diff options
Diffstat (limited to 'source4/auth/kerberos/kerberos_util.c')
| -rw-r--r-- | source4/auth/kerberos/kerberos_util.c | 717 |
1 files changed, 11 insertions, 706 deletions
diff --git a/source4/auth/kerberos/kerberos_util.c b/source4/auth/kerberos/kerberos_util.c index c68efa96a8..4798df0ee9 100644 --- a/source4/auth/kerberos/kerberos_util.c +++ b/source4/auth/kerberos/kerberos_util.c @@ -28,16 +28,8 @@ #include "auth/credentials/credentials_krb5.h" #include "auth/kerberos/kerberos_credentials.h" #include "auth/kerberos/kerberos_util.h" -#include <ldb.h> -#include "param/secrets.h" -struct principal_container { - struct smb_krb5_context *smb_krb5_context; - krb5_principal principal; - const char *string_form; /* Optional */ -}; - -static krb5_error_code free_principal(struct principal_container *pc) +krb5_error_code free_principal(struct principal_container *pc) { /* current heimdal - 0.6.3, which we need anyway, fixes segfaults here */ krb5_free_principal(pc->smb_krb5_context->krb5_context, pc->principal); @@ -46,7 +38,7 @@ static krb5_error_code free_principal(struct principal_container *pc) } -static krb5_error_code parse_principal(TALLOC_CTX *parent_ctx, +krb5_error_code parse_principal(TALLOC_CTX *parent_ctx, const char *princ_string, struct smb_krb5_context *smb_krb5_context, krb5_principal *princ, @@ -84,235 +76,6 @@ static krb5_error_code parse_principal(TALLOC_CTX *parent_ctx, return 0; } -static krb5_error_code principals_from_msg(TALLOC_CTX *parent_ctx, - struct ldb_message *msg, - struct smb_krb5_context *smb_krb5_context, - struct principal_container ***principals_out, - const char **error_string) -{ - unsigned int i; - krb5_error_code ret; - char *upper_realm; - const char *realm = ldb_msg_find_attr_as_string(msg, "realm", NULL); - const char *samAccountName = ldb_msg_find_attr_as_string(msg, - "samAccountName", NULL); - struct ldb_message_element *spn_el = ldb_msg_find_element(msg, - "servicePrincipalName"); - TALLOC_CTX *tmp_ctx; - struct principal_container **principals; - tmp_ctx = talloc_new(parent_ctx); - if (!tmp_ctx) { - *error_string = "Cannot allocate tmp_ctx"; - return ENOMEM; - } - - if (!realm) { - *error_string = "Cannot have a kerberos secret in " - "secrets.ldb without a realm"; - return EINVAL; - } - - upper_realm = strupper_talloc(tmp_ctx, realm); - if (!upper_realm) { - talloc_free(tmp_ctx); - *error_string = "Cannot allocate full upper case realm"; - return ENOMEM; - } - - principals = talloc_array(tmp_ctx, struct principal_container *, - spn_el ? (spn_el->num_values + 2) : 2); - - spn_el = ldb_msg_find_element(msg, "servicePrincipalName"); - for (i=0; spn_el && i < spn_el->num_values; i++) { - principals[i] = talloc(principals, struct principal_container); - if (!principals[i]) { - talloc_free(tmp_ctx); - *error_string = "Cannot allocate mem_ctx"; - return ENOMEM; - } - - principals[i]->smb_krb5_context = - talloc_reference(principals[i], smb_krb5_context); - principals[i]->string_form = - talloc_asprintf(principals[i], "%*.