_ Git - BearSSL/blob - inc/bearssl_pem.h

   1 /*
   2  * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining
   5  * a copy of this software and associated documentation files (the
   6  * "Software"), to deal in the Software without restriction, including
   7  * without limitation the rights to use, copy, modify, merge, publish,
   8  * distribute, sublicense, and/or sell copies of the Software, and to
   9  * permit persons to whom the Software is furnished to do so, subject to
  10  * the following conditions:
  11  *
  12  * The above copyright notice and this permission notice shall be
  13  * included in all copies or substantial portions of the Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  16  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  18  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  19  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  20  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  21  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  22  * SOFTWARE.
  23  */
  24
  25 #ifndef BR_BEARSSL_PEM_H__
  26 #define BR_BEARSSL_PEM_H__
  27
  28 #include <stddef.h>
  29 #include <stdint.h>
  30
  31 /*
  32  * Context for a PEM decoder.
  33  */
  34 typedef struct {
  35         /* CPU for the T0 virtual machine. */
  36         struct {
  37                 uint32_t *dp;
  38                 uint32_t *rp;
  39                 const unsigned char *ip;
  40         } cpu;
  41         uint32_t dp_stack[32];
  42         uint32_t rp_stack[32];
  43         int err;
  44
  45         const unsigned char *hbuf;
  46         size_t hlen;
  47
  48         void (*dest)(void *dest_ctx, const void *src, size_t len);
  49         void *dest_ctx;
  50
  51         unsigned char event;
  52         char name[128];
  53         unsigned char buf[255];
  54         size_t ptr;
  55
  56 } br_pem_decoder_context;
  57
  58 /*
  59  * Initialise a PEM decoder structure.
  60  */
  61 void br_pem_decoder_init(br_pem_decoder_context *ctx);
  62
  63 /*
  64  * Push some bytes into the decoder. Returned value is the number of
  65  * bytes actually consumed; this may be less than the number of provided
  66  * bytes if an event is produced. When an event is produced, it must
  67  * be read (with br_pem_decoder_event()); until the event is read, this
  68  * function will return 0.
  69  */
  70 size_t br_pem_decoder_push(br_pem_decoder_context *ctx,
  71         const void *data, size_t len);
  72
  73 /*
  74  * Set the receiver for decoded data. The provided function (with opaque
  75  * context pointer) will be called with successive data chunks.
  76  */
  77 static inline void
  78 br_pem_decoder_setdest(br_pem_decoder_context *ctx,
  79         void (*dest)(void *dest_ctx, const void *src, size_t len),
  80         void *dest_ctx)
  81 {
  82         ctx->dest = dest;
  83         ctx->dest_ctx = dest_ctx;
  84 }
  85
  86 /*
  87  * Get the last event. This is 0 if no event has been produced. Calling
  88  * ths function clears the event and allows new source bytes to be
  89  * processed.
  90  */
  91 int br_pem_decoder_event(br_pem_decoder_context *ctx);
  92
  93 /*
  94  * This event is called when the start of a new object has been detected.
  95  * The object name (normalised to uppercase) can be accessed with
  96  * br_pem_decoder_name(). The caller MUST provide an appropriate receiver
  97  * (with br_pem_decoder_setdest()) before sending new data bytes.
  98  */
  99 #define BR_PEM_BEGIN_OBJ   1
 100
 101 /*
 102  * This event is called when the end of the current object is reached
 103  * (normally).
 104  */
 105 #define BR_PEM_END_OBJ     2
 106
 107 /*
 108  * This event is called when decoding fails while decoding an object.
 109  * This formally closes the current object and brings the decoder back
 110  * to the "out of any object" state. The offending line in the source
 111  * is consumed.
 112  */
 113 #define BR_PEM_ERROR       3
 114
 115 /*
 116  * Get the name of the encountered object. That name is normalised to
 117  * uppercase (for ASCII characters).
 118  */
 119 static inline const char *
 120 br_pem_decoder_name(br_pem_decoder_context *ctx)
 121 {
 122         return ctx->name;
 123 }
 124
 125 #endif