1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
2  * All rights reserved.
3  *
4  * This package is an SSL implementation written
5  * by Eric Young (eay@cryptsoft.com).
6  * The implementation was written so as to conform with Netscapes SSL.
7  *
8  * This library is free for commercial and non-commercial use as long as
9  * the following conditions are aheared to.  The following conditions
10  * apply to all code found in this distribution, be it the RC4, RSA,
11  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
12  * included with this distribution is covered by the same copyright terms
13  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
14  *
15  * Copyright remains Eric Young's, and as such any Copyright notices in
16  * the code are not to be removed.
17  * If this package is used in a product, Eric Young should be given attribution
18  * as the author of the parts of the library used.
19  * This can be in the form of a textual message at program startup or
20  * in documentation (online or textual) provided with the package.
21  *
22  * Redistribution and use in source and binary forms, with or without
23  * modification, are permitted provided that the following conditions
24  * are met:
25  * 1. Redistributions of source code must retain the copyright
26  *    notice, this list of conditions and the following disclaimer.
27  * 2. Redistributions in binary form must reproduce the above copyright
28  *    notice, this list of conditions and the following disclaimer in the
29  *    documentation and/or other materials provided with the distribution.
30  * 3. All advertising materials mentioning features or use of this software
31  *    must display the following acknowledgement:
32  *    "This product includes cryptographic software written by
33  *     Eric Young (eay@cryptsoft.com)"
34  *    The word 'cryptographic' can be left out if the rouines from the library
35  *    being used are not cryptographic related :-).
36  * 4. If you include any Windows specific code (or a derivative thereof) from
37  *    the apps directory (application code) you must include an acknowledgement:
38  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
39  *
40  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50  * SUCH DAMAGE.
51  *
52  * The licence and distribution terms for any publically available version or
53  * derivative of this code cannot be changed.  i.e. this code cannot simply be
54  * copied and put under another distribution licence
55  * [including the GNU Public Licence.] */
56 
57 #ifndef OPENSSL_HEADER_DIGEST_H
58 #define OPENSSL_HEADER_DIGEST_H
59 
60 #include <openssl/base.h>
61 
62 #if defined(__cplusplus)
63 extern "C" {
64 #endif
65 
66 
67 /* Digest functions.
68  *
69  * An EVP_MD abstracts the details of a specific hash function allowing code to
70  * deal with the concept of a "hash function" without needing to know exactly
71  * which hash function it is. */
72 
73 
74 /* Hash algorithms.
75  *
76  * The following functions return |EVP_MD| objects that implement the named hash
77  * function. */
78 
79 OPENSSL_EXPORT const EVP_MD *EVP_md4(void);
80 OPENSSL_EXPORT const EVP_MD *EVP_md5(void);
81 OPENSSL_EXPORT const EVP_MD *EVP_sha1(void);
82 OPENSSL_EXPORT const EVP_MD *EVP_sha224(void);
83 OPENSSL_EXPORT const EVP_MD *EVP_sha256(void);
84 OPENSSL_EXPORT const EVP_MD *EVP_sha384(void);
85 OPENSSL_EXPORT const EVP_MD *EVP_sha512(void);
86 
87 /* EVP_md5_sha1 is a TLS-specific |EVP_MD| which computes the concatenation of
88  * MD5 and SHA-1, as used in TLS 1.1 and below. */
89 OPENSSL_EXPORT const EVP_MD *EVP_md5_sha1(void);
90 
91 /* EVP_get_digestbynid returns an |EVP_MD| for the given NID, or NULL if no
92  * such digest is known. */
93 OPENSSL_EXPORT const EVP_MD *EVP_get_digestbynid(int nid);
94 
95 /* EVP_get_digestbyobj returns an |EVP_MD| for the given |ASN1_OBJECT|, or NULL
96  * if no such digest is known. */
97 OPENSSL_EXPORT const EVP_MD *EVP_get_digestbyobj(const ASN1_OBJECT *obj);
98 
99 
100 /* Digest contexts.
