=pod =head1 NAME provider-base - The basic OpenSSL library E-E provider functions =head1 SYNOPSIS #include /* * None of these are actual functions, but are displayed like this for * the function signatures for functions that are offered as function * pointers in OSSL_DISPATCH arrays. */ /* Functions offered by libcrypto to the providers */ const OSSL_ITEM *core_gettable_params(const OSSL_CORE_HANDLE *handle); int core_get_params(const OSSL_CORE_HANDLE *handle, OSSL_PARAM params[]); int core_thread_start(const OSSL_CORE_HANDLE *handle, OSSL_thread_stop_handler_fn handfn); OPENSSL_CORE_CTX *core_get_library_context(const OSSL_CORE_HANDLE *handle); void core_new_error(const OSSL_CORE_HANDLE *handle); void core_set_error_debug(const OSSL_CORE_HANDLE *handle, const char *file, int line, const char *func); void core_vset_error(const OSSL_CORE_HANDLE *handle, uint32_t reason, const char *fmt, va_list args); /* * Some OpenSSL functionality is directly offered to providers via * dispatch */ void *CRYPTO_malloc(size_t num, const char *file, int line); void *CRYPTO_zalloc(size_t num, const char *file, int line); void *CRYPTO_memdup(const void *str, size_t siz, const char *file, int line); char *CRYPTO_strdup(const char *str, const char *file, int line); char *CRYPTO_strndup(const char *str, size_t s, const char *file, int line); void CRYPTO_free(void *ptr, const char *file, int line); void CRYPTO_clear_free(void *ptr, size_t num, const char *file, int line); void *CRYPTO_realloc(void *addr, size_t num, const char *file, int line); void *CRYPTO_clear_realloc(void *addr, size_t old_num, size_t num, const char *file, int line); void *CRYPTO_secure_malloc(size_t num, const char *file, int line); void *CRYPTO_secure_zalloc(size_t num, const char *file, int line); void CRYPTO_secure_free(void *ptr, const char *file, int line); void CRYPTO_secure_clear_free(void *ptr, size_t num, const char *file, int line); int CRYPTO_secure_allocated(const void *ptr); void OPENSSL_cleanse(void *ptr, size_t len); OSSL_CORE_BIO * BIO_new_file(const char *filename, const char *mode) OSSL_CORE_BIO * BIO_new_membuf(const void *buf, int len) int BIO_read_ex(OSSL_CORE_BIO *bio, void *data, size_t data_len, size_t *bytes_read)) int BIO_write_ex(OSSL_CORE_BIO *bio, const void *data, size_t data_len, size_t *written) int BIO_free(OSSL_CORE_BIO *bio)) int BIO_vprintf(OSSL_CORE_BIO *bio, const char *format, va_list args) int BIO_vsnprintf(char *buf, size_t n, const char *fmt, va_list args) void self_test_cb(OPENSSL_CORE_CTX *ctx, OSSL_CALLBACK **cb, void **cbarg) /* Functions offered by the provider to libcrypto */ void provider_teardown(void *provctx); const OSSL_ITEM *provider_gettable_params(void *provctx); int provider_get_params(void *provctx, OSSL_PARAM params[]); const OSSL_ALGORITHM *provider_query_operation(void *provctx, int operation_id, const int *no_store); const OSSL_ITEM *provider_get_reason_strings(void *provctx); =head1 DESCRIPTION All "functions" mentioned here are passed as function pointers between F and the provider in B arrays, in the call of the provider initialization function. See L for a description of the initialization function. All these "functions" have a corresponding function type definition named B, and a helper function to retrieve the function pointer from a B element named B. For example, the "function" core_gettable_params() has these: typedef OSSL_PARAM * (OSSL_core_gettable_params_fn)(const OSSL_CORE_HANDLE *handle); static ossl_inline OSSL_NAME_core_gettable_params_fn OSSL_get_core_gettable_params(const OSSL_DISPATCH *opf); B arrays are indexed by numbers that are provided as macros in L, as follows: For I (the B array passed from F to the provider): core_gettable_params OSSL_FUNC_CORE_GETTABLE_PARAMS core_get_params OSSL_FUNC_CORE_GET_PARAMS core_thread_start OSSL_FUNC_CORE_THREAD_START core_get_library_context