key.c - security/openssh-library - Rivoreo Source Code Repositories

 /*
  * read_bignum():
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
  *
  * As far as I am concerned, the code I have written for this software
  * can be used freely for any purpose.  Any derived versions of this
  * software must be clearly marked as such, and if the derived work is
  * incompatible with the protocol description in the RFC file, it must be
  * called by a name other than "ssh" or "Secure Shell".
  *
  *
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */

 #include "includes.h"
 #include "ssh.h"
 #include <openssl/rsa.h>
 #include <openssl/dsa.h>
 #include <openssl/evp.h>
 #include "xmalloc.h"
 #include "key.h"
 #include "dsa.h"
 #include "uuencode.h"

 RCSID("$OpenBSD: key.c,v 1.11 2000/09/07 20:27:51 deraadt Exp $");

 #define SSH_DSS "ssh-dss"

 Key *
 key_new(int type)
 {
 	Key *k;
 	RSA *rsa;
 	DSA *dsa;
 	k = xmalloc(sizeof(*k));
 	k->type = type;
 	k->dsa = NULL;
 	k->rsa = NULL;
 	switch (k->type) {
 	case KEY_RSA:
 		rsa = RSA_new();
 		rsa->n = BN_new();
 		rsa->e = BN_new();
 		k->rsa = rsa;
 		break;
 	case KEY_DSA:
 		dsa = DSA_new();
 		dsa->p = BN_new();
 		dsa->q = BN_new();
 		dsa->g = BN_new();
 		dsa->pub_key = BN_new();
 		k->dsa = dsa;
 		break;
 	case KEY_EMPTY:
 		break;
 	default:
 		fatal("key_new: bad key type %d", k->type);
 		break;
 	}
 	return k;
 }
 void
 key_free(Key *k)
 {
 	switch (k->type) {
 	case KEY_RSA:
 		if (k->rsa != NULL)
 			RSA_free(k->rsa);
 		k->rsa = NULL;
 		break;
 	case KEY_DSA:
 		if (k->dsa != NULL)
 			DSA_free(k->dsa);
 		k->dsa = NULL;
 		break;
 	default:
 		fatal("key_free: bad key type %d", k->type);
 		break;
 	}
 	xfree(k);
 }
 int
 key_equal(Key *a, Key *b)
 {
 	if (a == NULL || b == NULL || a->type != b->type)
 		return 0;
 	switch (a->type) {
 	case KEY_RSA:
 		return a->rsa != NULL && b->rsa != NULL &&
 		    BN_cmp(a->rsa->e, b->rsa->e) == 0 &&
 		    BN_cmp(a->rsa->n, b->rsa->n) == 0;
 		break;
 	case KEY_DSA:
 		return a->dsa != NULL && b->dsa != NULL &&
 		    BN_cmp(a->dsa->p, b->dsa->p) == 0 &&
 		    BN_cmp(a->dsa->q, b->dsa->q) == 0 &&
 		    BN_cmp(a->dsa->g, b->dsa->g) == 0 &&
 		    BN_cmp(a->dsa->pub_key, b->dsa->pub_key) == 0;
 		break;
 	default:
 		fatal("key_equal: bad key type %d", a->type);
 		break;
 	}
 	return 0;
 }

 /*
  * Generate key fingerprint in ascii format.
  * Based on ideas and code from Bjoern Groenvall <bg@sics.se>
  */
 char *
 key_fingerprint(Key *k)
 {
 	static char retval[(EVP_MAX_MD_SIZE+1)*3];
 	unsigned char *blob = NULL;
 	int len = 0;
 	int nlen, elen;

 	switch (k->type) {
 	case KEY_RSA:
 		nlen = BN_num_bytes(k->rsa->n);
 		elen = BN_num_bytes(k->rsa->e);
 		len = nlen + elen;
 		blob = xmalloc(len);
 		BN_bn2bin(k->rsa->n, blob);
 		BN_bn2bin(k->rsa->e, blob + nlen);
 		break;
 	case KEY_DSA:
 		dsa_make_key_blob(k, &blob, &len);
 		break;
 	default:
 		fatal("key_fingerprint: bad key type %d", k->type);
 		break;
 	}
 	retval[0] = '\0';

