1 #include <stdio.h>
2 #include <string.h>
3 #include <stdlib.h>
4 #include <errno.h>
5 #include <openssl/evp.h>
6
7 #include "libcryptsetup.h"
8 #include "internal.h"
9
init_crypto(void)10 int init_crypto(void)
11 {
12 return 0;
13 }
14
hash(const char * backend_name,const char * hash_name,char * result,size_t size,const char * passphrase,size_t sizep)15 int hash(const char *backend_name, const char *hash_name,
16 char *result, size_t size,
17 const char *passphrase, size_t sizep)
18 {
19 EVP_MD_CTX *mdctx;
20 const EVP_MD *md;
21 size_t pad = 0;
22 int r = -ENOENT;
23
24 OpenSSL_add_all_digests();
25 md = EVP_get_digestbyname(hash_name);
26 if (md == NULL) {
27 set_error("Unknown hash type %s", hash_name);
28 goto out;
29 }
30
31 if (EVP_MD_size(md) > size) {
32 set_error("requested hash length (%zd) > key length (%zd)", EVP_MD_size(md), size);
33 return -EINVAL;
34 }
35
36 pad = size - EVP_MD_size(md);
37
38 mdctx = EVP_MD_CTX_new();
39 EVP_DigestInit(mdctx, md);
40 EVP_DigestUpdate(mdctx, passphrase, sizep);
41 r = !EVP_DigestFinal(mdctx, result, NULL);
42
43 if (pad) {
44 memset(result+size, 0, pad);
45 }
46
47 EVP_MD_CTX_free(mdctx);
48
49 out:
50 return r;
51 }
52
53