diff options
| -rw-r--r-- | crypto/Makefile.objs | 1 | ||||
| -rw-r--r-- | crypto/tls-cipher-suites.c | 126 | ||||
| -rw-r--r-- | crypto/trace-events | 5 | ||||
| -rw-r--r-- | docs/specs/fw_cfg.txt | 13 | ||||
| -rw-r--r-- | hw/nvram/fw_cfg.c | 35 | ||||
| -rw-r--r-- | include/crypto/tls-cipher-suites.h | 39 | ||||
| -rw-r--r-- | include/hw/nvram/fw_cfg.h | 43 | ||||
| -rw-r--r-- | qemu-options.hx | 37 | ||||
| -rw-r--r-- | softmmu/vl.c | 37 |
9 files changed, 326 insertions, 10 deletions
diff --git a/crypto/Makefile.objs b/crypto/Makefile.objs index 707c02a..f1965b1 100644 --- a/crypto/Makefile.objs +++ b/crypto/Makefile.objs @@ -13,6 +13,7 @@ crypto-obj-y += cipher.o crypto-obj-$(CONFIG_AF_ALG) += afalg.o crypto-obj-$(CONFIG_AF_ALG) += cipher-afalg.o crypto-obj-$(CONFIG_AF_ALG) += hash-afalg.o +crypto-obj-$(CONFIG_GNUTLS) += tls-cipher-suites.o crypto-obj-y += tlscreds.o crypto-obj-y += tlscredsanon.o crypto-obj-y += tlscredspsk.o diff --git a/crypto/tls-cipher-suites.c b/crypto/tls-cipher-suites.c new file mode 100644 index 0000000..0d305b6 --- /dev/null +++ b/crypto/tls-cipher-suites.c @@ -0,0 +1,126 @@ +/* + * QEMU TLS Cipher Suites + * + * Copyright (c) 2018-2020 Red Hat, Inc. + * + * Author: Philippe Mathieu-Daudé <philmd@redhat.com> + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#include "qemu/osdep.h" +#include "qapi/error.h" +#include "qom/object_interfaces.h" +#include "crypto/tlscreds.h" +#include "crypto/tls-cipher-suites.h" +#include "hw/nvram/fw_cfg.h" +#include "trace.h" + +/* + * IANA registered TLS ciphers: + * https://www.iana.org/assignments/tls-parameters/tls-parameters.xhtml#tls-parameters-4 + */ +typedef struct { + uint8_t data[2]; +} QEMU_PACKED IANA_TLS_CIPHER; + +GByteArray *qcrypto_tls_cipher_suites_get_data(QCryptoTLSCipherSuites *obj, + Error **errp) +{ + QCryptoTLSCreds *creds = QCRYPTO_TLS_CREDS(obj); + gnutls_priority_t pcache; + GByteArray *byte_array; + const char *err; + size_t i; + int ret; + + trace_qcrypto_tls_cipher_suite_priority(creds->priority); + ret = gnutls_priority_init(&pcache, creds->priority, &err); + if (ret < 0) { + error_setg(errp, "Syntax error using priority '%s': %s", + creds->priority, gnutls_strerror(ret)); + return NULL; + } + + byte_array = g_byte_array_new(); + + for (i = 0;; i++) { + int ret; + unsigned idx; + const char *name; + IANA_TLS_CIPHER cipher; + gnutls_protocol_t protocol; + const char *version; + + ret = gnutls_priority_get_cipher_suite_index(pcache, i, &idx); + if (ret == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE) { + break; + } + if (ret == GNUTLS_E_UNKNOWN_CIPHER_SUITE) { + continue; + } + + name = gnutls_cipher_suite_info(idx, (unsigned char *)&cipher, + NULL, NULL, NULL, &protocol); + if (name == NULL) { + continue; + } + + version = gnutls_protocol_get_name(protocol); + g_byte_array_append(byte_array, cipher.data, 2); + trace_qcrypto_tls_cipher_suite_info(cipher.data[0], + cipher.data[1], + version, name); + } + trace_qcrypto_tls_cipher_suite_count(byte_array->len); + gnutls_priority_deinit(pcache); + + return byte_array; +} + +static void qcrypto_tls_cipher_suites_complete(UserCreatable *uc, + Error **errp) +{ + QCryptoTLSCreds *creds = QCRYPTO_TLS_CREDS(uc); + + if (!creds->priority) { + error_setg(errp, "'priority' property is not set"); + return; + } +} + +static GByteArray *qcrypto_tls_cipher_suites_fw_cfg_gen_data(Object *obj, + Error **errp) +{ + return qcrypto_tls_cipher_suites_get_data(QCRYPTO_TLS_CIPHER_SUITES(obj), + errp); +} + +static void qcrypto_tls_cipher_suites_class_init(ObjectClass *oc, void *data) +{ + UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc); + FWCfgDataGeneratorClass *fwgc = FW_CFG_DATA_GENERATOR_CLASS(oc); + + ucc->complete = qcrypto_tls_cipher_suites_complete; + fwgc->get_data = qcrypto_tls_cipher_suites_fw_cfg_gen_data; +} + +static const TypeInfo qcrypto_tls_cipher_suites_info = { + .parent = TYPE_QCRYPTO_TLS_CREDS, + .name = TYPE_QCRYPTO_TLS_CIPHER_SUITES, + .instance_size = sizeof(QCryptoTLSCreds), + .class_size = sizeof(QCryptoTLSCredsClass), + .class_init = qcrypto_tls_cipher_suites_class_init, + .interfaces = (InterfaceInfo[]) { + { TYPE_USER_CREATABLE }, + { TYPE_FW_CFG_DATA_GENERATOR_INTERFACE }, + { } + } +}; + +static void qcrypto_tls_cipher_suites_register_types(void) +{ + type_register_static(&qcrypto_tls_cipher_suites_info); +} + +type_init(qcrypto_tls_cipher_suites_register_types); diff --git a/crypto/trace-events b/crypto/trace-events index 9e594d3..798b606 100644 --- a/crypto/trace-events +++ b/crypto/trace-events @@ -21,3 +21,8 @@ qcrypto_tls_creds_x509_load_cert_list(void *creds, const char *file) "TLS creds # tlssession.c qcrypto_tls_session_new(void *session, void *creds, const char *hostname, const char *authzid, int endpoint) "TLS session new session=%p creds=%p hostname=%s authzid=%s endpoint=%d" qcrypto_tls_session_check_creds(void *session, const char *status) "TLS session check creds session=%p status=%s" + +# tls-cipher-suites.c +qcrypto_tls_cipher_suite_priority(const char *name) "priority: %s" +qcrypto_tls_cipher_suite_info(uint8_t data0, uint8_t data1, const char *version, const char *name) "data=[0x%02x,0x%02x] version=%s name=%s" +qcrypto_tls_cipher_suite_count(unsigned count) "count: %u" diff --git a/docs/specs/fw_cfg.txt b/docs/specs/fw_cfg.txt index 8f1ebc6..3e6d586 100644 --- a/docs/specs/fw_cfg.txt +++ b/docs/specs/fw_cfg.txt @@ -219,7 +219,7 @@ To check the result, read the "control" field: = Externally Provided Items = -As of v2.4, "file" fw_cfg items (i.e., items with selector keys above +Since v2.4, "file" fw_cfg items (i.e., items with selector keys above FW_CFG_FILE_FIRST, and with a corresponding entry in the fw_cfg file directory structure) may be inserted via the QEMU command line, using the following syntax: @@ -230,6 +230,13 @@ Or -fw_cfg [name=]<item_name>,string=<string> +Since v5.1, QEMU allows some objects to generate fw_cfg-specific content, +the content is then associated with a "file" item using the 'gen_id' option +in the command line, using the following syntax: + + -object <generator-type>,id=<generated_id>,[generator-specific-options] \ + -fw_cfg [name=]<item_name>,gen_id=<generated_id> + See QEMU man page for more documentation. Using item_name with plain ASCII characters only is recommended. @@ -251,4 +258,8 @@ Prefix "opt/org.qemu/" is reserved for QEMU itself. Use of names not beginning with "opt/" is potentially dangerous and entirely unsupported. QEMU will warn if you try. +Use of names not beginning with "opt/" is tolerated with 'gen_id' (that +is, the warning is suppressed), but you must know exactly what you're +doing. + All externally provided fw_cfg items are read-only to the guest. diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c