EVP Message Digests - Revision history

Jwalton: Add info on EVP_MD_CTX_create and EVP_MD_CTX_destroy from OpenSSL 1.0.2.

2022-01-12T01:51:21Z

Add info on EVP_MD_CTX_create and EVP_MD_CTX_destroy from OpenSSL 1.0.2.

2020-01-27T09:15:23Z

An Example use of a Hash Function

2017-04-28T23:00:21Z

Add links to all EVP articles.

2017-04-28T22:59:13Z

Add InfoBox

2016-04-05T23:13:32Z

Add const-ness

2016-04-05T23:03:31Z

Added message_len parameter; used message_len in call to EVP_DigestUpdate.

2013-05-07T20:42:42Z

Modified manual links to point to the wiki manual pages

2013-03-28T18:17:02Z

SHA-2 Category usage

2013-03-24T18:11:18Z

2013-03-24T18:07:01Z

@@ Line 45: / Line 45: @@
 	EVP_MD_CTX_free(mdctx);
+}
 </pre>

@@ Line 28: / Line 28: @@
 	EVP_MD_CTX *mdctx;
-	if((mdctx = EVP_MD_CTX_create()) == NULL)
+	if((mdctx = EVP_MD_CTX_new()) == NULL)
 		handleErrors();
@@ Line 43: / Line 43: @@
 		handleErrors();
-	EVP_MD_CTX_destroy(mdctx);
+	EVP_MD_CTX_free(mdctx);
+}
 </pre>

@@ Line 52: / Line 52: @@
 * [[EVP]]
 * [[Libcrypto API]]
 [[Category:Crypto API]]
 [[Category:C level]]
 [[Category:Examples]]

← Older revision		Revision as of 22:59, 28 April 2017
Line 1:		Line 1:
		+	{{DocInclude
		+	\|Name=Message Digests
		+	\|Url=http://wiki.openssl.org/index.php/Manual:Evp(3)
		+	\|Include=evp.h}}
		+
	A Message Digest or Hash Function takes any arbitrary message (with any content or length) as an input and provides a fixed size hash value as a result. Specifically the function exhibits the following properties:		A Message Digest or Hash Function takes any arbitrary message (with any content or length) as an input and provides a fixed size hash value as a result. Specifically the function exhibits the following properties:
	* It is simple to create a hash value for any given message		* It is simple to create a hash value for any given message

@@ Line 19: / Line 19: @@
 <pre>
-void digest_message(unsigned char *message, size_t message_len, unsigned char **digest, unsigned int *digest_len)
+void digest_message(const unsigned char *message, size_t message_len, unsigned char **digest, unsigned int *digest_len)
+{
 	EVP_MD_CTX *mdctx;

@@ Line 42: / Line 42: @@
 </pre>
-Refer to the OpenSSL manual page for further details http://www.openssl.org/docs/crypto/EVP_DigestInit.html
+Refer to the OpenSSL manual page for further details [[Manual:EVP_DigestInit(3)]]
 ==See also==

@@ Line 5: / Line 5: @@
 * It is infeasible to find two messages that result in the same hash
-The OpenSSL library supports a wide number of different hash functions including the popular SHA-2 set of hash functions (i.e. SHA-224, SHA-256, SHA-384 and SHA-512).
+The OpenSSL library supports a wide number of different hash functions including the popular [[:Category:SHA-2]] set of hash functions (i.e. [[SHA-224]], [[SHA-256]], [[SHA-384]] and [[SHA-512]]).
 ==An Example use of a Hash Function==