OSSL_FUNC_CORE_GET_LIBRARY_CONTEXT core_new_error OSSL_FUNC_CORE_NEW_ERROR core_set_error_debug OSSL_FUNC_CORE_SET_ERROR_DEBUG core_set_error OSSL_FUNC_CORE_SET_ERROR CRYPTO_malloc OSSL_FUNC_CRYPTO_MALLOC CRYPTO_zalloc OSSL_FUNC_CRYPTO_ZALLOC CRYPTO_memdup OSSL_FUNC_CRYPTO_MEMDUP CRYPTO_strdup OSSL_FUNC_CRYPTO_STRDUP CRYPTO_strndup OSSL_FUNC_CRYPTO_STRNDUP CRYPTO_free OSSL_FUNC_CRYPTO_FREE CRYPTO_clear_free OSSL_FUNC_CRYPTO_CLEAR_FREE CRYPTO_realloc OSSL_FUNC_CRYPTO_REALLOC CRYPTO_clear_realloc OSSL_FUNC_CRYPTO_CLEAR_REALLOC CRYPTO_secure_malloc OSSL_FUNC_CRYPTO_SECURE_MALLOC CRYPTO_secure_zalloc OSSL_FUNC_CRYPTO_SECURE_ZALLOC CRYPTO_secure_free OSSL_FUNC_CRYPTO_SECURE_FREE CRYPTO_secure_clear_free OSSL_FUNC_CRYPTO_SECURE_CLEAR_FREE CRYPTO_secure_allocated OSSL_FUNC_CRYPTO_SECURE_ALLOCATED BIO_new_file OSSL_FUNC_BIO_NEW_FILE BIO_new_mem_buf OSSL_FUNC_BIO_NEW_MEMBUF BIO_read_ex OSSL_FUNC_BIO_READ_EX BIO_free OSSL_FUNC_BIO_FREE BIO_vprintf OSSL_FUNC_BIO_VPRINTF OPENSSL_cleanse OSSL_FUNC_OPENSSL_CLEANSE OSSL_SELF_TEST_set_callback OSSL_FUNC_SELF_TEST_CB For I<*out> (the B array passed from the provider to F): provider_teardown OSSL_FUNC_PROVIDER_TEARDOWN provider_gettable_params OSSL_FUNC_PROVIDER_GETTABLE_PARAMS provider_get_params OSSL_FUNC_PROVIDER_GET_PARAMS provider_query_operation OSSL_FUNC_PROVIDER_QUERY_OPERATION provider_get_reason_strings OSSL_FUNC_PROVIDER_GET_REASON_STRINGS =head2 Core functions core_gettable_params() returns a constant array of descriptor B, for parameters that core_get_params() can handle. core_get_params() retrieves parameters from the core for the given I. See L below for a description of currently known parameters. =for comment core_thread_start() TBA core_get_library_context() retrieves the library context in which the library object for the current provider is stored, accessible through the I. This may sometimes be useful if the provider wishes to store a reference to its context in the same library context. core_new_error(), core_set_error_debug() and core_set_error() are building blocks for reporting an error back to the core, with reference to the I. =over 4 =item core_new_error() allocates a new thread specific error record. This corresponds to the OpenSSL function L. =item core_set_error_debug() sets debugging information in the current thread specific error record. The debugging information includes the name of the file I, the line I and the function name I where the error occurred. This corresponds to the OpenSSL function L. =item core_set_error() sets the I for the error, along with any addition data. The I is a number defined by the provider and used to index the reason strings table that's returned by provider_get_reason_strings(). The additional data is given as a format string I and a set of arguments I, which are treated in the same manner as with BIO_vsnprintf(). I and I may also be passed to indicate exactly where the error occurred or was reported. This corresponds to the OpenSSL function L. =back CRYPTO_malloc(), CRYPTO_zalloc(), CRYPTO_memdup(), CRYPTO_strdup(), CRYPTO_strndup(), CRYPTO_free(), CRYPTO_clear_free(), CRYPTO_realloc(), CRYPTO_clear_realloc(), CRYPTO_secure_malloc(), CRYPTO_secure_zalloc(), CRYPTO_secure_free(), CRYPTO_secure_clear_free(), CRYPTO_secure_allocated(), BIO_new_file(), BIO_new_mem_buf(), BIO_read_ex(), BIO_free(), BIO_vprintf(), OPENSSL_cleanse(), and OPENSSL_hexstr2buf() correspond exactly to the public functions with the same name. As a matter of fact, the pointers in the B array are direct pointers to those public functions. Note that the BIO functions take an B type rather than the standard B type. This is to ensure that a provider does not mix BIOs from the core with BIOs used on the provider side (the two are not compatible). OSSL_SELF_TEST_set_callback() is used to set an optional callback that can be passed into a provider. This may