[331] | 1 | /*
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| 2 | * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
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| 3 | *
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| 4 | * Licensed under the OpenSSL license (the "License"). You may not use
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| 5 | * this file except in compliance with the License. You can obtain a copy
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| 6 | * in the file LICENSE in the source distribution or at
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| 7 | * https://www.openssl.org/source/license.html
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| 8 | */
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| 9 |
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| 10 | /*-
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| 11 | From: Arne Ansper <arne@cyber.ee>
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| 12 |
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| 13 | Why BIO_f_reliable?
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| 14 |
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| 15 | I wrote function which took BIO* as argument, read data from it
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| 16 | and processed it. Then I wanted to store the input file in
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| 17 | encrypted form. OK I pushed BIO_f_cipher to the BIO stack
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| 18 | and everything was OK. BUT if user types wrong password
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| 19 | BIO_f_cipher outputs only garbage and my function crashes. Yes
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| 20 | I can and I should fix my function, but BIO_f_cipher is
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| 21 | easy way to add encryption support to many existing applications
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| 22 | and it's hard to debug and fix them all.
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| 23 |
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| 24 | So I wanted another BIO which would catch the incorrect passwords and
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| 25 | file damages which cause garbage on BIO_f_cipher's output.
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| 26 |
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| 27 | The easy way is to push the BIO_f_md and save the checksum at
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| 28 | the end of the file. However there are several problems with this
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| 29 | approach:
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| 30 |
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| 31 | 1) you must somehow separate checksum from actual data.
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| 32 | 2) you need lot's of memory when reading the file, because you
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| 33 | must read to the end of the file and verify the checksum before
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| 34 | letting the application to read the data.
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| 35 |
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| 36 | BIO_f_reliable tries to solve both problems, so that you can
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| 37 | read and write arbitrary long streams using only fixed amount
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| 38 | of memory.
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| 39 |
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| 40 | BIO_f_reliable splits data stream into blocks. Each block is prefixed
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| 41 | with it's length and suffixed with it's digest. So you need only
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| 42 | several Kbytes of memory to buffer single block before verifying
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| 43 | it's digest.
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| 44 |
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| 45 | BIO_f_reliable goes further and adds several important capabilities:
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| 46 |
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| 47 | 1) the digest of the block is computed over the whole stream
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| 48 | -- so nobody can rearrange the blocks or remove or replace them.
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| 49 |
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| 50 | 2) to detect invalid passwords right at the start BIO_f_reliable
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| 51 | adds special prefix to the stream. In order to avoid known plain-text
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| 52 | attacks this prefix is generated as follows:
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| 53 |
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| 54 | *) digest is initialized with random seed instead of
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| 55 | standardized one.
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| 56 | *) same seed is written to output
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| 57 | *) well-known text is then hashed and the output
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| 58 | of the digest is also written to output.
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| 59 |
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| 60 | reader can now read the seed from stream, hash the same string
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| 61 | and then compare the digest output.
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| 62 |
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| 63 | Bad things: BIO_f_reliable knows what's going on in EVP_Digest. I
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| 64 | initially wrote and tested this code on x86 machine and wrote the
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| 65 | digests out in machine-dependent order :( There are people using
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| 66 | this code and I cannot change this easily without making existing
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| 67 | data files unreadable.
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| 68 |
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| 69 | */
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| 70 |
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| 71 | #include <stdio.h>
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| 72 | #include <errno.h>
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| 73 | #include <assert.h>
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| 74 | #include "internal/cryptlib.h"
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| 75 | #include <openssl/buffer.h>
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| 76 | #include "internal/bio.h"
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| 77 | #include <openssl/evp.h>
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| 78 | #include <openssl/rand.h>
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| 79 | #include "internal/evp_int.h"
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| 80 |
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| 81 | static int ok_write(BIO *h, const char *buf, int num);
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| 82 | static int ok_read(BIO *h, char *buf, int size);
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| 83 | static long ok_ctrl(BIO *h, int cmd, long arg1, void *arg2);
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| 84 | static int ok_new(BIO *h);
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| 85 | static int ok_free(BIO *data);
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| 86 | static long ok_callback_ctrl(BIO *h, int cmd, bio_info_cb *fp);
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| 87 |
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| 88 | static __owur int sig_out(BIO *b);
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| 89 | static __owur int sig_in(BIO *b);
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| 90 | static __owur int block_out(BIO *b);
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| 91 | static __owur int block_in(BIO *b);
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| 92 | #define OK_BLOCK_SIZE (1024*4)
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| 93 | #define OK_BLOCK_BLOCK 4
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| 94 | #define IOBS (OK_BLOCK_SIZE+ OK_BLOCK_BLOCK+ 3*EVP_MAX_MD_SIZE)
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| 95 | #define WELLKNOWN "The quick brown fox jumped over the lazy dog's back."
