Add the STORE module

This STORE module adds the following functionality:

- A function OSSL_STORE_open(), OSSL_STORE_load() and OSSL_STORE_close()
  that accesses a URI and helps loading the supported objects (PKEYs,
  CERTs and CRLs for the moment) from it.
- An opaque type OSSL_STORE_INFO that holds information on each loaded
  object.
- A few functions to retrieve desired data from a OSSL_STORE_INFO
  reference.
- Functions to register and unregister loaders for different URI
  schemes.  This enables dynamic addition of loaders from applications
  or from engines.

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3542)

4 files changed, 267 insertions, 2 deletions

diff --git a/include/openssl/err.h b/include/openssl/err.h
index 4020f4224b..9b807b4b01 100644
--- a/include/openssl/err.h
+++ b/include/openssl/err.h
@@ -84,7 +84,7 @@ typedef struct err_state_st {
 # define ERR_LIB_COMP            41
 # define ERR_LIB_ECDSA           42
 # define ERR_LIB_ECDH            43
-# define ERR_LIB_STORE           44
+# define ERR_LIB_OSSL_STORE      44
 # define ERR_LIB_FIPS            45
 # define ERR_LIB_CMS             46
 # define ERR_LIB_TS              47
@@ -123,7 +123,7 @@ typedef struct err_state_st {
 # define COMPerr(f,r) ERR_PUT_error(ERR_LIB_COMP,(f),(r),OPENSSL_FILE,OPENSSL_LINE)
 # define ECDSAerr(f,r)  ERR_PUT_error(ERR_LIB_ECDSA,(f),(r),OPENSSL_FILE,OPENSSL_LINE)
 # define ECDHerr(f,r)  ERR_PUT_error(ERR_LIB_ECDH,(f),(r),OPENSSL_FILE,OPENSSL_LINE)
-# define STOREerr(f,r) ERR_PUT_error(ERR_LIB_STORE,(f),(r),OPENSSL_FILE,OPENSSL_LINE)
+# define OSSL_STOREerr(f,r) ERR_PUT_error(ERR_LIB_OSSL_STORE,(f),(r),OPENSSL_FILE,OPENSSL_LINE)
 # define FIPSerr(f,r) ERR_PUT_error(ERR_LIB_FIPS,(f),(r),OPENSSL_FILE,OPENSSL_LINE)
 # define CMSerr(f,r) ERR_PUT_error(ERR_LIB_CMS,(f),(r),OPENSSL_FILE,OPENSSL_LINE)
 # define TSerr(f,r) ERR_PUT_error(ERR_LIB_TS,(f),(r),OPENSSL_FILE,OPENSSL_LINE)
@@ -131,6 +131,7 @@ typedef struct err_state_st {
 # define CTerr(f,r) ERR_PUT_error(ERR_LIB_CT,(f),(r),OPENSSL_FILE,OPENSSL_LINE)
 # define ASYNCerr(f,r) ERR_PUT_error(ERR_LIB_ASYNC,(f),(r),OPENSSL_FILE,OPENSSL_LINE)
 # define KDFerr(f,r) ERR_PUT_error(ERR_LIB_KDF,(f),(r),OPENSSL_FILE,OPENSSL_LINE)
+# define OSSL_STOREerr(f,r) ERR_PUT_error(ERR_LIB_OSSL_STORE,(f),(r),OPENSSL_FILE,OPENSSL_LINE)
 
 # define ERR_PACK(l,f,r) ( \
         (((unsigned int)(l) & 0x0FF) << 24L) | \
@@ -183,6 +184,7 @@ typedef struct err_state_st {
 # define ERR_R_ENGINE_LIB ERR_LIB_ENGINE/* 38 */
 # define ERR_R_UI_LIB    ERR_LIB_UI/* 40 */
 # define ERR_R_ECDSA_LIB ERR_LIB_ECDSA/* 42 */
+# define ERR_R_OSSL_STORE_LIB ERR_LIB_OSSL_STORE/* 44 */
 
 # define ERR_R_NESTED_ASN1_ERROR                 58
 # define ERR_R_MISSING_ASN1_EOS                  63
diff --git a/include/openssl/ossl_typ.h b/include/openssl/ossl_typ.h
index deea03899a..173a42d3ff 100644
--- a/include/openssl/ossl_typ.h
+++ b/include/openssl/ossl_typ.h
@@ -171,6 +171,8 @@ typedef struct ctlog_st CTLOG;
 typedef struct ctlog_store_st CTLOG_STORE;
 typedef struct ct_policy_eval_ctx_st CT_POLICY_EVAL_CTX;
 
