key.c

OpenSSL Source code for SFTP, SSH, and many others

		} else if (ret->type != type) {
			/* is a key, but different type */
			debug3("key_read: type mismatch");
			return -1;
		}
		len = 2*strlen(cp);
		blob = xmalloc(len);
		n = uudecode(cp, blob, len);
		if (n < 0) {
			error("key_read: uudecode %s failed", cp);
			xfree(blob);
			return -1;
		}
		k = key_from_blob(blob, n);
		xfree(blob);
		if (k == NULL) {
			error("key_read: key_from_blob %s failed", cp);
			return -1;
		}
		if (k->type != type) {
			error("key_read: type mismatch: encoding error");
			key_free(k);
			return -1;
		}
/*XXXX*/
		if (ret->type == KEY_RSA) {
			if (ret->rsa != NULL)
				RSA_free(ret->rsa);
			ret->rsa = k->rsa;
			k->rsa = NULL;
			success = 1;
#ifdef DEBUG_PK
			RSA_print_fp(stderr, ret->rsa, 8);
#endif
		} else {
			if (ret->dsa != NULL)
				DSA_free(ret->dsa);
			ret->dsa = k->dsa;
			k->dsa = NULL;
			success = 1;
#ifdef DEBUG_PK
			DSA_print_fp(stderr, ret->dsa, 8);
#endif
		}
/*XXXX*/
		key_free(k);
		if (success != 1)
			break;
		/* 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 success;
}
int
key_write(Key *key, FILE *f)
{
	int n, success = 0;
	u_int len, bits = 0;
	u_char *blob, *uu;

	if (key->type == KEY_RSA1 && 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) ||
	    (key->type == KEY_RSA && key->rsa != NULL)) {
		key_to_blob(key, &blob, &len);
		uu = xmalloc(2*len);
		n = uuencode(blob, len, uu, 2*len);
		if (n > 0) {
			fprintf(f, "%s %s", key_ssh_name(key), uu);
			success = 1;
		}
		xfree(blob);
		xfree(uu);
	}
	return success;
}
char *
key_type(Key *k)
{
	switch (k->type) {
	case KEY_RSA1:
		return "RSA1";
		break;
	case KEY_RSA:
		return "RSA";
		break;
	case KEY_DSA:
		return "DSA";
		break;
	}
	return "unknown";
}
char *
key_ssh_name(Key *k)
{
	switch (k->type) {
	case KEY_RSA:
		return "ssh-rsa";
		break;
	case KEY_DSA:
		return "ssh-dss";
		break;
	}
	return "ssh-unknown";
}
u_int
key_size(Key *k)
{
	switch (k->type) {
	case KEY_RSA1:
	case KEY_RSA:
		return BN_num_bits(k->rsa->n);
		break;
	case KEY_DSA:
		return BN_num_bits(k->dsa->p);
		break;
	}
	return 0;
}

static RSA *
rsa_generate_private_key(u_int bits)
{
	RSA *private;
	private = RSA_generate_key(bits, 35, NULL, NULL);
	if (private == NULL)
		fatal("rsa_generate_private_key: key generation failed.");
	return private;
}

static DSA*
dsa_generate_private_key(u_int bits)
{
	DSA *private = DSA_generate_parameters(bits, NULL, 0, NULL, NULL, NULL, NULL);
	if (private == NULL)
		fatal("dsa_generate_private_key: DSA_generate_parameters failed");
	if (!DSA_generate_key(private))
		fatal("dsa_generate_private_key: DSA_generate_key failed.");
	if (private == NULL)
		fatal("dsa_generate_private_key: NULL.");
	return private;
}

Key *
key_generate(int type, u_int bits)
{
	Key *k = key_new(KEY_UNSPEC);
	switch (type) {
	case KEY_DSA:
		k->dsa = dsa_generate_private_key(bits);
		break;
	case KEY_RSA:
	case KEY_RSA1:
		k->rsa = rsa_generate_private_key(bits);
		break;
	default:
		fatal("key_generate: unknown type %d", type);
	}
	k->type = type;
	return k;
}

Key *
key_from_private(Key *k)
{
	Key *n = NULL;
	switch (k->type) {
	case KEY_DSA:
		n = key_new(k->type);
		BN_copy(n->dsa->p, k->dsa->p);
		BN_copy(n->dsa->q, k->dsa->q);
		BN_copy(n->dsa->g, k->dsa->g);
		BN_copy(n->dsa->pub_key, k->dsa->pub_key);
		break;
	case KEY_RSA:
	case KEY_RSA1:
		n = key_new(k->type);
		BN_copy(n->rsa->n, k->rsa->n);
		BN_copy(n->rsa->e, k->rsa->e);
		break;
	default:
		fatal("key_from_private: unknown type %d", k->type);
		break;
	}
	return n;
}

int
key_type_from_name(char *name)
{
	if (strcmp(name, "rsa1") == 0) {
		return KEY_RSA1;
	} else if (strcmp(name, "rsa") == 0) {
		return KEY_RSA;
	} else if (strcmp(name, "dsa") == 0) {
		return KEY_DSA;
	} else if (strcmp(name, "ssh-rsa") == 0) {
		return KEY_RSA;
	} else if (strcmp(name, "ssh-dss") == 0) {
		return KEY_DSA;
	}
	debug2("key_type_from_name: unknown key type '%s'", name);
	return KEY_UNSPEC;
}

int
key_names_valid2(const char *names)
{
	char *s, *cp, *p;

	if (names == NULL || strcmp(names, "") == 0)
		return 0;
	s = cp = xstrdup(names);
	for ((p = strsep(&cp, ",")); p && *p != '\0';
	    (p = strsep(&cp, ","))) {
		switch (key_type_from_name(p)) {
		case KEY_RSA1:
		case KEY_UNSPEC:
			xfree(s);
			return 0;
		}
	}
	debug3("key names ok: [%s]", names);
	xfree(s);
	return 1;
}

