/* * Copyright (c) 1997 - 2008 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" struct _krb5_key_usage { unsigned usage; struct _krb5_key_data key; }; #ifndef HEIMDAL_SMALLER #define DES3_OLD_ENCTYPE 1 #endif static krb5_error_code _get_derived_key(krb5_context, krb5_crypto, unsigned, struct _krb5_key_data**); static struct _krb5_key_data *_new_derived_key(krb5_crypto crypto, unsigned usage); static void free_key_schedule(krb5_context, struct _krb5_key_data *, struct _krb5_encryption_type *); /* * Converts etype to a user readable string and sets as a side effect * the krb5_error_message containing this string. Returns * KRB5_PROG_ETYPE_NOSUPP in not the conversion of the etype failed in * which case the error code of the etype convesion is returned. */ static krb5_error_code unsupported_enctype(krb5_context context, krb5_enctype etype) { krb5_error_code ret; char *name; ret = krb5_enctype_to_string(context, etype, &name); if (ret) return ret; krb5_set_error_message(context, KRB5_PROG_ETYPE_NOSUPP, N_("Encryption type %s not supported", ""), name); free(name); return KRB5_PROG_ETYPE_NOSUPP; } /* * */ KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_enctype_keysize(krb5_context context, krb5_enctype type, size_t *keysize) { struct _krb5_encryption_type *et = _krb5_find_enctype(type); if(et == NULL) { return unsupported_enctype (context, type); } *keysize = et->keytype->size; return 0; } KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_enctype_keybits(krb5_context context, krb5_enctype type, size_t *keybits) { struct _krb5_encryption_type *et = _krb5_find_enctype(type); if(et == NULL) { return unsupported_enctype (context, type); } *keybits = et->keytype->bits; return 0; } KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_generate_random_keyblock(krb5_context context, krb5_enctype type, krb5_keyblock *key) { krb5_error_code ret; struct _krb5_encryption_type *et = _krb5_find_enctype(type); if(et == NULL) { return unsupported_enctype (context, type); } 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 _krb5_key_data *key) { krb5_error_code ret; struct _krb5_encryption_type *et; struct _krb5_key_type *kt; if (key->schedule != NULL) return 0; et = _krb5_find_enctype(key->key->keytype); if (et == NULL) { return unsupported_enctype (context, key->key->keytype); } kt = et->keytype; if(kt->schedule == NULL) return 0; ALLOC(key->schedule, 1); if (key->schedule == NULL) return krb5_enomem(context); ret = krb5_data_alloc(key->schedule, kt->schedule_size); if(ret) { free(key->schedule); key->schedule = NULL; return ret; } (*kt->schedule)(context, kt, key); return 0; } /************************************************************ * * ************************************************************/ static krb5_error_code EVP_unkeyed_checksum(krb5_context context, krb5_crypto crypto, struct _krb5_key_data *key, unsigned usage, const struct krb5_crypto_iov *iov, int niov, Checksum *C, const EVP_MD *md) { if (_krb5_evp_digest_iov(crypto, iov, niov, C->checksum.data, NULL, md, NULL) != 1) krb5_abortx(context, "unkeyed checksum failed"); return 0; } #define EVP_SHA_CHECKSUM(name) \ \ static krb5_error_code \ SHA ## name ##_checksum(krb5_context context, \ krb5_crypto crypto, \ struct _krb5_key_data *key, \ unsigned usage, \ const struct krb5_crypto_iov *iov, \ int niov, \ Checksum *C) \ { \ return EVP_unkeyed_checksum(context, crypto, key, \ usage, iov, niov, \ C, EVP_sha##name()); \ } EVP_SHA_CHECKSUM(1) EVP_SHA_CHECKSUM(256) EVP_SHA_CHECKSUM(384) EVP_SHA_CHECKSUM(512) /* HMAC according to RFC2104 */ KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL _krb5_internal_hmac_iov(krb5_context context, krb5_crypto crypto, struct _krb5_checksum_type *cm, unsigned usage, const struct krb5_crypto_iov *iov, int niov, struct _krb5_key_data *keyblock, Checksum *result) { unsigned char *ipad, *opad; unsigned char *key; struct krb5_crypto_iov *working; size_t key_len; size_t i; ipad = malloc(cm->blocksize); if (ipad == NULL) return ENOMEM; opad = malloc(cm->blocksize + cm->checksumsize); if (opad == NULL) { free(ipad); return ENOMEM; } working = calloc(niov + 1, sizeof(struct krb5_crypto_iov)); if (working == NULL) { free(ipad); free(opad); return ENOMEM; } memset(ipad, 0x36, cm->blocksize); memset(opad, 0x5c, cm->blocksize); if(keyblock->key->keyvalue.length > cm->blocksize){ working[0].data = keyblock->key->keyvalue; working[0].flags = KRB5_CRYPTO_TYPE_DATA; (*cm->checksum)(context, crypto, keyblock, usage, working, 1, result); key = result->checksum.data; key_len = result->checksum.length; } else { key = keyblock->key->keyvalue.data; key_len = keyblock->key->keyvalue.length; } for(i = 0; i < key_len; i++){ ipad[i] ^= key[i]; opad[i] ^= key[i]; } working[0].data.data = ipad; working[0].data.length = cm->blocksize; working[0].flags = KRB5_CRYPTO_TYPE_DATA; for (i = 0; i < niov; i++) working[i + 1] = iov[i]; (*cm->checksum)(context, crypto, keyblock, usage, working, niov + 1, result); memcpy(opad + cm->blocksize, result->checksum.data, result->checksum.length); working[0].data.data = opad; working[0].data.length = cm->blocksize + cm->checksumsize; working[0].flags = KRB5_CRYPTO_TYPE_DATA; (*cm->checksum)(context, crypto, keyblock, usage, working, 1, result); memset(ipad, 0, cm->blocksize); free(ipad); memset(opad, 0, cm->blocksize + cm->checksumsize); free(opad); free(working); return 0; } KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL _krb5_internal_hmac(krb5_context context, krb5_crypto crypto, struct _krb5_checksum_type *cm, const void *data, size_t len, unsigned usage, struct _krb5_key_data *keyblock, Checksum *result) { struct krb5_crypto_iov iov[1]; iov[0].data.data = (void *) data; iov[0].data.length = len; iov[0].flags = KRB5_CRYPTO_TYPE_DATA; return _krb5_internal_hmac_iov(context, crypto, cm, usage, iov, 1, keyblock, result); } KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_hmac(krb5_context context, krb5_cksumtype cktype, const void *data, size_t len, unsigned usage, krb5_keyblock *key, Checksum *result) { struct _krb5_checksum_type *c = _krb5_find_checksum(cktype); struct _krb5_key_data kd; krb5_error_code ret; if (c == NULL) { krb5_set_error_message (context, KRB5_PROG_SUMTYPE_NOSUPP, N_("checksum type %d not supported", ""), cktype); return KRB5_PROG_SUMTYPE_NOSUPP; } kd.key = key; kd.schedule = NULL; ret = _krb5_internal_hmac(context, NULL, c, data, len, usage, &kd, result); if (kd.schedule) krb5_free_data(context, kd.schedule); return ret; } krb5_error_code _krb5_SP_HMAC_SHA1_checksum(krb5_context context, krb5_crypto crypto, struct _krb5_key_data *key, unsigned usage, const struct krb5_crypto_iov *iov, int niov, Checksum *result) { krb5_error_code ret; unsigned char hmac[EVP_MAX_MD_SIZE]; unsigned int hmaclen = sizeof(hmac); ret = _krb5_evp_hmac_iov(context, crypto, key, iov, niov, hmac, &hmaclen, EVP_sha1(), NULL); if (ret) return ret; heim_assert(result->checksum.length <= hmaclen, "SHA1 checksum too short"); memcpy(result->checksum.data, hmac, result->checksum.length); return 0; } krb5_error_code _krb5_SP_HMAC_SHA1_verify(krb5_context context, krb5_crypto crypto, struct _krb5_key_data *key, unsigned usage, const struct krb5_crypto_iov *iov, int niov, Checksum *verify) { krb5_error_code ret; unsigned char hmac[EVP_MAX_MD_SIZE]; unsigned int hmaclen = sizeof(hmac); krb5_data data; ret = _krb5_evp_hmac_iov(context, crypto, key, iov, niov, hmac, &hmaclen, EVP_sha1(), NULL); if (ret) return ret; data.data = hmac; data.length = min(hmaclen, verify->checksum.length); if(krb5_data_ct_cmp(&data, &verify->checksum) != 0) return KRB5KRB_AP_ERR_BAD_INTEGRITY; return 0; } #define SHA_CHECKSUM(name, blocksize, outputsize) \ struct _krb5_checksum_type _krb5_checksum_sha##name = { \ CKSUMTYPE_SHA##name, \ "sha" #name, \ blocksize, \ outputsize, \ F_CPROOF, \ SHA##name##_checksum, \ NULL \ }; SHA_CHECKSUM(1, 64, 20); SHA_CHECKSUM(256, 64, 32); SHA_CHECKSUM(384, 128, 48); SHA_CHECKSUM(512, 128, 64); KRB5_LIB_FUNCTION struct _krb5_checksum_type * KRB5_LIB_CALL _krb5_find_checksum(krb5_cksumtype type) { int i; for(i = 0; i < _krb5_num_checksums; i++) if(_krb5_checksum_types[i]->type == type) return _krb5_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 _krb5_checksum_type *ct, struct _krb5_key_data **key) { krb5_error_code ret = 0; struct _krb5_checksum_type *kct = NULL; if (crypto == NULL) { krb5_set_error_message(context, KRB5_BAD_ENCTYPE, N_("Checksum type %s is keyed but no " "crypto context (key) was passed in", ""), ct->name); return KRB5_BAD_ENCTYPE; } kct = crypto->et->keyed_checksum; if (kct == NULL || kct->type != ct->type) { krb5_set_error_message(context, KRB5_BAD_ENCTYPE, N_("Checksum type %s is keyed, but " "the key type %s passed didnt have that checksum " "type as the keyed type", ""), ct->name, crypto->et->name); return KRB5_BAD_ENCTYPE; } if(ct->flags & F_DERIVED) ret = _get_derived_key(context, crypto, usage, key); else if(ct->flags & F_VARIANT) { size_t i; *key = _new_derived_key(crypto, 0xff/* KRB5_KU_RFC1510_VARIANT */); if (*key == NULL) return krb5_enomem(context); 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 create_checksum_iov(krb5_context context, struct _krb5_checksum_type *ct, krb5_crypto crypto, unsigned usage, struct krb5_crypto_iov *iov, int niov, krb5_flags flags, Checksum *result) { krb5_error_code ret; struct _krb5_key_data *dkey; if (ct->flags & F_DISABLED) { krb5_clear_error_message (context); return KRB5_PROG_SUMTYPE_NOSUPP; } if (ct->flags & F_KEYED) { ret = get_checksum_key(context, crypto, usage, ct, &dkey); if (ret) return ret; } else if ((flags & KRB5_CRYPTO_FLAG_ALLOW_UNKEYED_CHECKSUM) == 0) { return EINVAL; } else dkey = NULL; result->cksumtype = ct->type; return (*ct->checksum)(context, crypto, dkey, usage, iov, niov, result); } static krb5_error_code create_checksum (krb5_context context, struct _krb5_checksum_type *ct, krb5_crypto crypto, unsigned usage, void *data, size_t len, krb5_flags flags, Checksum *result) { int ret; struct krb5_crypto_iov iov[1]; ret = krb5_data_alloc(&result->checksum, ct->checksumsize); if (ret) return ret; iov[0].data.data = data; iov[0].data.length = len; iov[0].flags = KRB5_CRYPTO_TYPE_DATA; return create_checksum_iov(context, ct, crypto, usage, iov, 1, flags, result); } static int arcfour_checksum_p(struct _krb5_checksum_type *ct, krb5_crypto crypto) { return (ct->type == CKSUMTYPE_HMAC_MD5) && (crypto->key.key->keytype == KEYTYPE_ARCFOUR); } static inline krb5_flags crypto_flags(krb5_crypto crypto) { /* If caller didn't specify a key, unkeyed checksums are the only option */ if (crypto == NULL) return KRB5_CRYPTO_FLAG_ALLOW_UNKEYED_CHECKSUM; else return crypto->flags; } KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_create_checksum(krb5_context context, krb5_crypto crypto, krb5_key_usage usage, int type, void *data, size_t len, Checksum *result) { struct _krb5_checksum_type *ct = NULL; unsigned keyusage; /* type 0 -> pick from crypto */ if (type) { ct = _krb5_find_checksum(type); } else if (crypto) { ct = crypto->et->keyed_checksum; if (ct == NULL) ct = crypto->et->checksum; } if(ct == NULL) { krb5_set_error_message (context, KRB5_PROG_SUMTYPE_NOSUPP, N_("checksum type %d not supported", ""), type); return KRB5_PROG_SUMTYPE_NOSUPP; } if (arcfour_checksum_p(ct, crypto)) { keyusage = usage; _krb5_usage2arcfour(context, &keyusage); } else keyusage = CHECKSUM_USAGE(usage); return create_checksum(context, ct, crypto, keyusage, data, len, crypto_flags(crypto), result); } static krb5_error_code verify_checksum_iov(krb5_context context, krb5_crypto crypto, unsigned usage, /* not krb5_key_usage */ struct krb5_crypto_iov *iov, int niov, krb5_flags flags, Checksum *cksum) { krb5_error_code ret; struct _krb5_key_data *dkey; Checksum c; struct _krb5_checksum_type *ct; ct = _krb5_find_checksum(cksum->cksumtype); if (ct == NULL || (ct->flags & F_DISABLED)) { krb5_set_error_message (context, KRB5_PROG_SUMTYPE_NOSUPP, N_("checksum type %d not supported", ""), cksum->cksumtype); return KRB5_PROG_SUMTYPE_NOSUPP; } if(ct->checksumsize != cksum->checksum.length) { krb5_clear_error_message (context); krb5_set_error_message(context, KRB5KRB_AP_ERR_BAD_INTEGRITY, N_("Decrypt integrity check failed for checksum type %s, " "length was %u, expected %u", ""), ct->name, (unsigned)cksum->checksum.length, (unsigned)ct->checksumsize); return KRB5KRB_AP_ERR_BAD_INTEGRITY; /* XXX */ } if (ct->flags & F_KEYED) { ret = get_checksum_key(context, crypto, usage, ct, &dkey); if (ret) return ret; } else if ((flags & KRB5_CRYPTO_FLAG_ALLOW_UNKEYED_CHECKSUM) == 0) { krb5_clear_error_message (context); krb5_set_error_message(context, KRB5KRB_AP_ERR_INAPP_CKSUM, N_("Unkeyed checksum type %s provided where keyed " "checksum was expected", ""), ct->name); return KRB5KRB_AP_ERR_INAPP_CKSUM; } else dkey = NULL; /* * If checksum have a verify function, lets use that instead of * calling ->checksum and then compare result. */ if(ct->verify) { ret = (*ct->verify)(context, crypto, dkey, usage, iov, niov, cksum); if (ret) krb5_set_error_message(context, ret, N_("Decrypt integrity check failed for checksum " "type %s, key type %s", ""), ct->name, (crypto != NULL)? crypto->et->name : "(none)"); return ret; } ret = krb5_data_alloc (&c.checksum, ct->checksumsize); if (ret) return ret; ret = (*ct->checksum)(context, crypto, dkey, usage, iov, niov, &c); if (ret) { krb5_data_free(&c.checksum); return ret; } if(krb5_data_ct_cmp(&c.checksum, &cksum->checksum) != 0) { ret = KRB5KRB_AP_ERR_BAD_INTEGRITY; krb5_set_error_message(context, ret, N_("Decrypt integrity check failed for checksum " "type %s, key type %s", ""), ct->name, crypto ? crypto->et->name : "(unkeyed)"); } else { ret = 0; } krb5_data_free (&c.checksum); return ret; } static krb5_error_code verify_checksum(krb5_context context, krb5_crypto crypto, unsigned usage, /* not krb5_key_usage */ void *data, size_t len, krb5_flags flags, Checksum *cksum) { struct krb5_crypto_iov iov[1]; iov[0].data.data = data; iov[0].data.length = len; iov[0].flags = KRB5_CRYPTO_TYPE_DATA; return verify_checksum_iov(context, crypto, usage, iov, 1, flags, cksum); } KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_verify_checksum(krb5_context context, krb5_crypto crypto, krb5_key_usage usage, void *data, size_t len, Checksum *cksum) { struct _krb5_checksum_type *ct; unsigned keyusage; ct = _krb5_find_checksum(cksum->cksumtype); if(ct == NULL) { krb5_set_error_message (context, KRB5_PROG_SUMTYPE_NOSUPP, N_("checksum type %d not supported", ""), cksum->cksumtype); return KRB5_PROG_SUMTYPE_NOSUPP; } if (arcfour_checksum_p(ct, crypto)) { keyusage = usage; _krb5_usage2arcfour(context, &keyusage); } else keyusage = CHECKSUM_USAGE(usage); return verify_checksum(context, crypto, keyusage, data, len, crypto_flags(crypto), cksum); } KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_crypto_get_checksum_type(krb5_context context, krb5_crypto crypto, krb5_cksumtype *type) { struct _krb5_checksum_type *ct = NULL; if (crypto != NULL) { ct = crypto->et->keyed_checksum; if (ct == NULL) ct = crypto->et->checksum; } if (ct == NULL) { krb5_set_error_message (context, KRB5_PROG_SUMTYPE_NOSUPP, N_("checksum type not found", "")); return KRB5_PROG_SUMTYPE_NOSUPP; } *type = ct->type; return 0; } KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_checksumsize(krb5_context context, krb5_cksumtype type, size_t *size) { struct _krb5_checksum_type *ct = _krb5_find_checksum(type); if(ct == NULL) { krb5_set_error_message (context, KRB5_PROG_SUMTYPE_NOSUPP, N_("checksum type %d not supported", ""), type); return KRB5_PROG_SUMTYPE_NOSUPP; } *size = ct->checksumsize; return 0; } KRB5_LIB_FUNCTION krb5_boolean KRB5_LIB_CALL krb5_checksum_is_keyed(krb5_context context, krb5_cksumtype type) { struct _krb5_checksum_type *ct = _krb5_find_checksum(type); if(ct == NULL) { if (context) krb5_set_error_message (context, KRB5_PROG_SUMTYPE_NOSUPP, N_("checksum type %d not supported", ""), type); return KRB5_PROG_SUMTYPE_NOSUPP; } return ct->flags & F_KEYED; } KRB5_LIB_FUNCTION krb5_boolean KRB5_LIB_CALL krb5_checksum_is_collision_proof(krb5_context context, krb5_cksumtype type) { struct _krb5_checksum_type *ct = _krb5_find_checksum(type); if(ct == NULL) { if (context) krb5_set_error_message (context, KRB5_PROG_SUMTYPE_NOSUPP, N_("checksum type %d not supported", ""), type); return KRB5_PROG_SUMTYPE_NOSUPP; } return ct->flags & F_CPROOF; } KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_checksum_disable(krb5_context context, krb5_cksumtype type) { struct _krb5_checksum_type *ct = _krb5_find_checksum(type); if(ct == NULL) { if (context) krb5_set_error_message (context, KRB5_PROG_SUMTYPE_NOSUPP, N_("checksum type %d not supported", ""), type); return KRB5_PROG_SUMTYPE_NOSUPP; } ct->flags |= F_DISABLED; return 0; } /************************************************************ * * ************************************************************/ KRB5_LIB_FUNCTION struct _krb5_encryption_type * KRB5_LIB_CALL _krb5_find_enctype(krb5_enctype type) { int i; for(i = 0; i < _krb5_num_etypes; i++) if(_krb5_etypes[i]->type == type) return _krb5_etypes[i]; return NULL; } KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_enctype_to_string(krb5_context context, krb5_enctype