+typedef struct ossl_store_info_st OSSL_STORE_INFO;
+
 #if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L && \
     defined(INTMAX_MAX) && defined(UINTMAX_MAX)
 typedef intmax_t ossl_intmax_t;
diff --git a/include/openssl/store.h b/include/openssl/store.h
new file mode 100644
index 0000000000..35f62ec9d3
--- /dev/null
+++ b/include/openssl/store.h
@@ -0,0 +1,205 @@
+/*
+ * Copyright 2016-2017 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the OpenSSL license (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
+ * https://www.openssl.org/source/license.html
+ */
+
+#ifndef HEADER_OSSL_STORE_H
+# define HEADER_OSSL_STORE_H
+
+# include <stdarg.h>
+# include <openssl/ossl_typ.h>
+# include <openssl/pem.h>
+# include <openssl/storeerr.h>
+
+# ifdef  __cplusplus
+extern "C" {
+# endif
+
+/*-
+ *  The main OSSL_STORE functions.
+ *  ------------------------------
+ *
+ *  These allow applications to open a channel to a resource with supported
+ *  data (keys, certs, crls, ...), read the data a piece at a time and decide
+ *  what to do with it, and finally close.
+ */
+
+typedef struct ossl_store_ctx_st OSSL_STORE_CTX;
+
+/*
+ * Typedef for the OSSL_STORE_INFO post processing callback.  This can be used
+ * to massage the given OSSL_STORE_INFO, or to drop it entirely (by returning
+ * NULL).
+ */
+typedef OSSL_STORE_INFO *(*OSSL_STORE_post_process_info_fn)(OSSL_STORE_INFO *,
+                                                            void *);
+
+/*
+ * Open a channel given a URI.  The given UI method will be used any time the
+ * loader needs extra input, for example when a password or pin is needed, and
+ * will be passed the same user data every time it's needed in this context.
+ *
+ * Returns a context reference which represents the channel to communicate
+ * through.
+ */
+OSSL_STORE_CTX *OSSL_STORE_open(const char *uri, const UI_METHOD *ui_method,
+                                void *ui_data,
+                                OSSL_STORE_post_process_info_fn post_process,
+                                void *post_process_data);
+
+/*
+ * Control / fine tune the OSSL_STORE channel.  |cmd| determines what is to be
+ * done, and depends on the underlying loader (use OSSL_STORE_get0_scheme to
+ * determine which loader is used), except for common commands (see below).
+ * Each command takes different arguments.
+ */
+int OSSL_STORE_ctrl(OSSL_STORE_CTX *ctx, int cmd, ... /* args */);
+
+/*
+ * Common ctrl commands that different loaders may choose to support.
+ */
+/* Where custom commands start */
+# define OSSL_STORE_C_CUSTOM_START    100
+
+/*
+ * Read one data item (a key, a cert, a CRL) that is supported by the OSSL_STORE
+ * functionality, given a context.
+ * Returns a OSSL_STORE_INFO pointer, from which OpenSSL typed data can be
+ * extracted with OSSL_STORE_INFO_get0_PKEY(), OSSL_STORE_INFO_get0_CERT(), ...
+ * NULL is returned on error, which may include that the data found at the URI
+ * can't be figured out for certain or is ambiguous.
+ */
+OSSL_STORE_INFO *OSSL_STORE_load(OSSL_STORE_CTX *ctx);
+
+/*
+ * Check if end of data (end of file) is reached
+ * Returns 1 on end, 0 otherwise.
+ */
+int OSSL_STORE_eof(OSSL_STORE_CTX *ctx);
+
+/*
+ * Check if an error occured
+ * Returns 1 if it did, 0 otherwise.
+ */
+int OSSL_STORE_error(OSSL_STORE_CTX *ctx);
+
+/*
+ * Close the channel
+ * Returns 1 on success, 0 on error.
+ */
+int OSSL_STORE_close(OSSL_STORE_CTX *ctx);
+
+
+/*-
+ *  Extracting OpenSSL types from and creating new OSSL_STORE_INFOs
+ *  ---------------------------------------------------------------
+ */