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| 96 |
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| 97 | typedef struct ok_struct {
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| 98 | size_t buf_len;
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| 99 | size_t buf_off;
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| 100 | size_t buf_len_save;
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| 101 | size_t buf_off_save;
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| 102 | int cont; /* <= 0 when finished */
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| 103 | int finished;
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| 104 | EVP_MD_CTX *md;
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| 105 | int blockout; /* output block is ready */
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| 106 | int sigio; /* must process signature */
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| 107 | unsigned char buf[IOBS];
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| 108 | } BIO_OK_CTX;
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| 109 |
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| 110 | static const BIO_METHOD methods_ok = {
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| 111 | BIO_TYPE_CIPHER, "reliable",
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| 112 | ok_write,
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| 113 | ok_read,
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| 114 | NULL, /* ok_puts, */
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| 115 | NULL, /* ok_gets, */
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| 116 | ok_ctrl,
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| 117 | ok_new,
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| 118 | ok_free,
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| 119 | ok_callback_ctrl,
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| 120 | };
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| 121 |
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| 122 | const BIO_METHOD *BIO_f_reliable(void)
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| 123 | {
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| 124 | return (&methods_ok);
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| 125 | }
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| 126 |
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| 127 | static int ok_new(BIO *bi)
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| 128 | {
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| 129 | BIO_OK_CTX *ctx;
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| 130 |
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| 131 | ctx = OPENSSL_zalloc(sizeof(*ctx));
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| 132 | if (ctx == NULL)
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| 133 | return 0;
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| 134 |
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| 135 | ctx->cont = 1;
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| 136 | ctx->sigio = 1;
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| 137 | ctx->md = EVP_MD_CTX_new();
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| 138 | if (ctx->md == NULL) {
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| 139 | OPENSSL_free(ctx);
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| 140 | return 0;
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| 141 | }
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| 142 | BIO_set_init(bi, 0);
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| 143 | BIO_set_data(bi, ctx);
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| 144 |
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| 145 | return 1;
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| 146 | }
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| 147 |
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| 148 | static int ok_free(BIO *a)
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| 149 | {
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| 150 | BIO_OK_CTX *ctx;
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| 151 |
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| 152 | if (a == NULL)
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| 153 | return 0;
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| 154 |
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| 155 | ctx = BIO_get_data(a);
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| 156 |
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| 157 | EVP_MD_CTX_free(ctx->md);
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| 158 | OPENSSL_clear_free(ctx, sizeof(BIO_OK_CTX));
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| 159 | BIO_set_data(a, NULL);
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| 160 | BIO_set_init(a, 0);
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| 161 |
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| 162 | return 1;
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| 163 | }
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| 164 |
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| 165 | static int ok_read(BIO *b, char *out, int outl)
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| 166 | {
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| 167 | int ret = 0, i, n;
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| 168 | BIO_OK_CTX *ctx;
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| 169 | BIO *next;
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| 170 |
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| 171 | if (out == NULL)
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| 172 | return 0;
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| 173 |
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| 174 | ctx = BIO_get_data(b);
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| 175 | next = BIO_next(b);
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| 176 |
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| 177 | if ((ctx == NULL) || (next == NULL) || (BIO_get_init(b) == 0))
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| 178 | return 0;
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| 179 |
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| 180 | while (outl > 0) {
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| 181 |
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| 182 | /* copy clean bytes to output buffer */
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| 183 | if (ctx->blockout) {
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| 184 | i = ctx->buf_len - ctx->buf_off;
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| 185 | if (i > outl)
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| 186 | i = outl;
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| 187 | memcpy(out, &(ctx->buf[ctx->buf_off]), i);
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| 188 | ret += i;
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| 189 | out += i;
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| 190 | outl -= i;
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| 191 | ctx->buf_off += i;
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| 192 |
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| 193 | /* all clean bytes are out */
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| 194 | if (ctx->buf_len == ctx->buf_off) {
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| 195 | ctx->buf_off = 0;
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| 196 |