index 0408a31..694722b 100644 --- a/hw/nvram/fw_cfg.c +++ b/hw/nvram/fw_cfg.c @@ -1032,6 +1032,35 @@ void *fw_cfg_modify_file(FWCfgState *s, const char *filename, return NULL; } +void fw_cfg_add_from_generator(FWCfgState *s, const char *filename, + const char *gen_id, Error **errp) +{ + FWCfgDataGeneratorClass *klass; + Error *local_err = NULL; + GByteArray *array; + Object *obj; + gsize size; + + obj = object_resolve_path_component(object_get_objects_root(), gen_id); + if (!obj) { + error_setg(errp, "Cannot find object ID '%s'", gen_id); + return; + } + if (!object_dynamic_cast(obj, TYPE_FW_CFG_DATA_GENERATOR_INTERFACE)) { + error_setg(errp, "Object ID '%s' is not a '%s' subclass", + gen_id, TYPE_FW_CFG_DATA_GENERATOR_INTERFACE); + return; + } + klass = FW_CFG_DATA_GENERATOR_GET_CLASS(obj); + array = klass->get_data(obj, &local_err); + if (local_err) { + error_propagate(errp, local_err); + return; + } + size = array->len; + fw_cfg_add_file(s, filename, g_byte_array_free(array, TRUE), size); +} + static void fw_cfg_machine_reset(void *opaque) { MachineClass *mc = MACHINE_GET_CLASS(qdev_get_machine()); @@ -1333,12 +1362,18 @@ static const TypeInfo fw_cfg_mem_info = { .class_init = fw_cfg_mem_class_init, }; +static const TypeInfo fw_cfg_data_generator_interface_info = { + .parent = TYPE_INTERFACE, + .name = TYPE_FW_CFG_DATA_GENERATOR_INTERFACE, + .class_size = sizeof(FWCfgDataGeneratorClass), +}; static void fw_cfg_register_types(void) { type_register_static(&fw_cfg_info); type_register_static(&fw_cfg_io_info); type_register_static(&fw_cfg_mem_info); + type_register_static(&fw_cfg_data_generator_interface_info); } type_init(fw_cfg_register_types) diff --git a/include/crypto/tls-cipher-suites.h b/include/crypto/tls-cipher-suites.h new file mode 100644 index 0000000..28b3a73 --- /dev/null +++ b/include/crypto/tls-cipher-suites.h @@ -0,0 +1,39 @@ +/* + * QEMU TLS Cipher Suites Registry (RFC8447) + * + * Copyright (c) 2018-2020 Red Hat, Inc. + * + * Author: Philippe Mathieu-Daudé <philmd@redhat.com> + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#ifndef QCRYPTO_TLSCIPHERSUITES_H +#define QCRYPTO_TLSCIPHERSUITES_H + +#include "qom/object.h" +#include "crypto/tlscreds.h" + +#define TYPE_QCRYPTO_TLS_CIPHER_SUITES "tls-cipher-suites" +#define QCRYPTO_TLS_CIPHER_SUITES(obj) \ + OBJECT_CHECK(QCryptoTLSCipherSuites, (obj), TYPE_QCRYPTO_TLS_CIPHER_SUITES) + +typedef struct QCryptoTLSCipherSuites { + /* <private> */ + QCryptoTLSCreds parent_obj; + /* <public> */ +} QCryptoTLSCipherSuites; + +/** + * qcrypto_tls_cipher_suites_get_data: + * @obj: pointer to a TLS cipher suites object + * @errp: pointer to a NULL-initialized error object + * + * Returns: reference to a byte array containing the data. + * The caller should release the reference when no longer + * required. + */ +GByteArray *qcrypto_tls_cipher_suites_get_data(QCryptoTLSCipherSuites *obj, + Error **errp); + +#endif /* QCRYPTO_TLSCIPHERSUITES_H */ diff --git a/include/hw/nvram/fw_cfg.h b/include/hw/nvram/fw_cfg.h index 25d9307..11feae3 100644 --- a/include/hw/nvram/fw_cfg.h +++ b/include/hw/nvram/fw_cfg.h @@ -9,11 +9,36 @@ #define TYPE_FW_CFG "fw_cfg" #define TYPE_FW_CFG_IO "fw_cfg_io" #define TYPE_FW_CFG_MEM "fw_cfg_mem" +#define TYPE_FW_CFG_DATA_GENERATOR_INTERFACE "fw_cfg-data-generator" #define FW_CFG(obj) OBJECT_CHECK(FWCfgState, (obj), TYPE_FW_CFG) #define