diff options
Diffstat (limited to 'src/lib/libcrypto/doc/EVP_DigestInit.pod')
-rw-r--r-- | src/lib/libcrypto/doc/EVP_DigestInit.pod | 278 |
1 files changed, 0 insertions, 278 deletions
diff --git a/src/lib/libcrypto/doc/EVP_DigestInit.pod b/src/lib/libcrypto/doc/EVP_DigestInit.pod deleted file mode 100644 index ccb19fc0a7..0000000000 --- a/src/lib/libcrypto/doc/EVP_DigestInit.pod +++ /dev/null | |||
@@ -1,278 +0,0 @@ | |||
1 | =pod | ||
2 | |||
3 | =head1 NAME | ||
4 | |||
5 | EVP_MD_CTX_init, EVP_MD_CTX_create, EVP_DigestInit_ex, EVP_DigestUpdate, | ||
6 | EVP_DigestFinal_ex, EVP_MD_CTX_cleanup, EVP_MD_CTX_destroy, EVP_MAX_MD_SIZE, | ||
7 | EVP_MD_CTX_copy_ex, EVP_MD_CTX_copy, EVP_MD_type, EVP_MD_pkey_type, | ||
8 | EVP_MD_size, EVP_MD_block_size, EVP_MD_CTX_md, EVP_MD_CTX_size, | ||
9 | EVP_MD_CTX_block_size, EVP_MD_CTX_type, EVP_md_null, EVP_md2, EVP_md5, EVP_sha, | ||
10 | EVP_sha1, EVP_sha224, EVP_sha256, EVP_sha384, EVP_sha512, EVP_dss, EVP_dss1, | ||
11 | EVP_ripemd160, EVP_get_digestbyname, EVP_get_digestbynid, | ||
12 | EVP_get_digestbyobj - EVP digest routines | ||
13 | |||
14 | =head1 SYNOPSIS | ||
15 | |||
16 | #include <openssl/evp.h> | ||
17 | |||
18 | void EVP_MD_CTX_init(EVP_MD_CTX *ctx); | ||
19 | EVP_MD_CTX *EVP_MD_CTX_create(void); | ||
20 | |||
21 | int EVP_DigestInit_ex(EVP_MD_CTX *ctx, const EVP_MD *type, ENGINE *impl); | ||
22 | int EVP_DigestUpdate(EVP_MD_CTX *ctx, const void *d, size_t cnt); | ||
23 | int EVP_DigestFinal_ex(EVP_MD_CTX *ctx, unsigned char *md, | ||
24 | unsigned int *s); | ||
25 | |||
26 | int EVP_MD_CTX_cleanup(EVP_MD_CTX *ctx); | ||
27 | void EVP_MD_CTX_destroy(EVP_MD_CTX *ctx); | ||
28 | |||
29 | int EVP_MD_CTX_copy_ex(EVP_MD_CTX *out,const EVP_MD_CTX *in); | ||
30 | |||
31 | int EVP_DigestInit(EVP_MD_CTX *ctx, const EVP_MD *type); | ||
32 | int EVP_DigestFinal(EVP_MD_CTX *ctx, unsigned char *md, | ||
33 | unsigned int *s); | ||
34 | |||
35 | int EVP_MD_CTX_copy(EVP_MD_CTX *out,EVP_MD_CTX *in); | ||
36 | |||
37 | #define EVP_MAX_MD_SIZE 64 /* SHA512 */ | ||
38 | |||
39 | int EVP_MD_type(const EVP_MD *md); | ||
40 | int EVP_MD_pkey_type(const EVP_MD *md); | ||
41 | int EVP_MD_size(const EVP_MD *md); | ||
42 | int EVP_MD_block_size(const EVP_MD *md); | ||
43 | |||
44 | const EVP_MD *EVP_MD_CTX_md(const EVP_MD_CTX *ctx); | ||
45 | #define EVP_MD_CTX_size(e) EVP_MD_size(EVP_MD_CTX_md(e)) | ||
46 | #define EVP_MD_CTX_block_size(e) EVP_MD_block_size((e)->digest) | ||
47 | #define EVP_MD_CTX_type(e) EVP_MD_type((e)->digest) | ||
48 | |||
49 | const EVP_MD *EVP_md_null(void); | ||
50 | const EVP_MD *EVP_md2(void); | ||
51 | const EVP_MD *EVP_md5(void); | ||
52 | const EVP_MD *EVP_sha(void); | ||
53 | const EVP_MD *EVP_sha1(void); | ||
54 | const EVP_MD *EVP_dss(void); | ||
55 | const EVP_MD *EVP_dss1(void); | ||
56 | const EVP_MD *EVP_ripemd160(void); | ||
57 | |||
58 | const EVP_MD *EVP_sha224(void); | ||
59 | const EVP_MD *EVP_sha256(void); | ||
60 | const EVP_MD *EVP_sha384(void); | ||
61 | const EVP_MD *EVP_sha512(void); | ||
62 | |||
63 | const EVP_MD *EVP_get_digestbyname(const char *name); | ||
64 | #define EVP_get_digestbynid(a) EVP_get_digestbyname(OBJ_nid2sn(a)) | ||
65 | #define EVP_get_digestbyobj(a) EVP_get_digestbynid(OBJ_obj2nid(a)) | ||
66 | |||
67 | =head1 DESCRIPTION | ||
68 | |||
69 | The EVP digest routines are a high level interface to message digests. | ||