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| 197 | /*
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| 198 | * copy start of the next block into proper place
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| 199 | */
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| 200 | if (ctx->buf_len_save - ctx->buf_off_save > 0) {
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| 201 | ctx->buf_len = ctx->buf_len_save - ctx->buf_off_save;
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| 202 | memmove(ctx->buf, &(ctx->buf[ctx->buf_off_save]),
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| 203 | ctx->buf_len);
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| 204 | } else {
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| 205 | ctx->buf_len = 0;
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| 206 | }
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| 207 | ctx->blockout = 0;
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| 208 | }
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| 209 | }
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| 210 |
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| 211 | /* output buffer full -- cancel */
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| 212 | if (outl == 0)
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| 213 | break;
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| 214 |
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| 215 | /* no clean bytes in buffer -- fill it */
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| 216 | n = IOBS - ctx->buf_len;
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| 217 | i = BIO_read(next, &(ctx->buf[ctx->buf_len]), n);
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| 218 |
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| 219 | if (i <= 0)
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| 220 | break; /* nothing new */
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| 221 |
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| 222 | ctx->buf_len += i;
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| 223 |
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| 224 | /* no signature yet -- check if we got one */
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| 225 | if (ctx->sigio == 1) {
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| 226 | if (!sig_in(b)) {
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| 227 | BIO_clear_retry_flags(b);
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| 228 | return 0;
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| 229 | }
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| 230 | }
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| 231 |
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| 232 | /* signature ok -- check if we got block */
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| 233 | if (ctx->sigio == 0) {
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| 234 | if (!block_in(b)) {
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| 235 | BIO_clear_retry_flags(b);
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| 236 | return 0;
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| 237 | }
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| 238 | }
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| 239 |
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| 240 | /* invalid block -- cancel */
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| 241 | if (ctx->cont <= 0)
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| 242 | break;
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| 243 |
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| 244 | }
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| 245 |
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| 246 | BIO_clear_retry_flags(b);
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| 247 | BIO_copy_next_retry(b);
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| 248 | return ret;
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| 249 | }
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| 250 |
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| 251 | static int ok_write(BIO *b, const char *in, int inl)
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| 252 | {
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| 253 | int ret = 0, n, i;
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| 254 | BIO_OK_CTX *ctx;
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| 255 | BIO *next;
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| 256 |
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| 257 | if (inl <= 0)
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| 258 | return inl;
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| 259 |
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| 260 | ctx = BIO_get_data(b);
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| 261 | next = BIO_next(b);
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| 262 | ret = inl;
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| 263 |
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| 264 | if ((ctx == NULL) || (next == NULL) || (BIO_get_init(b) == 0))
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| 265 | return (0);
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| 266 |
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| 267 | if (ctx->sigio && !sig_out(b))
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| 268 | return 0;
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| 269 |
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| 270 | do {
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| 271 | BIO_clear_retry_flags(b);
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| 272 | n = ctx->buf_len - ctx->buf_off;
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| 273 | while (ctx->blockout && n > 0) {
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| 274 | i = BIO_write(next, &(ctx->buf[ctx->buf_off]), n);
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| 275 | if (i <= 0) {
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| 276 | BIO_copy_next_retry(b);
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| 277 | if (!BIO_should_retry(b))
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| 278 | ctx->cont = 0;
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| 279 | return (i);
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| 280 | }
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| 281 | ctx->buf_off += i;
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| 282 | n -= i;
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| 283 | }
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| 284 |
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| 285 | /* at this point all pending data has been written */
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| 286 | ctx->blockout = 0;
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| 287 | if (ctx->buf_len == ctx->buf_off) {
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| 288 | ctx->buf_len = OK_BLOCK_BLOCK;
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| 289 | ctx->buf_off = 0;
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| 290 | }
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| 291 |
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| 292 | if ((in == NULL) || (inl <= 0))
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| 293 | return (0);
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| 294 |
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| 295 | n = (inl + ctx->buf_len > OK_BLOCK_SIZE + OK_BLOCK_BLOCK) ?
