mirror of
https://github.com/bol-van/zapret.git
synced 2024-11-15 02:58:34 +05:00
338 lines
9.7 KiB
C
338 lines
9.7 KiB
C
/**************************** hkdf.c ***************************/
|
|
/***************** See RFC 6234 for details. *******************/
|
|
/* Copyright (c) 2011 IETF Trust and the persons identified as */
|
|
/* authors of the code. All rights reserved. */
|
|
/* See sha.h for terms of use and redistribution. */
|
|
|
|
/*
|
|
* Description:
|
|
* This file implements the HKDF algorithm (HMAC-based
|
|
* Extract-and-Expand Key Derivation Function, RFC 5869),
|
|
* expressed in terms of the various SHA algorithms.
|
|
*/
|
|
|
|
#include "sha.h"
|
|
#include <string.h>
|
|
#include <stdlib.h>
|
|
|
|
/*
|
|
* hkdf
|
|
*
|
|
* Description:
|
|
* This function will generate keying material using HKDF.
|
|
*
|
|
* Parameters:
|
|
* whichSha: [in]
|
|
* One of SHA1, SHA224, SHA256, SHA384, SHA512
|
|
* salt[ ]: [in]
|
|
* The optional salt value (a non-secret random value);
|
|
* if not provided (salt == NULL), it is set internally
|
|
* to a string of HashLen(whichSha) zeros.
|
|
* salt_len: [in]
|
|
* The length of the salt value. (Ignored if salt == NULL.)
|
|
* ikm[ ]: [in]
|
|
* Input keying material.
|
|
* ikm_len: [in]
|
|
* The length of the input keying material.
|
|
* info[ ]: [in]
|
|
* The optional context and application specific information.
|
|
* If info == NULL or a zero-length string, it is ignored.
|
|
* info_len: [in]
|
|
* The length of the optional context and application specific
|
|
* information. (Ignored if info == NULL.)
|
|
* okm[ ]: [out]
|
|
* Where the HKDF is to be stored.
|
|
* okm_len: [in]
|
|
* The length of the buffer to hold okm.
|
|
* okm_len must be <= 255 * USHABlockSize(whichSha)
|
|
*
|
|
* Notes:
|
|
* Calls hkdfExtract() and hkdfExpand().
|
|
*
|
|
* Returns:
|
|
* sha Error Code.
|
|
*
|
|
*/
|
|
int hkdf(SHAversion whichSha,
|
|
const unsigned char *salt, size_t salt_len,
|
|
const unsigned char *ikm, size_t ikm_len,
|
|
const unsigned char *info, size_t info_len,
|
|
uint8_t okm[], size_t okm_len)
|
|
{
|
|
uint8_t prk[USHAMaxHashSize];
|
|
return hkdfExtract(whichSha, salt, salt_len, ikm, ikm_len, prk) ||
|
|
hkdfExpand(whichSha, prk, USHAHashSize(whichSha), info,
|
|
info_len, okm, okm_len);
|
|
}
|
|
|
|
/*
|
|
* hkdfExtract
|
|
*
|
|
* Description:
|
|
* This function will perform HKDF extraction.
|
|
*
|
|
* Parameters:
|
|
* whichSha: [in]
|
|
* One of SHA1, SHA224, SHA256, SHA384, SHA512
|
|
* salt[ ]: [in]
|
|
* The optional salt value (a non-secret random value);
|
|
* if not provided (salt == NULL), it is set internally
|
|
* to a string of HashLen(whichSha) zeros.
|
|
* salt_len: [in]
|
|
* The length of the salt value. (Ignored if salt == NULL.)
|
|
* ikm[ ]: [in]
|
|
* Input keying material.
|
|
* ikm_len: [in]
|
|
* The length of the input keying material.
|
|
* prk[ ]: [out]
|
|
* Array where the HKDF extraction is to be stored.
|
|
* Must be larger than USHAHashSize(whichSha);
|
|
*
|
|
* Returns:
|
|
* sha Error Code.
|
|
*
|
|
*/
|
|
int hkdfExtract(SHAversion whichSha,
|
|
const unsigned char *salt, size_t salt_len,
|
|
const unsigned char *ikm, size_t ikm_len,
|
|
uint8_t prk[USHAMaxHashSize])
|
|
{
|
|
unsigned char nullSalt[USHAMaxHashSize];
|
|
if (salt == 0) {
|
|
salt = nullSalt;
|
|
salt_len = USHAHashSize(whichSha);
|
|
memset(nullSalt, '\0', salt_len);
|
|
}
|
|
else if (salt_len < 0) {
|
|
return shaBadParam;
|
|
}
|
|
return hmac(whichSha, ikm, ikm_len, salt, salt_len, prk);
|
|
}
|
|
|
|
/*
|
|
* hkdfExpand
|
|
*
|
|
* Description:
|
|
* This function will perform HKDF expansion.
