1 /*
2  * libwebsockets - small server side websockets and web server implementation
3  *
4  * Copyright (C) 2010 - 2019 Andy Green <andy@warmcat.com>
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to
8  * deal in the Software without restriction, including without limitation the
9  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
10  * sell copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
22  * IN THE SOFTWARE.
23  */
24 
25 /*! \defgroup generichash Generic Hash
26  * ## Generic Hash related functions
27  *
28  * Lws provides generic hash / digest accessors that abstract the ones
29  * provided by whatever tls library you are linking against.
30  *
31  * It lets you use the same code if you build against mbedtls or OpenSSL
32  * for example.
33  */
34 ///@{
35 
36 enum lws_genhash_types {
37 	LWS_GENHASH_TYPE_UNKNOWN,
38 	LWS_GENHASH_TYPE_MD5,
39 	LWS_GENHASH_TYPE_SHA1,
40 	LWS_GENHASH_TYPE_SHA256,
41 	LWS_GENHASH_TYPE_SHA384,
42 	LWS_GENHASH_TYPE_SHA512,
43 };
44 
45 enum lws_genhmac_types {
46 	LWS_GENHMAC_TYPE_UNKNOWN,
47 	LWS_GENHMAC_TYPE_SHA256,
48 	LWS_GENHMAC_TYPE_SHA384,
49 	LWS_GENHMAC_TYPE_SHA512,
50 };
51 
52 #define LWS_GENHASH_LARGEST 64
53 
54 struct lws_genhash_ctx {
55         uint8_t type;
56 #if defined(LWS_WITH_MBEDTLS)
57         union {
58 		mbedtls_md5_context md5;
59         	mbedtls_sha1_context sha1;
60 		mbedtls_sha256_context sha256;
61 		mbedtls_sha512_context sha512; /* 384 also uses this */
62 		const mbedtls_md_info_t *hmac;
63         } u;
64 #else
65         const EVP_MD *evp_type;
66         EVP_MD_CTX *mdctx;
67 #endif
68 };
69 
70 struct lws_genhmac_ctx {
71         uint8_t type;
72 #if defined(LWS_WITH_MBEDTLS)
73 	const mbedtls_md_info_t *hmac;
74 	mbedtls_md_context_t ctx;
75 #else
76 	const EVP_MD *evp_type;
77 #if defined(LWS_HAVE_HMAC_CTX_new)
78         HMAC_CTX *ctx;
79 #else
80         HMAC_CTX ctx;
81 #endif
82 #endif
83 };
84 
85 /** lws_genhash_size() - get hash size in bytes
86  *
87  * \param type:	one of LWS_GENHASH_TYPE_...
88  *
89  * Returns number of bytes in this type of hash
90  */
91 LWS_VISIBLE LWS_EXTERN size_t LWS_WARN_UNUSED_RESULT
92 lws_genhash_size(enum lws_genhash_types type);
93 
94 /** lws_genhmac_size() - get hash size in bytes
95  *
96  * \param type:	one of LWS_GENHASH_TYPE_...
97  *
98  * Returns number of bytes in this type of hmac
99  */
100 LWS_VISIBLE LWS_EXTERN size_t LWS_WARN_UNUSED_RESULT
101 lws_genhmac_size(enum lws_genhmac_types type);
102 
103 /** lws_genhash_init() - prepare your struct lws_genhash_ctx for use
104  *
105  * \param ctx: your struct lws_genhash_ctx
106  * \param type:	one of LWS_GENHASH_TYPE_...
107  *
108  * Initializes the hash context for the type you requested
109  */
110 LWS_VISIBLE LWS_EXTERN int LWS_WARN_UNUSED_RESULT
111 lws_genhash_init(struct lws_genhash_ctx *ctx, enum lws_genhash_types type);
112 
113 /** lws_genhash_update() - digest len bytes of the buffer starting at in
114  *
115  * \param ctx: your struct lws_genhash_ctx
116  * \param in: start of the bytes to digest
117  * \param len: count of bytes to digest
118  *
119  * Updates the state of your hash context to reflect digesting len bytes from in
120  */
121 LWS_VISIBLE LWS_EXTERN int LWS_WARN_UNUSED_RESULT
122 lws_genhash_update(struct lws_genhash_ctx *ctx, const void *in, size_t len);
123 
124 /** lws_genhash_destroy() - copy out the result digest and destroy the ctx
125  *
126  * \param ctx: your struct lws_genhash_ctx
127  * \param result: NULL, or where to copy the result hash
128  *
129  * Finalizes the hash and copies out the digest.  Destroys any allocations such
130  * that ctx can safely go out of scope after calling this.
131  *
132  * NULL result is supported so that you can destroy the ctx cleanly on error
133  * conditions, where there is no valid result.
134  */
135 LWS_VISIBLE LWS_EXTERN int
136 lws_genhash_destroy(struct lws_genhash_ctx *ctx, void *result);
137 
138 /** lws_genhmac_init() - prepare your struct lws_genhmac_ctx for use
139  *
140  * \param ctx: your struct lws_genhmac_ctx
141  * \param type:	one of LWS_GENHMAC_TYPE_...
142  * \param key: pointer to the start of the HMAC key
143  * \param key_len: length of the HMAC key
144  *
145  * Initializes the hash context for the type you requested
146  *
147  * If the return is nonzero, it failed and there is nothing needing to be
148  * destroyed.
149  */
150 LWS_VISIBLE LWS_EXTERN int LWS_WARN_UNUSED_RESULT
151 lws_genhmac_init(struct lws_genhmac_ctx *ctx, enum lws_genhmac_types type,
152 		 const uint8_t *key, size_t key_len);
153 
154 /** lws_genhmac_update() - digest len bytes of the buffer starting at in
155  *
156  * \param ctx: your struct lws_genhmac_ctx
157  * \param in: start of the bytes to digest
158  * \param len: count of bytes to digest
159  *
160  * Updates the state of your hash context to reflect digesting len bytes from in
161  *
162  * If the return is nonzero, it failed and needs destroying.
163  */
164 LWS_VISIBLE LWS_EXTERN int LWS_WARN_UNUSED_RESULT
165 lws_genhmac_update(struct lws_genhmac_ctx *ctx, const void *in, size_t len);
166 
167 /** lws_genhmac_destroy() - copy out the result digest and destroy the ctx
168  *
169  * \param ctx: your struct lws_genhmac_ctx
170  * \param result: NULL, or where to copy the result hash
171  *
172  * Finalizes the hash and copies out the digest.  Destroys any allocations such
173  * that ctx can safely go out of scope after calling this.
174  *
175  * NULL result is supported so that you can destroy the ctx cleanly on error
176  * conditions, where there is no valid result.
177  */
178 LWS_VISIBLE LWS_EXTERN int
179 lws_genhmac_destroy(struct lws_genhmac_ctx *ctx, void *result);
180 ///@}
181