*s@%s", - (int)spn_el->values[i].length, - (int)spn_el->values[i].length, - (const char *)spn_el->values[i].data, - upper_realm); - if (!principals[i]->string_form) { - talloc_free(tmp_ctx); - *error_string = "Cannot allocate full samAccountName"; - return ENOMEM; - } - - ret = krb5_parse_name(smb_krb5_context->krb5_context, - principals[i]->string_form, - &principals[i]->principal); - - if (ret) { - talloc_free(tmp_ctx); - (*error_string) = smb_get_krb5_error_message( - smb_krb5_context->krb5_context, - ret, parent_ctx); - return ret; - } - - /* This song-and-dance effectivly puts the principal - * into talloc, so we can't loose it. */ - talloc_set_destructor(principals[i], free_principal); - } - - if (samAccountName) { - principals[i] = talloc(principals, struct principal_container); - if (!principals[i]) { - talloc_free(tmp_ctx); - *error_string = "Cannot allocate mem_ctx"; - return ENOMEM; - } - - principals[i]->smb_krb5_context = - talloc_reference(principals[i], smb_krb5_context); - principals[i]->string_form = - talloc_asprintf(parent_ctx, "%s@%s", - samAccountName, upper_realm); - if (!principals[i]->string_form) { - talloc_free(tmp_ctx); - *error_string = "Cannot allocate full samAccountName"; - return ENOMEM; - } - - ret = krb5_make_principal(smb_krb5_context->krb5_context, - &principals[i]->principal, - upper_realm, samAccountName, - NULL); - if (ret) { - talloc_free(tmp_ctx); - (*error_string) = smb_get_krb5_error_message( - smb_krb5_context->krb5_context, - ret, parent_ctx); - return ret; - } - - /* This song-and-dance effectively puts the principal - * into talloc, so we can't loose it. */ - talloc_set_destructor(principals[i], free_principal); - i++; - } - - principals[i] = NULL; - *principals_out = talloc_steal(parent_ctx, principals); - - talloc_free(tmp_ctx); - return ret; -} - -static krb5_error_code salt_principal_from_msg(TALLOC_CTX *parent_ctx, - struct ldb_message *msg, - struct smb_krb5_context *smb_krb5_context, - krb5_principal *salt_princ, - const char **error_string) -{ - const char *salt_principal = ldb_msg_find_attr_as_string(msg, - "saltPrincipal", NULL); - const char *samAccountName = ldb_msg_find_attr_as_string(msg, - "samAccountName", NULL); - const char *realm = ldb_msg_find_attr_as_string(msg, "realm", NULL); - - struct principal_container *mem_ctx; - krb5_error_code ret; - char *machine_username; - char *salt_body; - char *lower_realm; - char *upper_realm; - - TALLOC_CTX *tmp_ctx; - - if (salt_principal) { - return parse_principal(parent_ctx, salt_principal, - smb_krb5_context, salt_princ, - error_string); - } - - if (!samAccountName) { - (*error_string) = "Cannot determine salt principal, no " - "saltPrincipal or samAccountName specified"; - return EINVAL; - } - - - mem_ctx = talloc(parent_ctx, struct principal_container); - if (!mem_ctx) { - *error_string = "Cannot allocate mem_ctx"; - return ENOMEM; - } - - tmp_ctx = talloc_new(mem_ctx); - if (!tmp_ctx) { - talloc_free(mem_ctx); - *error_string = "Cannot allocate tmp_ctx"; - return ENOMEM; - } - - if (!realm) { - *error_string = "Cannot have a kerberos secret in " - "secrets.ldb without a realm"; - return EINVAL; - } - - machine_username = talloc_strdup(tmp_ctx, samAccountName); - if (!machine_username) { - talloc_free(mem_ctx); - *error_string = "Cannot duplicate samAccountName"; - return ENOMEM; - } - - if (machine_username[strlen(machine_username)-1] == '$') { - machine_username[strlen(machine_username)-1] = '\0'; - } - - lower_realm = strlower_talloc(tmp_ctx, realm); - if (!lower_realm) { - talloc_free(mem_ctx); - *error_string = "Cannot allocate to lower case realm"; - return ENOMEM; - } - - upper_realm = strupper_talloc(tmp_ctx, realm); - if (!upper_realm) { - talloc_free(mem_ctx); - *error_string = "Cannot allocate to upper case realm"; - return ENOMEM; - } - - salt_body = talloc_asprintf(tmp_ctx, "%s.