/* HMAC-KDF-Extract.
* RFC 5869 - HMAC-based Extract-and-Expand Key Derivation Function (HKDF).
*
* type The hash algorithm type.
* salt The optional salt value.
* saltSz The size of the salt.
* inKey The input keying material.
* inKeySz The size of the input keying material.
* out The pseudorandom key with the length that of the hash.
* returns 0 on success, otherwise failure.
*/
int wc_HKDF_Extract(int type, const byte* salt, word32 saltSz,
const byte* inKey, word32 inKeySz, byte* out)
{
byte tmp[WC_MAX_DIGEST_SIZE]; /* localSalt helper */
Hmac myHmac;
int ret;
const byte* localSalt; /* either points to user input or tmp */
int hashSz;
ret = wc_HmacSizeByType(type);
if (ret < 0)
return ret;
hashSz = ret;
localSalt = salt;
if (localSalt == NULL) {
XMEMSET(tmp, 0, hashSz);
localSalt = tmp;
saltSz = hashSz;
}
ret = wc_HmacInit(&myHmac, NULL, INVALID_DEVID);
if (ret == 0) {
ret = wc_HmacSetKey(&myHmac, type, localSalt, saltSz);
if (ret == 0)
ret = wc_HmacUpdate(&myHmac, inKey, inKeySz);
if (ret == 0)
ret = wc_HmacFinal(&myHmac, out);
wc_HmacFree(&myHmac);
}
return ret;
}
/* HMAC-KDF-Expand.
* RFC 5869 - HMAC-based Extract-and-Expand Key Derivation Function (HKDF).
*
* type The hash algorithm type.
* inKey The input key.
* inKeySz The size of the input key.
* info The application specific information.
* infoSz The size of the application specific information.
* out The output keying material.
* returns 0 on success, otherwise failure.
*/
int wc_HKDF_Expand(int type, const byte* inKey, word32 inKeySz,
const byte* info, word32 infoSz, byte* out, word32 outSz)
{
byte tmp[WC_MAX_DIGEST_SIZE];
Hmac myHmac;
int ret = 0;
word32 outIdx = 0;
word32 hashSz = wc_HmacSizeByType(type);
byte n = 0x1;
ret = wc_HmacInit(&myHmac, NULL, INVALID_DEVID);
if (ret != 0)
return ret;
while (outIdx < outSz) {
int tmpSz = (n == 1) ? 0 : hashSz;
word32 left = outSz - outIdx;
ret = wc_HmacSetKey(&myHmac, type, inKey, inKeySz);
if (ret != 0)
break;
ret = wc_HmacUpdate(&myHmac, tmp, tmpSz);
if (ret != 0)
break;
ret = wc_HmacUpdate(&myHmac, info, infoSz);
if (ret != 0)
break;
ret = wc_HmacUpdate(&myHmac, &n, 1);
if (ret != 0)
break;
ret = wc_HmacFinal(&myHmac, tmp);
if (ret != 0)
break;
left = min(left, hashSz);
XMEMCPY(out+outIdx, tmp, left);
outIdx += hashSz;
n++;
}
wc_HmacFree(&myHmac);
return ret;
}
int wc_HmacInit_Id(Hmac* hmac, unsigned char* id, int len, void* heap,
int devId)
{
int ret = 0;
if (hmac == NULL)
ret = BAD_FUNC_ARG;
if (ret == 0 && (len < 0 || len > HMAC_MAX_ID_LEN))
ret = BUFFER_E;
if (ret == 0)
ret = wc_HmacInit(hmac, heap, devId);
if (ret == 0) {
XMEMCPY(hmac->id, id, len);
hmac->idLen = len;
}
return ret;
}
int wc_PBKDF2(byte* output, const byte* passwd, int pLen, const byte* salt,
int sLen, int iterations, int kLen, int hashType)
{
word32 i = 1;
int hLen;
int j, ret;
Hmac hmac;
#ifdef WOLFSSL_SMALL_STACK
byte* buffer;
#else
byte buffer[MAX_DIGEST_SIZE];
#endif
hLen = GetDigestSize(hashType);
if (hLen < 0)
return BAD_FUNC_ARG;
#ifdef WOLFSSL_SMALL_STACK
buffer = (byte*)XMALLOC(MAX_DIGEST_SIZE, NULL, DYNAMIC_TYPE_TMP_BUFFER);
if (buffer == NULL)
return MEMORY_E;
#endif
ret = wc_HmacInit(&hmac, NULL, INVALID_DEVID);
if (ret == 0) {
ret = wc_HmacSetKey(&hmac, hashType, passwd, pLen);
while (ret == 0 && kLen) {
int currentLen;
ret = wc_HmacUpdate(&hmac, salt, sLen);
if (ret != 0)
break;
/* encode i */
for (j = 0; j < 4; j++) {
byte b = (byte)(i >> ((3-j) * 8));
ret = wc_HmacUpdate(&hmac, &b, 1);
if (ret != 0)
break;
}
/* check ret from inside for loop */
if (ret != 0)
break;
ret = wc_HmacFinal(&hmac, buffer);
if (ret != 0)
break;
currentLen = min(kLen, hLen);
XMEMCPY(output, buffer, currentLen);
for (j = 1; j < iterations; j++) {
ret = wc_HmacUpdate(&hmac, buffer, hLen);
if (ret != 0)
break;
ret = wc_HmacFinal(&hmac, buffer);
if (ret != 0)
break;
xorbuf(output, buffer, currentLen);
}
/* check ret from inside for loop */
if (ret != 0)
break;
output += currentLen;
kLen -= currentLen;
i++;
}
wc_HmacFree(&hmac);
}