be ignored by a provider. =head2 Provider functions provider_teardown() is called when a provider is shut down and removed from the core's provider store. It must free the passed I. provider_gettable_params() should return a constant array of descriptor B, for parameters that provider_get_params() can handle. provider_get_params() should process the B array I, setting the values of the parameters it understands. provider_query_operation() should return a constant B that corresponds to the given I. It should indicate if the core may store a reference to this array by setting I<*no_store> to 0 (core may store a reference) or 1 (core may not store a reference). provider_get_reason_strings() should return a constant B array that provides reason strings for reason codes the provider may use when reporting errors using core_put_error(). None of these functions are mandatory, but a provider is fairly useless without at least provider_query_operation(), and provider_gettable_params() is fairly useless if not accompanied by provider_get_params(). =head2 Provider parameters provider_get_params() can return the following provider parameters to the core: =over 4 =item "name" (B) This points to a string that should give a unique name for the provider. =item "version" (B) This points to a string that is a version number associated with this provider. OpenSSL in-built providers use OPENSSL_VERSION_STR, but this may be different for any third party provider. This string is for informational purposes only. =item "buildinfo" (B) This points to a string that is a build information associated with this provider. OpenSSL in-built providers use OPENSSL_FULL_VERSION_STR, but this may be different for any third party provider. =back provider_gettable_params() should return the above parameters. =head2 Core parameters core_get_params() can retrieve the following core parameters for each provider: =over 4 =item "openssl-version" (B) This points to the OpenSSL libraries' full version string, i.e. the string expanded from the macro B. =item "provider-name" (B) This points to the OpenSSL libraries' idea of what the calling provider is named. =item "module-filename" (B) This points to a string containing the full filename of the providers module file. =back Additionally, provider specific configuration parameters from the config file are available, in dotted name form. The dotted name form is a concatenation of section names and final config command name separated by periods. For example, let's say we have the following config example: openssl_conf = openssl_init [openssl_init] providers = providers_sect [providers_sect] foo = foo_sect [foo_sect] activate = 1 data1 = 2 data2 = str more = foo_more [foo_more] data3 = foo,bar The provider will have these additional parameters available: =over 4 =item "activate" pointing at the string "1" =item "data1" pointing at the string "2" =item "data2" pointing at the string "str" =item "more.data3" pointing at the string "foo,bar" =back For more information on handling parameters, see L as L. =head1 EXAMPLES This is an example of a simple provider made available as a dynamically loadable module. It implements the fictitious algorithm C for the fictitious operation C. #include #include #include /* Errors used in this provider */ #define E_MALLOC 1 static const OSSL_ITEM reasons[] = { { E_MALLOC, "memory allocation failure" }. { 0, NULL } /* Termination */ }; /* * To ensure we get the function signature right, forward declare * them using function types provided by openssl/core_numbers.h */ OSSL_OP_bar_newctx_fn foo_newctx; OSSL_OP_bar_freectx_fn foo_freectx; OSSL_OP_bar_init_fn foo_init; OSSL_OP_bar_update_fn foo_update; OSSL_OP_bar_final_fn foo_final; OSSL_provider_query_operation_fn p_query; OSSL_provider_get_reason_strings_fn p_reasons; OSSL_provider_teardown_fn p_teardown; OSSL_provider_init_fn