%s", machine_username, - lower_realm); - talloc_free(lower_realm); - talloc_free(machine_username); - if (!salt_body) { - talloc_free(mem_ctx); - *error_string = "Cannot form salt principal body"; - return ENOMEM; - } - - ret = krb5_make_principal(smb_krb5_context->krb5_context, salt_princ, - upper_realm, - "host", salt_body, NULL); - if (ret == 0) { - /* This song-and-dance effectively puts the principal - * into talloc, so we can't loose it. */ - mem_ctx->smb_krb5_context = talloc_reference(mem_ctx, - smb_krb5_context); - mem_ctx->principal = *salt_princ; - talloc_set_destructor(mem_ctx, free_principal); - } else { - (*error_string) = smb_get_krb5_error_message( - smb_krb5_context->krb5_context, - ret, parent_ctx); - } - talloc_free(tmp_ctx); - return ret; -} - /* Obtain the principal set on this context. Requires a * smb_krb5_context because we are doing krb5 principal parsing with * the library routines. The returned princ is placed in the talloc @@ -557,16 +320,19 @@ static krb5_error_code free_keytab_container(struct keytab_container *ktc) } krb5_error_code smb_krb5_get_keytab_container(TALLOC_CTX *mem_ctx, - struct smb_krb5_context *smb_krb5_context, - const char *keytab_name, struct keytab_container **ktc) + struct smb_krb5_context *smb_krb5_context, + const char *keytab_name, + struct keytab_container **ktc) { krb5_keytab keytab; krb5_error_code ret; - ret = krb5_kt_resolve(smb_krb5_context->krb5_context, keytab_name, &keytab); + ret = krb5_kt_resolve(smb_krb5_context->krb5_context, + keytab_name, &keytab); if (ret) { - DEBUG(1,("failed to open krb5 keytab: %s\n", - smb_get_krb5_error_message(smb_krb5_context->krb5_context, - ret, mem_ctx))); + DEBUG(1,("failed to open krb5 keytab: %s\n", + smb_get_krb5_error_message( + smb_krb5_context->krb5_context, + ret, mem_ctx))); return ret; } @@ -582,423 +348,6 @@ krb5_error_code smb_krb5_get_keytab_container(TALLOC_CTX *mem_ctx, return 0; } -static krb5_error_code keytab_add_keys(TALLOC_CTX *parent_ctx, - struct principal_container **principals, - krb5_principal salt_princ, - int kvno, - const char *password_s, - krb5_context krb5_context, - krb5_enctype *enctypes, - krb5_keytab keytab, - const char **error_string) -{ - unsigned int i, p; - krb5_error_code ret; - krb5_data password; - - password.data = discard_const_p(char *, password_s); - password.length = strlen(password_s); - - for (i = 0; enctypes[i]; i++) { - krb5_keytab_entry entry; - - ZERO_STRUCT(entry); - - ret = create_kerberos_key_from_string_direct(krb5_context, - salt_princ, &password, - &entry.keyblock, enctypes[i]); - if (ret != 0) { - return ret; - } - - entry.vno = kvno; - - for (p = 0; principals[p]; p++) { - entry.principal = principals[p]->principal; - ret = krb5_kt_add_entry(krb5_context, - keytab, &entry); - if (ret != 0) { - char *k5_error_string = - smb_get_krb5_error_message( - krb5_context, ret, NULL); - *error_string = talloc_asprintf(parent_ctx, - "Failed to add enctype %d entry for " - "%s(kvno %d) to keytab: %s\n", - (int)enctypes[i], - principals[p]->string_form, - kvno, k5_error_string); - - talloc_free(k5_error_string); - krb5_free_keyblock_contents(krb5_context, - &entry.keyblock); - return ret; - } - - DEBUG(5, ("Added %s(kvno %d) to keytab (enctype %d)\n", - principals[p]->string_form, kvno, - (int)enctypes[i])); - } - krb5_free_keyblock_contents(krb5_context, &entry.keyblock); - } - return 0; -} - -static krb5_error_code ms_suptypes_to_ietf_enctypes(TALLOC_CTX *mem_ctx, - uint32_t enctype_bitmap, - krb5_enctype **enctypes); - -static krb5_error_code create_keytab(TALLOC_CTX *parent_ctx, - struct ldb_message *msg, - struct principal_container **principals, - struct smb_krb5_context *smb_krb5_context, - krb5_keytab keytab, - bool add_old, - const char **error_string) -{ - krb5_error_code ret; - const char *password_s; - const char *old_secret; - int kvno; - uint32_t enctype_bitmap; - krb5_principal salt_princ; - krb5_enctype *enctypes; - TALLOC_CTX *mem_ctx = talloc_new(parent_ctx); - if (!mem_ctx) { - *error_string = "unable to allocate tmp_ctx for create_keytab"; - return ENOMEM; - } - - /* The salt used to generate these entries may be different however, - * fetch that */ - ret = salt_principal_from_msg(mem_ctx, msg, - smb_krb5_context, - &salt_princ, error_string); - if (ret) { - talloc_free(mem_ctx); - return ret; - } - - kvno = ldb_msg_find_attr_as_int(msg, "msDS-KeyVersionNumber", 0); - - /* Finally, do the dance to get the password to put in the entry */ - password_s = ldb_msg_find_attr_as_string(msg, "secret", NULL); - - if (!password_s) { - /* There is no password here, so nothing to do */ - talloc_free(mem_ctx); - return 0; - } - - if (add_old && kvno != 0) { - old_secret = ldb_msg_find_attr_as_string(msg, - "priorSecret", NULL); - } else { - old_secret = NULL; - } - - enctype_bitmap = (uint32_t)ldb_msg_find_attr_as_int(msg, - "msDS-SupportedEncryptionTypes", - ENC_ALL_TYPES); - - ret = ms_suptypes_to_ietf_enctypes(mem_ctx, enctype_bitmap, &enctypes); - if (ret) { - *error_string = talloc_asprintf(parent_ctx, - "create_keytab: generating list of " - "encryption types failed (%s)\n", - smb_get_krb5_error_message( - smb_krb5_context->krb5_context, - ret, mem_ctx)); - talloc_free(mem_ctx); - return ret; - } - - ret = keytab_add_keys(mem_ctx, principals, - salt_princ, kvno, password_s, - smb_krb5_context->krb5_context, - enctypes, keytab, error_string); - if (ret) { - talloc_free(mem_ctx); - return ret; - } - - if (old_secret) { - ret = keytab_add_keys(mem_ctx, principals, - salt_princ, kvno - 1, old_secret, - smb_krb5_context->krb5_context, - enctypes, keytab, error_string); - if (ret) { - talloc_free(mem_ctx); - return ret; - } - } - - talloc_free(mem_ctx); - return ret; -} - -/* - * Walk the keytab, looking for entries of this principal name, - * with KVNO other than current kvno -1. - * - * These entries are now stale, - * we only keep the current and previous entries around. - * - * Inspired by the code in Samba3 for 'use kerberos keytab'. - */ - -static krb5_error_code remove_old_entries(TALLOC_CTX *parent_ctx, - struct ldb_message *msg, - struct principal_container **principals, - bool delete_all_kvno, - krb5_context krb5_context, - krb5_keytab keytab, - bool *found_previous, - const char **error_string) -{ - krb5_error_code ret, ret2; - krb5_kt_cursor cursor; - int kvno; - TALLOC_CTX *mem_ctx = talloc_new(parent_ctx); - - if (!mem_ctx) { - return ENOMEM; - } - - *found_previous = false; - - kvno = ldb_msg_find_attr_as_int(msg, "msDS-KeyVersionNumber", 0); - - /* for each entry in the keytab */ - ret = krb5_kt_start_seq_get(krb5_context, keytab, &cursor); - switch (ret) { - case 0: - break; - case HEIM_ERR_OPNOTSUPP: - case ENOENT: - case KRB5_KT_END: - /* no point enumerating if there isn't anything here */ - talloc_free(mem_ctx); - return 0; - default: - *error_string = talloc_asprintf(parent_ctx, - "failed to open keytab for read of old entries: %s\n", - smb_get_krb5_error_message(krb5_context, - ret, mem_ctx)); - talloc_free(mem_ctx); - return ret; - } - - while (!ret) { - unsigned int i; - bool matched = false; - krb5_keytab_entry entry; - ret = krb5_kt_next_entry(krb5_context, keytab, - &entry, &cursor); - if (ret) { - break; - } - for (i = 0; principals[i]; i++) { - /* if it matches our principal */ - if (krb5_kt_compare(krb5_context, &entry, - principals[i]->principal, 0, 0)) { - matched = true; - break; - } - } - - if (!matched) { - /* Free the entry, - * it wasn't the one we were looking for anyway */ - krb5_kt_free_entry(krb5_context, &entry); - continue; - } - - /* delete it, if it is not kvno -1 */ - if (entry.vno != (kvno - 1 )) { - /* Release the enumeration. We are going to - * have to start this from the top again, - * because deletes during enumeration may not - * always be consistent. - * - * Also, the enumeration locks a FILE: keytab - */ - - krb5_kt_end_seq_get(krb5_context, keytab, &cursor); - - ret = krb5_kt_remove_entry(krb5_context, keytab, &entry); - krb5_kt_free_entry(krb5_context, &entry); - - /* Deleted: Restart from the top */ - ret2 = krb5_kt_start_seq_get(krb5_context, - keytab, &cursor); - if (ret2) { - krb5_kt_free_entry(krb5_context, &entry); - DEBUG(1, ("failed to restart enumeration of keytab: %s\n", - smb_get_krb5_error_message(krb5_context, - ret, mem_ctx))); - - talloc_free(mem_ctx); - return ret2; - } - - if (ret) { - break; - } - - } else { - *found_previous = true; - } - - /* Free the entry, we don't need it any more */ - krb5_kt_free_entry(krb5_context, &entry); - } - krb5_kt_end_seq_get(krb5_context, keytab, &cursor); - - switch (ret) { - case 0: - break; - case ENOENT: - case KRB5_KT_END: - ret = 0; - break; - default: - *error_string = talloc_asprintf(parent_ctx, - "failed in deleting old entries for principal: %s\n", - smb_get_krb5_error_message(krb5_context, - ret, mem_ctx)); - } - talloc_free(mem_ctx); - return ret; -} - -krb5_error_code smb_krb5_update_keytab(TALLOC_CTX *parent_ctx, - struct smb_krb5_context *smb_krb5_context, - struct ldb_context *ldb, - struct ldb_message *msg, - bool delete_all_kvno, - const char **error_string) -{ - krb5_error_code ret; - bool found_previous; - TALLOC_CTX *mem_ctx = talloc_new(NULL); - struct keytab_container *keytab_container; - struct principal_container **principals; - const char *keytab_name; - - if (!mem_ctx) { - return ENOMEM; - } - - keytab_name = keytab_name_from_msg(mem_ctx, ldb, msg); - if (!keytab_name) { - return ENOENT; - } - - ret = smb_krb5_get_keytab_container(mem_ctx, smb_krb5_context, - keytab_name, &keytab_container); - - if (ret != 0) { - talloc_free(mem_ctx); - return ret; - } - - DEBUG(5, ("Opened keytab %s\n", keytab_name)); - - /* Get the principal we will store the new keytab entries under */ - ret = principals_from_msg(mem_ctx, msg, smb_krb5_context, - &principals, error_string); - - if (ret != 0) { - *error_string = talloc_asprintf(parent_ctx, - "Failed to load principals from ldb message: %s\n", - *error_string); - talloc_free(mem_ctx); - return ret; - } - - ret = remove_old_entries(mem_ctx, msg, principals, delete_all_kvno, - smb_krb5_context->krb5_context, - keytab_container->keytab, - &found_previous, error_string); - if (ret != 0) { - *error_string = talloc_asprintf(parent_ctx, - "Failed to remove old principals from keytab: %s\n", - *error_string); - talloc_free(mem_ctx); - return ret; - } - - if (!delete_all_kvno) { - /* Create a new keytab. If during the cleanout