 	if (blob != NULL) {
 		int i;
 		unsigned char digest[EVP_MAX_MD_SIZE];
 		EVP_MD *md = EVP_md5();
 		EVP_MD_CTX ctx;
 		EVP_DigestInit(&ctx, md);
 		EVP_DigestUpdate(&ctx, blob, len);
 		EVP_DigestFinal(&ctx, digest, NULL);
 		for(i = 0; i < md->md_size; i++) {
 			char hex[4];
 			snprintf(hex, sizeof(hex), "%02x:", digest[i]);
 			strlcat(retval, hex, sizeof(retval));
 		}
 		retval[strlen(retval) - 1] = '\0';
 		memset(blob, 0, len);
 		xfree(blob);
 	}
 	return retval;
 }

 /*
  * Reads a multiple-precision integer in decimal from the buffer, and advances
  * the pointer.  The integer must already be initialized.  This function is
  * permitted to modify the buffer.  This leaves *cpp to point just beyond the
  * last processed (and maybe modified) character.  Note that this may modify
  * the buffer containing the number.
  */
 int
 read_bignum(char **cpp, BIGNUM * value)
 {
 	char *cp = *cpp;
 	int old;

 	/* Skip any leading whitespace. */
 	for (; *cp == ' ' || *cp == '\t'; cp++)
 		;

 	/* Check that it begins with a decimal digit. */
 	if (*cp < '0' || *cp > '9')
 		return 0;

 	/* Save starting position. */
 	*cpp = cp;

 	/* Move forward until all decimal digits skipped. */
 	for (; *cp >= '0' && *cp <= '9'; cp++)
 		;

 	/* Save the old terminating character, and replace it by \0. */
 	old = *cp;
 	*cp = 0;

 	/* Parse the number. */
 	if (BN_dec2bn(&value, *cpp) == 0)
 		return 0;

 	/* Restore old terminating character. */
 	*cp = old;

 	/* Move beyond the number and return success. */
 	*cpp = cp;
 	return 1;
 }
 int
 write_bignum(FILE *f, BIGNUM *num)
 {
 	char *buf = BN_bn2dec(num);
 	if (buf == NULL) {
 		error("write_bignum: BN_bn2dec() failed");
 		return 0;
 	}
 	fprintf(f, " %s", buf);
 	free(buf);
 	return 1;
 }
 unsigned int
 key_read(Key *ret, char **cpp)
 {
 	Key *k;
 	unsigned int bits = 0;
 	char *cp;
 	int len, n;
 	unsigned char *blob;

 	cp = *cpp;

 	switch(ret->type) {
 	case KEY_RSA:
 		/* Get number of bits. */
 		if (*cp < '0' || *cp > '9')
 			return 0;	/* Bad bit count... */
 		for (bits = 0; *cp >= '0' && *cp <= '9'; cp++)
 			bits = 10 * bits + *cp - '0';
 		if (bits == 0)
 			return 0;
 		*cpp = cp;
 		/* Get public exponent, public modulus. */
 		if (!read_bignum(cpp, ret->rsa->e))
 			return 0;
 		if (!read_bignum(cpp, ret->rsa->n))
 			return 0;
 		break;
 	case KEY_DSA:
 		if (strncmp(cp, SSH_DSS " ", 7) != 0)
 			return 0;
 		cp += 7;
 		len = 2*strlen(cp);
 		blob = xmalloc(len);
 		n = uudecode(cp, blob, len);
 		if (n < 0) {
 			error("key_read: uudecode %s failed", cp);
 			return 0;
 		}
 		k = dsa_key_from_blob(blob, n);
 		if (k == NULL) {
 			error("key_read: dsa_key_from_blob %s failed", cp);
 			return 0;
 		}
 		xfree(blob);
 		if (ret->dsa != NULL)
 			DSA_free(ret->dsa);
 		ret->dsa = k->dsa;
 		k->dsa = NULL;
 		key_free(k);
 		bits = BN_num_bits(ret->dsa->p);
 		/* advance cp: skip whitespace and data */
 		while (*cp == ' ' || *cp == '\t')
 			cp++;
 		while (*cp != '\0' && *cp != ' ' && *cp != '\t')
 			cp++;
 		*cpp = cp;
 		break;
 	default:
 		fatal("key_read: bad key type: %d", ret->type);
 		break;
 	}
 	return bits;
 }
 int
 key_write(Key *key, FILE *f)
 {
 	int success = 0;
 	unsigned int bits = 0;