70 | |||
71 | EVP_MD_CTX_init() initializes digest context B<ctx>. | ||
72 | |||
73 | EVP_MD_CTX_create() allocates, initializes and returns a digest context. | ||
74 | |||
75 | EVP_DigestInit_ex() sets up digest context B<ctx> to use a digest | ||
76 | B<type> from ENGINE B<impl>. B<ctx> must be initialized before calling this | ||
77 | function. B<type> will typically be supplied by a function such as EVP_sha1(). | ||
78 | If B<impl> is NULL then the default implementation of digest B<type> is used. | ||
79 | |||
80 | EVP_DigestUpdate() hashes B<cnt> bytes of data at B<d> into the | ||
81 | digest context B<ctx>. This function can be called several times on the | ||
82 | same B<ctx> to hash additional data. | ||
83 | |||
84 | EVP_DigestFinal_ex() retrieves the digest value from B<ctx> and places | ||
85 | it in B<md>. If the B<s> parameter is not NULL then the number of | ||
86 | bytes of data written (i.e. the length of the digest) will be written | ||
87 | to the integer at B<s>, at most B<EVP_MAX_MD_SIZE> bytes will be written. | ||
88 | After calling EVP_DigestFinal_ex() no additional calls to EVP_DigestUpdate() | ||
89 | can be made, but EVP_DigestInit_ex() can be called to initialize a new | ||
90 | digest operation. | ||
91 | |||
92 | EVP_MD_CTX_cleanup() cleans up digest context B<ctx>, it should be called | ||
93 | after a digest context is no longer needed. | ||
94 | |||
95 | EVP_MD_CTX_destroy() cleans up digest context B<ctx> and frees up the | ||
96 | space allocated to it, it should be called only on a context created | ||
97 | using EVP_MD_CTX_create(). | ||
98 | |||
99 | EVP_MD_CTX_copy_ex() can be used to copy the message digest state from | ||
100 | B<in> to B<out>. This is useful if large amounts of data are to be | ||
101 | hashed which only differ in the last few bytes. B<out> must be initialized | ||
102 | before calling this function. | ||
103 | |||
104 | EVP_DigestInit() behaves in the same way as EVP_DigestInit_ex() except | ||
105 | the passed context B<ctx> does not have to be initialized, and it always | ||
106 | uses the default digest implementation. | ||
107 | |||
108 | EVP_DigestFinal() is similar to EVP_DigestFinal_ex() except the digest | ||
109 | context B<ctx> is automatically cleaned up. | ||
110 | |||
111 | EVP_MD_CTX_copy() is similar to EVP_MD_CTX_copy_ex() except the destination | ||
112 | B<out> does not have to be initialized. | ||
113 | |||
114 | EVP_MD_size() and EVP_MD_CTX_size() return the size of the message digest | ||
115 | when passed an B<EVP_MD> or an B<EVP_MD_CTX> structure, i.e. the size of the | ||
116 | hash. | ||
117 | |||
118 | EVP_MD_block_size() and EVP_MD_CTX_block_size() return the block size of the | ||
119 | message digest when passed an B<EVP_MD> or an B<EVP_MD_CTX> structure. | ||
120 | |||
121 | EVP_MD_type() and EVP_MD_CTX_type() return the NID of the OBJECT IDENTIFIER | ||
122 | representing the given message digest when passed an B<EVP_MD> structure. | ||
123 | For example EVP_MD_type(EVP_sha1()) returns B<NID_sha1>. This function is | ||
124 | normally used when setting ASN1 OIDs. | ||
125 | |||
126 | EVP_MD_CTX_md() returns the B<EVP_MD> structure corresponding to the passed | ||
127 | B<EVP_MD_CTX>. | ||
128 | |||
129 | EVP_MD_pkey_type() returns the NID of the public key signing algorithm | ||
