crypto.c

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    RC4_set_key (kd->schedule->data,
		 kd->key->keyvalue.length, kd->key->keyvalue.data);
}

static krb5_error_code
ARCFOUR_string_to_key(krb5_context context,
		  krb5_enctype enctype,
		  krb5_data password,
		  krb5_salt salt,
		  krb5_data opaque,
		  krb5_keyblock *key)
{
    char *s, *p;
    size_t len;
    int i;
    MD4_CTX m;
    krb5_error_code ret;

    len = 2 * password.length;
    s = malloc (len);
    if (len != 0 && s == NULL) {
	krb5_set_error_string(context, "malloc: out of memory");
	ret = ENOMEM;
	goto out;
    }
    for (p = s, i = 0; i < password.length; ++i) {
	*p++ = ((char *)password.data)[i];
	*p++ = 0;
    }
    MD4_Init (&m);
    MD4_Update (&m, s, len);
    key->keytype = enctype;
    ret = krb5_data_alloc (&key->keyvalue, 16);
    if (ret) {
	krb5_set_error_string(context, "malloc: out of memory");
	goto out;
    }
    MD4_Final (key->keyvalue.data, &m);
    memset (s, 0, len);
    ret = 0;
out:
    free (s);
    return ret;
}

/*
 * AES
 */

int _krb5_AES_string_to_default_iterator = 4096;

static krb5_error_code
AES_string_to_key(krb5_context context,
		  krb5_enctype enctype,
		  krb5_data password,
		  krb5_salt salt,
		  krb5_data opaque,
		  krb5_keyblock *key)
{
    krb5_error_code ret;
    uint32_t iter;
    struct encryption_type *et;
    struct key_data kd;

    if (opaque.length == 0)
	iter = _krb5_AES_string_to_default_iterator;
    else if (opaque.length == 4) {
	unsigned long v;
	_krb5_get_int(opaque.data, &v, 4);
	iter = ((uint32_t)v);
    } else
	return KRB5_PROG_KEYTYPE_NOSUPP; /* XXX */
	
    et = _find_enctype(enctype);
    if (et == NULL)
	return KRB5_PROG_KEYTYPE_NOSUPP;

    kd.schedule = NULL;
    ALLOC(kd.key, 1);
    if(kd.key == NULL) {
	krb5_set_error_string (context, "malloc: out of memory");
	return ENOMEM;
    }
    kd.key->keytype = enctype;
    ret = krb5_data_alloc(&kd.key->keyvalue, et->keytype->size);
    if (ret) {
	krb5_set_error_string(context, "Failed to allocate pkcs5 key");
	return ret;
    }

    ret = PKCS5_PBKDF2_HMAC_SHA1(password.data, password.length,
				 salt.saltvalue.data, salt.saltvalue.length,
				 iter, 
				 et->keytype->size, kd.key->keyvalue.data);
    if (ret != 1) {
	free_key_data(context, &kd);
	krb5_set_error_string(context, "Error calculating s2k");
	return KRB5_PROG_KEYTYPE_NOSUPP;
    }

    ret = derive_key(context, et, &kd, "kerberos", strlen("kerberos"));
    if (ret == 0)
	ret = krb5_copy_keyblock_contents(context, kd.key, key);
    free_key_data(context, &kd);

    return ret;
}

struct krb5_aes_schedule {
    AES_KEY ekey;
    AES_KEY dkey;
};

static void
AES_schedule(krb5_context context,
	     struct key_data *kd)
{
    struct krb5_aes_schedule *key = kd->schedule->data;
    int bits = kd->key->keyvalue.length * 8;

    memset(key, 0, sizeof(*key));
    AES_set_encrypt_key(kd->key->keyvalue.data, bits, &key->ekey);
    AES_set_decrypt_key(kd->key->keyvalue.data, bits, &key->dkey);
}

