ZDIGEST(3) CZMQ Manual ZDIGEST(3) NAME zdigest - Class for provides hashing functions (SHA-1 at present) SYNOPSIS // This is a stable class, and may not change except for emergencies. It // is provided in stable builds. // Constructor - creates new digest object, which you use to build up a // digest by repeatedly calling zdigest_update() on chunks of data. CZMQ_EXPORT zdigest_t * zdigest_new (void); // Destroy a digest object CZMQ_EXPORT void zdigest_destroy (zdigest_t **self_p); // Add buffer into digest calculation CZMQ_EXPORT void zdigest_update (zdigest_t *self, const byte *buffer, size_t length); // Return final digest hash data. If built without crypto support, // returns NULL. CZMQ_EXPORT const byte * zdigest_data (zdigest_t *self); // Return final digest hash size CZMQ_EXPORT size_t zdigest_size (zdigest_t *self); // Return digest as printable hex string; caller should not modify nor // free this string. After calling this, you may not use zdigest_update() // on the same digest. If built without crypto support, returns NULL. CZMQ_EXPORT char * zdigest_string (zdigest_t *self); // Self test of this class. CZMQ_EXPORT void zdigest_test (bool verbose); Please add '@interface' section in './../src/zdigest.c'. DESCRIPTION The zdigest class generates a hash from zchunks of data. The current algo- rithm is SHA-1, chosen for speed. We are aiming to generate a unique digest for a file, and there are no security issues in this use case. The current code depends on OpenSSL, which might be replaced by hard coded SHA-1 implementation to reduce build dependencies. EXAMPLE From zdigest_test method. byte *buffer = (byte *) zmalloc (1024); memset (buffer, 0xAA, 1024); zdigest_t *digest = zdigest_new (); assert (digest); zdigest_update (digest, buffer, 1024); const byte *data = zdigest_data (digest); assert (data [0] == 0xDE); assert (data [1] == 0xB2); assert (data [2] == 0x38); assert (data [3] == 0x07); assert (streq (zdigest_string (digest), "DEB23807D4FE025E900FE9A9C7D8410C3DDE9671")); zdigest_destroy (&digest); freen (buffer); #if defined (__WINDOWS__) zsys_shutdown(); #endif AUTHORS The czmq manual was written by the authors in the AUTHORS file. RESOURCES Main web site: Report bugs to the email <zeromq-dev@lists.zeromq.org[1]> COPYRIGHT Copyright (c) the Contributors as noted in the AUTHORS file. This file is part of CZMQ, the high-level C binding for 0MQ: http://czmq.zeromq.org. This Source Code Form is subject to the terms of the Mozilla Public Li- cense, v. 2.0. If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/. LICENSE included with the czmq distribution. NOTES 1. zeromq-dev@lists.zeromq.org mailto:zeromq-dev@lists.zeromq.org CZMQ 4.2.1 08/27/2026 ZDIGEST(3)
NAME | SYNOPSIS | DESCRIPTION | EXAMPLE | AUTHORS | RESOURCES | COPYRIGHT | NOTES
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