etype, char **string) { struct _krb5_encryption_type *e; e = _krb5_find_enctype(etype); if(e == NULL) { krb5_set_error_message (context, KRB5_PROG_ETYPE_NOSUPP, N_("encryption type %d not supported", ""), etype); *string = NULL; return KRB5_PROG_ETYPE_NOSUPP; } *string = strdup(e->name); if (*string == NULL) return krb5_enomem(context); return 0; } KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_string_to_enctype(krb5_context context, const char *string, krb5_enctype *etype) { int i; for(i = 0; i < _krb5_num_etypes; i++) { if(strcasecmp(_krb5_etypes[i]->name, string) == 0){ *etype = _krb5_etypes[i]->type; return 0; } if(_krb5_etypes[i]->alias != NULL && strcasecmp(_krb5_etypes[i]->alias, string) == 0){ *etype = _krb5_etypes[i]->type; return 0; } } krb5_set_error_message (context, KRB5_PROG_ETYPE_NOSUPP, N_("encryption type %s not supported", ""), string); return KRB5_PROG_ETYPE_NOSUPP; } KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_enctype_to_keytype(krb5_context context, krb5_enctype etype, krb5_keytype *keytype) { struct _krb5_encryption_type *e = _krb5_find_enctype(etype); if(e == NULL) { return unsupported_enctype (context, etype); } *keytype = (krb5_keytype)e->keytype->type; return 0; } /** * Check if a enctype is valid, return 0 if it is. * * @param context Kerberos context * @param etype enctype to check if its valid or not * * @return Return an error code for an failure or 0 on success (enctype valid). * @ingroup krb5_crypto */ KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_enctype_valid(krb5_context context, krb5_enctype etype) { struct _krb5_encryption_type *e = _krb5_find_enctype(etype); if(e && (e->flags & F_DISABLED) == 0) return 0; if (context == NULL) return KRB5_PROG_ETYPE_NOSUPP; if(e == NULL) { return unsupported_enctype (context, etype); } /* Must be (e->flags & F_DISABLED) */ krb5_set_error_message (context, KRB5_PROG_ETYPE_NOSUPP, N_("encryption type %s is disabled", ""), e->name); return KRB5_PROG_ETYPE_NOSUPP; } /** * Return the coresponding encryption type for a checksum type. * * @param context Kerberos context * @param ctype The checksum type to get the result enctype for * @param etype The returned encryption, when the matching etype is * not found, etype is set to ETYPE_NULL. * * @return Return an error code for an failure or 0 on success. * @ingroup krb5_crypto */ KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_cksumtype_to_enctype(krb5_context context, krb5_cksumtype ctype, krb5_enctype *etype) { int i; *etype = ETYPE_NULL; for(i = 0; i < _krb5_num_etypes; i++) { if(_krb5_etypes[i]->keyed_checksum && _krb5_etypes[i]->keyed_checksum->type == ctype) { *etype = _krb5_etypes[i]->type; return 0; } } krb5_set_error_message (context, KRB5_PROG_SUMTYPE_NOSUPP, N_("checksum type %d not supported", ""), (int)ctype); return KRB5_PROG_SUMTYPE_NOSUPP; } KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_cksumtype_valid(krb5_context context, krb5_cksumtype ctype) { struct _krb5_checksum_type *c = _krb5_find_checksum(ctype); if (c == NULL) { krb5_set_error_message (context, KRB5_PROG_SUMTYPE_NOSUPP, N_("checksum type %d not supported", ""), ctype); return KRB5_PROG_SUMTYPE_NOSUPP; } if (c->flags & F_DISABLED) { krb5_set_error_message (context, KRB5_PROG_SUMTYPE_NOSUPP, N_("checksum type %s is disabled", ""), c->name); return KRB5_PROG_SUMTYPE_NOSUPP; } return 0; } 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, const void *data, size_t len, krb5_data *result, void *ivec) { size_t sz, block_sz, checksum_sz, total_sz; Checksum cksum; unsigned char *p, *q; krb5_error_code ret; struct _krb5_key_data *dkey; const struct _krb5_encryption_type *et = crypto->et; checksum_sz = CHECKSUMSIZE(et->keyed_checksum); sz = et->confoundersize + len; block_sz = (sz + et->padsize - 1) &~ (et->padsize - 1); /* pad */ total_sz = block_sz + checksum_sz; p = calloc(1, total_sz); if (p == NULL) return krb5_enomem(context); q = p; krb5_generate_random_block(q, et->confoundersize); /* XXX */ q += et->confoundersize; memcpy(q, data, len); ret = create_checksum(context, et->keyed_checksum, crypto, INTEGRITY_USAGE(usage), p, block_sz, 0, &cksum); if(ret == 0 && cksum.checksum.length != checksum_sz) { free_Checksum (&cksum); krb5_clear_error_message (context); ret = KRB5_CRYPTO_INTERNAL; } if(ret) goto fail; memcpy(p + block_sz, cksum.checksum.data, cksum.checksum.length); free_Checksum (&cksum); ret = _get_derived_key(context, crypto, ENCRYPTION_USAGE(usage), &dkey); if(ret) goto fail; ret = _key_schedule(context, dkey); if(ret) goto fail; ret = (*et->encrypt)(context, dkey, p, block_sz, 1, usage, ivec); if (ret) goto fail; result->data = p; result->length = total_sz; return 0; fail: memset(p, 0, total_sz); free(p); return ret; } static krb5_error_code encrypt_internal_enc_then_cksum(krb5_context context, krb5_crypto crypto, unsigned usage, const void *data, size_t len, krb5_data *result, void *ivec) { size_t sz, block_sz, checksum_sz, total_sz; Checksum cksum; unsigned char *p, *q, *ivc = NULL; krb5_error_code ret; struct _krb5_key_data *dkey; const struct _krb5_encryption_type *et = crypto->et; checksum_sz = CHECKSUMSIZE(et->keyed_checksum); sz = et->confoundersize + len; block_sz = (sz + et->padsize - 1) &~ (et->padsize - 1); /* pad */ total_sz = block_sz + checksum_sz; p = calloc(1, total_sz); if (p == NULL) return krb5_enomem(context); q = p; krb5_generate_random_block(q, et->confoundersize); /* XXX */ q += et->confoundersize; memcpy(q, data, len); ret = _get_derived_key(context, crypto, ENCRYPTION_USAGE(usage), &dkey); if(ret) goto fail; ret = _key_schedule(context, dkey); if(ret) goto fail; /* XXX EVP style update API would avoid needing to allocate here */ ivc = malloc(et->blocksize + block_sz); if (ivc == NULL) { ret = krb5_enomem(context); goto fail; } if (ivec) memcpy(ivc, ivec, et->blocksize); else memset(ivc, 0, et->blocksize); ret = (*et->encrypt)(context, dkey, p, block_sz, 1, usage, ivec); if (ret) goto fail; memcpy(&ivc[et->blocksize], p, block_sz); ret = create_checksum(context, et->keyed_checksum, crypto, INTEGRITY_USAGE(usage), ivc, et->blocksize + block_sz, 0, &cksum); if(ret == 0 && cksum.checksum.length != checksum_sz) { free_Checksum (&cksum); krb5_clear_error_message (context); ret = KRB5_CRYPTO_INTERNAL; } if(ret) goto fail; memcpy(p + block_sz, cksum.checksum.data, cksum.checksum.length); free_Checksum (&cksum); result->data = p; result->length = total_sz; free(ivc); return 0; fail: memset_s(p, total_sz, 0, total_sz); free(p); free(ivc); return ret; } static krb5_error_code encrypt_internal(krb5_context context, krb5_crypto crypto, const void *data, size_t len, krb5_data *result, void *ivec) { size_t sz, block_sz, checksum_sz; Checksum cksum; unsigned char *p, *q; krb5_error_code ret; const struct _krb5_encryption_type *et = crypto->et; checksum_sz = CHECKSUMSIZE(et->checksum); sz = et->confoundersize + checksum_sz + len; block_sz = (sz + et->padsize - 1) &~ (et->padsize - 1); /* pad */ p = calloc(1, block_sz); if (p == NULL) return krb5_enomem(context); 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, et->checksum, crypto, 0, p, block_sz, KRB5_CRYPTO_FLAG_ALLOW_UNKEYED_CHECKSUM, &cksum); if(ret == 0 && cksum.checksum.length != checksum_sz) { krb5_clear_error_message (context); free_Checksum(&cksum); ret = KRB5_CRYPTO_INTERNAL; } if(ret) goto fail; memcpy(p + et->confoundersize, cksum.checksum.data, cksum.checksum.length); free_Checksum(&cksum); ret = _key_schedule(context, &crypto->key); if(ret) goto fail; ret = (*et->encrypt)(context, &crypto->key, p, block_sz, 1, 0, ivec); if (ret) { memset(p, 0, block_sz); free(p); return ret; } result->data = p; result->length = block_sz; return 0; fail: memset(p, 0, block_sz); free(p); return ret; } static krb5_error_code encrypt_internal_special(krb5_context context, krb5_crypto crypto, int usage, const void *data, size_t len, krb5_data *result, void *ivec) { struct _krb5_encryption_type *et = crypto->et; size_t cksum_sz = CHECKSUMSIZE(et->checksum); size_t sz = len + cksum_sz + et->confoundersize; char *tmp, *p; krb5_error_code ret; tmp = malloc (sz); if (tmp == NULL) return krb5_enomem(context); p = tmp; memset (p, 0, cksum_sz); p += cksum_sz; krb5_generate_random_block(p, et->confoundersize); p += et->confoundersize; memcpy (p, data, len); ret = (*et->encrypt)(context, &crypto->key, tmp, sz, TRUE, usage, ivec); if (ret) { memset(tmp, 0, sz); free(tmp); return ret; } result->data = tmp; result->length = 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, void *ivec) { size_t checksum_sz; Checksum cksum; unsigned char *p; krb5_error_code ret; struct _krb5_key_data *dkey; struct _krb5_encryption_type *et = crypto->et; unsigned long l; checksum_sz = CHECKSUMSIZE(et->keyed_checksum); if (len < checksum_sz + et->confoundersize) { krb5_set_error_message(context, KRB5_BAD_MSIZE, N_("Encrypted data shorter then " "checksum + confunder", "")); return KRB5_BAD_MSIZE; } if (((len - checksum_sz) % et->padsize) != 0) { krb5_clear_error_message(context); return KRB5_BAD_MSIZE; } p = malloc(len); if (len != 0 && p == NULL) return krb5_enomem(context); memcpy(p, data, len); 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; } ret = (*et->encrypt)(context, dkey, p, len, 0, usage, ivec); if (ret) { free(p); return ret; } 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, 0, &cksum); if(ret) { free(p); return ret; } l = len - et->confoundersize; memmove(p, p + et->confoundersize, l); result->data = p; result->length = l; return 0; } static krb5_error_code decrypt_internal_enc_then_cksum(krb5_context context, krb5_crypto crypto, unsigned usage, void *data, size_t len, krb5_data *result, void *ivec) { size_t checksum_sz; Checksum cksum; unsigned char *p; krb5_error_code ret; struct _krb5_key_data *dkey; struct _krb5_encryption_type *et = crypto->et; unsigned long l; checksum_sz = CHECKSUMSIZE(et->keyed_checksum); if (len < checksum_sz + et->confoundersize) { krb5_set_error_message(context, KRB5_BAD_MSIZE, N_("Encrypted data shorter then " "checksum + confunder", "")); return KRB5_BAD_MSIZE; } if (((len - checksum_sz) % et->padsize) != 0) { krb5_clear_error_message(context); return KRB5_BAD_MSIZE; } len -= checksum_sz; p = malloc(et->blocksize + len); if (p == NULL) return krb5_enomem(context); if (ivec) memcpy(p, ivec, et->blocksize); else memset(p, 0, et->blocksize); memcpy(&p[et->blocksize], data, len); cksum.checksum.data = (unsigned char *)data + len; cksum.checksum.length = checksum_sz; cksum.cksumtype = CHECKSUMTYPE(et->keyed_checksum); ret = verify_checksum(context, crypto, INTEGRITY_USAGE(usage), p, et->blocksize + len, 0, &cksum); if(ret) { free(p); return ret; } 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; } ret = (*et->encrypt)(context, dkey, &p[et->blocksize], len, 0, usage, ivec); if (ret) { free(p); return ret; } l = len - et->confoundersize; memmove(p, p + et->blocksize + et->confoundersize, l); result->data = p; 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, void *ivec) { krb5_error_code ret; unsigned char *p; Checksum cksum; size_t checksum_sz, l; struct _krb5_encryption_type *et = crypto->et; if ((len % et->padsize) != 0) { krb5_clear_error_message(context); return KRB5_BAD_MSIZE; } checksum_sz = CHECKSUMSIZE(et->checksum); if (len < checksum_sz + et->confoundersize) { krb5_set_error_message(context, KRB5_BAD_MSIZE, N_("Encrypted data shorter then " "checksum + confunder", "")); return KRB5_BAD_MSIZE; } p = malloc(len); if (len != 0 && p == NULL) return krb5_enomem(context); memcpy(p, data, len); ret = _key_schedule(context, &crypto->key); if(ret) { free(p); return ret; } ret = (*et->encrypt)(context, &crypto->key, p, len, 0, 0, ivec); if (ret) { free(p); return ret; } 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->checksum); ret = verify_checksum(context, NULL, 0, p, len, KRB5_CRYPTO_FLAG_ALLOW_UNKEYED_CHECKSUM, &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 = p; result->length = l; return 0; } static krb5_error_code decrypt_internal_special(krb5_context context, krb5_crypto crypto, int usage, void *data, size_t len, krb5_data *result, void *ivec) { struct _krb5_encryption_type *et = crypto->et; size_t cksum_sz = CHECKSUMSIZE(et->checksum); size_t sz = len - cksum_sz - et->confoundersize; unsigned char *p; krb5_error_code ret; if ((len % et->padsize) != 0) { krb5_clear_error_message(context); return KRB5_BAD_MSIZE; } if (len < cksum_sz + et->confoundersize) { krb5_set_error_message(context, KRB5_BAD_MSIZE, N_("Encrypted data shorter then " "checksum + confunder", "")); return KRB5_BAD_MSIZE; } p = malloc (len); if (p == NULL) return krb5_enomem(context); memcpy(p, data, len); ret = (*et->encrypt)(context, &crypto->key, p, len, FALSE, usage, ivec); if (ret) { free(p); return ret; } memmove (p, p + cksum_sz + et->confoundersize, sz); result->data = p; result->length = sz; return 0; } static krb5_crypto_iov * iov_find(krb5_crypto_iov *data, size_t num_data, unsigned type) { size_t i; for (i = 0; i < num_data; i++) if (data[i].flags == type) return &data[i]; return NULL; } static size_t iov_enc_data_len(krb5_crypto_iov *data, int num_data) { size_t i, len; for (len = 0, i = 0; i < num_data; i++) { if (data[i].flags != KRB5_CRYPTO_TYPE_DATA) continue; len += data[i].data.length; } return len; } static size_t iov_sign_data_len(krb5_crypto_iov *data, int num_data) { size_t i, len; for (len = 0, i = 0; i < num_data; i++) { /* Can't use should_sign, because we must only count data, not * header/trailer */ if (data[i].flags == KRB5_CRYPTO_TYPE_DATA || data[i].flags == KRB5_CRYPTO_TYPE_SIGN_ONLY) len += data[i].data.length; } return len; } static krb5_error_code iov_coalesce(krb5_context context, krb5_data *prefix, krb5_crypto_iov *data, int num_data, krb5_boolean inc_sign_data, krb5_data *out) { unsigned char *p, *q; krb5_crypto_iov *hiv, *piv; size_t len; unsigned int i; hiv = iov_find(data, num_data, KRB5_CRYPTO_TYPE_HEADER); piv = iov_find(data, num_data, KRB5_CRYPTO_TYPE_PADDING); len = 0; if (prefix) len += prefix->length; len += hiv->data.length; if (inc_sign_data) len += iov_sign_data_len(data, num_data); else len += iov_enc_data_len(data, num_data); if (piv) len += piv->data.length; p = q = malloc(len); if (p == NULL) return krb5_enomem(context); if (prefix) { memcpy(q, prefix->data, prefix->length); q += prefix->length; } memcpy(q, hiv->data.data, hiv->data.length); q += hiv->data.length; for (i = 0; i < num_data; i++) { if (data[i].flags == KRB5_CRYPTO_TYPE_DATA || (inc_sign_data && data[i].flags == KRB5_CRYPTO_TYPE_SIGN_ONLY)) { memcpy(q, data[i].data.data, data[i].data.length); q += data[i].data.length; } } if (piv) memset(q, 0, piv->data.length); out->length = len; out->data = p; return 0; } static krb5_error_code iov_uncoalesce(krb5_context context, krb5_data *enc_data, krb5_crypto_iov *data, int num_data) { unsigned char *q = enc_data->data; krb5_crypto_iov *hiv, *piv; unsigned int i; hiv = iov_find(data, num_data, KRB5_CRYPTO_TYPE_HEADER); piv = iov_find(data, num_data, KRB5_CRYPTO_TYPE_PADDING); memcpy(hiv->data.data, q, hiv->data.length); q += hiv->data.length; for (i = 0; i < num_data; i++) { if (data[i].flags != KRB5_CRYPTO_TYPE_DATA) continue; memcpy(data[i].data.data, q, data[i].data.length); q += data[i].data.length; } if (piv) memcpy(piv->data.data, q, piv->data.length); return 0; } static krb5_error_code iov_pad_validate(const struct _krb5_encryption_type *et, krb5_crypto_iov *data, int num_data, krb5_crypto_iov **ppiv) { krb5_crypto_iov *piv; size_t sz, headersz, block_sz, pad_sz, len; len = iov_enc_data_len(data, num_data); headersz = et->confoundersize; sz = headersz + len; block_sz = (sz + et->padsize - 1) &~ (et->padsize - 1); /* pad */ pad_sz = block_sz - sz; piv = iov_find(data, num_data, KRB5_CRYPTO_TYPE_PADDING); /* its ok to have no TYPE_PADDING if there is no padding */ if (piv == NULL && pad_sz != 0) return KRB5_BAD_MSIZE; if (piv) { if (piv->data.length < pad_sz) return KRB5_BAD_MSIZE; piv->data.length = pad_sz; if (pad_sz) memset(piv->data.data, 0, pad_sz); else piv = NULL; } *ppiv = piv; return 0; } /** * Inline encrypt a kerberos message * * @param context Kerberos context * @param crypto Kerberos crypto context * @param usage Key usage for this buffer * @param data array of buffers to process * @param num_data length of array * @param ivec initial cbc/cts vector * * @return Return an error code or 0. * @ingroup krb5_crypto * * Kerberos encrypted data look like this: * * 1. KRB5_CRYPTO_TYPE_HEADER * 2. array [1,...] KRB5_CRYPTO_TYPE_DATA and array [0,...] * KRB5_CRYPTO_TYPE_SIGN_ONLY in any order, however the receiver * have to aware of the order. KRB5_CRYPTO_TYPE_SIGN_ONLY is * commonly used headers and trailers. * 3. KRB5_CRYPTO_TYPE_PADDING, at least on padsize long if padsize > 1 * 4. KRB5_CRYPTO_TYPE_TRAILER */ KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_encrypt_iov_ivec(krb5_context context, krb5_crypto crypto, unsigned usage, krb5_crypto_iov *data, int num_data, void *ivec) { size_t headersz, trailersz; Checksum cksum; krb5_data enc_data, sign_data; krb5_error_code ret; struct _krb5_key_data *dkey; const struct _krb5_encryption_type *et = crypto->et; krb5_crypto_iov *tiv, *piv, *hiv; if (num_data < 