101  *
102  * An EVP_MD_CTX represents the state of a specific digest operation in
103  * progress. */
104 
105 /* EVP_MD_CTX_init initialises an, already allocated, |EVP_MD_CTX|. */
106 OPENSSL_EXPORT void EVP_MD_CTX_init(EVP_MD_CTX *ctx);
107 
108 /* EVP_MD_CTX_create allocates and initialises a fresh |EVP_MD_CTX| and returns
109  * it, or NULL on allocation failure. */
110 OPENSSL_EXPORT EVP_MD_CTX *EVP_MD_CTX_create(void);
111 
112 /* EVP_MD_CTX_cleanup frees any resources owned by |ctx| and resets it to a
113  * freshly initialised state. It does not free |ctx| itself. It returns one. */
114 OPENSSL_EXPORT int EVP_MD_CTX_cleanup(EVP_MD_CTX *ctx);
115 
116 /* EVP_MD_CTX_destroy calls |EVP_MD_CTX_cleanup| and then frees |ctx| itself. */
117 OPENSSL_EXPORT void EVP_MD_CTX_destroy(EVP_MD_CTX *ctx);
118 
119 /* EVP_MD_CTX_copy_ex sets |out|, which must already be initialised, to be a
120  * copy of |in|. It returns one on success and zero on error. */
121 OPENSSL_EXPORT int EVP_MD_CTX_copy_ex(EVP_MD_CTX *out, const EVP_MD_CTX *in);
122 
123 
124 /* Digest operations. */
125 
126 /* EVP_DigestInit_ex configures |ctx|, which must already have been
127  * initialised, for a fresh hashing operation using |type|. It returns one on
128  * success and zero otherwise. */
129 OPENSSL_EXPORT int EVP_DigestInit_ex(EVP_MD_CTX *ctx, const EVP_MD *type,
130                                      ENGINE *engine);
131 
132 /* EVP_DigestInit acts like |EVP_DigestInit_ex| except that |ctx| is
133  * initialised before use. */
134 OPENSSL_EXPORT int EVP_DigestInit(EVP_MD_CTX *ctx, const EVP_MD *type);
135 
136 /* EVP_DigestUpdate hashes |len| bytes from |data| into the hashing operation
137  * in |ctx|. It returns one. */
138 OPENSSL_EXPORT int EVP_DigestUpdate(EVP_MD_CTX *ctx, const void *data,
139                                     size_t len);
140 
141 /* EVP_MAX_MD_SIZE is the largest digest size supported, in bytes.
142  * Functions that output a digest generally require the buffer have
143  * at least this much space. */
144 #define EVP_MAX_MD_SIZE 64 /* SHA-512 is the longest so far. */
145 
146 /* EVP_DigestFinal_ex finishes the digest in |ctx| and writes the output to
147  * |md_out|. At most |EVP_MAX_MD_SIZE| bytes are written. If |out_size| is not
148  * NULL then |*out_size| is set to the number of bytes written. It returns one.
149  * After this call, the hash cannot be updated or finished again until
150  * |EVP_DigestInit_ex| is called to start another hashing operation. */
151 OPENSSL_EXPORT int EVP_DigestFinal_ex(EVP_MD_CTX *ctx, uint8_t *md_out,
152                                       unsigned int *out_size);
153 
154 /* EVP_DigestFinal acts like |EVP_DigestFinal_ex| except that
155  * |EVP_MD_CTX_cleanup| is called on |ctx| before returning. */
156 OPENSSL_EXPORT int EVP_DigestFinal(EVP_MD_CTX *ctx, uint8_t *md_out,
157                                    unsigned int *out_size);
158 
159 /* EVP_Digest performs a complete hashing operation in one call. It hashes
160  * |len| bytes from |data| and writes the digest to |md_out|. At most
161  * |EVP_MAX_MD_SIZE| bytes are written. If |out_size| is not NULL then
162  * |*out_size| is set to the number of bytes written. It returns one on success
163  * and zero otherwise. */
164 OPENSSL_EXPORT int EVP_Digest(const void *data, size_t len, uint8_t *md_out,
165                               unsigned int *md_out_size, const EVP_MD *type,
166                               ENGINE *impl);
167 
168 
169 /* Digest function accessors.