/*
 *
 */

static struct salt_type des_salt[] = {
    {
	KRB5_PW_SALT,
	"pw-salt",
	krb5_DES_string_to_key
    },
#ifdef ENABLE_AFS_STRING_TO_KEY
    {
	KRB5_AFS3_SALT,
	"afs3-salt",
	DES_AFS3_string_to_key
    },
#endif
    { 0 }
};

static struct salt_type des3_salt[] = {
    {
	KRB5_PW_SALT,
	"pw-salt",
	DES3_string_to_key
    },
    { 0 }
};

static struct salt_type des3_salt_derived[] = {
    {
	KRB5_PW_SALT,
	"pw-salt",
	DES3_string_to_key_derived
    },
    { 0 }
};

static struct salt_type AES_salt[] = {
    {
	KRB5_PW_SALT,
	"pw-salt",
	AES_string_to_key
    },
    { 0 }
};

static struct salt_type arcfour_salt[] = {
    {
	KRB5_PW_SALT,
	"pw-salt",
	ARCFOUR_string_to_key
    },
    { 0 }
};

/*
 *
 */

static struct key_type keytype_null = {
    KEYTYPE_NULL,
    "null",
    0,
    0,
    0,
    NULL,
    NULL,
    NULL
};

static struct key_type keytype_des = {
    KEYTYPE_DES,
    "des",
    56,
    sizeof(DES_cblock),
    sizeof(DES_key_schedule),
    krb5_DES_random_key,
    krb5_DES_schedule,
    des_salt,
    krb5_DES_random_to_key
};

static struct key_type keytype_des3 = {
    KEYTYPE_DES3,
    "des3",
    168,
    3 * sizeof(DES_cblock), 
    3 * sizeof(DES_key_schedule), 
    DES3_random_key,
    DES3_schedule,
    des3_salt,
    DES3_random_to_key
};

static struct key_type keytype_des3_derived = {
    KEYTYPE_DES3,
    "des3",
    168,
    3 * sizeof(DES_cblock),
    3 * sizeof(DES_key_schedule), 
    DES3_random_key,
    DES3_schedule,
    des3_salt_derived,
    DES3_random_to_key
};

static struct key_type keytype_aes128 = {
    KEYTYPE_AES128,
    "aes-128",
    128,
    16,
    sizeof(struct krb5_aes_schedule),
    NULL,
    AES_schedule,
    AES_salt
};

static struct key_type keytype_aes256 = {
    KEYTYPE_AES256,
    "aes-256",
    256,
    32,
    sizeof(struct krb5_aes_schedule),
    NULL,
    AES_schedule,
    AES_salt
};

static struct key_type keytype_arcfour = {
    KEYTYPE_ARCFOUR,
    "arcfour",
    128,
    16,
    sizeof(RC4_KEY),
    NULL,
    ARCFOUR_schedule,
    arcfour_salt
};

static struct key_type *keytypes[] = {
    &keytype_null,
    &keytype_des,
    &keytype_des3_derived,
    &keytype_des3,
    &keytype_aes128,
    &keytype_aes256,
    &keytype_arcfour
};

static int num_keytypes = sizeof(keytypes) / sizeof(keytypes[0]);

static struct key_type *
_find_keytype(krb5_keytype type)
{
    int i;
    for(i = 0; i < num_keytypes; i++)
	if(keytypes[i]->type == type)
	    return keytypes[i];
    return NULL;
}


krb5_error_code KRB5_LIB_FUNCTION
krb5_salttype_to_string (krb5_context context,
			 krb5_enctype etype,
			 krb5_salttype stype,
			 char **string)
{
    struct encryption_type *e;
    struct salt_type *st;

    e = _find_enctype (etype);
    if (e == NULL) {
	krb5_set_error_string(context, "encryption type %d not supported",
			      etype);
	return KRB5_PROG_ETYPE_NOSUPP;
    }
    for (st = e->keytype->string_to_key; st && st->type; st++) {
	if (st->type == stype) {
	    *string = strdup (st->name);
	    if (*string == NULL) {
		krb5_set_error_string(context, "malloc: out of memory");
		return ENOMEM;
	    }
	    return 0;
	}
    }
    krb5_set_error_string(context, "salttype %d not supported", stype);
    return HEIM_ERR_SALTTYPE_NOSUPP;
}