|
|
*
|
|
* Parameters:
|
|
* whichSha: [in]
|
|
* One of SHA1, SHA224, SHA256, SHA384, SHA512
|
|
* prk[ ]: [in]
|
|
* The pseudo-random key to be expanded; either obtained
|
|
* directly from a cryptographically strong, uniformly
|
|
* distributed pseudo-random number generator, or as the
|
|
* output from hkdfExtract().
|
|
* prk_len: [in]
|
|
* The length of the pseudo-random key in prk;
|
|
* should at least be equal to USHAHashSize(whichSHA).
|
|
* info[ ]: [in]
|
|
* The optional context and application specific information.
|
|
* If info == NULL or a zero-length string, it is ignored.
|
|
* info_len: [in]
|
|
* The length of the optional context and application specific
|
|
* information. (Ignored if info == NULL.)
|
|
* okm[ ]: [out]
|
|
* Where the HKDF is to be stored.
|
|
* okm_len: [in]
|
|
* The length of the buffer to hold okm.
|
|
* okm_len must be <= 255 * USHABlockSize(whichSha)
|
|
*
|
|
* Returns:
|
|
* sha Error Code.
|
|
*
|
|
*/
|
|
int hkdfExpand(SHAversion whichSha, const uint8_t prk[], size_t prk_len,
|
|
const unsigned char *info, size_t info_len,
|
|
uint8_t okm[], size_t okm_len)
|
|
{
|
|
size_t hash_len, N;
|
|
unsigned char T[USHAMaxHashSize];
|
|
size_t Tlen, where, i;
|
|
|
|
if (info == 0) {
|
|
info = (const unsigned char *)"";
|
|
info_len = 0;
|
|
}
|
|
else if (info_len < 0) {
|
|
return shaBadParam;
|
|
}
|
|
if (okm_len <= 0) return shaBadParam;
|
|
if (!okm) return shaBadParam;
|
|
|
|
hash_len = USHAHashSize(whichSha);
|
|
if (prk_len < hash_len) return shaBadParam;
|
|
N = okm_len / hash_len;
|
|
if ((okm_len % hash_len) != 0) N++;
|
|
if (N > 255) return shaBadParam;
|
|
|
|
Tlen = 0;
|
|
where = 0;
|
|
for (i = 1; i <= N; i++) {
|
|
HMACContext context;
|
|
unsigned char c = i;
|
|
int ret = hmacReset(&context, whichSha, prk, prk_len) ||
|
|
hmacInput(&context, T, Tlen) ||
|
|
hmacInput(&context, info, info_len) ||
|
|
hmacInput(&context, &c, 1) ||
|
|
hmacResult(&context, T);
|
|
if (ret != shaSuccess) return ret;
|
|
memcpy(okm + where, T,
|
|
(i != N) ? hash_len : (okm_len - where));
|
|
where += hash_len;
|
|
Tlen = hash_len;
|
|
}
|
|
return shaSuccess;
|
|
}
|
|
|
|
/*
|
|
* hkdfReset
|
|
*
|
|
* Description:
|
|
* This function will initialize the hkdfContext in preparation
|
|
* for key derivation using the modular HKDF interface for
|
|
* arbitrary length inputs.
|
|
*
|
|
* Parameters:
|
|
* context: [in/out]
|
|
* The context to reset.
|
|
* whichSha: [in]
|
|
* One of SHA1, SHA224, SHA256, SHA384, SHA512
|
|
* salt[ ]: [in]
|
|
* The optional salt value (a non-secret random value);
|
|
* if not provided (salt == NULL), it is set internally
|
|
* to a string of HashLen(whichSha) zeros.
|
|
* salt_len: [in]
|
|
* The length of the salt value. (Ignored if salt == NULL.)
|
|
*
|
|
* Returns:
|
|
* sha Error Code.