170  *
171  * These functions allow code to learn details about an abstract hash
172  * function. */
173 
174 /* EVP_MD_type returns a NID identifing |md|. (For example, |NID_sha256|.) */
175 OPENSSL_EXPORT int EVP_MD_type(const EVP_MD *md);
176 
177 /* EVP_MD_flags returns the flags for |md|, which is a set of |EVP_MD_FLAG_*|
178  * values, ORed together. */
179 OPENSSL_EXPORT uint32_t EVP_MD_flags(const EVP_MD *md);
180 
181 /* EVP_MD_size returns the digest size of |md|, in bytes. */
182 OPENSSL_EXPORT size_t EVP_MD_size(const EVP_MD *md);
183 
184 /* EVP_MD_block_size returns the native block-size of |md|, in bytes. */
185 OPENSSL_EXPORT size_t EVP_MD_block_size(const EVP_MD *md);
186 
187 /* EVP_MD_FLAG_PKEY_DIGEST indicates the the digest function is used with a
188  * specific public key in order to verify signatures. (For example,
189  * EVP_dss1.) */
190 #define EVP_MD_FLAG_PKEY_DIGEST 1
191 
192 /* EVP_MD_FLAG_DIGALGID_ABSENT indicates that the parameter type in an X.509
193  * DigestAlgorithmIdentifier representing this digest function should be
194  * undefined rather than NULL. */
195 #define EVP_MD_FLAG_DIGALGID_ABSENT 2
196 
197 
198 /* Deprecated functions. */
199 
200 /* EVP_MD_CTX_copy sets |out|, which must /not/ be initialised, to be a copy of
201  * |in|. It returns one on success and zero on error. */
202 OPENSSL_EXPORT int EVP_MD_CTX_copy(EVP_MD_CTX *out, const EVP_MD_CTX *in);
203 
204 /* EVP_add_digest does nothing and returns one. It exists only for
205  * compatibility with OpenSSL. */
206 OPENSSL_EXPORT int EVP_add_digest(const EVP_MD *digest);
207 
208 /* EVP_get_digestbyname returns an |EVP_MD| given a human readable name in
209  * |name|, or NULL if the name is unknown. */
210 OPENSSL_EXPORT const EVP_MD *EVP_get_digestbyname(const char *);
211 
212 
213 /* Digest operation accessors. */
214 
215 /* EVP_MD_CTX_md returns the underlying digest function, or NULL if one has not
216  * been set. */
217 OPENSSL_EXPORT const EVP_MD *EVP_MD_CTX_md(const EVP_MD_CTX *ctx);
218 
219 /* EVP_MD_CTX_size returns the digest size of |ctx|, in bytes. It
220  * will crash if a digest hasn't been set on |ctx|. */
221 OPENSSL_EXPORT unsigned EVP_MD_CTX_size(const EVP_MD_CTX *ctx);
222 
223 /* EVP_MD_CTX_block_size returns the block size of the digest function used by
224  * |ctx|, in bytes. It will crash if a digest hasn't been set on |ctx|. */
225 OPENSSL_EXPORT unsigned EVP_MD_CTX_block_size(const EVP_MD_CTX *ctx);
226 
227 /* EVP_MD_CTX_type returns a NID describing the digest function used by |ctx|.
228  * (For example, |NID_sha256|.) It will crash if a digest hasn't been set on
229  * |ctx|. */
230 OPENSSL_EXPORT int EVP_MD_CTX_type(const EVP_MD_CTX *ctx);
231 
232 
233 struct evp_md_pctx_ops;
234 
235 struct env_md_ctx_st {
236   /* digest is the underlying digest function, or NULL if not set. */
237   const EVP_MD *digest;
238   /* md_data points to a block of memory that contains the hash-specific
239    * context. */
240   void *md_data;
241 
242   /* pctx is an opaque (at this layer) pointer to additional context that
243    * EVP_PKEY functions may store in this object. */
244   EVP_PKEY_CTX *pctx;
245 
246   /* pctx_ops, if not NULL, points to a vtable that contains functions to
247    * manipulate |pctx|. */
248   const struct evp_md_pctx_ops *pctx_ops;
249 } /* EVP_MD_CTX */;
250 
251 
252 #if defined(__cplusplus)
253 }  /* extern C */
254 #endif
255 
256 #define DIGEST_R_INPUT_NOT_INITIALIZED 100
257 
258 #endif  /* OPENSSL_HEADER_DIGEST_H */
259