 	if (key->type == KEY_RSA && key->rsa != NULL) {
 		/* size of modulus 'n' */
 		bits = BN_num_bits(key->rsa->n);
 		fprintf(f, "%u", bits);
 		if (write_bignum(f, key->rsa->e) &&
 		    write_bignum(f, key->rsa->n)) {
 			success = 1;
 		} else {
 			error("key_write: failed for RSA key");
 		}
 	} else if (key->type == KEY_DSA && key->dsa != NULL) {
 		int len, n;
 		unsigned char *blob, *uu;
 		dsa_make_key_blob(key, &blob, &len);
 		uu = xmalloc(2*len);
 		n = uuencode(blob, len, uu, 2*len);
 		if (n > 0) {
 			fprintf(f, "%s %s", SSH_DSS, uu);
 			success = 1;
 		}
 		xfree(blob);
 		xfree(uu);
 	}
 	return success;
 }
 char *
 key_type(Key *k)
 {
 	switch (k->type) {
 	case KEY_RSA:
 		return "RSA";
 		break;
 	case KEY_DSA:
 		return "DSA";
 		break;
 	}
 	return "unknown";
 }
 unsigned int
 key_size(Key *k){
 	switch (k->type) {
 	case KEY_RSA:
 		return BN_num_bits(k->rsa->n);
 		break;
 	case KEY_DSA:
 		return BN_num_bits(k->dsa->p);
 		break;
 	}
 	return 0;
 }
	/*
	* read_bignum():
	* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
	*
	* As far as I am concerned, the code I have written for this software
	* can be used freely for any purpose. Any derived versions of this
	* software must be clearly marked as such, and if the derived work is
	* incompatible with the protocol description in the RFC file, it must be
	* called by a name other than "ssh" or "Secure Shell".
	*
	*
	* Copyright (c) 2000 Markus Friedl. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	* 2. Redistributions in binary form must reproduce the above copyright
	* notice, this list of conditions and the following disclaimer in the
	* documentation and/or other materials provided with the distribution.
	*
	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*/

	#include "includes.h"
	#include "ssh.h"
	#include <openssl/rsa.h>
	#include <openssl/dsa.h>
	#include <openssl/evp.h>
	#include "xmalloc.h"
	#include "key.h"
	#include "dsa.h"
	#include "uuencode.h"

	RCSID("$OpenBSD: key.c,v 1.11 2000/09/07 20:27:51 deraadt Exp $");

	#define SSH_DSS "ssh-dss"

