diff options
Diffstat (limited to 'crypto/heimdal/lib/krb5/crypto.c')
| -rw-r--r-- | crypto/heimdal/lib/krb5/crypto.c | 2314 |
1 files changed, 2314 insertions, 0 deletions
diff --git a/crypto/heimdal/lib/krb5/crypto.c b/crypto/heimdal/lib/krb5/crypto.c new file mode 100644 index 0000000..b6db6ce --- /dev/null +++ b/crypto/heimdal/lib/krb5/crypto.c @@ -0,0 +1,2314 @@ +/* + * Copyright (c) 1997, 1998, 1999 Kungliga Tekniska Högskolan + * (Royal Institute of Technology, Stockholm, Sweden). + * 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. + * + * 3. Neither the name of the Institute nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``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 INSTITUTE OR CONTRIBUTORS 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 "krb5_locl.h" +RCSID("$Id: crypto.c,v 1.28 2000/01/06 20:21:13 assar Exp $"); + +#undef CRYPTO_DEBUG +#ifdef CRYPTO_DEBUG +static void krb5_crypto_debug(krb5_context, int, size_t, krb5_keyblock*); +#endif + + +struct key_data { + krb5_keyblock *key; + krb5_data *schedule; +}; + +struct key_usage { + unsigned usage; + struct key_data key; +}; + +struct krb5_crypto_data { + struct encryption_type *et; + struct key_data key; + int num_key_usage; + struct key_usage *key_usage; +}; + +#define CRYPTO_ETYPE(C) ((C)->et->type) + +/* bits for `flags' below */ +#define F_KEYED 1 /* checksum is keyed */ +#define F_CPROOF 2 /* checksum is collision proof */ +#define F_DERIVED 4 /* uses derived keys */ +#define F_VARIANT 8 /* uses `variant' keys (6.4.3) */ +#define F_PSEUDO 16 /* not a real protocol type */ + +struct salt_type { + krb5_salttype type; + const char *name; + krb5_error_code (*string_to_key)(krb5_context, krb5_enctype, krb5_data, + krb5_salt, krb5_keyblock*); +}; + +struct key_type { + krb5_keytype type; /* XXX */ + const char *name; + size_t bits; + size_t size; + size_t schedule_size; +#if 0 + krb5_enctype best_etype; +#endif + void (*random_key)(krb5_context, krb5_keyblock*); + void (*schedule)(krb5_context, struct key_data *); + struct salt_type *string_to_key; +}; + +struct checksum_type { + krb5_cksumtype type; + const char *name; + size_t blocksize; + size_t checksumsize; + unsigned flags; + void (*checksum)(krb5_context, struct key_data*, void*, size_t, Checksum*); + krb5_error_code (*verify)(krb5_context, struct key_data*, + void*, size_t, Checksum*); +}; + +struct encryption_type { + krb5_enctype type; + const char *name; + size_t blocksize; + size_t confoundersize; + struct key_type *keytype; + struct checksum_type *cksumtype; + struct checksum_type *keyed_checksum; + unsigned flags; + void (*encrypt)(struct key_data *, void *, size_t, int); +}; + +#define ENCRYPTION_USAGE(U) (((U) << 8) | 0xAA) +#define INTEGRITY_USAGE(U) (((U) << 8) | 0x55) +#define CHECKSUM_USAGE(U) (((U) << 8) | 0x99) + +static struct checksum_type *_find_checksum(krb5_cksumtype type); +static struct encryption_type *_find_enctype(krb5_enctype type); +static struct key_type *_find_keytype(krb5_keytype type); +static krb5_error_code _get_derived_key(krb5_context, krb5_crypto, + unsigned, struct key_data**); +static struct key_data *_new_derived_key(krb5_crypto crypto, unsigned usage); + +/************************************************************ + * * + ************************************************************/ + +static void +DES_random_key(krb5_context context, + krb5_keyblock *key) +{ + des_cblock *k = key->keyvalue.data; + do { + krb5_generate_random_block(k, sizeof(des_cblock)); + des_set_odd_parity(k); + } while(des_is_weak_key(k)); +} + +static void +DES_schedule(krb5_context context, + struct key_data *key) +{ + des_set_key(key->key->keyvalue.data, key->schedule->data); +} + +static krb5_error_code +DES_string_to_key(krb5_context context, + krb5_enctype enctype, + krb5_data password, + krb5_salt salt, + krb5_keyblock *key) +{ + char *s; + size_t len; + des_cblock tmp; + + len = password.length + salt.saltvalue.length + 1; + s = malloc(len); + if(s == NULL) + return ENOMEM; + memcpy(s, password.data, password.length); + memcpy(s + password.length, salt.saltvalue.data, salt.saltvalue.length); + s[len - 1] = '\0'; + des_string_to_key(s, &tmp); + key->keytype = enctype; + krb5_data_copy(&key->keyvalue, tmp, sizeof(tmp)); + memset(&tmp, 0, sizeof(tmp)); + memset(s, 0, len); + free(s); + return 0; +} + +/* This defines the Andrew string_to_key function. It accepts a password + * string as input and converts its via a one-way encryption algorithm to a DES + * encryption key. It is compatible with the original Andrew authentication + * service password database. + */ + +/* + * Short passwords, i.e 8 characters or less. + */ +static void +DES_AFS3_CMU_string_to_key (krb5_data pw, + krb5_data cell, + des_cblock *key) +{ + char password[8+1]; /* crypt is limited to 8 chars anyway */ + int i; + + for(i = 0; i < 8; i++) { + char c = ((i < pw.length) ? ((char*)pw.data)[i] : 0) ^ + ((i < cell.length) ? ((char*)cell.data)[i] : 0); + password[i] = c ? c : 'X'; + } + password[8] = '\0'; + + memcpy(key, crypt(password, "#~") + 2, sizeof(des_cblock)); + + /* parity is inserted into the LSB so left shift each byte up one + bit. This allows ascii characters with a zero MSB to retain as + much significance as possible. */ + for (i = 0; i < sizeof(des_cblock); i++) + ((unsigned char*)key)[i] <<= 1; + des_set_odd_parity (key); +} + +/* + * Long passwords, i.e 9 characters or more. + */ +static void +DES_AFS3_Transarc_string_to_key (krb5_data pw, + krb5_data cell, + des_cblock *key) +{ + des_key_schedule schedule; + des_cblock temp_key; + des_cblock ivec; + char password[512]; + size_t passlen; + + memcpy(password, pw.data, min(pw.length, sizeof(password))); + if(pw.length < sizeof(password)) + memcpy(password + pw.length, + cell.data, min(cell.length, + sizeof(password) - pw.length)); + passlen = min(sizeof(password), pw.length + cell.length); + memcpy(&ivec, "kerberos", 8); + memcpy(&temp_key, "kerberos", 8); + des_set_odd_parity (&temp_key); + des_set_key (&temp_key, schedule); + des_cbc_cksum ((des_cblock *)password, &ivec, passlen, schedule, &ivec); + + memcpy(&temp_key, &ivec, 8); + des_set_odd_parity (&temp_key); + des_set_key (&temp_key, schedule); + des_cbc_cksum ((des_cblock *)password, key, passlen, schedule, &ivec); + memset(&schedule, 0, sizeof(schedule)); + memset(&temp_key, 0, sizeof(temp_key)); + memset(&ivec, 0, sizeof(ivec)); + memset(password, 0, sizeof(password)); + + des_set_odd_parity (key); +} + +static krb5_error_code +DES_AFS3_string_to_key(krb5_context context, + krb5_enctype enctype, + krb5_data password, + krb5_salt salt, + krb5_keyblock *key) +{ + des_cblock tmp; + if(password.length > 8) + DES_AFS3_Transarc_string_to_key(password, salt.saltvalue, &tmp); + else + DES_AFS3_CMU_string_to_key(password, salt.saltvalue, &tmp); + key->keytype = enctype; + krb5_data_copy(&key->keyvalue, tmp, sizeof(tmp)); + memset(&key, 0, sizeof(key)); + return 0; +} + +static void +DES3_random_key(krb5_context context, + krb5_keyblock *key) +{ + des_cblock *k = key->keyvalue.data; + do { + krb5_generate_random_block(k, 3 * sizeof(des_cblock)); + des_set_odd_parity(&k[0]); + des_set_odd_parity(&k[1]); + des_set_odd_parity(&k[2]); + } while(des_is_weak_key(&k[0]) || + des_is_weak_key(&k[1]) || + des_is_weak_key(&k[2])); +} + +static void +DES3_schedule(krb5_context context, + struct key_data *key) +{ + des_cblock *k = key->key->keyvalue.data; + des_key_schedule *s = key->schedule->data; + des_set_key(&k[0], s[0]); + des_set_key(&k[1], s[1]); + des_set_key(&k[2], s[2]); +} + +/* + * A = A xor B. A & B are 8 bytes. + */ + +static void +xor (des_cblock *key, const unsigned char *b) +{ + unsigned char *a = (unsigned char*)key; + a[0] ^= b[0]; + a[1] ^= b[1]; + a[2] ^= b[2]; + a[3] ^= b[3]; + a[4] ^= b[4]; + a[5] ^= b[5]; + a[6] ^= b[6]; + a[7] ^= b[7]; +} + +static krb5_error_code +DES3_string_to_key(krb5_context context, + krb5_enctype enctype, + krb5_data password, + krb5_salt salt, + krb5_keyblock *key) +{ + char *str; + size_t len; + unsigned char tmp[24]; + des_cblock keys[3]; + + len = password.length + salt.saltvalue.length; + str = malloc(len); + if(len != 0 && str == NULL) + return ENOMEM; + memcpy(str, password.data, password.length); + memcpy(str + password.length, salt.saltvalue.data, salt.saltvalue.length); + { + des_cblock ivec; + des_key_schedule s[3]; + int i; + + _krb5_n_fold(str, len, tmp, 24); + + for(i = 0; i < 3; i++){ + memcpy(keys + i, tmp + i * 8, sizeof(keys[i])); + des_set_odd_parity(keys + i); + if(des_is_weak_key(keys + i)) + xor(keys + i, (unsigned char*)"\0\0\0\0\0\0\0\xf0"); + des_set_key(keys + i, s[i]); + } + memset(&ivec, 0, sizeof(ivec)); + des_ede3_cbc_encrypt((void*)tmp, (void*)tmp, sizeof(tmp), + s[0], s[1], s[2], &ivec, DES_ENCRYPT); + memset(s, 0, sizeof(s)); + memset(&ivec, 0, sizeof(ivec)); + for(i = 0; i < 3; i++){ + memcpy(keys + i, tmp + i * 8, sizeof(keys[i])); + des_set_odd_parity(keys + i); + if(des_is_weak_key(keys + i)) + xor(keys + i, (unsigned char*)"\0\0\0\0\0\0\0\xf0"); + } + memset(tmp, 0, sizeof(tmp)); + } + key->keytype = enctype; + krb5_data_copy(&key->keyvalue, keys, sizeof(keys)); + memset(keys, 0, sizeof(keys)); + memset(str, 0, len); + free(str); + return 0; +} + +static krb5_error_code +DES3_string_to_key_derived(krb5_context context, + krb5_enctype enctype, + krb5_data password, + krb5_salt salt, + krb5_keyblock *key) +{ + krb5_error_code ret; + size_t len = password.length + salt.saltvalue.length; + char *s; + + s = malloc(len); + if(len != 0 && s == NULL) + return ENOMEM; + memcpy(s, password.data, password.length); + memcpy(s + password.length, salt.saltvalue.data, salt.saltvalue.length); + ret = krb5_string_to_key_derived(context, + s, + len, + enctype, + key); + memset(s, 0, len); + free(s); + return ret; +} + +/* + * ARCFOUR + */ + +static void +ARCFOUR_random_key(krb5_context context, krb5_keyblock *key) +{ + krb5_generate_random_block (key->keyvalue.data, + key->keyvalue.length); +} + +static void +ARCFOUR_schedule(krb5_context context, struct key_data *kd) +{ + 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_keyblock *key) +{ + char *s, *p; + size_t len; + int i; + struct md4 m; + + len = 2 * (password.length + salt.saltvalue.length); + s = malloc (len); + if (len != 0 && s == NULL) + return ENOMEM; + for (p = s, i = 0; i < password.length; ++i) { + *p++ = ((char *)password.data)[i]; + *p++ = 0; + } + for (i = 0; i < salt.saltvalue.length; ++i) { + *p++ = ((char *)salt.saltvalue.data)[i]; + *p++ = 0; + } + md4_init(&m); + md4_update(&m, s, len); + key->keytype = enctype; + krb5_data_alloc (&key->keyvalue, 16); + md4_finito(&m, key->keyvalue.data); + memset (s, 0, len); + free (s); + return 0; +} + +extern struct salt_type des_salt[], + des3_salt[], des3_salt_derived[], arcfour_salt[]; + +struct key_type keytype_null = { + KEYTYPE_NULL, + "null", + 0, + 0, + 0, + NULL, + NULL, + NULL +}; + +struct key_type keytype_des = { + KEYTYPE_DES, + "des", + 56, + sizeof(des_cblock), + sizeof(des_key_schedule), + DES_random_key, + DES_schedule, + des_salt +}; + +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 +}; + +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 +}; + +struct key_type keytype_arcfour = { + KEYTYPE_ARCFOUR, + "arcfour", + 128, + 16, + sizeof(RC4_KEY), + ARCFOUR_random_key, + ARCFOUR_schedule, + arcfour_salt +}; + +struct key_type *keytypes[] = { + &keytype_null, + &keytype_des, + &keytype_des3_derived, + &keytype_des3, + &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; +} + + +struct salt_type des_salt[] = { + { + KRB5_PW_SALT, + "pw-salt", + DES_string_to_key + }, + { + KRB5_AFS3_SALT, + "afs3-salt", + DES_AFS3_string_to_key + }, + { 0 } +}; + +struct salt_type des3_salt[] = { + { + KRB5_PW_SALT, + "pw-salt", + DES3_string_to_key + }, + { 0 } +}; + +struct salt_type des3_salt_derived[] = { + { + KRB5_PW_SALT, + "pw-salt", + DES3_string_to_key_derived + }, + { 0 } +}; + +struct salt_type