130 | associated with this digest. For example EVP_sha1() is associated with RSA so | ||
131 | this will return B<NID_sha1WithRSAEncryption>. Since digests and signature | ||
132 | algorithms are no longer linked this function is only retained for | ||
133 | compatibility reasons. | ||
134 | |||
135 | EVP_md2(), EVP_md5(), EVP_sha(), EVP_sha1(), EVP_sha224(), EVP_sha256(), | ||
136 | EVP_sha384(), EVP_sha512() and EVP_ripemd160() return B<EVP_MD> | ||
137 | structures for the MD2, MD5, SHA, SHA1, SHA224, SHA256, SHA384, SHA512 | ||
138 | and RIPEMD160 digest algorithms respectively. | ||
139 | |||
140 | EVP_dss() and EVP_dss1() return B<EVP_MD> structures for SHA and SHA1 digest | ||
141 | algorithms but using DSS (DSA) for the signature algorithm. Note: there is | ||
142 | no need to use these pseudo-digests in OpenSSL 1.0.0 and later, they are | ||
143 | however retained for compatibility. | ||
144 | |||
145 | EVP_md_null() is a "null" message digest that does nothing: i.e. the hash it | ||
146 | returns is of zero length. | ||
147 | |||
148 | EVP_get_digestbyname(), EVP_get_digestbynid() and EVP_get_digestbyobj() | ||
149 | return an B<EVP_MD> structure when passed a digest name, a digest NID or | ||
150 | an ASN1_OBJECT structure respectively. The digest table must be initialized | ||
151 | using, for example, OpenSSL_add_all_digests() for these functions to work. | ||
152 | |||
153 | =head1 RETURN VALUES | ||
154 | |||
155 | EVP_DigestInit_ex(), EVP_DigestUpdate() and EVP_DigestFinal_ex() return 1 for | ||
156 | success and 0 for failure. | ||
157 | |||
158 | EVP_MD_CTX_copy_ex() returns 1 if successful or 0 for failure. | ||
159 | |||
160 | EVP_MD_type(), EVP_MD_pkey_type() and EVP_MD_type() return the NID of the | ||
161 | corresponding OBJECT IDENTIFIER or NID_undef if none exists. | ||
162 | |||
163 | EVP_MD_size(), EVP_MD_block_size(), EVP_MD_CTX_size() and | ||
164 | EVP_MD_CTX_block_size() return the digest or block size in bytes. | ||
165 | |||
166 | EVP_md_null(), EVP_md2(), EVP_md5(), EVP_sha(), EVP_sha1(), EVP_dss(), | ||
167 | EVP_dss1() and EVP_ripemd160() return pointers to the | ||
168 | corresponding EVP_MD structures. | ||
169 | |||
170 | EVP_get_digestbyname(), EVP_get_digestbynid() and EVP_get_digestbyobj() | ||
171 | return either an B<EVP_MD> structure or NULL if an error occurs. | ||
172 | |||
173 | =head1 NOTES | ||
174 | |||
175 | The B<EVP> interface to message digests should almost always be used in | ||
176 | preference to the low level interfaces. This is because the code then becomes | ||
177 | transparent to the digest used and much more flexible. | ||
178 | |||
179 | New applications should use the SHA2 digest algorithms such as SHA256. | ||
180 | The other digest algorithms are still in common use. | ||
181 | |||
182 | For most applications the B<impl> parameter to EVP_DigestInit_ex() will be | ||
183 | set to NULL to use the default digest implementation. | ||
184 | |||
185 | The functions EVP_DigestInit(), EVP_DigestFinal() and EVP_MD_CTX_copy() are | ||
186 | obsolete but are retained to maintain compatibility with existing code. New | ||
187 | applications should use EVP_DigestInit_ex(), EVP_DigestFinal_ex() and | ||
188 | EVP_MD_CTX_copy_ex() because they can efficiently reuse a digest context | ||
189 | instead of initializing and cleaning it up on each call and allow non default | ||
