177 lines
3.9 KiB
C
177 lines
3.9 KiB
C
/*
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*
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* rsa.c
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*
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* Author: Tatu Ylonen <ylo@cs.hut.fi>
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*
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* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
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* All rights reserved
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*
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* Created: Fri Mar 3 22:07:06 1995 ylo
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*
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* Description of the RSA algorithm can be found e.g. from the following sources:
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*
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* Bruce Schneier: Applied Cryptography. John Wiley & Sons, 1994.
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*
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* Jennifer Seberry and Josed Pieprzyk: Cryptography: An Introduction to
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* Computer Security. Prentice-Hall, 1989.
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*
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* Man Young Rhee: Cryptography and Secure Data Communications. McGraw-Hill,
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* 1994.
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*
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* R. Rivest, A. Shamir, and L. M. Adleman: Cryptographic Communications
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* System and Method. US Patent 4,405,829, 1983.
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*
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* Hans Riesel: Prime Numbers and Computer Methods for Factorization.
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* Birkhauser, 1994.
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*
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* The RSA Frequently Asked Questions document by RSA Data Security, Inc., 1995.
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*
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* RSA in 3 lines of perl by Adam Back <aba@atlax.ex.ac.uk>, 1995, as included
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* below:
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*
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* [gone - had to be deleted - what a pity]
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*
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* $FreeBSD$
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*/
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#include "includes.h"
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RCSID("$Id: rsa.c,v 1.14 2000/04/14 10:30:32 markus Exp $");
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#include "rsa.h"
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#include "ssh.h"
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#include "xmalloc.h"
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int rsa_verbose = 1;
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int
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rsa_alive()
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{
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RSA *key;
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key = RSA_generate_key(32, 3, NULL, NULL);
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if (key == NULL)
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return (0);
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RSA_free(key);
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return (1);
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}
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/*
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* Generates RSA public and private keys. This initializes the data
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* structures; they should be freed with rsa_clear_private_key and
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* rsa_clear_public_key.
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*/
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void
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rsa_generate_key(RSA *prv, RSA *pub, unsigned int bits)
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{
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RSA *key;
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if (rsa_verbose) {
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printf("Generating RSA keys: ");
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fflush(stdout);
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}
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key = RSA_generate_key(bits, 35, NULL, NULL);
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if (key == NULL)
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fatal("rsa_generate_key: key generation failed.");
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/* Copy public key parameters */
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pub->n = BN_new();
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BN_copy(pub->n, key->n);
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pub->e = BN_new();
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BN_copy(pub->e, key->e);
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/* Copy private key parameters */
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prv->n = BN_new();
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BN_copy(prv->n, key->n);
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prv->e = BN_new();
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BN_copy(prv->e, key->e);
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prv->d = BN_new();
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BN_copy(prv->d, key->d);
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prv->p = BN_new();
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BN_copy(prv->p, key->p);
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prv->q = BN_new();
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BN_copy(prv->q, key->q);
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prv->dmp1 = BN_new();
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BN_copy(prv->dmp1, key->dmp1);
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prv->dmq1 = BN_new();
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BN_copy(prv->dmq1, key->dmq1);
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prv->iqmp = BN_new();
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BN_copy(prv->iqmp, key->iqmp);
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RSA_free(key);
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if (rsa_verbose)
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printf("Key generation complete.\n");
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}
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void
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rsa_public_encrypt(BIGNUM *out, BIGNUM *in, RSA *key)
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{
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unsigned char *inbuf, *outbuf;
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int len, ilen, olen;
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if (BN_num_bits(key->e) < 2 || !BN_is_odd(key->e))
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fatal("rsa_public_encrypt() exponent too small or not odd");
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olen = BN_num_bytes(key->n);
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outbuf = xmalloc(olen);
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ilen = BN_num_bytes(in);
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inbuf = xmalloc(ilen);
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BN_bn2bin(in, inbuf);
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if ((len = RSA_public_encrypt(ilen, inbuf, outbuf, key,
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RSA_PKCS1_PADDING)) <= 0)
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if (BN_num_bits(key->n) > 1024 && RSA_libversion() == RSALIB_RSAREF)
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fatal("rsa_private_encrypt() failed: RSAREF cannot handle keys larger than 1024 bits.");
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else
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fatal("rsa_private_encrypt() failed.");
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BN_bin2bn(outbuf, len, out);
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memset(outbuf, 0, olen);
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memset(inbuf, 0, ilen);
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xfree(outbuf);
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xfree(inbuf);
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}
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void
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rsa_private_decrypt(BIGNUM *out, BIGNUM *in, RSA *key)
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{
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unsigned char *inbuf, *outbuf;
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int len, ilen, olen;
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olen = BN_num_bytes(key->n);
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outbuf = xmalloc(olen);
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ilen = BN_num_bytes(in);
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inbuf = xmalloc(ilen);
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BN_bn2bin(in, inbuf);
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if ((len = RSA_private_decrypt(ilen, inbuf, outbuf, key,
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RSA_PKCS1_PADDING)) <= 0)
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if (BN_num_bits(key->n) > 1024 && RSA_libversion() == RSALIB_RSAREF)
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fatal("rsa_private_decrypt() failed: RSAREF cannot handle keys larger than 1024 bits.");
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else
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fatal("rsa_private_decrypt() failed.");
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BN_bin2bn(outbuf, len, out);
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memset(outbuf, 0, olen);
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memset(inbuf, 0, ilen);
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xfree(outbuf);
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xfree(inbuf);
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}
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/* Set whether to output verbose messages during key generation. */
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void
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rsa_set_verbose(int verbose)
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{
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rsa_verbose = verbose;
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}
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