FW_CFG_IO(obj) OBJECT_CHECK(FWCfgIoState, (obj), TYPE_FW_CFG_IO) #define FW_CFG_MEM(obj) OBJECT_CHECK(FWCfgMemState, (obj), TYPE_FW_CFG_MEM) +#define FW_CFG_DATA_GENERATOR_CLASS(class) \ + OBJECT_CLASS_CHECK(FWCfgDataGeneratorClass, (class), \ + TYPE_FW_CFG_DATA_GENERATOR_INTERFACE) +#define FW_CFG_DATA_GENERATOR_GET_CLASS(obj) \ + OBJECT_GET_CLASS(FWCfgDataGeneratorClass, (obj), \ + TYPE_FW_CFG_DATA_GENERATOR_INTERFACE) + +typedef struct FWCfgDataGeneratorClass { + /*< private >*/ + InterfaceClass parent_class; + /*< public >*/ + + /** + * get_data: + * @obj: the object implementing this interface + * @errp: pointer to a NULL-initialized error object + * + * Returns: reference to a byte array containing the data. + * The caller should release the reference when no longer + * required. + */ + GByteArray *(*get_data)(Object *obj, Error **errp); +} FWCfgDataGeneratorClass; + typedef struct fw_cfg_file FWCfgFile; #define FW_CFG_ORDER_OVERRIDE_VGA 70 @@ -263,6 +288,24 @@ void fw_cfg_add_file_callback(FWCfgState *s, const char *filename, void *fw_cfg_modify_file(FWCfgState *s, const char *filename, void *data, size_t len); +/** + * fw_cfg_add_from_generator: + * @s: fw_cfg device being modified + * @filename: name of new fw_cfg file item + * @gen_id: name of object implementing FW_CFG_DATA_GENERATOR interface + * @errp: pointer to a NULL initialized error object + * + * Add a new NAMED fw_cfg item with the content generated from the + * @gen_id object. The data generated by the @gen_id object is copied + * into the data structure of the fw_cfg device. + * The next available (unused) selector key starting at FW_CFG_FILE_FIRST + * will be used; also, a new entry will be added to the file directory + * structure residing at key value FW_CFG_FILE_DIR, containing the item name, + * data size, and assigned selector key value. + */ +void fw_cfg_add_from_generator(FWCfgState *s, const char *filename, + const char *gen_id, Error **errp); + FWCfgState *fw_cfg_init_io_dma(uint32_t iobase, uint32_t dma_iobase, AddressSpace *dma_as); FWCfgState *fw_cfg_init_io(uint32_t iobase); diff --git a/qemu-options.hx b/qemu-options.hx index fa1b19d..c6edb40 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -4579,6 +4579,43 @@ SRST string as described at https://gnutls.org/manual/html_node/Priority-Strings.html. + ``-object tls-cipher-suites,id=id,priority=priority`` + Creates a TLS cipher suites object, which can be used to control + the TLS cipher/protocol algorithms that applications are permitted + to use. + + The ``id`` parameter is a unique ID which frontends will use to + access the ordered list of permitted TLS cipher suites from the + host. + + The ``priority`` parameter allows to override the global default + priority used by gnutls. This can be useful if the system + administrator needs to use a weaker set of crypto priorities for + QEMU without potentially forcing the weakness onto all + applications. Or conversely if one wants wants a stronger + default for QEMU than for all other applications, they can do + this through this parameter. Its format is a gnutls priority + string as described at + https://gnutls.org/manual/html_node/Priority-Strings.html. + + An example of use of this object is to control UEFI HTTPS Boot. + The tls-cipher-suites object exposes the ordered list of permitted + TLS cipher