1*4882a593Smuzhiyun
2*4882a593Smuzhiyun #include <memory.h>
3*4882a593Smuzhiyun #include <openssl/evp.h>
4*4882a593Smuzhiyun
5*4882a593Smuzhiyun // ----- KDF FUNCTIONS START -----
6*4882a593Smuzhiyun //typedef void *(*KDF)(const void *in, size_t inlen, void *out, size_t *outlen);
7*4882a593Smuzhiyun
x9_63_kdf(const EVP_MD * md,const unsigned char * share,size_t sharelen,size_t keylen,unsigned char * outkey)8*4882a593Smuzhiyun int x9_63_kdf(const EVP_MD *md, const unsigned char *share, size_t sharelen, size_t keylen, unsigned char *outkey)
9*4882a593Smuzhiyun {
10*4882a593Smuzhiyun int ret = 0;
11*4882a593Smuzhiyun
12*4882a593Smuzhiyun EVP_MD_CTX ctx;
13*4882a593Smuzhiyun unsigned char counter[4] = {0, 0, 0, 1};
14*4882a593Smuzhiyun unsigned char dgst[EVP_MAX_MD_SIZE];
15*4882a593Smuzhiyun unsigned int dgstlen;
16*4882a593Smuzhiyun int rlen = (int)keylen;
17*4882a593Smuzhiyun unsigned char * pp;
18*4882a593Smuzhiyun
19*4882a593Smuzhiyun pp = outkey;
20*4882a593Smuzhiyun
21*4882a593Smuzhiyun if (keylen > (size_t)EVP_MD_size(md)*255)
22*4882a593Smuzhiyun {
23*4882a593Smuzhiyun fprintf(stderr, "%s(%d):", __FILE__, __LINE__);
24*4882a593Smuzhiyun goto end;
25*4882a593Smuzhiyun }
26*4882a593Smuzhiyun
27*4882a593Smuzhiyun while (rlen > 0)
28*4882a593Smuzhiyun {
29*4882a593Smuzhiyun EVP_MD_CTX_init(&ctx);
30*4882a593Smuzhiyun
31*4882a593Smuzhiyun if (!EVP_DigestInit(&ctx, md))
32*4882a593Smuzhiyun {
33*4882a593Smuzhiyun fprintf(stderr, "%s(%d):", __FILE__, __LINE__);
34*4882a593Smuzhiyun goto end;
35*4882a593Smuzhiyun }
36*4882a593Smuzhiyun
37*4882a593Smuzhiyun if (!EVP_DigestUpdate(&ctx, share, sharelen))
38*4882a593Smuzhiyun {
39*4882a593Smuzhiyun fprintf(stderr, "%s(%d):", __FILE__, __LINE__);
40*4882a593Smuzhiyun goto end;
41*4882a593Smuzhiyun }
42*4882a593Smuzhiyun if (!EVP_DigestUpdate(&ctx, counter, 4))
43*4882a593Smuzhiyun {
44*4882a593Smuzhiyun fprintf(stderr, "%s(%d):", __FILE__, __LINE__);
45*4882a593Smuzhiyun goto end;
46*4882a593Smuzhiyun }
47*4882a593Smuzhiyun if (!EVP_DigestFinal(&ctx, dgst, &dgstlen))
48*4882a593Smuzhiyun {
49*4882a593Smuzhiyun fprintf(stderr, "%s(%d):", __FILE__, __LINE__);
50*4882a593Smuzhiyun goto end;
51*4882a593Smuzhiyun }
52*4882a593Smuzhiyun
53*4882a593Smuzhiyun EVP_MD_CTX_cleanup(&ctx);
54*4882a593Smuzhiyun
55*4882a593Smuzhiyun memcpy(pp, dgst, keylen>=dgstlen ? dgstlen:keylen);
56*4882a593Smuzhiyun
57*4882a593Smuzhiyun rlen -= dgstlen;
58*4882a593Smuzhiyun pp += dgstlen;
59*4882a593Smuzhiyun counter[3]++;
60*4882a593Smuzhiyun }
61*4882a593Smuzhiyun
62*4882a593Smuzhiyun ret = 1;
63*4882a593Smuzhiyun
64*4882a593Smuzhiyun end:
65*4882a593Smuzhiyun return ret;
66*4882a593Smuzhiyun }
67*4882a593Smuzhiyun
68*4882a593Smuzhiyun // ----- KDF FUNCTIONS END -----