	Key *
	key_new(int type)
	{
	Key *k;
	RSA *rsa;
	DSA *dsa;
	k = xmalloc(sizeof(*k));
	k->type = type;
	k->dsa = NULL;
	k->rsa = NULL;
	switch (k->type) {
	case KEY_RSA:
	rsa = RSA_new();
	rsa->n = BN_new();
	rsa->e = BN_new();
	k->rsa = rsa;
	break;
	case KEY_DSA:
	dsa = DSA_new();
	dsa->p = BN_new();
	dsa->q = BN_new();
	dsa->g = BN_new();
	dsa->pub_key = BN_new();
	k->dsa = dsa;
	break;
	case KEY_EMPTY:
	break;
	default:
	fatal("key_new: bad key type %d", k->type);
	break;
	}
	return k;
	}
	void
	key_free(Key *k)
	{
	switch (k->type) {
	case KEY_RSA:
	if (k->rsa != NULL)
	RSA_free(k->rsa);
	k->rsa = NULL;
	break;
	case KEY_DSA:
	if (k->dsa != NULL)
	DSA_free(k->dsa);
	k->dsa = NULL;
	break;
	default:
	fatal("key_free: bad key type %d", k->type);
	break;
	}
	xfree(k);
	}
	int
	key_equal(Key a, Key b)
	{
	if (a == NULL \|\| b == NULL \|\| a->type != b->type)
	return 0;
	switch (a->type) {
	case KEY_RSA:
	return a->rsa != NULL && b->rsa != NULL &&
	BN_cmp(a->rsa->e, b->rsa->e) == 0 &&
	BN_cmp(a->rsa->n, b->rsa->n) == 0;
	break;
	case KEY_DSA:
	return a->dsa != NULL && b->dsa != NULL &&
	BN_cmp(a->dsa->p, b->dsa->p) == 0 &&
	BN_cmp(a->dsa->q, b->dsa->q) == 0 &&
	BN_cmp(a->dsa->g, b->dsa->g) == 0 &&
	BN_cmp(a->dsa->pub_key, b->dsa->pub_key) == 0;
	break;
	default:
	fatal("key_equal: bad key type %d", a->type);
	break;
	}
	return 0;
	}

	/*
	* Generate key fingerprint in ascii format.
	* Based on ideas and code from Bjoern Groenvall <bg@sics.se>
	*/
	char *
	key_fingerprint(Key *k)
	{
	static char retval[(EVP_MAX_MD_SIZE+1)*3];
	unsigned char *blob = NULL;
	int len = 0;
	int nlen, elen;

	switch (k->type) {
	case KEY_RSA:
	nlen = BN_num_bytes(k->rsa->n);
	elen = BN_num_bytes(k->rsa->e);
	len = nlen + elen;
	blob = xmalloc(len);
	BN_bn2bin(k->rsa->n, blob);
	BN_bn2bin(k->rsa->e, blob + nlen);
	break;
	case KEY_DSA:
	dsa_make_key_blob(k, &blob, &len);
	break;
	default:
	fatal("key_fingerprint: bad key type %d", k->type);
	break;
	}
	retval[0] = '\0';

	if (blob != NULL) {
	int i;
	unsigned char digest[EVP_MAX_MD_SIZE];
	EVP_MD *md = EVP_md5();
	EVP_MD_CTX ctx;
	EVP_DigestInit(&ctx, md);
	EVP_DigestUpdate(&ctx, blob, len);
	EVP_DigestFinal(&ctx, digest, NULL);
	for(i = 0; i < md->md_size; i++) {
	char hex[4];
	snprintf(hex, sizeof(hex), "%02x:", digest[i]);
	strlcat(retval, hex, sizeof(retval));
	}
	retval[strlen(retval) - 1] = '\0';
	memset(blob, 0, len);
	xfree(blob);
	}
	return retval;
	}

	/*
	* Reads a multiple-precision integer in decimal from the buffer, and advances
	* the pointer. The integer must already be initialized. This function is
	* permitted to modify the buffer. This leaves *cpp to point just beyond the
	* last processed (and maybe modified) character. Note that this may modify
	* the buffer containing the number.
	*/
	int
	read_bignum(char *cpp, BIGNUM value)
	{
	char cp = cpp;
	int old;

	/* Skip any leading whitespace. */
	for (; cp == ' ' \|\| cp == '\t'; cp++)
	;

	/* Check that it begins with a decimal digit. */
	if (cp < '0' \|\| cp > '9')
	return 0;

	/* Save starting position. */
	*cpp = cp;

	/* Move forward until all decimal digits skipped. */
	for (; cp >= '0' && cp <= '9'; cp++)
	;