suites from the host side to the guest firmware, via + fw_cfg. The list is represented as an array of IANA_TLS_CIPHER + objects. The firmware uses the IANA_TLS_CIPHER array for configuring + guest-side TLS. + + In the following example, the priority at which the host-side policy + is retrieved is given by the ``priority`` property. + Given that QEMU uses GNUTLS, ``priority=@SYSTEM`` may be used to + refer to /etc/crypto-policies/back-ends/gnutls.config. + + .. parsed-literal:: + + # |qemu_system| \ + -object tls-cipher-suites,id=mysuite0,priority=@SYSTEM \ + -fw_cfg name=etc/edk2/https/ciphers,gen_id=mysuite0 + ``-object filter-buffer,id=id,netdev=netdevid,interval=t[,queue=all|rx|tx][,status=on|off][,position=head|tail|id=<id>][,insert=behind|before]`` Interval t can't be 0, this filter batches the packet delivery: all packets arriving in a given interval on netdev netdevid are diff --git a/softmmu/vl.c b/softmmu/vl.c index 3f58ffd..f3ff5d0 100644 --- a/softmmu/vl.c +++ b/softmmu/vl.c @@ -489,6 +489,11 @@ static QemuOptsList qemu_fw_cfg_opts = { .name = "string", .type = QEMU_OPT_STRING, .help = "Sets content of the blob to be inserted from a string", + }, { + .name = "gen_id", + .type = QEMU_OPT_STRING, + .help = "Sets id of the object generating the fw_cfg blob " + "to be inserted", }, { /* end of list */ } }, @@ -2020,7 +2025,7 @@ static int parse_fw_cfg(void *opaque, QemuOpts *opts, Error **errp) { gchar *buf; size_t size; - const char *name, *file, *str; + const char *name, *file, *str, *gen_id; FWCfgState *fw_cfg = (FWCfgState *) opaque; if (fw_cfg == NULL) { @@ -2030,14 +2035,13 @@ static int parse_fw_cfg(void *opaque, QemuOpts *opts, Error **errp) name = qemu_opt_get(opts, "name"); file = qemu_opt_get(opts, "file"); str = qemu_opt_get(opts, "string"); + gen_id = qemu_opt_get(opts, "gen_id"); - /* we need name and either a file or the content string */ - if (!(nonempty_str(name) && (nonempty_str(file) || nonempty_str(str)))) { - error_setg(errp, "invalid argument(s)"); - return -1; - } - if (nonempty_str(file) && nonempty_str(str)) { - error_setg(errp, "file and string are mutually exclusive"); + /* we need the name, and exactly one of: file, content string, gen_id */ + if (!nonempty_str(name) || + nonempty_str(file) + nonempty_str(str) + nonempty_str(gen_id) != 1) { + error_setg(errp, "name, plus exactly one of file," + " string and gen_id, are needed"); return -1; } if (strlen(name) > FW_CFG_MAX_FILE_PATH - 1) { @@ -2045,13 +2049,28 @@ static int parse_fw_cfg(void *opaque, QemuOpts *opts, Error **errp) FW_CFG_MAX_FILE_PATH - 1); return -1; } - if (strncmp(name, "opt/", 4) != 0) { + if (nonempty_str(gen_id)) { + /* + * In this particular case where the content is populated + * internally, the "etc/" namespace protection is relaxed, + * so do not emit a warning. + */ + } else if (strncmp(name, "opt/", 4) != 0) { warn_report("externally provided fw_cfg item names " "should be prefixed with \"opt/\""); } if (nonempty_str(str)) { size = strlen(str); /* NUL terminator NOT included in fw_cfg blob */ buf = g_memdup(str, size); + } else if (nonempty_str(gen_id)) { + Error *local_err = NULL; + + fw_cfg_add_from_generator(fw_cfg, name, gen_id, errp); + if (local_err) { + error_propagate(errp, local_err); + return -1; + } + return 0; } else { GError *err = NULL; if (!g_file_get_contents(file, &buf, &size, &err)) { |