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| 296 | (int)(OK_BLOCK_SIZE + OK_BLOCK_BLOCK - ctx->buf_len) : inl;
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| 297 |
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| 298 | memcpy(&ctx->buf[ctx->buf_len], in, n);
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| 299 | ctx->buf_len += n;
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| 300 | inl -= n;
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| 301 | in += n;
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| 302 |
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| 303 | if (ctx->buf_len >= OK_BLOCK_SIZE + OK_BLOCK_BLOCK) {
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| 304 | if (!block_out(b)) {
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| 305 | BIO_clear_retry_flags(b);
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| 306 | return 0;
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| 307 | }
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| 308 | }
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| 309 | } while (inl > 0);
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| 310 |
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| 311 | BIO_clear_retry_flags(b);
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| 312 | BIO_copy_next_retry(b);
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| 313 | return (ret);
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| 314 | }
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| 315 |
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| 316 | static long ok_ctrl(BIO *b, int cmd, long num, void *ptr)
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| 317 | {
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| 318 | BIO_OK_CTX *ctx;
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| 319 | EVP_MD *md;
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| 320 | const EVP_MD **ppmd;
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| 321 | long ret = 1;
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| 322 | int i;
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| 323 | BIO *next;
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| 324 |
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| 325 | ctx = BIO_get_data(b);
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| 326 | next = BIO_next(b);
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| 327 |
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| 328 | switch (cmd) {
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| 329 | case BIO_CTRL_RESET:
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| 330 | ctx->buf_len = 0;
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| 331 | ctx->buf_off = 0;
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| 332 | ctx->buf_len_save = 0;
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| 333 | ctx->buf_off_save = 0;
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| 334 | ctx->cont = 1;
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| 335 | ctx->finished = 0;
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| 336 | ctx->blockout = 0;
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| 337 | ctx->sigio = 1;
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| 338 | ret = BIO_ctrl(next, cmd, num, ptr);
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| 339 | break;
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| 340 | case BIO_CTRL_EOF: /* More to read */
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| 341 | if (ctx->cont <= 0)
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| 342 | ret = 1;
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| 343 | else
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| 344 | ret = BIO_ctrl(next, cmd, num, ptr);
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| 345 | break;
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| 346 | case BIO_CTRL_PENDING: /* More to read in buffer */
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| 347 | case BIO_CTRL_WPENDING: /* More to read in buffer */
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| 348 | ret = ctx->blockout ? ctx->buf_len - ctx->buf_off : 0;
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| 349 | if (ret <= 0)
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| 350 | ret = BIO_ctrl(next, cmd, num, ptr);
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| 351 | break;
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| 352 | case BIO_CTRL_FLUSH:
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| 353 | /* do a final write */
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| 354 | if (ctx->blockout == 0)
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| 355 | if (!block_out(b))
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| 356 | return 0;
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| 357 |
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| 358 | while (ctx->blockout) {
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| 359 | i = ok_write(b, NULL, 0);
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| 360 | if (i < 0) {
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| 361 | ret = i;
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| 362 | break;
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| 363 | }
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| 364 | }
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| 365 |
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| 366 | ctx->finished = 1;
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| 367 | ctx->buf_off = ctx->buf_len = 0;
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| 368 | ctx->cont = (int)ret;
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| 369 |
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| 370 | /* Finally flush the underlying BIO */
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| 371 | ret = BIO_ctrl(next, cmd, num, ptr);
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| 372 | break;
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| 373 | case BIO_C_DO_STATE_MACHINE:
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| 374 | BIO_clear_retry_flags(b);