+
+/*
+ * Types of data that can be ossl_stored in a OSSL_STORE_INFO.
+ * OSSL_STORE_INFO_NAME is typically found when getting a listing of
+ * available "files" / "tokens" / what have you.
+ */
+# define OSSL_STORE_INFO_NAME           1   /* char * */
+# define OSSL_STORE_INFO_PARAMS         2   /* EVP_PKEY * */
+# define OSSL_STORE_INFO_PKEY           3   /* EVP_PKEY * */
+# define OSSL_STORE_INFO_CERT           4   /* X509 * */
+# define OSSL_STORE_INFO_CRL            5   /* X509_CRL * */
+
+/*
+ * Functions to generate OSSL_STORE_INFOs, one function for each type we
+ * support having in them.  Along with each of them, one macro that
+ * can be used to determine what types are supported.
+ *
+ * In all cases, ownership of the object is transfered to the OSSL_STORE_INFO
+ * and will therefore be freed when the OSSL_STORE_INFO is freed.
+ */
+OSSL_STORE_INFO *OSSL_STORE_INFO_new_NAME(char *name);
+int OSSL_STORE_INFO_set0_NAME_description(OSSL_STORE_INFO *info, char *desc);
+OSSL_STORE_INFO *OSSL_STORE_INFO_new_PARAMS(EVP_PKEY *params);
+OSSL_STORE_INFO *OSSL_STORE_INFO_new_PKEY(EVP_PKEY *pkey);
+OSSL_STORE_INFO *OSSL_STORE_INFO_new_CERT(X509 *x509);
+OSSL_STORE_INFO *OSSL_STORE_INFO_new_CRL(X509_CRL *crl);
+
+/*
+ * Functions to try to extract data from a OSSL_STORE_INFO.
+ */
+int OSSL_STORE_INFO_get_type(const OSSL_STORE_INFO *info);
+const char *OSSL_STORE_INFO_get0_NAME(const OSSL_STORE_INFO *info);
+char *OSSL_STORE_INFO_get1_NAME(const OSSL_STORE_INFO *info);
+const char *OSSL_STORE_INFO_get0_NAME_description(const OSSL_STORE_INFO *info);
+char *OSSL_STORE_INFO_get1_NAME_description(const OSSL_STORE_INFO *info);
+EVP_PKEY *OSSL_STORE_INFO_get0_PARAMS(const OSSL_STORE_INFO *info);
+EVP_PKEY *OSSL_STORE_INFO_get1_PARAMS(const OSSL_STORE_INFO *info);
+EVP_PKEY *OSSL_STORE_INFO_get0_PKEY(const OSSL_STORE_INFO *info);
+EVP_PKEY *OSSL_STORE_INFO_get1_PKEY(const OSSL_STORE_INFO *info);
+X509 *OSSL_STORE_INFO_get0_CERT(const OSSL_STORE_INFO *info);
+X509 *OSSL_STORE_INFO_get1_CERT(const OSSL_STORE_INFO *info);
+X509_CRL *OSSL_STORE_INFO_get0_CRL(const OSSL_STORE_INFO *info);
+X509_CRL *OSSL_STORE_INFO_get1_CRL(const OSSL_STORE_INFO *info);
+
+const char *OSSL_STORE_INFO_type_string(int type);
+
+/*
+ * Free the OSSL_STORE_INFO
+ */
+void OSSL_STORE_INFO_free(OSSL_STORE_INFO *info);
+
+
+/*-
+ *  Function to register a loader for the given URI scheme.
+ *  -------------------------------------------------------
+ *
+ *  The loader receives all the main components of an URI except for the
+ *  scheme.
+ */
+
+typedef struct ossl_store_loader_st OSSL_STORE_LOADER;
+OSSL_STORE_LOADER *OSSL_STORE_LOADER_new(const char *scheme);
+const char *OSSL_STORE_LOADER_get0_scheme(const OSSL_STORE_LOADER *loader);
+/* struct ossl_store_loader_ctx_st is defined differently by each loader */
+typedef struct ossl_store_loader_ctx_st OSSL_STORE_LOADER_CTX;
+typedef OSSL_STORE_LOADER_CTX *(*OSSL_STORE_open_fn)(const OSSL_STORE_LOADER
+                                                     *loader,
+                                                     const char *uri,
+                                                     const UI_METHOD *ui_method,
+                                                     void *ui_data);
+int OSSL_STORE_LOADER_set_open(OSSL_STORE_LOADER *loader,
+                               OSSL_STORE_open_fn open_function);
+typedef int (*OSSL_STORE_ctrl_fn)(OSSL_STORE_LOADER_CTX *ctx, int cmd,
+                                  va_list args);
+int OSSL_STORE_LOADER_set_ctrl(OSSL_STORE_LOADER *loader,
+                               OSSL_STORE_ctrl_fn ctrl_function);
