Move RSA key generation into the wrappers.
[tinc] / src / gcrypt / rsagen.c
diff --git a/src/gcrypt/rsagen.c b/src/gcrypt/rsagen.c
new file mode 100644 (file)
index 0000000..d9f42b7
--- /dev/null
@@ -0,0 +1,222 @@
+/*
+    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;
+}