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| 375 | ret = BIO_ctrl(next, cmd, num, ptr);
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| 376 | BIO_copy_next_retry(b);
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| 377 | break;
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| 378 | case BIO_CTRL_INFO:
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| 379 | ret = (long)ctx->cont;
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| 380 | break;
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| 381 | case BIO_C_SET_MD:
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| 382 | md = ptr;
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| 383 | if (!EVP_DigestInit_ex(ctx->md, md, NULL))
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| 384 | return 0;
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| 385 | BIO_set_init(b, 1);
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| 386 | break;
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| 387 | case BIO_C_GET_MD:
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| 388 | if (BIO_get_init(b)) {
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| 389 | ppmd = ptr;
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| 390 | *ppmd = EVP_MD_CTX_md(ctx->md);
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| 391 | } else
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| 392 | ret = 0;
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| 393 | break;
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| 394 | default:
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| 395 | ret = BIO_ctrl(next, cmd, num, ptr);
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| 396 | break;
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| 397 | }
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| 398 | return ret;
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| 399 | }
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| 400 |
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| 401 | static long ok_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp)
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| 402 | {
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| 403 | long ret = 1;
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| 404 | BIO *next;
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| 405 |
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| 406 | next = BIO_next(b);
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| 407 |
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| 408 | if (next == NULL)
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| 409 | return 0;
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| 410 |
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| 411 | switch (cmd) {
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| 412 | default:
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| 413 | ret = BIO_callback_ctrl(next, cmd, fp);
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| 414 | break;
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| 415 | }
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| 416 |
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| 417 | return ret;
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| 418 | }
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| 419 |
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| 420 | static void longswap(void *_ptr, size_t len)
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| 421 | {
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| 422 | const union {
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| 423 | long one;
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| 424 | char little;
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| 425 | } is_endian = {
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| 426 | 1
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| 427 | };
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| 428 |
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| 429 | if (is_endian.little) {
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| 430 | size_t i;
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| 431 | unsigned char *p = _ptr, c;
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| 432 |
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| 433 | for (i = 0; i < len; i += 4) {
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| 434 | c = p[0], p[0] = p[3], p[3] = c;
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| 435 | c = p[1], p[1] = p[2], p[2] = c;
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| 436 | }
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| 437 | }
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| 438 | }
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| 439 |
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| 440 | static int sig_out(BIO *b)
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| 441 | {
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| 442 | BIO_OK_CTX *ctx;
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| 443 | EVP_MD_CTX *md;
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| 444 | const EVP_MD *digest;
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| 445 | int md_size;
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| 446 | void *md_data;
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| 447 |
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| 448 | ctx = BIO_get_data(b);
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| 449 | md = ctx->md;
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| 450 | digest = EVP_MD_CTX_md(md);
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| 451 | md_size = EVP_MD_size(digest);
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| 452 | md_data = EVP_MD_CTX_md_data(md);
|
---|
| 453 |
|
---|
| 454 | if (ctx->buf_len + 2 * md_size > OK_BLOCK_SIZE)
|
---|
| 455 | return 1;
|
---|
| 456 |
|
---|
| 457 | if (!EVP_DigestInit_ex(md, digest, NULL))
|
---|
| 458 | goto berr;
|
---|
| 459 | /*
|
---|
| 460 | * FIXME: there's absolutely no guarantee this makes any sense at all,
|
---|
| 461 | * particularly now EVP_MD_CTX has been restructured.