krb5_error_code KRB5_LIB_FUNCTION
krb5_string_to_salttype (krb5_context context,
			 krb5_enctype etype,
			 const char *string,
			 krb5_salttype *salttype)
{
    struct encryption_type *e;
    struct salt_type *st;

    e = _find_enctype (etype);
    if (e == NULL) {
	krb5_set_error_string(context, "encryption type %d not supported",
			      etype);
	return KRB5_PROG_ETYPE_NOSUPP;
    }
    for (st = e->keytype->string_to_key; st && st->type; st++) {
	if (strcasecmp (st->name, string) == 0) {
	    *salttype = st->type;
	    return 0;
	}
    }
    krb5_set_error_string(context, "salttype %s not supported", string);
    return HEIM_ERR_SALTTYPE_NOSUPP;
}

krb5_error_code KRB5_LIB_FUNCTION
krb5_get_pw_salt(krb5_context context,
		 krb5_const_principal principal,
		 krb5_salt *salt)
{
    size_t len;
    int i;
    krb5_error_code ret;
    char *p;
     
    salt->salttype = KRB5_PW_SALT;
    len = strlen(principal->realm);
    for (i = 0; i < principal->name.name_string.len; ++i)
	len += strlen(principal->name.name_string.val[i]);
    ret = krb5_data_alloc (&salt->saltvalue, len);
    if (ret)
	return ret;
    p = salt->saltvalue.data;
    memcpy (p, principal->realm, strlen(principal->realm));
    p += strlen(principal->realm);
    for (i = 0; i < principal->name.name_string.len; ++i) {
	memcpy (p,
		principal->name.name_string.val[i],
		strlen(principal->name.name_string.val[i]));
	p += strlen(principal->name.name_string.val[i]);
    }
    return 0;
}

krb5_error_code KRB5_LIB_FUNCTION
krb5_free_salt(krb5_context context, 
	       krb5_salt salt)
{
    krb5_data_free(&salt.saltvalue);
    return 0;
}

krb5_error_code KRB5_LIB_FUNCTION
krb5_string_to_key_data (krb5_context context,
			 krb5_enctype enctype,
			 krb5_data password,
			 krb5_principal principal,
			 krb5_keyblock *key)
{
    krb5_error_code ret;
    krb5_salt salt;

    ret = krb5_get_pw_salt(context, principal, &salt);
    if(ret)
	return ret;
    ret = krb5_string_to_key_data_salt(context, enctype, password, salt, key);
    krb5_free_salt(context, salt);
    return ret;
}

krb5_error_code KRB5_LIB_FUNCTION
krb5_string_to_key (krb5_context context,
		    krb5_enctype enctype,
		    const char *password,
		    krb5_principal principal,
		    krb5_keyblock *key)
{
    krb5_data pw;
    pw.data = rk_UNCONST(password);
    pw.length = strlen(password);
    return krb5_string_to_key_data(context, enctype, pw, principal, key);
}

krb5_error_code KRB5_LIB_FUNCTION
krb5_string_to_key_data_salt (krb5_context context,
			      krb5_enctype enctype,
			      krb5_data password,
			      krb5_salt salt,
			      krb5_keyblock *key)
{
    krb5_data opaque;
    krb5_data_zero(&opaque);
    return krb5_string_to_key_data_salt_opaque(context, enctype, password, 
					       salt, opaque, key);
}