Key *
key_from_blob(u_char *blob, int blen)
{
	Buffer b;
	char *ktype;
	int rlen, type;
	Key *key = NULL;

#ifdef DEBUG_PK
	dump_base64(stderr, blob, blen);
#endif
	buffer_init(&b);
	buffer_append(&b, blob, blen);
	ktype = buffer_get_string(&b, NULL);
	type = key_type_from_name(ktype);

	switch (type) {
	case KEY_RSA:
		key = key_new(type);
		buffer_get_bignum2(&b, key->rsa->e);
		buffer_get_bignum2(&b, key->rsa->n);
#ifdef DEBUG_PK
		RSA_print_fp(stderr, key->rsa, 8);
#endif
		break;
	case KEY_DSA:
		key = key_new(type);
		buffer_get_bignum2(&b, key->dsa->p);
		buffer_get_bignum2(&b, key->dsa->q);
		buffer_get_bignum2(&b, key->dsa->g);
		buffer_get_bignum2(&b, key->dsa->pub_key);
#ifdef DEBUG_PK
		DSA_print_fp(stderr, key->dsa, 8);
#endif
		break;
	case KEY_UNSPEC:
		key = key_new(type);
		break;
	default:
		error("key_from_blob: cannot handle type %s", ktype);
		break;
	}
	rlen = buffer_len(&b);
	if (key != NULL && rlen != 0)
		error("key_from_blob: remaining bytes in key blob %d", rlen);
	xfree(ktype);
	buffer_free(&b);
	return key;
}

int
key_to_blob(Key *key, u_char **blobp, u_int *lenp)
{
	Buffer b;
	int len;
	u_char *buf;

	if (key == NULL) {
		error("key_to_blob: key == NULL");
		return 0;
	}
	buffer_init(&b);
	switch (key->type) {
	case KEY_DSA:
		buffer_put_cstring(&b, key_ssh_name(key));
		buffer_put_bignum2(&b, key->dsa->p);
		buffer_put_bignum2(&b, key->dsa->q);
		buffer_put_bignum2(&b, key->dsa->g);
		buffer_put_bignum2(&b, key->dsa->pub_key);
		break;
	case KEY_RSA:
		buffer_put_cstring(&b, key_ssh_name(key));
		buffer_put_bignum2(&b, key->rsa->e);
		buffer_put_bignum2(&b, key->rsa->n);
		break;
	default:
		error("key_to_blob: unsupported key type %d", key->type);
		buffer_free(&b);
		return 0;
	}
	len = buffer_len(&b);
	buf = xmalloc(len);
	memcpy(buf, buffer_ptr(&b), len);
	memset(buffer_ptr(&b), 0, len);
	buffer_free(&b);
	if (lenp != NULL)
		*lenp = len;
	if (blobp != NULL)
		*blobp = buf;
	return len;
}

int
key_sign(
    Key *key,
    u_char **sigp, u_int *lenp,
    u_char *data, u_int datalen)
{
	switch (key->type) {
	case KEY_DSA:
		return ssh_dss_sign(key, sigp, lenp, data, datalen);
		break;
	case KEY_RSA:
		return ssh_rsa_sign(key, sigp, lenp, data, datalen);
		break;
	default:
		error("key_sign: illegal key type %d", key->type);
		return -1;
		break;
	}
}

/*
 * key_verify returns 1 for a correct signature, 0 for an incorrect signature
 * and -1 on error.
 */
int
key_verify(
    Key *key,
    u_char *signature, u_int signaturelen,
    u_char *data, u_int datalen)
{
	if (signaturelen == 0)
		return -1;

	switch (key->type) {
	case KEY_DSA:
		return ssh_dss_verify(key, signature, signaturelen, data, datalen);
		break;
	case KEY_RSA:
		return ssh_rsa_verify(key, signature, signaturelen, data, datalen);
		break;
	default:
		error("key_verify: illegal key type %d", key->type);
		return -1;
		break;
	}
}

/* Converts a private to a public key */

Key *
key_demote(Key *k)
{
	Key *pk;

	pk = xmalloc(sizeof(*pk));
	pk->type = k->type;
	pk->flags = k->flags;
	pk->dsa = NULL;
	pk->rsa = NULL;

	switch (k->type) {
	case KEY_RSA1:
	case KEY_RSA:
		if ((pk->rsa = RSA_new()) == NULL)
			fatal("key_demote: RSA_new failed");
		if ((pk->rsa->e = BN_dup(k->rsa->e)) == NULL)
			fatal("key_demote: BN_dup failed");
		if ((pk->rsa->n = BN_dup(k->rsa->n)) == NULL)
			fatal("key_demote: BN_dup failed");
		break;
	case KEY_DSA:
		if ((pk->dsa = DSA_new()) == NULL)
			fatal("key_demote: DSA_new failed");
		if ((pk->dsa->p = BN_dup(k->dsa->p)) == NULL)
			fatal("key_demote: BN_dup failed");
		if ((pk->dsa->q = BN_dup(k->dsa->q)) == NULL)
			fatal("key_demote: BN_dup failed");
		if ((pk->dsa->g = BN_dup(k->dsa->g)) == NULL)
			fatal("key_demote: BN_dup failed");
		if ((pk->dsa->pub_key = BN_dup(k->dsa->pub_key)) == NULL)
			fatal("key_demote: BN_dup failed");
		break;
	default:
		fatal("key_free: bad key type %d", k->type);
		break;
	}

	return (pk);
}