/* * Copyright (c) 1997 - 2000 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 1.29 2000/01/25 23:06:55 assar Exp $"); /* RCSID("$FreeBSD$"); */ #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 ((const void *)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 ((const void *)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((const 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; MD4_CTX 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; } MD4Init (&m); MD4Update (&m, s, len); key->keytype = enctype; krb5_data_alloc (&key->keyvalue, 16); MD4Final (key->keyvalue.data, &m); 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) { MD4_CTX m; MD4Init (&m); MD4Update (&m, data, len); MD4Final (C->checksum.data, &m); } static void RSA_MD4_DES_checksum(krb5_context context, struct key_data *key, void *data, size_t len, Checksum *cksum) { MD4_CTX md4; des_cblock ivec; unsigned char *p = cksum->checksum.data; krb5_generate_random_block(p, 8); MD4Init (&md4); MD4Update (&md4, p, 8); MD4Update (&md4, data, len); MD4Final (p + 8, &md4); memset (&ivec, 0, sizeof(ivec)); des_cbc_encrypt((const void *)p, (void *)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) { MD4_CTX 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); MD4Init (&md4); MD4Update (&md4, tmp, 8); /* confounder */ MD4Update (&md4, data, len); MD4Final (res, &md4); 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) { MD5_CTX m; MD5Init (&m); MD5Update(&m, data, len); MD5Final (C->checksum.data, &m); } static void RSA_MD5_DES_checksum(krb5_context context, struct key_data *key, void *data, size_t len, Checksum *C) { MD5_CTX md5; des_cblock ivec; unsigned char *p = C->checksum.data; krb5_generate_random_block(p, 8); MD5Init (&md5); MD5Update (&md5, p, 8); MD5Update (&md5, data, len); MD5Final (p + 8, &md5); memset (&ivec, 0, sizeof(ivec)); des_cbc_encrypt((const void *)p, (void *)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) { MD5_CTX 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); MD5Init (&md5); MD5Update (&md5, tmp, 8); /* confounder */ MD5Update (&md5, data, len); MD5Final (res, &md5); 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) { MD5_CTX md5; des_cblock ivec; unsigned char *p = C->checksum.data; des_key_schedule *sched = key->schedule->data; krb5_generate_random_block(p, 8); MD5Init (&md5); MD5Update (&md5, p, 8); MD5Update (&md5, data, len); MD5Final (p + 8, &md5); memset (&ivec, 0, sizeof(ivec)); des_ede3_cbc_encrypt((const void *)p, (void *)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) { MD5_CTX 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); MD5Init (&md5); MD5Update (&md5, tmp, 8); /* confounder */ MD5Update (&md5, data, len); MD5Final (res, &md5); 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) { SHA1_CTX m; SHA_Init(&m); SHA_Update(&m, data, len); SHA_Final(C->checksum.data, &m); } /* 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) { MD5_CTX md5; unsigned char tmp[16]; MD5Init (&md5); MD5Update (&md5, key->keyvalue.data, key->keyvalue.length); MD5Final (tmp, &md5); *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 */