/* * * rsa.c * * Author: Tatu Ylonen * * Copyright (c) 1995 Tatu Ylonen , 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 , 1995, as included * below: * * [gone - had to be deleted - what a pity] * */ #include "includes.h" RCSID("\$Id: rsa.c,v 1.10 2000/03/09 10:27:51 damien Exp \$"); #include "rsa.h" #include "ssh.h" #include "xmalloc.h" #include "random.h" int rsa_verbose = 1; /* * Seed OpenSSL's random number generator */ void seed_rng() { char buf[64]; get_random_bytes(buf, sizeof(buf)); RAND_seed(buf, sizeof(buf)); memset(buf, 0, sizeof(buf)); } int rsa_alive() { RSA *key; seed_rng(); key = RSA_generate_key(32, 3, NULL, NULL); if (key == NULL) return (0); RSA_free(key); return (1); } /* * Key generation progress meter callback */ void keygen_progress(int p, int n, void *arg) { const char progress_chars[] = ".o+O?"; if ((p < 0) || (p > (sizeof(progress_chars) - 2))) p = sizeof(progress_chars) - 2; putchar(progress_chars[p]); fflush(stdout); } /* * 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; seed_rng(); if (rsa_verbose) { printf("Generating RSA keys: "); fflush(stdout); key = RSA_generate_key(bits, 35, keygen_progress, NULL); printf("\n"); } else { key = RSA_generate_key(bits, 35, NULL, NULL); } if (key == NULL) fatal("rsa_generate_key: key generation failed."); /* 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, ilen, olen; if (BN_num_bits(key->e) < 2 || !BN_is_odd(key->e)) fatal("rsa_public_encrypt() exponent too small or not odd"); olen = BN_num_bytes(key->n); outbuf = xmalloc(olen); ilen = BN_num_bytes(in); inbuf = xmalloc(ilen); BN_bn2bin(in, inbuf); if ((len = RSA_public_encrypt(ilen, inbuf, outbuf, key, RSA_PKCS1_PADDING)) <= 0) fatal("rsa_public_encrypt() failed"); BN_bin2bn(outbuf, len, out); memset(outbuf, 0, olen); memset(inbuf, 0, ilen); xfree(outbuf); xfree(inbuf); } void rsa_private_decrypt(BIGNUM *out, BIGNUM *in, RSA *key) { char *inbuf, *outbuf; int len, ilen, olen; olen = BN_num_bytes(key->n); outbuf = xmalloc(olen); ilen = BN_num_bytes(in); inbuf = xmalloc(ilen); BN_bn2bin(in, inbuf); if ((len = RSA_private_decrypt(ilen, inbuf, outbuf, key, RSA_PKCS1_PADDING)) <= 0) fatal("rsa_private_decrypt() failed"); BN_bin2bn(outbuf, len, out); memset(outbuf, 0, olen); memset(inbuf, 0, ilen); xfree(outbuf); xfree(inbuf); } /* Set whether to output verbose messages during key generation. */ void rsa_set_verbose(int verbose) { rsa_verbose = verbose; }