|
|
*
|
|
*/
|
|
int hkdfReset(HKDFContext *context, enum SHAversion whichSha,
|
|
const unsigned char *salt, size_t salt_len)
|
|
{
|
|
unsigned char nullSalt[USHAMaxHashSize];
|
|
if (!context) return shaNull;
|
|
|
|
context->whichSha = whichSha;
|
|
context->hashSize = USHAHashSize(whichSha);
|
|
if (salt == 0) {
|
|
salt = nullSalt;
|
|
salt_len = context->hashSize;
|
|
memset(nullSalt, '\0', salt_len);
|
|
}
|
|
|
|
return hmacReset(&context->hmacContext, whichSha, salt, salt_len);
|
|
}
|
|
|
|
/*
|
|
* hkdfInput
|
|
*
|
|
* Description:
|
|
* This function accepts an array of octets as the next portion
|
|
* of the input keying material. It may be called multiple times.
|
|
*
|
|
* Parameters:
|
|
* context: [in/out]
|
|
* The HKDF context to update.
|
|
* ikm[ ]: [in]
|
|
* An array of octets representing the next portion of
|
|
* the input keying material.
|
|
* ikm_len: [in]
|
|
* The length of ikm.
|
|
*
|
|
* Returns:
|
|
* sha Error Code.
|
|
*
|
|
*/
|
|
int hkdfInput(HKDFContext *context, const unsigned char *ikm,
|
|
size_t ikm_len)
|
|
{
|
|
if (!context) return shaNull;
|
|
if (context->Corrupted) return context->Corrupted;
|
|
if (context->Computed) return context->Corrupted = shaStateError;
|
|
return hmacInput(&context->hmacContext, ikm, ikm_len);
|
|
}
|
|
|
|
/*
|
|
* hkdfFinalBits
|
|
*
|
|
* Description:
|
|
* This function will add in any final bits of the
|
|
* input keying material.
|
|
*
|
|
* Parameters:
|
|
* context: [in/out]
|
|
* The HKDF context to update
|
|
* ikm_bits: [in]
|
|
* The final bits of the input keying material, in the upper
|
|
* portion of the byte. (Use 0b###00000 instead of 0b00000###
|
|
* to input the three bits ###.)
|
|
* ikm_bit_count: [in]
|
|
* The number of bits in message_bits, between 1 and 7.
|
|
*
|
|
* Returns:
|
|
* sha Error Code.
|
|
*/
|
|
int hkdfFinalBits(HKDFContext *context, uint8_t ikm_bits,
|
|
unsigned int ikm_bit_count)
|
|
{
|
|
if (!context) return shaNull;
|
|
if (context->Corrupted) return context->Corrupted;
|
|
if (context->Computed) return context->Corrupted = shaStateError;
|
|
return hmacFinalBits(&context->hmacContext, ikm_bits, ikm_bit_count);
|
|
}
|
|
|
|
/*
|
|
* hkdfResult
|
|
*
|
|
* Description:
|
|
* This function will finish the HKDF extraction and perform the
|
|
* final HKDF expansion.
|
|
*
|
|
* Parameters:
|
|
* context: [in/out]
|
|
* The HKDF context to use to calculate the HKDF hash.
|
|
* prk[ ]: [out]
|
|
* An optional location to store the HKDF extraction.
|
|
* Either NULL, or pointer to a buffer that must be
|
|
* larger than USHAHashSize(whichSha);
|
|
* info[ ]: [in]
|
|
* The optional context and application specific information.
|
|
* If info == NULL or a zero-length string, it is ignored.
|
|
* info_len: [in]
|
|
* The length of the optional context and application specific
|
|
* information. (Ignored if info == NULL.)
|
|
* okm[ ]: [out]
|
|
* Where the HKDF is to be stored.
|
|
* okm_len: [in]
|
|
* The length of the buffer to hold okm.
|
|
* okm_len must be <= 255 * USHABlockSize(whichSha)
|
|
*
|
|
* Returns:
|
|
* sha Error Code.
|
|
*
|
|
*/
|
|
int hkdfResult(HKDFContext *context,
|
|
uint8_t prk[USHAMaxHashSize],
|
|
const unsigned char *info, size_t info_len,
|
|
uint8_t okm[], size_t okm_len)
|
|
{
|
|
uint8_t prkbuf[USHAMaxHashSize];
|
|
int ret;
|
|
|
|
if (!context) return shaNull;
|
|
if (context->Corrupted) return context->Corrupted;
|
|
if (context->Computed) return context->Corrupted = shaStateError;
|
|
if (!okm) return context->Corrupted = shaBadParam;
|
|
if (!prk) prk = prkbuf;
|
|
|
|
ret = hmacResult(&context->hmacContext, prk) ||
|
|
hkdfExpand(context->whichSha, prk, context->hashSize, info,
|
|
info_len, okm, okm_len);
|
|
context->Computed = 1;
|
|
return context->Corrupted = ret;
|
|
}
|
|
|