OSSL_provider_init; OSSL_core_put_error *c_put_error = NULL; /* Provider context */ struct prov_ctx_st { OSSL_CORE_HANDLE *handle; } /* operation context for the algorithm FOO */ struct foo_ctx_st { struct prov_ctx_st *provctx; int b; }; static void *foo_newctx(void *provctx) { struct foo_ctx_st *fooctx = malloc(sizeof(*fooctx)); if (fooctx != NULL) fooctx->provctx = provctx; else c_put_error(provctx->handle, E_MALLOC, __FILE__, __LINE__); return fooctx; } static void foo_freectx(void *fooctx) { free(fooctx); } static int foo_init(void *vfooctx) { struct foo_ctx_st *fooctx = vfooctx; fooctx->b = 0x33; } static int foo_update(void *vfooctx, unsigned char *in, size_t inl) { struct foo_ctx_st *fooctx = vfooctx; /* did you expect something serious? */ if (inl == 0) return 1; for (; inl-- > 0; in++) *in ^= fooctx->b; return 1; } static int foo_final(void *vfooctx) { struct foo_ctx_st *fooctx = vfooctx; fooctx->b = 0x66; } static const OSSL_DISPATCH foo_fns[] = { { OSSL_FUNC_BAR_NEWCTX, (void (*)(void))foo_newctx }, { OSSL_FUNC_BAR_FREECTX, (void (*)(void))foo_freectx }, { OSSL_FUNC_BAR_INIT, (void (*)(void))foo_init }, { OSSL_FUNC_BAR_UPDATE, (void (*)(void))foo_update }, { OSSL_FUNC_BAR_FINAL, (void (*)(void))foo_final }, { 0, NULL } }; static const OSSL_ALGORITHM bars[] = { { "FOO", "provider=chumbawamba", foo_fns }, { NULL, NULL, NULL } }; static const OSSL_ALGORITHM *p_query(void *provctx, int operation_id, int *no_store) { switch (operation_id) { case OSSL_OP_BAR: return bars; } return NULL; } static const OSSL_ITEM *p_reasons(void *provctx) { return reasons; } static void p_teardown(void *provctx) { free(provctx); } static const OSSL_DISPATCH prov_fns[] = { { OSSL_FUNC_PROVIDER_TEARDOWN, (void (*)(void))p_teardown }, { OSSL_FUNC_PROVIDER_QUERY_OPERATION, (void (*)(void))p_query }, { OSSL_FUNC_PROVIDER_GET_REASON_STRINGS, (void (*)(void))p_reasons }, { 0, NULL } }; int OSSL_provider_init(const OSSL_CORE_HANDLE *handle, const OSSL_DISPATCH *in, const OSSL_DISPATCH **out, void **provctx) { struct prov_ctx_st *pctx = NULL; for (; in->function_id != 0; in++) switch (in->function_id) { case OSSL_FUNC_CORE_PUT_ERROR: c_put_error = OSSL_get_core_put_error(in); break; } *out = prov_fns; if ((pctx = malloc(sizeof(*pctx))) == NULL) { /* * ALEA IACTA EST, if the core retrieves the reason table * regardless, that string will be displayed, otherwise not. */ c_put_error(handle, E_MALLOC, __FILE__, __LINE__); return 0; } pctx->handle = handle; return 1; } This relies on a few things existing in F: #define OSSL_OP_BAR 4711 #define OSSL_FUNC_BAR_NEWCTX 1 typedef void *(OSSL_OP_bar_newctx_fn)(void *provctx); static ossl_inline OSSL_get_bar_newctx(const OSSL_DISPATCH *opf) { return (OSSL_OP_bar_newctx_fn *)opf->function; } #define OSSL_FUNC_BAR_FREECTX 2 typedef void (OSSL_OP_bar_freectx_fn)(void *ctx); static ossl_inline OSSL_get_bar_newctx(const OSSL_DISPATCH *opf) { return (OSSL_OP_bar_freectx_fn *)opf->function; } #define OSSL_FUNC_BAR_INIT 3 typedef void *(OSSL_OP_bar_init_fn)(void *ctx); static ossl_inline OSSL_get_bar_init(const OSSL_DISPATCH *opf) { return (OSSL_OP_bar_init_fn *)opf->function; } #define OSSL_FUNC_BAR_UPDATE 4 typedef void *(OSSL_OP_bar_update_fn)(void *ctx, unsigned char *in, size_t inl); static ossl_inline OSSL_get_bar_update(const OSSL_DISPATCH *opf) { return (OSSL_OP_bar_update_fn *)opf->function; } #define OSSL_FUNC_BAR_FINAL 5 typedef void *(OSSL_OP_bar_final_fn)(void *ctx); static ossl_inline OSSL_get_bar_final(const OSSL_DISPATCH *opf) { return (OSSL_OP_bar_final_fn *)opf->function; } =head1 SEE ALSO L =head1 HISTORY The concept of providers and everything surrounding them was introduced in OpenSSL 3.0. =head1 COPYRIGHT Copyright 2019-2020 The OpenSSL Project Authors. All Rights Reserved. Licensed under the Apache License 2.0 (the "License"). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at L. =cut