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Diffstat (limited to 'rsa.c')
| -rw-r--r-- | rsa.c | 164 |
1 files changed, 164 insertions, 0 deletions
@@ -0,0 +1,164 @@ +/* + +rsa.c + +Author: Tatu Ylonen <ylo@cs.hut.fi> + +Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland + All rights reserved + +Created: Fri Mar 3 22:07:06 1995 ylo + +Description of the RSA algorithm can be found e.g. from the following sources: + + Bruce Schneier: Applied Cryptography. John Wiley & Sons, 1994. + + Jennifer Seberry and Josed Pieprzyk: Cryptography: An Introduction to + Computer Security. Prentice-Hall, 1989. + + Man Young Rhee: Cryptography and Secure Data Communications. McGraw-Hill, + 1994. + + R. Rivest, A. Shamir, and L. M. Adleman: Cryptographic Communications + System and Method. US Patent 4,405,829, 1983. + + Hans Riesel: Prime Numbers and Computer Methods for Factorization. + Birkhauser, 1994. + + The RSA Frequently Asked Questions document by RSA Data Security, Inc., 1995. + + RSA in 3 lines of perl by Adam Back <aba@atlax.ex.ac.uk>, 1995, as included + below: + + gone - had to be deleted - what a pity + +*/ + +#include "includes.h" +RCSID("$Id: rsa.c,v 1.1 1999/10/27 03:42:44 damien Exp $"); + +#include "rsa.h" +#include "ssh.h" +#include "xmalloc.h" + +int rsa_verbose = 1; + +int +rsa_alive() +{ + RSA *key; + + key = RSA_generate_key(32, 3, NULL, NULL); + if (key == NULL) + return (0); + RSA_free(key); + return (1); +} + +/* Generates RSA public and private keys. This initializes the data + structures; they should be freed with rsa_clear_private_key and + rsa_clear_public_key. */ + +void +rsa_generate_key(RSA *prv, RSA *pub, unsigned int bits) +{ + RSA *key; + + if (rsa_verbose) { + printf("Generating RSA keys: "); + fflush(stdout); + } + + key = RSA_generate_key(bits, 35, NULL, NULL); + + assert(key != NULL); + + /* Copy public key parameters */ + pub->n = BN_new(); + BN_copy(pub->n, key->n); + pub->e = BN_new(); + BN_copy(pub->e, key->e); + + /* Copy private key parameters */ + prv->n = BN_new(); + BN_copy(prv->n, key->n); + prv->e = BN_new(); + BN_copy(prv->e, key->e); + prv->d = BN_new(); + BN_copy(prv->d, key->d); + prv->p = BN_new(); + BN_copy(prv->p, key->p); + prv->q = BN_new(); + BN_copy(prv->q, key->q); + + prv->dmp1 = BN_new(); + BN_copy(prv->dmp1, key->dmp1); + + prv->dmq1 = BN_new(); + BN_copy(prv->dmq1, key->dmq1); + + prv->iqmp = BN_new(); + BN_copy(prv->iqmp, key->iqmp); + + RSA_free(key); + + if (rsa_verbose) + printf("Key generation complete.\n"); +} + +void +rsa_public_encrypt(BIGNUM *out, BIGNUM *in, RSA* key) +{ + char *inbuf, *outbuf; + int len; + + if (BN_num_bits(key->e) < 2 || !BN_is_odd(key->e)) + fatal("rsa_public_encrypt() exponent too small or not odd"); + + len = BN_num_bytes(key->n); + outbuf = xmalloc(len); + + len = BN_num_bytes(in); + inbuf = xmalloc(len); + BN_bn2bin(in, inbuf); + + if ((len = RSA_public_encrypt(len, inbuf, outbuf, key, + RSA_PKCS1_PADDING)) <= 0) + fatal("rsa_public_encrypt() failed"); + + BN_bin2bn(outbuf, len, out); + + xfree(outbuf); + xfree(inbuf); +} + +void +rsa_private_decrypt(BIGNUM *out, BIGNUM *in, RSA *key) +{ + char *inbuf, *outbuf; + int len; + + len = BN_num_bytes(key->n); + outbuf = xmalloc(len); + + len = BN_num_bytes(in); + inbuf = xmalloc(len); + BN_bn2bin(in, inbuf); + + if ((len = RSA_private_decrypt(len, inbuf, outbuf, key, + RSA_SSLV23_PADDING)) <= 0) + fatal("rsa_private_decrypt() failed"); + + BN_bin2bn(outbuf, len, out); + + xfree(outbuf); + xfree(inbuf); +} + +/* Set whether to output verbose messages during key generation. */ + +void +rsa_set_verbose(int verbose) +{ + rsa_verbose = verbose; +} |