf, seqlen);
+ *p += seqlen;
+ *buflen -= seqlen;
+
+ return true;
+}
+
+static bool ber_write_mpi(uint8_t **p, size_t *buflen, gcry_mpi_t mpi) {
+ uint8_t tmpbuf[1024];
+ size_t tmplen = sizeof tmpbuf;
+ gcry_error_t err;
+
+ err = gcry_mpi_aprint(GCRYMPI_FMT_USG, &tmpbuf, &tmplen, mpi);
+ if(err)
+ return false;
+
+ if(!ber_write_id(p, buflen, 0x02) || !ber_write_len(p, buflen, tmplen) || *buflen < tmplen)
+ return false;
+
+ memcpy(*p, tmpbuf, tmplen);
+ *p += tmplen;
+ *buflen -= tmplen;
+
+ return true;
+}
+
+// Write PEM RSA keys
+
+bool rsa_write_pem_public_key(rsa_t *rsa, FILE *fp) {
+ uint8_t derbuf1[8096];
+ uint8_t derbuf2[8096];
+ uint8_t *derp1 = derbuf1;
+ uint8_t *derp2 = derbuf2;
+ size_t derlen1 = sizeof derbuf1;
+ size_t derlen2 = sizeof derbuf2;
+
+ if(!ber_write_mpi(&derp1, &derlen1, &rsa->n)
+ || !ber_write_mpi(&derp1, &derlen1, &rsa->e)
+ || !ber_write_sequence(&derp2, &derlen2, derbuf1, derlen1)) {
+ logger(LOG_ERR, _("Error while encoding RSA public key"));
+ return false;
+ }
+
+ if(!pem_encode(fp, "RSA PUBLIC KEY", derbuf2, derlen2)) {
+ logger(LOG_ERR, _("Unable to write RSA public key: %s"), strerror(errno));
+ return false;
+ }
+
+ return true;
+}
+
+bool rsa_write_pem_private_key(rsa_t *rsa, FILE *fp) {
+ uint8_t derbuf1[8096];
+ uint8_t derbuf2[8096];
+ uint8_t *derp1 = derbuf1;
+ uint8_t *derp2 = derbuf2;
+ size_t derlen1 = sizeof derbuf1;
+ size_t derlen2 = sizeof derbuf2;
+
+ if(!ber_write_mpi(&derp1, &derlen1, &bits)
+ || ber_write_mpi(&derp1, &derlen1, &rsa->n) // modulus
+ || ber_write_mpi(&derp1, &derlen1, &rsa->e) // public exponent
+ || ber_write_mpi(&derp1, &derlen1, &rsa->d) // private exponent
+ || ber_write_mpi(&derp1, &derlen1, &p)
+ || ber_write_mpi(&derp1, &derlen1, &q)
+ || ber_write_mpi(&derp1, &derlen1, &exp1)
+ || ber_write_mpi(&derp1, &derlen1, &exp2)
+ || ber_write_mpi(&derp1, &derlen1, &coeff))
+ logger(LOG_ERR, _("Error while encoding RSA private key"));
+ return false;
+ }
+
+ if(!pem_encode(fp, "RSA PRIVATE KEY", derbuf2, derlen2)) {
+ logger(LOG_ERR, _("Unable to write RSA private key: %s"), strerror(errno));
+ return false;
+ }
+
+ return true;
+}
+#endif
+
+bool rsa_write_pem_public_key(rsa_t *rsa, FILE *fp) {
+ return false;
+}
+
+bool rsa_write_pem_private_key(rsa_t *rsa, FILE *fp) {
+ return false;
+}
+
+bool rsa_generate(rsa_t *rsa, size_t bits, unsigned long exponent) {
+ fprintf(stderr, _("Generating RSA keys with libgcrypt not implemented yet\n"));
+ return false;
+}
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