1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
|
// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifdef UNSAFE_BUFFERS_BUILD
// TODO(crbug.com/390223051): Remove C-library calls to fix the errors.
#pragma allow_unsafe_libc_calls
#endif
#ifndef CRYPTO_OPENSSL_UTIL_H_
#define CRYPTO_OPENSSL_UTIL_H_
#include <stddef.h>
#include <string.h>
#include "base/location.h"
#include "base/memory/raw_ptr.h"
#include "crypto/crypto_export.h"
namespace crypto {
// Provides a buffer of at least MIN_SIZE bytes, for use when calling OpenSSL's
// SHA256, HMAC, etc functions, adapting the buffer sizing rules to meet those
// of our base wrapper APIs.
// This allows the library to write directly to the caller's buffer if it is of
// sufficient size, but if not it will write to temporary |min_sized_buffer_|
// of required size and then its content is automatically copied out on
// destruction, with truncation as appropriate.
template<int MIN_SIZE>
class ScopedOpenSSLSafeSizeBuffer {
public:
ScopedOpenSSLSafeSizeBuffer(unsigned char* output, size_t output_len)
: output_(output),
output_len_(output_len) {
}
ScopedOpenSSLSafeSizeBuffer(const ScopedOpenSSLSafeSizeBuffer&) = delete;
ScopedOpenSSLSafeSizeBuffer& operator=(const ScopedOpenSSLSafeSizeBuffer&) =
delete;
~ScopedOpenSSLSafeSizeBuffer() {
if (output_len_ < MIN_SIZE) {
// Copy the temporary buffer out, truncating as needed.
memcpy(output_, min_sized_buffer_, output_len_);
}
// else... any writing already happened directly into |output_|.
}
unsigned char* safe_buffer() {
return output_len_ < MIN_SIZE ? min_sized_buffer_ : output_.get();
}
private:
// Pointer to the caller's data area and its associated size, where data
// written via safe_buffer() will [eventually] end up.
raw_ptr<unsigned char> output_;
size_t output_len_;
// Temporary buffer writen into in the case where the caller's
// buffer is not of sufficient size.
unsigned char min_sized_buffer_[MIN_SIZE];
};
// Drains the OpenSSL ERR_get_error stack. On a debug build the error codes
// are send to VLOG(1), on a release build they are disregarded. In most
// cases you should pass FROM_HERE as the |location|.
CRYPTO_EXPORT void ClearOpenSSLERRStack(const base::Location& location);
// Place an instance of this class on the call stack to automatically clear
// the OpenSSL error stack on function exit.
class OpenSSLErrStackTracer {
public:
OpenSSLErrStackTracer() = delete;
// Pass FROM_HERE as |location|, to help track the source of OpenSSL error
// messages. Note any diagnostic emitted will be tagged with the location of
// the constructor call as it's not possible to trace a destructor's callsite.
explicit OpenSSLErrStackTracer(const base::Location& location)
: location_(location) {}
OpenSSLErrStackTracer(const OpenSSLErrStackTracer&) = delete;
OpenSSLErrStackTracer& operator=(const OpenSSLErrStackTracer&) = delete;
~OpenSSLErrStackTracer() {
ClearOpenSSLERRStack(location_);
}
private:
const base::Location location_;
};
} // namespace crypto
#endif // CRYPTO_OPENSSL_UTIL_H_
|