arcfour_salt[] = { + { + KRB5_PW_SALT, + "pw-salt", + ARCFOUR_string_to_key + }, + { 0 } +}; + +krb5_error_code +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) + 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) + return ENOMEM; + return 0; + } + } + return HEIM_ERR_SALTTYPE_NOSUPP; +} + +krb5_error_code +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) + 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; + } + } + return HEIM_ERR_SALTTYPE_NOSUPP; +} + +krb5_error_code +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_free_salt(krb5_context context, + krb5_salt salt) +{ + krb5_data_free(&salt.saltvalue); + return 0; +} + +krb5_error_code +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_string_to_key (krb5_context context, + krb5_enctype enctype, + const char *password, + krb5_principal principal, + krb5_keyblock *key) +{ + krb5_data pw; + pw.data = (void*)password; + pw.length = strlen(password); + return krb5_string_to_key_data(context, enctype, pw, principal, key); +} + +krb5_error_code +krb5_string_to_key_data_salt (krb5_context context, + krb5_enctype enctype, + krb5_data password, + krb5_salt salt, + krb5_keyblock *key) +{ + struct encryption_type *et =_find_enctype(enctype); + struct salt_type *st; + if(et == NULL) + 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, key); + return HEIM_ERR_SALTTYPE_NOSUPP; +} + +krb5_error_code +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 = (void*)password; + pw.length = strlen(password); + return krb5_string_to_key_data_salt(context, enctype, pw, salt, key); +} + +krb5_error_code +krb5_keytype_to_string(krb5_context context, + krb5_keytype keytype, + char **string) +{ + struct key_type *kt = _find_keytype(keytype); + if(kt == NULL) + return KRB5_PROG_KEYTYPE_NOSUPP; + *string = strdup(kt->name); + if(*string == NULL) + return ENOMEM; + return 0; +} + +krb5_error_code +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; + } + return KRB5_PROG_KEYTYPE_NOSUPP; +} + +krb5_error_code +krb5_generate_random_keyblock(krb5_context context, + krb5_enctype type, + krb5_keyblock *key) +{ + krb5_error_code ret; + struct encryption_type *et = _find_enctype(type); + if(et == NULL) + return KRB5_PROG_ETYPE_NOSUPP; + ret = krb5_data_alloc(&key->keyvalue, et->keytype->size); + if(ret) + return ret; + key->keytype = type; + if(et->keytype->random_key) + (*et->keytype->random_key)(context, key); + else + krb5_generate_random_block(key->keyvalue.data, + key->keyvalue.length); + return 0; +} + +static krb5_error_code +_key_schedule(krb5_context context, + struct key_data *key) +{ + krb5_error_code ret; + struct encryption_type *et = _find_enctype(key->key->keytype); + struct key_type *kt = et->keytype; + + if(kt->schedule == NULL) + return 0; + ALLOC(key->schedule, 1); + if(key->schedule == NULL) + return ENOMEM; + ret = krb5_data_alloc(key->schedule, kt->schedule_size); + if(ret) { + free(key->schedule); + key->schedule = NULL; + return ret; + } + (*kt->schedule)(context, key); + return 0; +} + +/************************************************************ + * * + ************************************************************/ + +static void +NONE_checksum(krb5_context context, + struct key_data *key, + void *data, + size_t len, + Checksum *C) +{ +} + +static void +CRC32_checksum(krb5_context context, + struct key_data *key, + void *data, + size_t len, + Checksum *C) +{ + u_int32_t crc; + unsigned char *r = C->checksum.data; + _krb5_crc_init_table (); + crc = _krb5_crc_update (data, len, 0); + r[0] = crc & 0xff; + r[1] = (crc >> 8) & 0xff; + r[2] = (crc >> 16) & 0xff; + r[3] = (crc >> 24) & 0xff; +} + +static void +RSA_MD4_checksum(krb5_context context, + struct key_data *key, + void *data, + size_t len, + Checksum *C) +{ + struct md4 m; + md4_init(&m); + md4_update(&m, data, len); + md4_finito(&m, C->checksum.data); +} + +static void +RSA_MD4_DES_checksum(krb5_context context, + struct key_data *key, + void *data, + size_t len, + Checksum *cksum) +{ + struct md4 md4; + des_cblock ivec; + unsigned char *p = cksum->checksum.data; + + krb5_generate_random_block(p, 8); + md4_init(&md4); + md4_update(&md4, p, 8); + md4_update(&md4, data, len); + md4_finito(&md4, p + 8); + memset (&ivec, 0, sizeof(ivec)); + des_cbc_encrypt((des_cblock*)p, + (des_cblock*)p, + 24, + key->schedule->data, + &ivec, + DES_ENCRYPT); +} + +static krb5_error_code +RSA_MD4_DES_verify(krb5_context context, + struct key_data *key, + void *data, + size_t len, + Checksum *C) +{ + struct md4 md4; + unsigned char tmp[24]; + unsigned char res[16]; + des_cblock ivec; + krb5_error_code ret = 0; + + memset(&ivec, 0, sizeof(ivec)); + des_cbc_encrypt(C->checksum.data, + (void*)tmp, + C->checksum.length, + key->schedule->data, + &ivec, + DES_DECRYPT); + md4_init(&md4); + md4_update(&md4, tmp, 8); /* confounder */ + md4_update(&md4, data, len); + md4_finito(&md4, res); + if(memcmp(res, tmp + 8, sizeof(res)) != 0) + ret = KRB5KRB_AP_ERR_BAD_INTEGRITY; + memset(tmp, 0, sizeof(tmp)); + memset(res, 0, sizeof(res)); + return ret; +} + +static void +RSA_MD5_checksum(krb5_context context, + struct key_data *key, + void *data, + size_t len, + Checksum *C) +{ + struct md5 m; + md5_init(&m); + md5_update(&m, data, len); + md5_finito(&m, C->checksum.data); +} + +static void +RSA_MD5_DES_checksum(krb5_context context, + struct key_data *key, + void *data, + size_t len, + Checksum *C) +{ + struct md5 md5; + des_cblock ivec; + unsigned char *p = C->checksum.data; + + krb5_generate_random_block(p, 8); + md5_init(&md5); + md5_update(&md5, p, 8); + md5_update(&md5, data, len); + md5_finito(&md5, p + 8); + memset (&ivec, 0, sizeof(ivec)); + des_cbc_encrypt((des_cblock*)p, + (des_cblock*)p, + 24, + key->schedule->data, + &ivec, + DES_ENCRYPT); +} + +static krb5_error_code +RSA_MD5_DES_verify(krb5_context context, + struct key_data *key, + void *data, + size_t len, + Checksum *C) +{ + struct md5 md5; + unsigned char tmp[24]; + unsigned char res[16]; + des_cblock ivec; + des_key_schedule *sched = key->schedule->data; + krb5_error_code