0) { krb5_clear_error_message(context); return KRB5_CRYPTO_INTERNAL; } if(!derived_crypto(context, crypto)) { krb5_clear_error_message(context); return KRB5_CRYPTO_INTERNAL; } krb5_data_zero(&enc_data); krb5_data_zero(&sign_data); headersz = et->confoundersize; trailersz = CHECKSUMSIZE(et->keyed_checksum); /* header */ hiv = iov_find(data, num_data, KRB5_CRYPTO_TYPE_HEADER); if (hiv == NULL || hiv->data.length != headersz) return KRB5_BAD_MSIZE; krb5_generate_random_block(hiv->data.data, hiv->data.length); /* padding */ ret = iov_pad_validate(et, data, num_data, &piv); if(ret) goto cleanup; /* trailer */ tiv = iov_find(data, num_data, KRB5_CRYPTO_TYPE_TRAILER); if (tiv == NULL || tiv->data.length != trailersz) { ret = KRB5_BAD_MSIZE; goto cleanup; } if (et->flags & F_ENC_THEN_CKSUM) { unsigned char old_ivec[EVP_MAX_IV_LENGTH]; krb5_data ivec_data; heim_assert(et->blocksize <= sizeof(old_ivec), "blocksize too big for ivec buffer"); ret = _get_derived_key(context, crypto, ENCRYPTION_USAGE(usage), &dkey); if(ret) goto cleanup; ret = _key_schedule(context, dkey); if(ret) goto cleanup; if (ivec) memcpy(old_ivec, ivec, et->blocksize); else memset(old_ivec, 0, et->blocksize); if (et->encrypt_iov != NULL) { ret = (*et->encrypt_iov)(context, dkey, data, num_data, 1, usage, ivec); if (ret) goto cleanup; } else { ret = iov_coalesce(context, NULL, data, num_data, FALSE, &enc_data); if (ret) goto cleanup; ret = (*et->encrypt)(context, dkey, enc_data.data, enc_data.length, 1, usage, ivec); if (ret) goto cleanup; ret = iov_uncoalesce(context, &enc_data, data, num_data); if (ret) goto cleanup; } ivec_data.length = et->blocksize; ivec_data.data = old_ivec; ret = iov_coalesce(context, &ivec_data, data, num_data, TRUE, &sign_data); if(ret) goto cleanup; ret = create_checksum(context, et->keyed_checksum, crypto, INTEGRITY_USAGE(usage), sign_data.data, sign_data.length, 0, &cksum); if(ret == 0 && cksum.checksum.length != trailersz) { free_Checksum (&cksum); krb5_clear_error_message (context); ret = KRB5_CRYPTO_INTERNAL; } if (ret) goto cleanup; /* save cksum at end */ memcpy(tiv->data.data, cksum.checksum.data, cksum.checksum.length); free_Checksum (&cksum); } else { cksum.checksum = tiv->data; ret = create_checksum_iov(context, et->keyed_checksum, crypto, INTEGRITY_USAGE(usage), data, num_data, 0, &cksum); if (ret) goto cleanup; /* create_checksum may realloc the derived key space, so any keys * obtained before it was called may no longer be valid */ ret = _get_derived_key(context, crypto, ENCRYPTION_USAGE(usage), &dkey); if(ret) goto cleanup; ret = _key_schedule(context, dkey); if(ret) goto cleanup; if (et->encrypt_iov != NULL) { ret = (*et->encrypt_iov)(context, dkey, data, num_data, 1, usage, ivec); if (ret) goto cleanup; } else { ret = iov_coalesce(context, NULL, data, num_data, FALSE, &enc_data); if (ret) goto cleanup; ret = (*et->encrypt)(context, dkey, enc_data.data, enc_data.length, 1, usage, ivec); if (ret) goto cleanup; ret = iov_uncoalesce(context, &enc_data, data, num_data); if (ret) goto cleanup; } } cleanup: if (enc_data.data) { memset_s(enc_data.data, enc_data.length, 0, enc_data.length); krb5_data_free(&enc_data); } if (sign_data.data) { memset_s(sign_data.data, sign_data.length, 0, sign_data.length); krb5_data_free(&sign_data); } return ret; } /** * Inline decrypt a Kerberos message. * * @param context Kerberos context * @param crypto Kerberos crypto context * @param usage Key usage for this buffer * @param data array of buffers to process * @param num_data length of array * @param ivec initial cbc/cts vector * * @return Return an error code or 0. * @ingroup krb5_crypto * * 1. KRB5_CRYPTO_TYPE_HEADER * 2. one KRB5_CRYPTO_TYPE_DATA and array [0,...] of KRB5_CRYPTO_TYPE_SIGN_ONLY in * any order, however the receiver have to aware of the * order. KRB5_CRYPTO_TYPE_SIGN_ONLY is commonly used unencrypoted * protocol headers and trailers. The output data will be of same * size as the input data or shorter. */ KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_decrypt_iov_ivec(krb5_context context, krb5_crypto crypto, unsigned usage, krb5_crypto_iov *data, unsigned int num_data, void *ivec) { Checksum cksum; krb5_data enc_data, sign_data; krb5_error_code ret; struct _krb5_key_data *dkey; struct _krb5_encryption_type *et = crypto->et; krb5_crypto_iov *tiv, *hiv; if(!derived_crypto(context, crypto)) { krb5_clear_error_message(context); return KRB5_CRYPTO_INTERNAL; } /* header */ hiv = iov_find(data, num_data, KRB5_CRYPTO_TYPE_HEADER); if (hiv == NULL || hiv->data.length != et->confoundersize) return KRB5_BAD_MSIZE; /* trailer */ tiv = iov_find(data, num_data, KRB5_CRYPTO_TYPE_TRAILER); if (tiv->data.length != CHECKSUMSIZE(et->keyed_checksum)) return KRB5_BAD_MSIZE; /* padding */ if ((iov_enc_data_len(data, num_data) % et->padsize) != 0) { krb5_clear_error_message(context); return KRB5_BAD_MSIZE; } krb5_data_zero(&enc_data); krb5_data_zero(&sign_data); if (!(et->flags & F_ENC_THEN_CKSUM)) { ret = _get_derived_key(context, crypto, ENCRYPTION_USAGE(usage), &dkey); if(ret) goto cleanup; ret = _key_schedule(context, dkey); if(ret) goto cleanup; if (et->encrypt_iov != NULL) { ret = (*et->encrypt_iov)(context, dkey, data, num_data, 0, usage, ivec); if(ret) goto cleanup; } else { ret = iov_coalesce(context, NULL, data, num_data, FALSE, &enc_data); if(ret) goto cleanup; ret = (*et->encrypt)(context, dkey, enc_data.data, enc_data.length, 0, usage, ivec); if(ret) goto cleanup; ret = iov_uncoalesce(context, &enc_data, data, num_data); if(ret) goto cleanup; } cksum.checksum.data = tiv->data.data; cksum.checksum.length = tiv->data.length; cksum.cksumtype = CHECKSUMTYPE(et->keyed_checksum); ret = verify_checksum_iov(context, crypto, INTEGRITY_USAGE(usage), data, num_data, 0, &cksum); if(ret) goto cleanup; } else { krb5_data ivec_data; static const unsigned char zero_ivec[EVP_MAX_IV_LENGTH]; heim_assert(et->blocksize <= sizeof(zero_ivec), "blocksize too big for ivec buffer"); ivec_data.length = et->blocksize; ivec_data.data = ivec ? ivec : rk_UNCONST(zero_ivec); ret = iov_coalesce(context, &ivec_data, data, num_data, TRUE, &sign_data); if(ret) goto cleanup; cksum.checksum.data = tiv->data.data; cksum.checksum.length = tiv->data.length; cksum.cksumtype = CHECKSUMTYPE(et->keyed_checksum); ret = verify_checksum(context, crypto, INTEGRITY_USAGE(usage), sign_data.data, sign_data.length, 0, &cksum); if(ret) goto cleanup; ret = iov_coalesce(context, NULL, data, num_data, FALSE, &enc_data); if(ret) goto cleanup; ret = _get_derived_key(context, crypto, ENCRYPTION_USAGE(usage), &dkey); if(ret) goto cleanup; ret = _key_schedule(context, dkey); if(ret) goto cleanup; ret = (*et->encrypt)(context, dkey, enc_data.data, enc_data.length, 0, usage, ivec); if(ret) goto cleanup; ret = iov_uncoalesce(context, &enc_data, data, num_data); if(ret) goto cleanup; } cleanup: if (enc_data.data) { memset_s(enc_data.data, enc_data.length, 0, enc_data.length); krb5_data_free(&enc_data); } if (sign_data.data) { memset_s(sign_data.data, sign_data.length, 0, sign_data.length); krb5_data_free(&sign_data); } return ret; } /** * Create a Kerberos message checksum. * * @param context Kerberos context * @param crypto Kerberos crypto context * @param usage Key usage for this buffer * @param data array of buffers to process * @param num_data length of array * @param type output data * * @return Return an error code or 0. * @ingroup krb5_crypto */ KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_create_checksum_iov(krb5_context context, krb5_crypto crypto, unsigned usage, krb5_crypto_iov *data, unsigned int num_data, krb5_cksumtype *type) { Checksum cksum; krb5_crypto_iov *civ; struct _krb5_checksum_type *ct; unsigned keyusage; krb5_error_code ret; civ = iov_find(data, num_data, KRB5_CRYPTO_TYPE_CHECKSUM); if (civ == NULL) return KRB5_BAD_MSIZE; ct = crypto->et->keyed_checksum; if (ct == NULL) ct = crypto->et->checksum; if(ct == NULL) { krb5_set_error_message (context, KRB5_PROG_SUMTYPE_NOSUPP, N_("checksum type not found", "")); return KRB5_PROG_SUMTYPE_NOSUPP; } if (arcfour_checksum_p(ct, crypto)) { keyusage = usage; _krb5_usage2arcfour(context, &keyusage); } else keyusage = CHECKSUM_USAGE(usage); if (ct->checksumsize > civ->data.length) { krb5_set_error_message(context, KRB5_BAD_MSIZE, N_("Checksum larger then input buffer", "")); return KRB5_BAD_MSIZE; } cksum.checksum = civ->data; ret = create_checksum_iov(context, ct, crypto, keyusage, data, num_data, crypto_flags(crypto), &cksum); if (ret == 0 && type) *type = cksum.cksumtype; return ret; } /** * Verify a Kerberos message checksum. * * @param context Kerberos context * @param crypto