| /*- |
| * 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; |
| } |