/*
 * Do a string -> key for encryption type `enctype' operation on
 * `password' (with salt `salt' and the enctype specific data string
 * `opaque'), returning the resulting key in `key'
 */

krb5_error_code KRB5_LIB_FUNCTION
krb5_string_to_key_data_salt_opaque (krb5_context context,
				     krb5_enctype enctype,
				     krb5_data password,
				     krb5_salt salt,
				     krb5_data opaque,
				     krb5_keyblock *key)
{
    struct encryption_type *et =_find_enctype(enctype);
    struct salt_type *st;
    if(et == NULL) {
	krb5_set_error_string(context, "encryption type %d not supported",
			      enctype);
	return KRB5_PROG_ETYPE_NOSUPP;
    }
    for(st = et->keytype->string_to_key; st && st->type; st++) 
	if(st->type == salt.salttype)
	    return (*st->string_to_key)(context, enctype, password, 
					salt, opaque, key);
    krb5_set_error_string(context, "salt type %d not supported",
			  salt.salttype);
    return HEIM_ERR_SALTTYPE_NOSUPP;
}

/*
 * Do a string -> key for encryption type `enctype' operation on the
 * string `password' (with salt `salt'), returning the resulting key
 * in `key'
 */

krb5_error_code KRB5_LIB_FUNCTION
krb5_string_to_key_salt (krb5_context context,
			 krb5_enctype enctype,
			 const char *password,
			 krb5_salt salt,
			 krb5_keyblock *key)
{
    krb5_data pw;
    pw.data = rk_UNCONST(password);
    pw.length = strlen(password);
    return krb5_string_to_key_data_salt(context, enctype, pw, salt, key);
}

krb5_error_code KRB5_LIB_FUNCTION
krb5_string_to_key_salt_opaque (krb5_context context,
				krb5_enctype enctype,
				const char *password,
				krb5_salt salt,
				krb5_data opaque,
				krb5_keyblock *key)
{
    krb5_data pw;
    pw.data = rk_UNCONST(password);
    pw.length = strlen(password);
    return krb5_string_to_key_data_salt_opaque(context, enctype, 
					       pw, salt, opaque, key);
}

krb5_error_code KRB5_LIB_FUNCTION
krb5_keytype_to_string(krb5_context context,
		       krb5_keytype keytype,
		       char **string)
{
    struct key_type *kt = _find_keytype(keytype);
    if(kt == NULL) {
	krb5_set_error_string(context, "key type %d not supported", keytype);
	return KRB5_PROG_KEYTYPE_NOSUPP;
    }
    *string = strdup(kt->name);
    if(*string == NULL) {
	krb5_set_error_string(context, "malloc: out of memory");
	return ENOMEM;
    }
    return 0;
}

krb5_error_code KRB5_LIB_FUNCTION
krb5_string_to_keytype(krb5_context context,
		       const char *string,
		       krb5_keytype *keytype)
{
    int i;
    for(i = 0; i < num_keytypes; i++)
	if(strcasecmp(keytypes[i]->name, string) == 0){
	    *keytype = keytypes[i]->type;
	    return 0;
	}
    krb5_set_error_string(context, "key type %s not supported", string);
    return KRB5_PROG_KEYTYPE_NOSUPP;
}

krb5_error_code KRB5_LIB_FUNCTION
krb5_enctype_keysize(krb5_context context,
		     krb5_enctype type,
		     size_t *keysize)
{
    struct encryption_type *et = _find_enctype(type);
    if(et == NULL) {
	krb5_set_error_string(context, "encryption type %d not supported",
			      type);
	return KRB5_PROG_ETYPE_NOSUPP;
    }
    *keysize = et->keytype->size;
    return 0;
}

krb5_error_code KRB5_LIB_FUNCTION
krb5_enctype_keybits(krb5_context context,
		     krb5_enctype type,
		     size_t *keybits)
{
    struct encryption_type *et = _find_enctype(type);
    if(et == NULL) {
	krb5_set_error_string(context, "encryption type %d not supported",
			      type);
	return KRB5_PROG_ETYPE_NOSUPP;
    }
    *keybits = et->keytype->bits;
    return 0;
}