|
---|
| 462 | */
|
---|
| 463 | if (RAND_bytes(md_data, md_size) <= 0)
|
---|
| 464 | goto berr;
|
---|
| 465 | memcpy(&(ctx->buf[ctx->buf_len]), md_data, md_size);
|
---|
| 466 | longswap(&(ctx->buf[ctx->buf_len]), md_size);
|
---|
| 467 | ctx->buf_len += md_size;
|
---|
| 468 |
|
---|
| 469 | if (!EVP_DigestUpdate(md, WELLKNOWN, strlen(WELLKNOWN)))
|
---|
| 470 | goto berr;
|
---|
| 471 | if (!EVP_DigestFinal_ex(md, &(ctx->buf[ctx->buf_len]), NULL))
|
---|
| 472 | goto berr;
|
---|
| 473 | ctx->buf_len += md_size;
|
---|
| 474 | ctx->blockout = 1;
|
---|
| 475 | ctx->sigio = 0;
|
---|
| 476 | return 1;
|
---|
| 477 | berr:
|
---|
| 478 | BIO_clear_retry_flags(b);
|
---|
| 479 | return 0;
|
---|
| 480 | }
|
---|
| 481 |
|
---|
| 482 | static int sig_in(BIO *b)
|
---|
| 483 | {
|
---|
| 484 | BIO_OK_CTX *ctx;
|
---|
| 485 | EVP_MD_CTX *md;
|
---|
| 486 | unsigned char tmp[EVP_MAX_MD_SIZE];
|
---|
| 487 | int ret = 0;
|
---|
| 488 | const EVP_MD *digest;
|
---|
| 489 | int md_size;
|
---|
| 490 | void *md_data;
|
---|
| 491 |
|
---|
| 492 | ctx = BIO_get_data(b);
|
---|
| 493 | md = ctx->md;
|
---|
| 494 | digest = EVP_MD_CTX_md(md);
|
---|
| 495 | md_size = EVP_MD_size(digest);
|
---|
| 496 | md_data = EVP_MD_CTX_md_data(md);
|
---|
| 497 |
|
---|
| 498 | if ((int)(ctx->buf_len - ctx->buf_off) < 2 * md_size)
|
---|
| 499 | return 1;
|
---|
| 500 |
|
---|
| 501 | if (!EVP_DigestInit_ex(md, digest, NULL))
|
---|
| 502 | goto berr;
|
---|
| 503 | memcpy(md_data, &(ctx->buf[ctx->buf_off]), md_size);
|
---|
| 504 | longswap(md_data, md_size);
|
---|
| 505 | ctx->buf_off += md_size;
|
---|
| 506 |
|
---|
| 507 | if (!EVP_DigestUpdate(md, WELLKNOWN, strlen(WELLKNOWN)))
|
---|
| 508 | goto berr;
|
---|
| 509 | if (!EVP_DigestFinal_ex(md, tmp, NULL))
|
---|
| 510 | goto berr;
|
---|
| 511 | ret = memcmp(&(ctx->buf[ctx->buf_off]), tmp, md_size) == 0;
|
---|
| 512 | ctx->buf_off += md_size;
|
---|
| 513 | if (ret == 1) {
|
---|
| 514 | ctx->sigio = 0;
|
---|
| 515 | if (ctx->buf_len != ctx->buf_off) {
|
---|
| 516 | memmove(ctx->buf, &(ctx->buf[ctx->buf_off]),
|
---|
| 517 | ctx->buf_len - ctx->buf_off);
|
---|
| 518 | }
|
---|
| 519 | ctx->buf_len -= ctx->buf_off;
|
---|
| 520 | ctx->buf_off = 0;
|
---|
| 521 | } else {
|
---|
| 522 | ctx->cont = 0;
|
---|
| 523 | }
|
---|
| 524 | return 1;
|
---|
| 525 | berr:
|
---|
| 526 | BIO_clear_retry_flags(b);
|
---|
| 527 | return 0;
|
---|
| 528 | }
|
---|
| 529 |
|
---|
| 530 | static int block_out(BIO *b)
|
---|
| 531 | {
|
---|
| 532 | BIO_OK_CTX *ctx;
|
---|
| 533 | EVP_MD_CTX *md;
|
---|
| 534 | unsigned long tl;