190 | implementations of digests to be specified. | ||
191 | |||
192 | In OpenSSL 0.9.7 and later if digest contexts are not cleaned up after use | ||
193 | memory leaks will occur. | ||
194 | |||
195 | Stack allocation of EVP_MD_CTX structures is common, for example: | ||
196 | |||
197 | EVP_MD_CTX mctx; | ||
198 | EVP_MD_CTX_init(&mctx); | ||
199 | |||
200 | This will cause binary compatibility issues if the size of EVP_MD_CTX | ||
201 | structure changes (this will only happen with a major release of OpenSSL). | ||
202 | Applications wishing to avoid this should use EVP_MD_CTX_create() instead: | ||
203 | |||
204 | EVP_MD_CTX *mctx; | ||
205 | mctx = EVP_MD_CTX_create(); | ||
206 | |||
207 | |||
208 | =head1 EXAMPLE | ||
209 | |||
210 | This example digests the data "Test Message\n" and "Hello World\n", using the | ||
211 | digest name passed on the command line. | ||
212 | |||
213 | #include <stdio.h> | ||
214 | #include <openssl/evp.h> | ||
215 | |||
216 | int | ||
217 | main(int argc, char *argv[]) | ||
218 | { | ||
219 | EVP_MD_CTX *mdctx; | ||
220 | const EVP_MD *md; | ||
221 | const char mess1[] = "Test Message\n"; | ||
222 | const char mess2[] = "Hello World\n"; | ||
223 | unsigned char md_value[EVP_MAX_MD_SIZE]; | ||
224 | int md_len, i; | ||
225 | |||
226 | OpenSSL_add_all_digests(); | ||
227 | |||
228 | if (argc <= 1) { | ||
229 | printf("Usage: mdtest digestname\n"); | ||
230 | exit(1); | ||
231 | } | ||
232 | |||
233 | md = EVP_get_digestbyname(argv[1]); | ||
234 | if (md == NULL) { | ||
235 | printf("Unknown message digest %s\n", argv[1]); | ||
236 | exit(1); | ||
237 | } | ||
238 | |||
239 | mdctx = EVP_MD_CTX_create(); | ||
240 | EVP_DigestInit_ex(mdctx, md, NULL); | ||
241 | EVP_DigestUpdate(mdctx, mess1, strlen(mess1)); | ||
242 | EVP_DigestUpdate(mdctx, mess2, strlen(mess2)); | ||
243 | EVP_DigestFinal_ex(mdctx, md_value, &md_len); | ||
244 | EVP_MD_CTX_destroy(mdctx); | ||
245 | |||
246 | printf("Digest is: "); | ||
247 | for(i = 0; i < md_len; i++) | ||
248 | printf("%02x", md_value[i]); | ||
249 | printf("\n"); | ||
250 | } | ||
251 | |||
252 | =head1 SEE ALSO | ||
253 | |||
254 | L<evp(3)|evp(3)>, L<hmac(3)|hmac(3)>, L<md2(3)|md2(3)>, | ||
255 | L<md5(3)|md5(3)>, L<ripemd(3)|ripemd(3)>, | ||
256 | L<sha(3)|sha(3)>, L<dgst(1)|dgst(1)> | ||
257 | |||
258 | =head1 HISTORY | ||
259 | |||
260 | EVP_DigestInit(), EVP_DigestUpdate() and EVP_DigestFinal() are | ||
261 | available in all versions of SSLeay and OpenSSL. | ||
262 | |||
263 | EVP_MD_CTX_init(), EVP_MD_CTX_create(), EVP_MD_CTX_copy_ex(), | ||
264 | EVP_MD_CTX_cleanup(), EVP_MD_CTX_destroy(), EVP_DigestInit_ex() | ||
265 | and EVP_DigestFinal_ex() were added in OpenSSL 0.9.7. | ||
266 | |||
267 | EVP_md_null(), EVP_md2(), EVP_md5(), EVP_sha(), EVP_sha1(), | ||
268 | EVP_dss(), EVP_dss1() and EVP_ripemd160() were | ||
269 | changed to return truely const EVP_MD * in OpenSSL 0.9.7. | ||
270 | |||
271 | The link between digests and signing algorithms was fixed in OpenSSL 1.0 and | ||
272 | later, so now EVP_sha1() can be used with RSA and DSA, there is no need to | ||
273 | use EVP_dss1() any more. | ||
274 | |||
275 | OpenSSL 1.0 and later does not include the MD2 digest algorithm in the | ||
276 | default configuration due to its security weaknesses. | ||
277 | |||
278 | =cut | ||