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- /*-
- * Copyright 2019-2021 The OpenSSL Project Authors. All Rights Reserved.
- *
- * Licensed under the Apache License 2.0 (the "License"). You may not use
- * this file except in compliance with the License. You can obtain a copy
- * in the file LICENSE in the source distribution or at
- * https://www.openssl.org/source/license.html
- */
- /*-
- * Example of using EVP_MD_fetch and EVP_Digest* methods to calculate
- * a digest of static buffers
- * You can find SHA3 test vectors from NIST here:
- * https://csrc.nist.gov/CSRC/media/Projects/Cryptographic-Algorithm-Validation-Program/documents/sha3/sha-3bytetestvectors.zip
- * For example, contains these lines:
- Len = 80
- Msg = 1ca984dcc913344370cf
- MD = 6915ea0eeffb99b9b246a0e34daf3947852684c3d618260119a22835659e4f23d4eb66a15d0affb8e93771578f5e8f25b7a5f2a55f511fb8b96325ba2cd14816
- * use xxd convert the hex message string to binary input for BIO_f_md:
- * echo "1ca984dcc913344370cf" | xxd -r -p | ./BIO_f_md
- * and then verify the output matches MD above.
- */
- #include <string.h>
- #include <stdio.h>
- #include <openssl/err.h>
- #include <openssl/bio.h>
- #include <openssl/evp.h>
- /*-
- * This demonstration will show how to digest data using
- * a BIO configured with a message digest
- * A message digest name may be passed as an argument.
- * The default digest is SHA3-512
- */
- int main(int argc, char * argv[])
- {
- int result = 1;
- OSSL_LIB_CTX *library_context = NULL;
- BIO *input = NULL;
- BIO *bio_digest = NULL;
- EVP_MD *md = NULL;
- unsigned char buffer[512];
- size_t readct, writect;
- size_t digest_size;
- char *digest_value=NULL;
- int j;
- input = BIO_new_fd(fileno(stdin), 1);
- if (input == NULL) {
- fprintf(stderr, "BIO_new_fd() for stdin returned NULL\n");
- goto cleanup;
- }
- library_context = OSSL_LIB_CTX_new();
- if (library_context == NULL) {
- fprintf(stderr, "OSSL_LIB_CTX_new() returned NULL\n");
- goto cleanup;
- }
- /*
- * Fetch a message digest by name
- * The algorithm name is case insensitive.
- * See providers(7) for details about algorithm fetching
- */
- md = EVP_MD_fetch(library_context, "SHA3-512", NULL);
- if (md == NULL) {
- fprintf(stderr, "EVP_MD_fetch did not find SHA3-512.\n");
- goto cleanup;
- }
- digest_size = EVP_MD_get_size(md);
- digest_value = OPENSSL_malloc(digest_size);
- if (digest_value == NULL) {
- fprintf(stderr, "Can't allocate %lu bytes for the digest value.\n", (unsigned long)digest_size);
- goto cleanup;
- }
- /* Make a bio that uses the digest */
- bio_digest = BIO_new(BIO_f_md());
- if (bio_digest == NULL) {
- fprintf(stderr, "BIO_new(BIO_f_md()) returned NULL\n");
- goto cleanup;
- }
- /* set our bio_digest BIO to digest data */
- if (BIO_set_md(bio_digest, md) != 1) {
- fprintf(stderr, "BIO_set_md failed.\n");
- goto cleanup;
- }
- /*-
- * We will use BIO chaining so that as we read, the digest gets updated
- * See the man page for BIO_push
- */
- BIO *reading = BIO_push(bio_digest, input);
- while (BIO_read(reading, buffer, sizeof(buffer)) > 0)
- ;
- /*-
- * BIO_gets must be used to calculate the final
- * digest value and then copy it to digest_value.
- */
- if (BIO_gets(bio_digest, digest_value, digest_size) != digest_size) {
- fprintf(stderr, "BIO_gets(bio_digest) failed\n");
- goto cleanup;
- }
- for (j = 0; j < digest_size; j++) {
- fprintf(stdout, "%02x", (unsigned char)digest_value[j]);
- }
- fprintf(stdout, "\n");
- result = 0;
- cleanup:
- if (result != 0)
- ERR_print_errors_fp(stderr);
- OPENSSL_free(digest_value);
- BIO_free(input);
- BIO_free(bio_digest);
- EVP_MD_free(md);
- OSSL_LIB_CTX_free(library_context);
- return result;
- }
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