|
---|
| 535 | const EVP_MD *digest;
|
---|
| 536 | int md_size;
|
---|
| 537 |
|
---|
| 538 | ctx = BIO_get_data(b);
|
---|
| 539 | md = ctx->md;
|
---|
| 540 | digest = EVP_MD_CTX_md(md);
|
---|
| 541 | md_size = EVP_MD_size(digest);
|
---|
| 542 |
|
---|
| 543 | tl = ctx->buf_len - OK_BLOCK_BLOCK;
|
---|
| 544 | ctx->buf[0] = (unsigned char)(tl >> 24);
|
---|
| 545 | ctx->buf[1] = (unsigned char)(tl >> 16);
|
---|
| 546 | ctx->buf[2] = (unsigned char)(tl >> 8);
|
---|
| 547 | ctx->buf[3] = (unsigned char)(tl);
|
---|
| 548 | if (!EVP_DigestUpdate(md,
|
---|
| 549 | (unsigned char *)&(ctx->buf[OK_BLOCK_BLOCK]), tl))
|
---|
| 550 | goto berr;
|
---|
| 551 | if (!EVP_DigestFinal_ex(md, &(ctx->buf[ctx->buf_len]), NULL))
|
---|
| 552 | goto berr;
|
---|
| 553 | ctx->buf_len += md_size;
|
---|
| 554 | ctx->blockout = 1;
|
---|
| 555 | return 1;
|
---|
| 556 | berr:
|
---|
| 557 | BIO_clear_retry_flags(b);
|
---|
| 558 | return 0;
|
---|
| 559 | }
|
---|
| 560 |
|
---|
| 561 | static int block_in(BIO *b)
|
---|
| 562 | {
|
---|
| 563 | BIO_OK_CTX *ctx;
|
---|
| 564 | EVP_MD_CTX *md;
|
---|
| 565 | unsigned long tl = 0;
|
---|
| 566 | unsigned char tmp[EVP_MAX_MD_SIZE];
|
---|
| 567 | int md_size;
|
---|
| 568 |
|
---|
| 569 | ctx = BIO_get_data(b);
|
---|
| 570 | md = ctx->md;
|
---|
| 571 | md_size = EVP_MD_size(EVP_MD_CTX_md(md));
|
---|
| 572 |
|
---|
| 573 | assert(sizeof(tl) >= OK_BLOCK_BLOCK); /* always true */
|
---|
| 574 | tl = ctx->buf[0];
|
---|
| 575 | tl <<= 8;
|
---|
| 576 | tl |= ctx->buf[1];
|
---|
| 577 | tl <<= 8;
|
---|
| 578 | tl |= ctx->buf[2];
|
---|
| 579 | tl <<= 8;
|
---|
| 580 | tl |= ctx->buf[3];
|
---|
| 581 |
|
---|
| 582 | if (ctx->buf_len < tl + OK_BLOCK_BLOCK + md_size)
|
---|
| 583 | return 1;
|
---|
| 584 |
|
---|
| 585 | if (!EVP_DigestUpdate(md,
|
---|
| 586 | (unsigned char *)&(ctx->buf[OK_BLOCK_BLOCK]), tl))
|
---|
| 587 | goto berr;
|
---|
| 588 | if (!EVP_DigestFinal_ex(md, tmp, NULL))
|
---|
| 589 | goto berr;
|
---|
| 590 | if (memcmp(&(ctx->buf[tl + OK_BLOCK_BLOCK]), tmp, md_size) == 0) {
|
---|
| 591 | /* there might be parts from next block lurking around ! */
|
---|
| 592 | ctx->buf_off_save = tl + OK_BLOCK_BLOCK + md_size;
|
---|
| 593 | ctx->buf_len_save = ctx->buf_len;
|
---|
| 594 | ctx->buf_off = OK_BLOCK_BLOCK;
|
---|
| 595 | ctx->buf_len = tl + OK_BLOCK_BLOCK;
|
---|
| 596 | ctx->blockout = 1;
|
---|
| 597 | } else {
|
---|
| 598 | ctx->cont = 0;
|
---|
| 599 | }
|
---|
| 600 | return 1;
|
---|
| 601 | berr:
|
---|
| 602 | BIO_clear_retry_flags(b);
|
---|
| 603 | return 0;
|
---|
| 604 | }
|
---|