Kerberos crypto context * @param usage Key usage for this buffer * @param data array of buffers to process * @param num_data length of array * @param type return checksum type if not NULL * * @return Return an error code or 0. * @ingroup krb5_crypto */ KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_verify_checksum_iov(krb5_context context, krb5_crypto crypto, unsigned usage, krb5_crypto_iov *data, unsigned int num_data, krb5_cksumtype *type) { struct _krb5_encryption_type *et = crypto->et; struct _krb5_checksum_type *ct; Checksum cksum; krb5_crypto_iov *civ; krb5_error_code ret; unsigned keyusage; civ = iov_find(data, num_data, KRB5_CRYPTO_TYPE_CHECKSUM); if (civ == NULL) return KRB5_BAD_MSIZE; cksum.cksumtype = CHECKSUMTYPE(et->keyed_checksum); cksum.checksum.length = civ->data.length; cksum.checksum.data = civ->data.data; ct = _krb5_find_checksum(cksum.cksumtype); if(ct == NULL) { krb5_set_error_message (context, KRB5_PROG_SUMTYPE_NOSUPP, N_("checksum type %d not supported", ""), cksum.cksumtype); return KRB5_PROG_SUMTYPE_NOSUPP; } if (arcfour_checksum_p(ct, crypto)) { keyusage = usage; _krb5_usage2arcfour(context, &keyusage); } else keyusage = CHECKSUM_USAGE(usage); ret = verify_checksum_iov(context, crypto, keyusage, data, num_data, crypto_flags(crypto), &cksum); if (ret == 0 && type) *type = cksum.cksumtype; return ret; } KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_crypto_length(krb5_context context, krb5_crypto crypto, int type, size_t *len) { if (!derived_crypto(context, crypto)) { krb5_set_error_message(context, EINVAL, "not a derived crypto"); return EINVAL; } switch(type) { case KRB5_CRYPTO_TYPE_EMPTY: *len = 0; return 0; case KRB5_CRYPTO_TYPE_HEADER: *len = crypto->et->blocksize; return 0; case KRB5_CRYPTO_TYPE_DATA: case KRB5_CRYPTO_TYPE_SIGN_ONLY: /* len must already been filled in */ return 0; case KRB5_CRYPTO_TYPE_PADDING: if (crypto->et->padsize > 1) *len = crypto->et->padsize; else *len = 0; return 0; case KRB5_CRYPTO_TYPE_TRAILER: if (crypto->et->keyed_checksum) *len = CHECKSUMSIZE(crypto->et->keyed_checksum); else *len = 0; return 0; case KRB5_CRYPTO_TYPE_CHECKSUM: if (crypto->et->keyed_checksum) *len = CHECKSUMSIZE(crypto->et->keyed_checksum); else *len = CHECKSUMSIZE(crypto->et->checksum); return 0; } krb5_set_error_message(context, EINVAL, "%d not a supported type", type); return EINVAL; } KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_crypto_length_iov(krb5_context context, krb5_crypto crypto, krb5_crypto_iov *data, unsigned int num_data) { krb5_error_code ret; size_t i; for (i = 0; i < num_data; i++) { ret = krb5_crypto_length(context, crypto, data[i].flags, &data[i].data.length); if (ret) return ret; } return 0; } KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_encrypt_ivec(krb5_context context, krb5_crypto crypto, unsigned usage, const void *data, size_t len, krb5_data *result, void *ivec) { krb5_error_code ret; switch (crypto->et->flags & F_CRYPTO_MASK) { case F_RFC3961_ENC: ret = encrypt_internal_derived(context, crypto, usage, data, len, result, ivec); break; case F_SPECIAL: ret = encrypt_internal_special (context, crypto, usage, data, len, result, ivec); break; case F_ENC_THEN_CKSUM: ret = encrypt_internal_enc_then_cksum(context, crypto, usage, data, len, result, ivec); break; default: ret = encrypt_internal(context, crypto, data, len, result, ivec); break; } return ret; } KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_encrypt(krb5_context context, krb5_crypto crypto, unsigned usage, const void *data, size_t len, krb5_data *result) { return krb5_encrypt_ivec(context, crypto, usage, data, len, result, NULL); } KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL 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_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_decrypt_ivec(krb5_context context, krb5_crypto crypto, unsigned usage, void *data, size_t len, krb5_data *result, void *ivec) { krb5_error_code ret; switch (crypto->et->flags & F_CRYPTO_MASK) { case F_RFC3961_ENC: ret = decrypt_internal_derived(context, crypto, usage, data, len, result, ivec); break; case F_SPECIAL: ret = decrypt_internal_special(context, crypto, usage, data, len, result, ivec); break; case F_ENC_THEN_CKSUM: ret = decrypt_internal_enc_then_cksum(context, crypto, usage, data, len, result, ivec); break; default: ret = decrypt_internal(context, crypto, data, len, result, ivec); break; } return ret; } KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_decrypt(krb5_context context, krb5_crypto crypto, unsigned usage, void *data, size_t len, krb5_data *result) { return krb5_decrypt_ivec (context, crypto, usage, data, len, result, NULL); } KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_decrypt_EncryptedData(krb5_context context, krb5_crypto crypto, unsigned usage, const EncryptedData *e, krb5_data *result) { return krb5_decrypt(context, crypto, usage, e->cipher.data, e->cipher.length, result); } /************************************************************ * * ************************************************************/ static krb5_error_code derive_key_rfc3961(krb5_context context, struct _krb5_encryption_type *et, struct _krb5_key_data *key, const void *constant, size_t len) { unsigned char *k = NULL; unsigned int nblocks = 0, i; krb5_error_code ret = 0; struct _krb5_key_type *kt = et->keytype; 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) { ret = krb5_enomem(context); goto out; } ret = _krb5_n_fold(constant, len, k, et->blocksize); if (ret) { krb5_enomem(context); goto out; } for(i = 0; i < nblocks; i++) { if(i > 0) memcpy(k + i * et->blocksize, k + (i - 1) * et->blocksize, et->blocksize); ret = (*et->encrypt)(context, key, k + i * et->blocksize, et->blocksize, 1, 0, NULL); if (ret) { krb5_set_error_message(context, ret, N_("encrypt failed", "")); goto out; } } } else { /* this case is probably broken, but won't be run anyway */ void *c = malloc(len); size_t res_len = (kt->bits + 7) / 8; if(len != 0 && c == NULL) { ret = krb5_enomem(context); goto out; } memcpy(c, constant, len); ret = (*et->encrypt)(context, key, c, len, 1, 0, NULL); if (ret) { free(c); krb5_set_error_message(context, ret, N_("encrypt failed", "")); goto out; } k = malloc(res_len); if(res_len != 0 && k == NULL) { free(c); ret = krb5_enomem(context); goto out; } ret = _krb5_n_fold(c, len, k, res_len); free(c); if (ret) { krb5_enomem(context); goto out; } } if (kt->type == KRB5_ENCTYPE_OLD_DES3_CBC_SHA1) _krb5_DES3_random_to_key(context, key->key, k, nblocks * et->blocksize); else memcpy(key->key->keyvalue.data, k, key->key->keyvalue.length); out: if (k) { memset_s(k, nblocks * et->blocksize, 0, nblocks * et->blocksize); free(k); } return ret; } static krb5_error_code derive_key_sp800_hmac(krb5_context context, struct _krb5_encryption_type *et, struct _krb5_key_data *key, const void *constant, size_t len) { krb5_error_code ret; struct _krb5_key_type *kt = et->keytype; krb5_data label; const EVP_MD *md = NULL; const unsigned char *c = constant; size_t key_len; krb5_data K1; ret = _krb5_aes_sha2_md_for_enctype(context, kt->type, &md); if (ret) return ret; /* * PRF usage: not handled here (output cannot be longer) * Integrity usage: truncated hash (half length) * Encryption usage: base key length */ if (len == 5 && (c[4] == 0x99 || c[4] == 0x55)) key_len = EVP_MD_size(md) / 2; else key_len = kt->size; ret = krb5_data_alloc(&K1, key_len); if (ret) return ret; label.data = (void *)constant; label.length = len; ret = _krb5_SP800_108_HMAC_KDF(context, &key->key->keyvalue, &label, NULL, md, &K1); if (ret == 0) { if (key->key->keyvalue.length > key_len) key->key->keyvalue.length = key_len; memcpy(key->key->keyvalue.data, K1.data, key_len); } memset_s(K1.data, K1.length, 0, K1.length); krb5_data_free(&K1); return ret; } KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL _krb5_derive_key(krb5_context context, struct _krb5_encryption_type *et, struct _krb5_key_data *key, const void *constant, size_t len) { krb5_error_code ret; ret = _key_schedule(context, key); if(ret) return ret; switch (et->flags & F_KDF_MASK) { case F_RFC3961_KDF: ret = derive_key_rfc3961(context, et, key, constant, len); break; case F_SP800_108_HMAC_KDF: ret = derive_key_sp800_hmac(context, et, key, constant, len); break; default: ret = KRB5_CRYPTO_INTERNAL; krb5_set_error_message(context, ret, N_("derive_key() called with unknown keytype (%u)", ""), et->keytype->type); break; } if (key->schedule) { free_key_schedule(context, key, et); key->schedule = NULL; } return ret; } static struct _krb5_key_data * _new_derived_key(krb5_crypto crypto, unsigned usage) { struct _krb5_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; } KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_derive_key(krb5_context context, const krb5_keyblock *key, krb5_enctype etype, const void *constant, size_t constant_len, krb5_keyblock **derived_key) { krb5_error_code ret; struct _krb5_encryption_type *et; struct _krb5_key_data d; *derived_key = NULL; et = _krb5_find_enctype (etype); if (et == NULL) { return unsupported_enctype (context, etype); } ret = krb5_copy_keyblock(context, key, &d.key); if (ret) return ret; d.schedule = NULL; ret = _krb5_derive_key(context, et, &d, constant, constant_len); if (ret == 0) ret = krb5_copy_keyblock(context, d.key, derived_key); _krb5_free_key_data(context, &d, et); return ret; } static krb5_error_code _get_derived_key(krb5_context context, krb5_crypto crypto, unsigned usage, struct _krb5_key_data **key) { int i; struct _krb5_key_data *d; unsigned char constant[5]; *key = NULL; 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 krb5_enomem(context); *key = d; krb5_copy_keyblock(context, crypto->key.key, &d->key); _krb5_put_int(constant, usage, sizeof(constant)); return _krb5_derive_key(context, crypto->et, d, constant, sizeof(constant)); } /** * Create a crypto context used for all encryption and signature * operation. The encryption type to use is taken from the key, but * can be overridden with the enctype parameter. This can be useful * for encryptions types which is compatiable (DES for example). * * To free the crypto context, use krb5_crypto_destroy(). * * @param context Kerberos context * @param key the key block information with all key data * @param etype the encryption type * @param crypto the resulting crypto context * * @return Return an error code or 0. * * @ingroup krb5_crypto */ KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_crypto_init(krb5_context context, const krb5_keyblock *key, krb5_enctype etype, krb5_crypto *crypto) { krb5_error_code ret; ALLOC(*crypto, 1); if (*crypto == NULL) return krb5_enomem(context); if(etype == ETYPE_NULL) etype = key->keytype; (*crypto)->et = _krb5_find_enctype(etype); if((*crypto)->et == NULL || ((*crypto)->et->flags & F_DISABLED)) { free(*crypto); *crypto = NULL; return unsupported_enctype(context, etype); } if((*crypto)->et->keytype->size != key->keyvalue.length) { free(*crypto); *crypto = NULL; krb5_set_error_message (context, KRB5_BAD_KEYSIZE, "encryption key has bad length"); return KRB5_BAD_KEYSIZE; } ret = krb5_copy_keyblock(context, key, &(*crypto)->key.key); if(ret) { free(*crypto); *crypto = NULL; return ret; } (*crypto)->key.schedule = NULL; (*crypto)->num_key_usage = 0; (*crypto)->key_usage = NULL; (*crypto)->flags = 0; return 0; } static void free_key_schedule(krb5_context context, struct _krb5_key_data *key, struct _krb5_encryption_type *et) { if (et->keytype->cleanup) (*et->keytype->cleanup)(context, key); memset(key->schedule->data, 0, key->schedule->length); krb5_free_data(context, key->schedule); } KRB5_LIB_FUNCTION void KRB5_LIB_CALL _krb5_free_key_data(krb5_context context, struct _krb5_key_data *key, struct _krb5_encryption_type *et) { krb5_free_keyblock(context, key->key); if(key->schedule) { free_key_schedule(context, key, et); key->schedule = NULL; } } static void free_key_usage(krb5_context context, struct _krb5_key_usage *ku, struct _krb5_encryption_type *et) { _krb5_free_key_data(context, &ku->key, et); } /** * Free a crypto context created by krb5_crypto_init(). * * @param context Kerberos context * @param crypto crypto context to free * * @return Return an error code or 0. * * @ingroup krb5_crypto */ KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL 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], crypto->et); free(crypto->key_usage); _krb5_free_key_data(context, &crypto->key, crypto->et); if (crypto->mdctx) EVP_MD_CTX_destroy(crypto->mdctx); if (crypto->hmacctx) HMAC_CTX_free(crypto->hmacctx); free (crypto); return 0; } /** * Return the blocksize used algorithm referenced by the crypto context * * @param context Kerberos context * @param crypto crypto context to query * @param blocksize the resulting blocksize * * @return Return an error code or 0. * * @ingroup krb5_crypto */ KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_crypto_getblocksize(krb5_context context, krb5_crypto crypto, size_t *blocksize) { *blocksize = crypto->et->blocksize; return 0; } /** * Return the encryption type used by the crypto context * * @param context Kerberos context * @param crypto crypto context to query * @param enctype the resulting encryption type * * @return Return an error code or 0. * * @ingroup krb5_crypto */ KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_crypto_getenctype(krb5_context context, krb5_crypto crypto, krb5_enctype *enctype) { *enctype = crypto->et->type; return 0; } /** * Return the padding size used by the crypto context * * @param context Kerberos context * @param crypto crypto context to query * @param padsize the return padding size * * @return Return an error code or 0. * * @ingroup krb5_crypto */ KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_crypto_getpadsize(krb5_context context, krb5_crypto crypto, size_t *padsize) { *padsize = crypto->et->padsize; return 0; } /** * Return the confounder size used by the crypto context * * @param context Kerberos context * @param crypto crypto context to query * @param confoundersize the returned confounder size * * @return Return an error code or 0. * * @ingroup krb5_crypto */ KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_crypto_getconfoundersize(krb5_context context, krb5_crypto crypto, size_t *confoundersize) { *confoundersize = crypto->et->confoundersize; return 0; } /** * Disable encryption type * * @param context Kerberos 5 context * @param enctype encryption type to disable * * @return Return an error code or 0. * * @ingroup krb5_crypto */ KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_enctype_disable(krb5_context context, krb5_enctype enctype) { struct _krb5_encryption_type *et = _krb5_find_enctype(enctype); if(et == NULL) { if (context) krb5_set_error_message (context, KRB5_PROG_ETYPE_NOSUPP, N_("encryption type %d not supported", ""), enctype); return KRB5_PROG_ETYPE_NOSUPP; } et->flags |= F_DISABLED; return 0; } /** * Enable encryption type * * @param context Kerberos 5 context * @param enctype encryption type to enable * * @return Return an error code or 0. * * @ingroup krb5_crypto */ KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_enctype_enable(krb5_context context, krb5_enctype enctype) { struct _krb5_encryption_type *et = _krb5_find_enctype(enctype); if(et == NULL) { if (context) krb5_set_error_message (context, KRB5_PROG_ETYPE_NOSUPP, N_("encryption type %d not supported", ""), enctype); return KRB5_PROG_ETYPE_NOSUPP; } et->flags &= ~F_DISABLED; return 0; } /** * Enable or disable all weak encryption types * * @param context Kerberos 5 context * @param enable true to enable, false to disable * * @return Return an error code or 0. * * @ingroup krb5_crypto */ KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_allow_weak_crypto(krb5_context context, krb5_boolean enable) { int i; for(i = 0; i < _krb5_num_etypes; i++) if(_krb5_etypes[i]->flags & F_WEAK) { if(enable) _krb5_etypes[i]->flags &= ~F_DISABLED; else _krb5_etypes[i]->flags |= F_DISABLED; } return 0; } /** * Returns is the encryption is strong or weak * * @param context Kerberos 5 context * @param enctype encryption type to probe * * @return Returns true if encryption type is weak or is not supported. * * @ingroup krb5_crypto */ KRB5_LIB_FUNCTION krb5_boolean KRB5_LIB_CALL krb5_is_enctype_weak(krb5_context context, krb5_enctype enctype) { struct _krb5_encryption_type *et = _krb5_find_enctype(enctype); if(et == NULL || (et->flags & F_WEAK)) return TRUE; return FALSE; } /** * Returns whether the encryption type is new or old * * @param context Kerberos 5 context * @param enctype encryption type to probe * * @return Returns true if encryption type is old or is not supported. * * @ingroup krb5_crypto */ KRB5_LIB_FUNCTION krb5_boolean KRB5_LIB_CALL krb5_is_enctype_old(krb5_context context, krb5_enctype enctype) { struct _krb5_encryption_type *et = _krb5_find_enctype(enctype); if (!et || (et->flags & F_OLD)) return TRUE; return FALSE; } /** * Returns whether the encryption type should use randomly generated salts * * @param context Kerberos 5 context * @param enctype encryption type to probe * * @return Returns true if generated salts should have random component * * @ingroup krb5_crypto */ KRB5_LIB_FUNCTION krb5_boolean KRB5_LIB_CALL _krb5_enctype_requires_random_salt(krb5_context context, krb5_enctype enctype) { struct _krb5_encryption_type *et; et = _krb5_find_enctype (enctype); return et && (et->flags & F_SP800_108_HMAC_KDF); } static size_t wrapped_length (krb5_context context, krb5_crypto crypto, size_t data_len) { struct _krb5_encryption_type *et = crypto->et; size_t padsize = et->padsize; size_t checksumsize = CHECKSUMSIZE(et->checksum); size_t res; res = et->confoundersize + checksumsize + data_len; res = (res + padsize - 1) / padsize * padsize; return res; } static size_t wrapped_length_dervied (krb5_context context, krb5_crypto crypto, size_t data_len) { struct _krb5_encryption_type *et = crypto->et; size_t padsize = et->padsize; size_t res; res = et->confoundersize + data_len; res = (res + padsize - 1) / padsize * padsize; if (et->keyed_checksum) res += et->keyed_checksum->checksumsize; else res += et->checksum->checksumsize; return res; } /* * Return the size of an encrypted packet of length `data_len' */ KRB5_LIB_FUNCTION size_t KRB5_LIB_CALL krb5_get_wrapped_length (krb5_context context, krb5_crypto crypto, size_t data_len) { if (derived_crypto (context, crypto)) return wrapped_length_dervied (context, crypto, data_len); else return wrapped_length (context, crypto, data_len); } /* * Return the size of an encrypted packet of length `data_len' */ static size_t crypto_overhead (krb5_context context, krb5_crypto crypto) { struct _krb5_encryption_type *et = crypto->et; size_t res; res = CHECKSUMSIZE(et->checksum); res += et->confoundersize; if (et->padsize > 1) res += et->padsize; return res; } static size_t crypto_overhead_dervied (krb5_context context, krb5_crypto crypto) { struct _krb5_encryption_type *et = crypto->et; size_t res; if (et->keyed_checksum) res = CHECKSUMSIZE(et->keyed_checksum); else res = CHECKSUMSIZE(et->checksum); res += et->confoundersize; if (et->padsize > 1) res += et->padsize; return res; } KRB5_LIB_FUNCTION size_t KRB5_LIB_CALL krb5_crypto_overhead (krb5_context context, krb5_crypto crypto) { if (derived_crypto (context, crypto)) return crypto_overhead_dervied (context, crypto); else return crypto_overhead (context, crypto); } /** * Converts the random bytestring to a protocol key according to * Kerberos crypto frame work. It may be assumed that all the bits of * the input string are equally random, even though the entropy * present in the random source may be limited. * * @param context Kerberos 5 context * @param type the enctype resulting key will be of * @param data input random data to convert to a key * @param size size of input random data, at least krb5_enctype_keysize() long * @param key key, output key, free with krb5_free_keyblock_contents() * * @return Return an error code or 0. * * @ingroup krb5_crypto */ KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_random_to_key(krb5_context context, krb5_enctype type, const void *data, size_t size, krb5_keyblock *key) { krb5_error_code ret; struct _krb5_encryption_type *et = _krb5_find_enctype(type); if(et == NULL) { krb5_set_error_message(context, KRB5_PROG_ETYPE_NOSUPP, N_("encryption type %d not supported", ""), type); return KRB5_PROG_ETYPE_NOSUPP; } if ((et->keytype->bits + 7) / 8 > size) { krb5_set_error_message(context, KRB5_PROG_ETYPE_NOSUPP, N_("encryption key %s needs %d bytes " "of random to make an encryption key " "out of it", ""), et->name, (int)et->keytype->size); 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_to_key) (*et->keytype->random_to_key)(context, key, data, size); else memcpy(key->keyvalue.data, data, et->keytype->size); return 0; } KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_crypto_prf_length(krb5_context context, krb5_enctype type, size_t *length) { struct _krb5_encryption_type *et = _krb5_find_enctype(type); if(et == NULL || et->prf_length == 0) { krb5_set_error_message(context, KRB5_PROG_ETYPE_NOSUPP, N_("encryption type %d not supported", ""), type); return KRB5_PROG_ETYPE_NOSUPP; } *length = et->prf_length; return 0; } KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_crypto_prf(krb5_context context, const krb5_crypto crypto, const krb5_data *input, krb5_data *output) { struct _krb5_encryption_type *et = crypto->et; krb5_data_zero(output); if(et->prf == NULL) { krb5_set_error_message(context, KRB5_PROG_ETYPE_NOSUPP, "kerberos prf for %s not supported", et->name); return KRB5_PROG_ETYPE_NOSUPP; } return (*et->prf)(context, crypto, input, output); } KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_crypto_prfplus(krb5_context context, const krb5_crypto crypto, const krb5_data *input, size_t length, krb5_data *output) { krb5_error_code ret; krb5_data input2; unsigned char i = 1; unsigned char *p; krb5_data_zero(&input2); krb5_data_zero(output); krb5_clear_error_message(context); ret = krb5_data_alloc(output, length); if (ret) goto out; ret = krb5_data_alloc(&input2, input->length + 1); if (ret) goto out; krb5_clear_error_message(context); memcpy(((unsigned char *)input2.data) + 1, input->data, input->length); p = output->data; while (length) { krb5_data block; ((unsigned char *)input2.data)[0] = i++; ret = krb5_crypto_prf(context, crypto, &input2, &block); if (ret) goto out; if (block.length < length) { memcpy(p, block.data, block.length); length -= block.length; } else { memcpy(p, block.data, length); length = 0; } p += block.length; krb5_data_free(&block); } out: krb5_data_free(&input2); if (ret) krb5_data_free(output); return ret; } /** * The FX-CF2 key derivation function, used in FAST and preauth framework. * * @param context Kerberos 5 context * @param crypto1 first key to combine * @param crypto2 second key to combine * @param pepper1 factor to combine with first key to guarantee uniqueness * @param pepper2 factor to combine with second key to guarantee uniqueness * @param enctype the encryption type of the resulting key * @param res allocated key, free with krb5_free_keyblock_contents() * * @return Return an error code or 0. * * @ingroup krb5_crypto */ KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_crypto_fx_cf2(krb5_context context, const krb5_crypto crypto1, const krb5_crypto crypto2, krb5_data *pepper1, krb5_data *pepper2, krb5_enctype enctype, krb5_keyblock *res) { krb5_error_code ret; krb5_data os1, os2; size_t i, keysize; memset(res, 0, sizeof(*res)); krb5_data_zero(&os1); krb5_data_zero(&os2); ret = krb5_enctype_keybits(context, enctype, &keysize); if (ret) return ret; keysize = (keysize + 7) / 8; ret = krb5_crypto_prfplus(context, crypto1, pepper1, keysize, &os1); if (ret) goto out; ret = krb5_crypto_prfplus(context, crypto2, pepper2, keysize, &os2); if (ret) goto out; res->keytype = enctype; { unsigned char *p1 = os1.data, *p2 = os2.data; for (i = 0; i < keysize; i++) p1[i] ^= p2[i]; } ret = krb5_random_to_key(context, enctype, os1.data, keysize, res); out: krb5_data_free(&os1); krb5_data_free(&os2); return ret; } KRB5_LIB_FUNCTION void KRB5_LIB_CALL _krb5_crypto_set_flags(krb5_context context, krb5_crypto crypto, krb5_flags flags) { crypto->flags |= flags; } #ifndef HEIMDAL_SMALLER /** * Deprecated: keytypes don't exist, they are really enctypes. * * @ingroup krb5_deprecated */ KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL krb5_keytype_to_enctypes (krb5_context context, krb5_keytype keytype, unsigned *len, krb5_enctype **val) KRB5_DEPRECATED_FUNCTION("Use X instead") { int i; unsigned n = 0; krb5_enctype *ret; for (i = _krb5_num_etypes - 1; i >= 0; --i) { if (_krb5_etypes[i]->keytype->type == keytype && !(_krb5_etypes[i]->flags & F_PSEUDO) && krb5_enctype_valid(context, _krb5_etypes[i]->type) == 0) ++n; } if (n == 0) { krb5_set_error_message(context, KRB5_PROG_KEYTYPE_NOSUPP, "Keytype has no mapping"); return KRB5_PROG_KEYTYPE_NOSUPP; } ret = malloc(n * sizeof(*ret)); if (ret == NULL && n != 0) return krb5_enomem(context); n = 0; for (i = _krb5_num_etypes - 1; i >= 0; --i) { if (_krb5_etypes[i]->keytype->type == keytype && !(_krb5_etypes[i]->flags & F_PSEUDO) && krb5_enctype_valid(context, _krb5_etypes[i]->type) == 0) ret[n++] = _krb5_etypes[i]->type; } *len = n; *val = ret; return 0; } /** * Deprecated: keytypes don't exist, they are really enctypes. * * @ingroup krb5_deprecated */ /* if two enctypes have compatible keys */ KRB5_LIB_FUNCTION krb5_boolean KRB5_LIB_CALL krb5_enctypes_compatible_keys(krb5_context context, krb5_enctype etype1, krb5_enctype etype2) KRB5_DEPRECATED_FUNCTION("Use X instead") { struct _krb5_encryption_type *e1 = _krb5_find_enctype(etype1); struct _krb5_encryption_type *e2 = _krb5_find_enctype(etype2); return e1 != NULL && e2 != NULL && e1->keytype == e2->keytype; } #endif /* HEIMDAL_SMALLER */