we found - * entires for kvno -1, then don't try and duplicate them. - * Otherwise, add kvno, and kvno -1 */ - - ret = create_keytab(mem_ctx, msg, principals, - smb_krb5_context, - keytab_container->keytab, - found_previous ? false : true, - error_string); - } - talloc_free(mem_ctx); - return ret; -} - -krb5_error_code smb_krb5_create_memory_keytab(TALLOC_CTX *parent_ctx, - struct cli_credentials *machine_account, - struct smb_krb5_context *smb_krb5_context, - struct keytab_container **keytab_container) -{ - krb5_error_code ret; - TALLOC_CTX *mem_ctx = talloc_new(parent_ctx); - const char *rand_string; - const char *keytab_name; - struct ldb_message *msg; - const char *error_string; - if (!mem_ctx) { - return ENOMEM; - } - - *keytab_container = talloc(mem_ctx, struct keytab_container); - - rand_string = generate_random_str(mem_ctx, 16); - if (!rand_string) { - talloc_free(mem_ctx); - return ENOMEM; - } - - keytab_name = talloc_asprintf(mem_ctx, "MEMORY:%s", - rand_string); - if (!keytab_name) { - talloc_free(mem_ctx); - return ENOMEM; - } - - ret = smb_krb5_get_keytab_container(mem_ctx, smb_krb5_context, keytab_name, keytab_container); - if (ret) { - return ret; - } - - msg = ldb_msg_new(mem_ctx); - if (!msg) { - talloc_free(mem_ctx); - return ENOMEM; - } - ldb_msg_add_string(msg, "krb5Keytab", keytab_name); - ldb_msg_add_string(msg, "secret", cli_credentials_get_password(machine_account)); - ldb_msg_add_string(msg, "samAccountName", cli_credentials_get_username(machine_account)); - ldb_msg_add_string(msg, "realm", cli_credentials_get_realm(machine_account)); - ldb_msg_add_fmt(msg, "msDS-KeyVersionNumber", "%d", (int)cli_credentials_get_kvno(machine_account)); - - ret = smb_krb5_update_keytab(mem_ctx, smb_krb5_context, NULL, msg, false, &error_string); - if (ret == 0) { - talloc_steal(parent_ctx, *keytab_container); - } else { - DEBUG(0, ("Failed to create in-memory keytab: %s\n", error_string)); - *keytab_container = NULL; - } - talloc_free(mem_ctx); - return ret; -} /* Translate between the IETF encryption type values and the Microsoft msDS-SupportedEncryptionTypes values */ uint32_t kerberos_enctype_to_bitmap(krb5_enctype enc_type_enum) { @@ -1017,47 +366,3 @@ uint32_t kerberos_enctype_to_bitmap(krb5_enctype enc_type_enum) return 0; } } - -/* Translate between the Microsoft msDS-SupportedEncryptionTypes values - * and the IETF encryption type values */ -static krb5_enctype ms_suptype_to_ietf_enctype(uint32_t enctype_bitmap) -{ - switch (enctype_bitmap) { - case ENC_CRC32: - return ENCTYPE_DES_CBC_CRC; - case ENC_RSA_MD5: - return ENCTYPE_DES_CBC_MD5; - case ENC_RC4_HMAC_MD5: - return ENCTYPE_ARCFOUR_HMAC_MD5; - case ENC_HMAC_SHA1_96_AES128: - return ENCTYPE_AES128_CTS_HMAC_SHA1_96; - case ENC_HMAC_SHA1_96_AES256: - return ENCTYPE_AES256_CTS_HMAC_SHA1_96; - default: - return 0; - } -} -/* Return an array of krb5_enctype values */ -static krb5_error_code ms_suptypes_to_ietf_enctypes(TALLOC_CTX *mem_ctx, - uint32_t enctype_bitmap, - krb5_enctype **enctypes) -{ - unsigned int i, j = 0; - *enctypes = talloc_zero_array(mem_ctx, krb5_enctype, - (8 * sizeof(enctype_bitmap)) + 1); - if (!*enctypes) { - return ENOMEM; - } - for (i = 0; i < (8 * sizeof(enctype_bitmap)); i++) { - uint32_t bit_value = (1 << i) & enctype_bitmap; - if (bit_value & enctype_bitmap) { - (*enctypes)[j] = ms_suptype_to_ietf_enctype(bit_value); - if (!(*enctypes)[j]) { - continue; - } - j++; - } - } - (*enctypes)[j] = 0; - return 0; -} |