+typedef OSSL_STORE_INFO *(*OSSL_STORE_load_fn)(OSSL_STORE_LOADER_CTX *ctx,
+                                               const UI_METHOD *ui_method,
+                                               void *ui_data);
+int OSSL_STORE_LOADER_set_load(OSSL_STORE_LOADER *loader,
+                               OSSL_STORE_load_fn load_function);
+typedef int (*OSSL_STORE_eof_fn)(OSSL_STORE_LOADER_CTX *ctx);
+int OSSL_STORE_LOADER_set_eof(OSSL_STORE_LOADER *loader,
+                              OSSL_STORE_eof_fn eof_function);
+typedef int (*OSSL_STORE_error_fn)(OSSL_STORE_LOADER_CTX *ctx);
+int OSSL_STORE_LOADER_set_error(OSSL_STORE_LOADER *loader,
+                                OSSL_STORE_error_fn error_function);
+typedef int (*OSSL_STORE_close_fn)(OSSL_STORE_LOADER_CTX *ctx);
+int OSSL_STORE_LOADER_set_close(OSSL_STORE_LOADER *loader,
+                                OSSL_STORE_close_fn close_function);
+void OSSL_STORE_LOADER_free(OSSL_STORE_LOADER *loader);
+
+int OSSL_STORE_register_loader(OSSL_STORE_LOADER *loader);
+OSSL_STORE_LOADER *OSSL_STORE_unregister_loader(const char *scheme);
+
+
+/*
+ * Error strings
+ */
+int ERR_load_OSSL_STORE_strings(void);
+
+# ifdef  __cplusplus
+}
+# endif
+#endif
diff --git a/include/openssl/storeerr.h b/include/openssl/storeerr.h
new file mode 100644
index 0000000000..1fca2db1ef
--- /dev/null
+++ b/include/openssl/storeerr.h
@@ -0,0 +1,56 @@
+/*
+ * Generated by util/mkerr.pl DO NOT EDIT
+ * Copyright 1995-2017 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the OpenSSL license (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
+ * https://www.openssl.org/source/license.html
+ */
+
+#ifndef HEADER_OSSL_STOREERR_H
+# define HEADER_OSSL_STOREERR_H
+
+# ifdef  __cplusplus
+extern "C" {
+# endif
+int ERR_load_OSSL_STORE_strings(void);
+# ifdef  __cplusplus
+}
+# endif
+
+/*
+ * OSSL_STORE function codes.
+ */
+# define OSSL_STORE_F_OSSL_STORE_GET0_LOADER_INT          100
+# define OSSL_STORE_F_OSSL_STORE_INFO_GET1_CERT           101
+# define OSSL_STORE_F_OSSL_STORE_INFO_GET1_CRL            102
+# define OSSL_STORE_F_OSSL_STORE_INFO_GET1_NAME           103
+# define OSSL_STORE_F_OSSL_STORE_INFO_GET1_NAME_DESCRIPTION 135
+# define OSSL_STORE_F_OSSL_STORE_INFO_GET1_PARAMS         104
+# define OSSL_STORE_F_OSSL_STORE_INFO_GET1_PKEY           105
+# define OSSL_STORE_F_OSSL_STORE_INFO_NEW_CERT            106
+# define OSSL_STORE_F_OSSL_STORE_INFO_NEW_CRL             107
+# define OSSL_STORE_F_OSSL_STORE_INFO_NEW_NAME            109
+# define OSSL_STORE_F_OSSL_STORE_INFO_NEW_PARAMS          110
+# define OSSL_STORE_F_OSSL_STORE_INFO_NEW_PKEY            111
+# define OSSL_STORE_F_OSSL_STORE_INFO_SET0_NAME_DESCRIPTION 134
+# define OSSL_STORE_F_OSSL_STORE_INIT_ONCE                112
+# define OSSL_STORE_F_OSSL_STORE_LOADER_NEW               113
+# define OSSL_STORE_F_OSSL_STORE_OPEN                     114
+# define OSSL_STORE_F_OSSL_STORE_OPEN_INT                 115
+# define OSSL_STORE_F_OSSL_STORE_REGISTER_LOADER_INT      117
+# define OSSL_STORE_F_OSSL_STORE_UNREGISTER_LOADER_INT    116
+
+/*
+ * OSSL_STORE reason codes.
+ */
+# define OSSL_STORE_R_INVALID_SCHEME                      106
+# define OSSL_STORE_R_NOT_A_CERTIFICATE                   100
+# define OSSL_STORE_R_NOT_A_CRL                           101
+# define OSSL_STORE_R_NOT_A_KEY                           102
+# define OSSL_STORE_R_NOT_A_NAME                          103
+# define OSSL_STORE_R_NOT_PARAMETERS                      104
+# define OSSL_STORE_R_UNREGISTERED_SCHEME                 105
+
+#endif