diff options
Diffstat (limited to 'third_party/heimdal/lib/krb5/crypto.c')
| -rw-r--r-- | third_party/heimdal/lib/krb5/crypto.c | 3264 |
1 files changed, 3264 insertions, 0 deletions
diff --git a/third_party/heimdal/lib/krb5/crypto.c b/third_party/heimdal/lib/krb5/crypto.c new file mode 100644 index 0000000..2fb4f06 --- /dev/null +++ b/third_party/heimdal/lib/krb5/crypto.c @@ -0,0 +1,3264 @@ +/* + * 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_BAD_INTEGRITY, + 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 = e->keytype->type; /* XXX */ + 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 = realloc(p, l); + if(result->data == NULL && l != 0) { + free(p); + return krb5_enomem(context); + } + 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 = realloc(p, l); + if(result->data == NULL && l != 0) { + free(p); + return krb5_enomem(context); + } + 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 = realloc(p, l); + if(result->data == NULL && l != 0) { + free(p); + return krb5_enomem(context); + } + 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 = realloc(p, sz); + if(result->data == NULL && sz != 0) { + free(p); + return krb5_enomem(context); + } + 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 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 : 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 garante uniqueness + * @param pepper2 factor to combine with second key to garante 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 doesn't exists, 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 have 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 doesn't exists, 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 */ |