ret = 0; + + memset(&ivec, 0, sizeof(ivec)); + des_cbc_encrypt(C->checksum.data, + (void*)tmp, + C->checksum.length, + sched[0], + &ivec, + DES_DECRYPT); + md5_init(&md5); + md5_update(&md5, tmp, 8); /* confounder */ + md5_update(&md5, data, len); + md5_finito(&md5, res); + if(memcmp(res, tmp + 8, sizeof(res)) != 0) + ret = KRB5KRB_AP_ERR_BAD_INTEGRITY; + memset(tmp, 0, sizeof(tmp)); + memset(res, 0, sizeof(res)); + return ret; +} + +static void +RSA_MD5_DES3_checksum(krb5_context context, + struct key_data *key, + void *data, + size_t len, + Checksum *C) +{ + struct md5 md5; + des_cblock ivec; + unsigned char *p = C->checksum.data; + des_key_schedule *sched = key->schedule->data; + + krb5_generate_random_block(p, 8); + md5_init(&md5); + md5_update(&md5, p, 8); + md5_update(&md5, data, len); + md5_finito(&md5, p + 8); + memset (&ivec, 0, sizeof(ivec)); + des_ede3_cbc_encrypt((des_cblock*)p, + (des_cblock*)p, + 24, + sched[0], sched[1], sched[2], + &ivec, + DES_ENCRYPT); +} + +static krb5_error_code +RSA_MD5_DES3_verify(krb5_context context, + struct key_data *key, + void *data, + size_t len, + Checksum *C) +{ + struct md5 md5; + unsigned char tmp[24]; + unsigned char res[16]; + des_cblock ivec; + des_key_schedule *sched = key->schedule->data; + krb5_error_code ret = 0; + + memset(&ivec, 0, sizeof(ivec)); + des_ede3_cbc_encrypt(C->checksum.data, + (void*)tmp, + C->checksum.length, + sched[0], sched[1], sched[2], + &ivec, + DES_DECRYPT); + md5_init(&md5); + md5_update(&md5, tmp, 8); /* confounder */ + md5_update(&md5, data, len); + md5_finito(&md5, res); + if(memcmp(res, tmp + 8, sizeof(res)) != 0) + ret = KRB5KRB_AP_ERR_BAD_INTEGRITY; + memset(tmp, 0, sizeof(tmp)); + memset(res, 0, sizeof(res)); + return ret; +} + +static void +SHA1_checksum(krb5_context context, + struct key_data *key, + void *data, + size_t len, + Checksum *C) +{ + struct sha m; + sha_init(&m); + sha_update(&m, data, len); + sha_finito(&m, C->checksum.data); +} + +/* HMAC according to RFC2104 */ +static void +hmac(krb5_context context, + struct checksum_type *cm, + void *data, + size_t len, + struct key_data *keyblock, + Checksum *result) +{ + unsigned char *ipad, *opad; + unsigned char *key; + size_t key_len; + int i; + + if(keyblock->key->keyvalue.length > cm->blocksize){ + (*cm->checksum)(context, + keyblock, + keyblock->key->keyvalue.data, + keyblock->key->keyvalue.length, + result); + key = result->checksum.data; + key_len = result->checksum.length; + } else { + key = keyblock->key->keyvalue.data; + key_len = keyblock->key->keyvalue.length; + } + ipad = malloc(cm->blocksize + len); + opad = malloc(cm->blocksize + cm->checksumsize); + memset(ipad, 0x36, cm->blocksize); + memset(opad, 0x5c, cm->blocksize); + for(i = 0; i < key_len; i++){ + ipad[i] ^= key[i]; + opad[i] ^= key[i]; + } + memcpy(ipad + cm->blocksize, data, len); + (*cm->checksum)(context, keyblock, ipad, cm->blocksize + len, result); + memcpy(opad + cm->blocksize, result->checksum.data, + result->checksum.length); + (*cm->checksum)(context, keyblock, opad, + cm->blocksize + cm->checksumsize, result); + memset(ipad, 0, cm->blocksize + len); + free(ipad); + memset(opad, 0, cm->blocksize + cm->checksumsize); + free(opad); +} + +static void +HMAC_SHA1_DES3_checksum(krb5_context context, + struct key_data *key, + void *data, + size_t len, + Checksum *result) +{ + struct checksum_type *c = _find_checksum(CKSUMTYPE_SHA1); + + hmac(context, c, data, len, key, result); +} + +struct checksum_type checksum_none = { + CKSUMTYPE_NONE, + "none", + 1, + 0, + 0, + NONE_checksum, + NULL +}; +struct checksum_type checksum_crc32 = { + CKSUMTYPE_CRC32, + "crc32", + 1, + 4, + 0, + CRC32_checksum, + NULL +}; +struct checksum_type checksum_rsa_md4 = { + CKSUMTYPE_RSA_MD4, + "rsa-md4", + 64, + 16, + F_CPROOF, + RSA_MD4_checksum, + NULL +}; +struct checksum_type checksum_rsa_md4_des = { + CKSUMTYPE_RSA_MD4_DES, + "rsa-md4-des", + 64, + 24, + F_KEYED | F_CPROOF | F_VARIANT, + RSA_MD4_DES_checksum, + RSA_MD4_DES_verify +}; +#if 0 +struct checksum_type checksum_des_mac = { + CKSUMTYPE_DES_MAC, + "des-mac", + 0, + 0, + 0, + DES_MAC_checksum, +}; +struct checksum_type checksum_des_mac_k = { + CKSUMTYPE_DES_MAC_K, + "des-mac-k", + 0, + 0, + 0, + DES_MAC_K_checksum, +}; +struct checksum_type checksum_rsa_md4_des_k = { + CKSUMTYPE_RSA_MD4_DES_K, + "rsa-md4-des-k", + 0, + 0, + 0, + RSA_MD4_DES_K_checksum, + RSA_MD4_DES_K_verify, +}; +#endif +struct checksum_type checksum_rsa_md5 = { + CKSUMTYPE_RSA_MD5, + "rsa-md5", + 64, + 16, + F_CPROOF, + RSA_MD5_checksum, + NULL +}; +struct checksum_type checksum_rsa_md5_des = { + CKSUMTYPE_RSA_MD5_DES, + "rsa-md5-des", + 64, + 24, + F_KEYED | F_CPROOF | F_VARIANT, + RSA_MD5_DES_checksum, + RSA_MD5_DES_verify, +}; +struct checksum_type checksum_rsa_md5_des3 = { + CKSUMTYPE_RSA_MD5_DES3, + "rsa-md5-des3", + 64, + 24, + F_KEYED | F_CPROOF | F_VARIANT, + RSA_MD5_DES3_checksum, + RSA_MD5_DES3_verify, +}; +struct checksum_type checksum_sha1 = { + CKSUMTYPE_SHA1, + "sha1", + 64, + 20, + F_CPROOF, + SHA1_checksum, + NULL +}; +struct checksum_type checksum_hmac_sha1_des3 = { + CKSUMTYPE_HMAC_SHA1_DES3, + "hmac-sha1-des3", + 64, + 20, + F_KEYED | F_CPROOF | F_DERIVED, + HMAC_SHA1_DES3_checksum, + NULL +}; + +struct checksum_type *checksum_types[] = { + &checksum_none, + &checksum_crc32, + &checksum_rsa_md4, + &checksum_rsa_md4_des, +#if 0 + &checksum_des_mac, + &checksum_des_mac_k, + &checksum_rsa_md4_des_k, +#endif + &checksum_rsa_md5, + &checksum_rsa_md5_des, + &checksum_rsa_md5_des3, + &checksum_sha1, + &checksum_hmac_sha1_des3 +}; + +static int num_checksums = sizeof(checksum_types) / sizeof(checksum_types[0]); + +static struct checksum_type * +_find_checksum(krb5_cksumtype type) +{ + int i; + for(i = 0; i < num_checksums; i++) + if(checksum_types[i]->type == type) + return checksum_types[i]; + return NULL; +} + +static krb5_error_code +get_checksum_key(krb5_context context, + krb5_crypto crypto, + unsigned usage, /* not krb5_key_usage */ + struct checksum_type *ct, + struct key_data **key) +{ + krb5_error_code ret = 0; + + if(ct->flags & F_DERIVED) + ret = _get_derived_key(context, crypto, usage, key); + else if(ct->flags & F_VARIANT) { + int i; + + *key = _new_derived_key(crypto, 0xff/* KRB5_KU_RFC1510_VARIANT */); + if(*key == NULL) + return ENOMEM; + ret = krb5_copy_keyblock(context, crypto->key.key, &(*key)->key); + if(ret) + return ret; + for(i = 0; i < (*key)->key->keyvalue.length; i++) + ((unsigned char*)(*key)->key->keyvalue.data)[i] ^= 0xF0; + } else { + *key = &crypto->key; + } + if(ret == 0) + ret = _key_schedule(context, *key); + return ret; +} + +static krb5_error_code +do_checksum (krb5_context context, + struct checksum_type *ct, + krb5_crypto crypto, + unsigned usage, + void *data, + size_t len, + Checksum *result) +{ + krb5_error_code ret; + struct key_data *dkey; + int keyed_checksum; + + keyed_checksum = (ct->flags & F_KEYED) != 0; + if(keyed_checksum && crypto == NULL) + return KRB5_PROG_SUMTYPE_NOSUPP; /* XXX */ + if(keyed_checksum) + ret = get_checksum_key(context, crypto, usage, ct, &dkey); + else + dkey = NULL; + result->cksumtype = ct->type; + krb5_data_alloc(&result->checksum, ct->checksumsize); + (*ct->checksum)(context, dkey, data, len, result); + return 0; +} + +static krb5_error_code +create_checksum(krb5_context context, + krb5_crypto crypto, + unsigned usage, /* not krb5_key_usage */ + krb5_cksumtype type, /* if crypto == NULL */ + void *data, + size_t len, + Checksum *result) +{ + struct checksum_type *ct; + + if(crypto) { + ct = crypto->et->keyed_checksum; + if(ct == NULL) + ct = crypto->et->cksumtype; + } else + ct = _find_checksum(type); + if(ct == NULL) + return KRB5_PROG_SUMTYPE_NOSUPP; + return do_checksum (context, ct, crypto, usage, data, len, result); +} + +krb5_error_code +krb5_create_checksum(krb5_context context, + krb5_crypto crypto, + unsigned usage_or_type, + void *data, + size_t len, + Checksum *result) +{ + return create_checksum(context, crypto, + CHECKSUM_USAGE(usage_or_type), + usage_or_type, data, len, result); +} + +static krb5_error_code +verify_checksum(krb5_context context, + krb5_crypto crypto, + unsigned usage, /* not krb5_key_usage */ + void *data, + size_t len, + Checksum *cksum) +{ + krb5_error_code ret; + struct key_data *dkey; + int keyed_checksum; + Checksum c; + struct checksum_type *ct; + + ct = _find_checksum(cksum->cksumtype); + if(ct == NULL) + return KRB5_PROG_SUMTYPE_NOSUPP; + if(ct->checksumsize != cksum->checksum.length) + return KRB5KRB_AP_ERR_BAD_INTEGRITY; /* XXX */ + keyed_checksum = (ct->flags & F_KEYED) != 0; + if(keyed_checksum && crypto == NULL) + return KRB5_PROG_SUMTYPE_NOSUPP; /* XXX */ + if(keyed_checksum) + ret = get_checksum_key(context, crypto, usage, ct, &dkey); + else + dkey = NULL; + if(ct->verify) + return (*ct->verify)(context, dkey, data, len, cksum); + + ret = krb5_data_alloc (&c.checksum, ct->checksumsize); + if (ret) + return ret; + + (*ct->checksum)(context, dkey, data, len, &c); + + if(c.checksum.length != cksum->checksum.length || + memcmp(c.checksum.data, cksum->checksum.data, c.checksum.length)) + ret = KRB5KRB_AP_ERR_BAD_INTEGRITY; + else + ret = 0; + krb5_data_free (&c.checksum); + return ret; +} + +krb5_error_code +krb5_verify_checksum(krb5_context context, + krb5_crypto crypto, + krb5_key_usage usage, + void *data, + size_t len, + Checksum *cksum) +{ + return verify_checksum(context, crypto, + CHECKSUM_USAGE(usage), data, len, cksum); +} + +krb5_error_code +krb5_checksumsize(krb5_context context, + krb5_cksumtype type, + size_t *size) +{ + struct checksum_type *ct = _find_checksum(type); + if(ct == NULL) + return KRB5_PROG_SUMTYPE_NOSUPP; + *size = ct->checksumsize; + return 0; +} + +krb5_boolean +krb5_checksum_is_keyed(krb5_context context, + krb5_cksumtype type) +{ + struct checksum_type *ct = _find_checksum(type); + if(ct == NULL) + return KRB5_PROG_SUMTYPE_NOSUPP; + return ct->flags & F_KEYED; +} + +krb5_boolean +krb5_checksum_is_collision_proof(krb5_context context, + krb5_cksumtype type) +{ + struct checksum_type *ct = _find_checksum(type); + if(ct == NULL) + return KRB5_PROG_SUMTYPE_NOSUPP; + return ct->flags & F_CPROOF; +} + +/************************************************************ + * * + ************************************************************/ + +static void +NULL_encrypt(struct key_data *key, + void *data, + size_t len, + krb5_boolean encrypt) +{ +} + +static void +DES_CBC_encrypt_null_ivec(struct key_data *key, + void *data, + size_t len, + krb5_boolean encrypt) +{ + des_cblock ivec; + des_key_schedule *s = key->schedule->data; + memset(&ivec, 0, sizeof(ivec)); + des_cbc_encrypt(data, data, len, *s, &ivec, encrypt); +} + +static void +DES_CBC_encrypt_key_ivec(struct key_data *key, + void *data, + size_t len, + krb5_boolean encrypt) +{ + des_cblock ivec; + des_key_schedule *s = key->schedule->data; + memcpy(&ivec, key->key->keyvalue.data, sizeof(ivec)); + des_cbc_encrypt(data, data, len, *s, &ivec, encrypt); +} + +static void +DES3_CBC_encrypt(struct key_data *key, + void *data, + size_t len, + krb5_boolean encrypt) +{ + des_cblock ivec; + des_key_schedule *s = key->schedule->data; + memset(&ivec, 0, sizeof(ivec)); + des_ede3_cbc_encrypt(data, data, len, s[0], s[1], s[2], &ivec, encrypt); +} + +static void +ARCFOUR_encrypt(struct key_data *key, + void *data, + size_t len, + krb5_boolean encrypt) +{ + +} + +/* + * these should currently be in reverse preference order. + */ + +static struct encryption_type etypes[] = { + { + ETYPE_NULL, + "null", + 1, + 0, + &keytype_null, + &checksum_none, + NULL, + 0, + NULL_encrypt, + }, + { + ETYPE_DES_CBC_CRC, + "des-cbc-crc", + 8, + 8, + &keytype_des, + &checksum_crc32, + NULL, + 0, + DES_CBC_encrypt_key_ivec, + }, + { + ETYPE_DES_CBC_MD4, + "des-cbc-md4", + 8, + 8, + &keytype_des, + &checksum_rsa_md4, + &checksum_rsa_md4_des, + 0, + DES_CBC_encrypt_null_ivec, + }, + { + ETYPE_DES_CBC_MD5, + "des-cbc-md5", + 8, + 8, + &keytype_des, + &checksum_rsa_md5, + &checksum_rsa_md5_des, + 