	/* Save the old terminating character, and replace it by \0. */
	old = *cp;
	*cp = 0;

	/* Parse the number. */
	if (BN_dec2bn(&value, *cpp) == 0)
	return 0;

	/* Restore old terminating character. */
	*cp = old;

	/* Move beyond the number and return success. */
	*cpp = cp;
	return 1;
	}
	int
	write_bignum(FILE f, BIGNUM num)
	{
	char *buf = BN_bn2dec(num);
	if (buf == NULL) {
	error("write_bignum: BN_bn2dec() failed");
	return 0;
	}
	fprintf(f, " %s", buf);
	free(buf);
	return 1;
	}
	unsigned int
	key_read(Key ret, char *cpp)
	{
	Key *k;
	unsigned int bits = 0;
	char *cp;
	int len, n;
	unsigned char *blob;

	cp = *cpp;

	switch(ret->type) {
	case KEY_RSA:
	/* Get number of bits. */
	if (cp < '0' \|\| cp > '9')
	return 0; /* Bad bit count... */
	for (bits = 0; cp >= '0' && cp <= '9'; cp++)
	bits = 10 * bits + *cp - '0';
	if (bits == 0)
	return 0;
	*cpp = cp;
	/* Get public exponent, public modulus. */
	if (!read_bignum(cpp, ret->rsa->e))
	return 0;
	if (!read_bignum(cpp, ret->rsa->n))
	return 0;
	break;
	case KEY_DSA:
	if (strncmp(cp, SSH_DSS " ", 7) != 0)
	return 0;
	cp += 7;
	len = 2*strlen(cp);
	blob = xmalloc(len);
	n = uudecode(cp, blob, len);
	if (n < 0) {
	error("key_read: uudecode %s failed", cp);
	return 0;
	}
	k = dsa_key_from_blob(blob, n);
	if (k == NULL) {
	error("key_read: dsa_key_from_blob %s failed", cp);
	return 0;
	}
	xfree(blob);
	if (ret->dsa != NULL)
	DSA_free(ret->dsa);
	ret->dsa = k->dsa;
	k->dsa = NULL;
	key_free(k);
	bits = BN_num_bits(ret->dsa->p);
	/* advance cp: skip whitespace and data */
	while (cp == ' ' \|\| cp == '\t')
	cp++;
	while (cp != '\0' && cp != ' ' && *cp != '\t')
	cp++;
	*cpp = cp;
	break;
	default:
	fatal("key_read: bad key type: %d", ret->type);
	break;
	}
	return bits;
	}
	int
	key_write(Key key, FILE f)
	{
	int success = 0;
	unsigned int bits = 0;

	if (key->type == KEY_RSA && key->rsa != NULL) {
	/* size of modulus 'n' */
	bits = BN_num_bits(key->rsa->n);
	fprintf(f, "%u", bits);
	if (write_bignum(f, key->rsa->e) &&
	write_bignum(f, key->rsa->n)) {
	success = 1;
	} else {
	error("key_write: failed for RSA key");
	}
	} else if (key->type == KEY_DSA && key->dsa != NULL) {
	int len, n;
	unsigned char blob, uu;
	dsa_make_key_blob(key, &blob, &len);
	uu = xmalloc(2*len);
	n = uuencode(blob, len, uu, 2*len);
	if (n > 0) {
	fprintf(f, "%s %s", SSH_DSS, uu);
	success = 1;
	}
	xfree(blob);
	xfree(uu);
	}
	return success;
	}
	char *
	key_type(Key *k)
	{
	switch (k->type) {
	case KEY_RSA:
	return "RSA";
	break;
	case KEY_DSA:
	return "DSA";
	break;
	}
	return "unknown";
	}
	unsigned int
	key_size(Key *k){
	switch (k->type) {
	case KEY_RSA:
	return BN_num_bits(k->rsa->n);
	break;
	case KEY_DSA:
	return BN_num_bits(k->dsa->p);
	break;
	}
	return 0;
	}