Some renaming to avoid spurious warnings on some old GCC versions.
[BearSSL] / README.txt
1 # Documentation
3 The most up-to-date documentation is supposed to be available on the
4 [BearSSL Web site](
6 # Disclaimer
8 BearSSL is for now considered alpha-level software. This means that it
9 probably still has some bugs, possibly very serious ones (e.g. buffer
10 overflows -- one of the perks of using C as programming language). It
11 still lacks some functionalities. The API will probably change and may
12 break both source and binary compatibility.
14 In other words, you would be quite mad to use it for any production
15 purpose. Right now, this is for learning, testing and possibly
16 contributing.
18 The usage license is explicited in the `LICENSE.txt` file. This is the
19 "MIT license". It can be summarised in the following way:
21 - You can use and reuse the library as you wish, and modify it, and
22 integrate it in your own code, and distribute it as is or in any
23 modified form, and so on.
25 - The only obligation that the license terms put upon you is that you
26 acknowledge and make it clear that if anything breaks, it is not my
27 fault, and I am not liable for anything, regardless of the type and
28 amount of collateral damage. The license terms say that the copyright
29 notice "shall be included in all copies or substantial portions of
30 the Software": this is how the disclaimer is "made explicit".
31 Basically, I have put it in every source file, so just keep it there.
33 # Installation
35 Right now, BearSSL is a simple library, along with a few test and debug
36 command-line tools. There is no installer yet. The library _can_ be
37 compiled as a shared library on some systems, but since the binary API
38 is not fully stabilised, this is not a very good idea to do that right
39 now.
41 To compile the code, just type `make`. This will try to use sane
42 "default" values. On a Windows system with Visual Studio, run a console
43 with the environment initialised for a specific version of the C compiler,
44 and type `nmake`.
46 To override the default settings, create a custom configuration file in
47 the `conf` directory, and invoke `make` (or `nmake`) with an explicit
48 `CONF=` parameter. For instance, to use the provided ``
49 configuration file (that targets cross-compilation for an Atmel board
50 that features a Cortex-M0+ CPU), type:
52 make CONF=samd20
54 The `conf/` file includes the `` file and then overrides
55 some of the parameters, including the destination directory. Any custom
56 configuration can be made the same way.
58 Some compile-time options can be set through macros, either on the
59 compiler command-line, or in the `src/config.h` file. See the comments
60 in that file. Some settings are autodetected but they can still be
61 explicitly overridden.
63 When compilation is done, the library (static and DLL, when appropriate)
64 and the command-line tools can be found in the designated build
65 directory (by default named `build`). The public headers (to be used
66 by applications linked against BearSSL) are in the `inc/` directory.
68 To run the tests:
70 - `testcrypto all` runs the cryptographic tests (test vectors on all
71 implemented cryptogaphic functions). It can be slow. You can also
72 run a selection of the tests by providing their names (run
73 `testcrypto` without any parameter to see the available names).
75 - `testspeed all` runs a number of performance benchmarks, there again
76 on cryptographic functions. It gives a taste of how things go on the
77 current platform. As for `testcrypto`, specific named benchmarks can
78 be executed.
80 - `testx509` runs X.509 validation tests. The test certificates are
81 all in `test/x509/`.
83 The `brssl` command-line tool produced in the build directory is a
84 stand-alone binary. It can exercise some of the functionalities of
85 BearSSL, in particular running a test SSL client or server. It is not
86 meant for production purposes (e.g. the SSL client has a mode where it
87 disregards the inability to validate the server's certificate, which is
88 inherently unsafe, but convenient for debug).
90 **Using the library** means writing some application code that invokes
91 it, and linking with the static library. The header files are all in the
92 `inc` directory; copy them wherever makes sense (e.g. in the
93 `/usr/local/include` directory). The library itself (`libbearssl.a`) is
94 what you link against.
96 Alternatively, you may want to copy the source files directly into your
97 own application code. This will make integrating ulterior versions of
98 BearSSL more difficult. If you still want to go down that road, then
99 simply copy all the `*.h` and `*.c` files from the `src` and `inc`
100 directories into your application source code. In the BearSSL source
101 archive, the source files are segregated into various sub-directories,
102 but this is for my convenience only. There is no technical requirement
103 for that, and all files can be dumped together in a simple directory.
105 Dependencies are simple and systematic:
107 - Each `*.c` file includes `inner.h`
108 - `inner.h` includes `config.h` and `bearssl.h`
109 - `bearssl.h` includes the other `bearssl_*.h`
111 # Versioning
113 I follow this simple version numbering scheme:
115 - Version numbers are `x.y` or `x.y.z` where `x`, `y` ans `z` are
116 decimal integers (possibly greater than 10). When the `.z` part is
117 missing, it is equivalent to `.0`.
119 - Backward compatibility is maintained, at both source and binary levels,
120 for each major version: this means that if some application code was
121 designed for version `x.y`, then it should compile, link and run
122 properly with any version `x.y'` for any `y'` greater than `y`.
124 The major version `0` is an exception. You shall not expect that any
125 version that starts with `0.` offers any kind of compatibility,
126 either source or binary, with any other `0.` version. (Of course I
127 will try to maintain some decent level of source compatibility, but I
128 make no promise in that respect. Since the API uses caller-allocated
129 context structures, I already know that binary compatibility _will_
130 be broken.)
132 - Sub-versions (the `y` part) are about added functionality. That is,
133 it can be expected that `1.3` will contain some extra functions when
134 compared to `1.2`. The next version level (the `z` part) is for
135 bugfixes that do not add any functionality.