0, + DES_CBC_encrypt_null_ivec, + }, + { + ETYPE_DES3_CBC_MD5, + "des3-cbc-md5", + 8, + 8, + &keytype_des3, + &checksum_rsa_md5, + &checksum_rsa_md5_des3, + 0, + DES3_CBC_encrypt, + }, + { + ETYPE_DES3_CBC_SHA1, + "des3-cbc-sha1", + 8, + 8, + &keytype_des3_derived, + &checksum_sha1, + &checksum_hmac_sha1_des3, + F_DERIVED, + DES3_CBC_encrypt, + }, + { + ETYPE_OLD_DES3_CBC_SHA1, + "old-des3-cbc-sha1", + 8, + 8, + &keytype_des3, + &checksum_sha1, + &checksum_hmac_sha1_des3, + 0, + DES3_CBC_encrypt, + }, + { + ETYPE_DES_CBC_NONE, + "des-cbc-none", + 8, + 0, + &keytype_des, + &checksum_none, + NULL, + F_PSEUDO, + DES_CBC_encrypt_null_ivec, + }, + { + ETYPE_DES3_CBC_NONE, + "des3-cbc-none", + 8, + 0, + &keytype_des3_derived, + &checksum_none, + NULL, + F_PSEUDO, + DES_CBC_encrypt_null_ivec, + }, +}; + +static unsigned num_etypes = sizeof(etypes) / sizeof(etypes[0]); + + +static struct encryption_type * +_find_enctype(krb5_enctype type) +{ + int i; + for(i = 0; i < num_etypes; i++) + if(etypes[i].type == type) + return &etypes[i]; + return NULL; +} + + +krb5_error_code +krb5_enctype_to_string(krb5_context context, + krb5_enctype etype, + char **string) +{ + struct encryption_type *e; + e = _find_enctype(etype); + if(e == NULL) + return KRB5_PROG_ETYPE_NOSUPP; + *string = strdup(e->name); + if(*string == NULL) + return ENOMEM; + return 0; +} + +krb5_error_code +krb5_string_to_enctype(krb5_context context, + const char *string, + krb5_enctype *etype) +{ + int i; + for(i = 0; i < num_etypes; i++) + if(strcasecmp(etypes[i].name, string) == 0){ + *etype = etypes[i].type; + return 0; + } + return KRB5_PROG_ETYPE_NOSUPP; +} + +krb5_error_code +krb5_enctype_to_keytype(krb5_context context, + krb5_enctype etype, + krb5_keytype *keytype) +{ + struct encryption_type *e = _find_enctype(etype); + if(e == NULL) + return KRB5_PROG_ETYPE_NOSUPP; + *keytype = e->keytype->type; /* XXX */ + return 0; +} + +#if 0 +krb5_error_code +krb5_keytype_to_enctype(krb5_context context, + krb5_keytype keytype, + krb5_enctype *etype) +{ + struct key_type *kt = _find_keytype(keytype); + krb5_warnx(context, "krb5_keytype_to_enctype(%u)", keytype); + if(kt == NULL) + return KRB5_PROG_KEYTYPE_NOSUPP; + *etype = kt->best_etype; + return 0; +} +#endif + +krb5_error_code +krb5_keytype_to_enctypes (krb5_context context, + krb5_keytype keytype, + unsigned *len, + int **val) +{ + int i; + unsigned n = 0; + int *ret; + + for (i = num_etypes - 1; i >= 0; --i) { + if (etypes[i].keytype->type == keytype + && !(etypes[i].flags & F_PSEUDO)) + ++n; + } + ret = malloc(n * sizeof(int)); + if (ret == NULL && n != 0) + return ENOMEM; + n = 0; + for (i = num_etypes - 1; i >= 0; --i) { + if (etypes[i].keytype->type == keytype + && !(etypes[i].flags & F_PSEUDO)) + ret[n++] = etypes[i].type; + } + *len = n; + *val = ret; + return 0; +} + +/* + * First take the configured list of etypes for `keytype' if available, + * else, do `krb5_keytype_to_enctypes'. + */ + +krb5_error_code +krb5_keytype_to_enctypes_default (krb5_context context, + krb5_keytype keytype, + unsigned *len, + int **val) +{ + int i, n; + int *ret; + + if (keytype != KEYTYPE_DES || context->etypes_des == NULL) + return krb5_keytype_to_enctypes (context, keytype, len, val); + + for (n = 0; context->etypes_des[n]; ++n) + ; + ret = malloc (n * sizeof(*ret)); + if (ret == NULL && n != 0) + return ENOMEM; + for (i = 0; i < n; ++i) + ret[i] = context->etypes_des[i]; + *len = n; + *val = ret; + return 0; +} + +krb5_error_code +krb5_enctype_valid(krb5_context context, + krb5_enctype etype) +{ + return _find_enctype(etype) != NULL; +} + +/* if two enctypes have compatible keys */ +krb5_boolean +krb5_enctypes_compatible_keys(krb5_context context, + krb5_enctype etype1, + krb5_enctype etype2) +{ + struct encryption_type *e1 = _find_enctype(etype1); + struct encryption_type *e2 = _find_enctype(etype2); + return e1 != NULL && e2 != NULL && e1->keytype == e2->keytype; +} + +static krb5_boolean +derived_crypto(krb5_context context, + krb5_crypto crypto) +{ + return (crypto->et->flags & F_DERIVED) != 0; +} + + +#define CHECKSUMSIZE(C) ((C)->checksumsize) +#define CHECKSUMTYPE(C) ((C)->type) + +static krb5_error_code +encrypt_internal_derived(krb5_context context, + krb5_crypto crypto, + unsigned usage, + void *data, + size_t len, + krb5_data *result) +{ + size_t sz, block_sz, checksum_sz; + Checksum cksum; + unsigned char *p, *q; + krb5_error_code ret; + struct key_data *dkey; + struct encryption_type *et = crypto->et; + + checksum_sz = CHECKSUMSIZE(et->keyed_checksum); + + sz = et->confoundersize + /* 4 - length */ len; + block_sz = (sz + et->blocksize - 1) &~ (et->blocksize - 1); /* pad */ + p = calloc(1, block_sz + checksum_sz); + if(p == NULL) + return ENOMEM; + + q = p; + krb5_generate_random_block(q, et->confoundersize); /* XXX */ + q += et->confoundersize; + memcpy(q, data, len); + + ret = create_checksum(context, + crypto, + INTEGRITY_USAGE(usage), + 0, + p, + block_sz, + &cksum); + if(ret == 0 && cksum.checksum.length != checksum_sz) + ret = KRB5_CRYPTO_INTERNAL; + if(ret) { + memset(p, 0, block_sz + checksum_sz); + free(p); + return ret; + } + memcpy(p + block_sz, cksum.checksum.data, cksum.checksum.length); + ret = _get_derived_key(context, crypto, ENCRYPTION_USAGE(usage), &dkey); + if(ret) { + memset(p, 0, block_sz + checksum_sz); + free(p); + return ret; + } + ret = _key_schedule(context, dkey); + if(ret) { + memset(p, 0, block_sz); + free(p); + return ret; + } +#ifdef CRYPTO_DEBUG + krb5_crypto_debug(context, 1, block_sz, dkey->key); +#endif + (*et->encrypt)(dkey, p, block_sz, 1); + result->data = p; + result->length = block_sz + checksum_sz; + return 0; +} + +static krb5_error_code +encrypt_internal(krb5_context context, + krb5_crypto crypto, + void *data, + size_t len, + krb5_data *result) +{ + size_t sz, block_sz, checksum_sz; + Checksum cksum; + unsigned char *p, *q; + krb5_error_code ret; + struct encryption_type *et = crypto->et; + + checksum_sz = CHECKSUMSIZE(et->cksumtype); + + sz = et->confoundersize + checksum_sz + len; + block_sz = (sz + et->blocksize - 1) &~ (et->blocksize - 1); /* pad */ + p = calloc(1, block_sz); + if(p == NULL) + return ENOMEM; + + q = p; + krb5_generate_random_block(q, et->confoundersize); /* XXX */ + q += et->confoundersize; + memset(q, 0, checksum_sz); + q += checksum_sz; + memcpy(q, data, len); + + ret = create_checksum(context, + NULL, + 0, + CHECKSUMTYPE(et->cksumtype), + p, + block_sz, + &cksum); + if(ret == 0 && cksum.checksum.length != checksum_sz) { + free_Checksum (&cksum); + ret = KRB5_CRYPTO_INTERNAL; + } + if(ret) { + memset(p, 0, block_sz); + free(p); + free_Checksum(&cksum); + return ret; + } + memcpy(p + et->confoundersize, cksum.checksum.data, cksum.checksum.length); + free_Checksum(&cksum); + ret = _key_schedule(context, &crypto->key); + if(ret) { + memset(p, 0, block_sz); + free(p); + return ret; + } +#ifdef CRYPTO_DEBUG + krb5_crypto_debug(context, 1, block_sz, crypto->key.key); +#endif + (*et->encrypt)(&crypto->key, p, block_sz, 1); + result->data = p; + result->length = block_sz; + return 0; +} + +static krb5_error_code +decrypt_internal_derived(krb5_context context, + krb5_crypto crypto, + unsigned usage, + void *data, + size_t len, + krb5_data *result) +{ + size_t checksum_sz; + Checksum cksum; + unsigned char *p; + krb5_error_code ret; + struct key_data *dkey; + struct encryption_type *et = crypto->et; + unsigned long l; + + p = malloc(len); + if(len != 0 && p == NULL) + return ENOMEM; + memcpy(p, data, len); + + checksum_sz = CHECKSUMSIZE(et->keyed_checksum); + len -= checksum_sz; + + ret = _get_derived_key(context, crypto, ENCRYPTION_USAGE(usage), &dkey); + if(ret) { + free(p); + return ret; + } + ret = _key_schedule(context, dkey); + if(ret) { + free(p); + return ret; + } +#ifdef CRYPTO_DEBUG + krb5_crypto_debug(context, 0, len, dkey->key); +#endif + (*et->encrypt)(dkey, p, len, 0); + + cksum.checksum.data = p + len; + cksum.checksum.length = checksum_sz; + cksum.cksumtype = CHECKSUMTYPE(et->keyed_checksum); + + ret = verify_checksum(context, + crypto, + INTEGRITY_USAGE(usage), + p, + len, + &cksum); + if(ret) { + free(p); + return ret; + } + l = len - et->confoundersize; + memmove(p, p + et->confoundersize, l); + result->data = realloc(p, l); + if(p == NULL) { + free(p); + return ENOMEM; + } + result->length = l; + return 0; +} + +static krb5_error_code +decrypt_internal(krb5_context context, + krb5_crypto crypto, + void *data, + size_t len, + krb5_data *result) +{ + krb5_error_code ret; + unsigned char *p; + Checksum cksum; + size_t checksum_sz, l; + struct encryption_type *et = crypto->et; + + checksum_sz = CHECKSUMSIZE(et->cksumtype); + p = malloc(len); + if(len != 0 && p == NULL) + return ENOMEM; + memcpy(p, data, len); + + ret = _key_schedule(context, &crypto->key); + if(ret) { + free(p); + return ret; + } +#ifdef CRYPTO_DEBUG + krb5_crypto_debug(context, 0, len, crypto->key.key); +#endif + (*et->encrypt)(&crypto->key, p, len, 0); + ret = krb5_data_copy(&cksum.checksum, p + et->confoundersize, checksum_sz); + if(ret) { + free(p); + return ret; + } + memset(p + et->confoundersize, 0, checksum_sz); + cksum.cksumtype = CHECKSUMTYPE(et->cksumtype); + ret = verify_checksum(context, NULL, 0, p, len, &cksum); + free_Checksum(&cksum); + if(ret) { + free(p); + return ret; + } + l = len - et->confoundersize - checksum_sz; + memmove(p, p + et->confoundersize + checksum_sz, l); + result->data = realloc(p, l); + if(result->data == NULL) { + free(p); + return ENOMEM; + } + result->length = l; + return 0; +} + +krb5_error_code +krb5_encrypt(krb5_context context, + krb5_crypto crypto, + unsigned usage, + void *data, + size_t len, + krb5_data *result) +{ + if(derived_crypto(context, crypto)) + return encrypt_internal_derived(context, crypto, usage, + data, len, result); + else + return encrypt_internal(context, crypto, data, len, result); +} + +krb5_error_code +krb5_encrypt_EncryptedData(krb5_context context, + krb5_crypto crypto, + unsigned usage, + void *data, + size_t len, + int kvno, + EncryptedData *result) +{ + result->etype = CRYPTO_ETYPE(crypto); + if(kvno){ + ALLOC(result->kvno, 1); + *result->kvno = kvno; + }else + result->kvno = NULL; + return krb5_encrypt(context, crypto, usage, data, len, &result->cipher); +} + +krb5_error_code +krb5_decrypt(krb5_context context, + krb5_crypto crypto, + unsigned usage, + void *data, + size_t len, + krb5_data *result) +{ + if(derived_crypto(context, crypto)) + return decrypt_internal_derived(context, crypto, usage, + data, len, result); + else + return decrypt_internal(context, crypto, data, len, result); +} + +krb5_error_code +krb5_decrypt_EncryptedData(krb5_context context, + krb5_crypto crypto, + unsigned usage, + EncryptedData *e, + krb5_data *result) +{ + return krb5_decrypt(context, crypto, usage, + e->cipher.data, e->cipher.length, result); +} + +/************************************************************ + * * + ************************************************************/ + +void +krb5_generate_random_block(void *buf, size_t len) +{ + des_cblock key, out; + static des_cblock counter; + static des_key_schedule schedule; + int i; + static int initialized = 0; + + if(!initialized) { + des_new_random_key(&key); + des_set_key(&key, schedule); + memset(&key, 0, sizeof(key)); + des_new_random_key(&counter); + } + while(len > 0) { + des_ecb_encrypt(&counter, &out, schedule, DES_ENCRYPT); + for(i = 7; i >=0; i--) + if(counter[i]++) + break; + memcpy(buf, out, min(len, sizeof(out))); + len -= min(len, sizeof(out)); + buf = (char*)buf + sizeof(out); + } +} + +static void +DES3_postproc(krb5_context context, + unsigned char *k, size_t len, struct key_data *key) +{ + unsigned char x[24]; + int i, j; + + memset(x, 0, sizeof(x)); + for (i = 0; i < 3; ++i) { + unsigned char foo; + + for (j = 0; j < 7; ++j) { + unsigned char b = k[7 * i + j]; + + x[8 * i + j] = b; + } + foo = 0; + for (j = 6; j >= 0; --j) { + foo |= k[7 * i + j] & 1; + foo <<= 1; + } + x[8 * i + 7] = foo; + } + k = key->key->keyvalue.data; + memcpy(k, x, 24); + memset(x, 0, sizeof(x)); + if (key->schedule) { + krb5_free_data(context, key->schedule); + key->schedule = NULL; + } + des_set_odd_parity((des_cblock*)k); + des_set_odd_parity((des_cblock*)(k + 8)); + des_set_odd_parity((des_cblock*)(k + 16)); +} + +static krb5_error_code +derive_key(krb5_context context, + struct encryption_type *et, + struct key_data *key, + void *constant, + size_t len) +{ + unsigned char *k; + unsigned int nblocks = 0, i; + krb5_error_code ret = 0; + + struct key_type *kt = et->keytype; + ret = _key_schedule(context, key); + if(ret) + return ret; + if(et->blocksize * 8 < kt->bits || + len != et->blocksize) { + nblocks = (kt->bits + et->blocksize * 8 - 1) / (et->blocksize * 8); + k = malloc(nblocks * et->blocksize); + if(k == NULL) + return ENOMEM; + _krb5_n_fold(constant, len, k, et->blocksize); + for(i = 0; i < nblocks; i++) { + if(i > 0) + memcpy(k + i * et->blocksize, + k + (i - 1) * et->blocksize, + et->blocksize); + (*et->encrypt)(key, k + i * et->blocksize, et->blocksize, 1); + } + } else { + void *c = malloc(len); + size_t res_len = (kt->bits + 7) / 8; + + if(len != 0 && c == NULL) + return ENOMEM; + memcpy(c, constant, len); + (*et->encrypt)(key, c, len, 1); + k = malloc(res_len); + if(res_len != 0 && k == NULL) + return ENOMEM; + _krb5_n_fold(c, len, k, res_len); + free(c); + } + + /* XXX keytype dependent post-processing */ + switch(kt->type) { + case KEYTYPE_DES3: + DES3_postproc(context, k, nblocks * et->blocksize, key); + break; + default: + krb5_warnx(context, "derive_key() called with unknown keytype (%u)", + kt->type); + ret = KRB5_CRYPTO_INTERNAL; + break; + } + memset(k, 0, nblocks * et->blocksize); + free(k); + return ret; +} + +static struct key_data * +_new_derived_key(krb5_crypto crypto, unsigned usage) +{ + struct key_usage *d = crypto->key_usage; + d = realloc(d, (crypto->num_key_usage + 1) * sizeof(*d)); + if(d == NULL) + return NULL; + crypto->key_usage = d; + d += crypto->num_key_usage++; + memset(d, 0, sizeof(*d)); + d->usage = usage; + return &d->key; +} + +static krb5_error_code +_get_derived_key(krb5_context context, + krb5_crypto crypto, + unsigned usage, + struct key_data **key) +{ + int i; + struct key_data *d; + unsigned char constant[5]; + + for(i = 0; i < crypto->num_key_usage; i++) + if(crypto->key_usage[i].usage == usage) { + *key = &crypto->key_usage[i].key; + return 0; + } + d = _new_derived_key(crypto, usage); + if(d == NULL) + return ENOMEM; + krb5_copy_keyblock(context, crypto->key.key, &d->key); + _krb5_put_int(constant, usage, 5); + derive_key(context, crypto->et, d, constant, sizeof(constant)); + *key = d; + return 0; +} + + +krb5_error_code +krb5_crypto_init(krb5_context context, + krb5_keyblock *key, + krb5_enctype etype, + krb5_crypto *crypto) +{ + krb5_error_code ret; + ALLOC(*crypto, 1); + if(*crypto == NULL) + return ENOMEM; + if(etype == ETYPE_NULL) + etype = key->keytype; + (*crypto)->et = _find_enctype(etype); + if((*crypto)->et == NULL) { + free(*crypto); + return KRB5_PROG_ETYPE_NOSUPP; + } + ret = krb5_copy_keyblock(context, key, &(*crypto)->key.key); + if(ret) { + free(*crypto); + return ret; + } + (*crypto)->key.schedule = NULL; + (*crypto)->num_key_usage = 0; + (*crypto)->key_usage = NULL; + return 0; +} + +static void +free_key_data(krb5_context context, struct key_data *key) +{ + krb5_free_keyblock(context, key->key); + if(key->schedule) { + memset(key->schedule->data, 0, key->schedule->length); + krb5_free_data(context, key->schedule); + } +} + +static void +free_key_usage(krb5_context context, struct key_usage *ku) +{ + free_key_data(context, &ku->key); +} + +krb5_error_code +krb5_crypto_destroy(krb5_context context, + krb5_crypto crypto) +{ + int i; + + for(i = 0; i < crypto->num_key_usage; i++) + free_key_usage(context, &crypto->key_usage[i]); + free(crypto->key_usage); + free_key_data(context, &crypto->key); + free (crypto); + return 0; +} + +krb5_error_code +krb5_string_to_key_derived(krb5_context context, + const void *str, + size_t len, + krb5_enctype etype, + krb5_keyblock *key) +{ + struct encryption_type *et = _find_enctype(etype); + krb5_error_code ret; + struct key_data kd; + u_char *tmp; + + if(et == NULL) + return KRB5_PROG_ETYPE_NOSUPP; + ALLOC(kd.key, 1); + kd.key->keytype = etype; + tmp = malloc (et->keytype->bits / 8); + _krb5_n_fold(str, len, tmp, et->keytype->bits / 8); + krb5_data_alloc(&kd.key->keyvalue, et->keytype->size); + kd.schedule = NULL; + DES3_postproc (context, tmp, et->keytype->bits / 8, &kd); /* XXX */ + ret = derive_key(context, + et, + &kd, + "kerberos", /* XXX well known constant */ + strlen("kerberos")); + ret = krb5_copy_keyblock_contents(context, kd.key, key); + free_key_data(context, &kd); + return ret; +} + +/* + * Return the size of an encrypted packet of length `data_len' + */ + +size_t +krb5_get_wrapped_length (krb5_context context, + krb5_crypto crypto, + size_t data_len) +{ + struct encryption_type *et = crypto->et; + size_t blocksize = et->blocksize; + size_t res; + + res = (data_len + blocksize - 1) / blocksize * blocksize; + res = res + et->confoundersize + et->cksumtype->checksumsize; + return res; +} + +#ifdef CRYPTO_DEBUG + +static krb5_error_code +krb5_get_keyid(krb5_context context, + krb5_keyblock *key, + u_int32_t *keyid) +{ + struct md5 md5; + unsigned char tmp[16]; + md5_init(&md5); + md5_update(&md5, key->keyvalue.data, key->keyvalue.length); + md5_finito(&md5, tmp); + *keyid = (tmp[12] << 24) | (tmp[13] << 16) | (tmp[14] << 8) | tmp[15]; + return 0; +} + +static void +krb5_crypto_debug(krb5_context context, + int encrypt, + size_t len, + krb5_keyblock *key) +{ + u_int32_t keyid; + char *kt; + krb5_get_keyid(context, key, &keyid); + krb5_enctype_to_string(context, key->keytype, &kt); + krb5_warnx(context, "%s %lu bytes with key-id %#x (%s)", + encrypt ? "encrypting" : "decrypting", + (unsigned long)len, + keyid, + kt); + free(kt); +} + +#endif /* CRYPTO_DEBUG */ |
