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853bd8b284
putty-source/sshsha.c
Simon Tatham 853bd8b284 Turn SSH-2 MACs into a classoid. 
This piece of tidying-up has come out particularly well in terms of
saving tedious repetition and boilerplate. I've managed to remove
three pointless methods from every MAC implementation by means of
writing them once centrally in terms of the implementation-specific
methods; another method (hmacmd5_sink) vanished because I was able to
make the interface type 'ssh2_mac' be directly usable as a BinarySink
by way of a new delegation system; and because all the method
implementations can now find their own vtable, I was even able to
merge a lot of keying and output functions that had previously
differed only in length parameters by having them look up the lengths
in whatever vtable they were passed.
2018-09-19 23:08:07 +01:00

697 lines
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/*
* SHA1 hash algorithm. Used in SSH-2 as a MAC, and the transform is
* also used as a `stirring' function for the PuTTY random number
* pool. Implemented directly from the specification by Simon
* Tatham.
*/
#include "ssh.h"
#include <assert.h>
/* ----------------------------------------------------------------------
* Core SHA algorithm: processes 16-word blocks into a message digest.
*/
#define rol(x,y) ( ((x) << (y)) | (((uint32)x) >> (32-y)) )
static void sha1_sw(SHA_State * s, const unsigned char *q, int len);
static void sha1_ni(SHA_State * s, const unsigned char *q, int len);
static void SHA_Core_Init(uint32 h[5])
{
h[0] = 0x67452301;
h[1] = 0xefcdab89;
h[2] = 0x98badcfe;
h[3] = 0x10325476;
h[4] = 0xc3d2e1f0;
}
void SHATransform(word32 * digest, word32 * block)
{
word32 w[80];
word32 a, b, c, d, e;
int t;
#ifdef RANDOM_DIAGNOSTICS
{
extern int random_diagnostics;
if (random_diagnostics) {
int i;
printf("SHATransform:");
for (i = 0; i < 5; i++)
printf(" %08x", digest[i]);
printf(" +");
for (i = 0; i < 16; i++)
printf(" %08x", block[i]);
}
}
#endif
for (t = 0; t < 16; t++)
w[t] = block[t];
for (t = 16; t < 80; t++) {
word32 tmp = w[t - 3] ^ w[t - 8] ^ w[t - 14] ^ w[t - 16];
w[t] = rol(tmp, 1);
}
a = digest[0];
b = digest[1];
c = digest[2];
d = digest[3];
e = digest[4];
for (t = 0; t < 20; t++) {
word32 tmp =
rol(a, 5) + ((b & c) | (d & ~b)) + e + w[t] + 0x5a827999;
e = d;
d = c;
c = rol(b, 30);
b = a;
a = tmp;
}
for (t = 20; t < 40; t++) {
word32 tmp = rol(a, 5) + (b ^ c ^ d) + e + w[t] + 0x6ed9eba1;
e = d;
d = c;
c = rol(b, 30);
b = a;
a = tmp;
}
for (t = 40; t < 60; t++) {
word32 tmp = rol(a,
5) + ((b & c) | (b & d) | (c & d)) + e + w[t] +
0x8f1bbcdc;
e = d;
d = c;
c = rol(b, 30);
b = a;
a = tmp;
}
for (t = 60; t < 80; t++) {
word32 tmp = rol(a, 5) + (b ^ c ^ d) + e + w[t] + 0xca62c1d6;
e = d;
d = c;
c = rol(b, 30);
b = a;
a = tmp;
}
digest[0] += a;
digest[1] += b;
digest[2] += c;
digest[3] += d;
digest[4] += e;
#ifdef RANDOM_DIAGNOSTICS
{
extern int random_diagnostics;
if (random_diagnostics) {
int i;
printf(" =");
for (i = 0; i < 5; i++)
printf(" %08x", digest[i]);
printf("\n");
}
}
#endif
}
/* ----------------------------------------------------------------------
* Outer SHA algorithm: take an arbitrary length byte string,
* convert it into 16-word blocks with the prescribed padding at
* the end, and pass those blocks to the core SHA algorithm.
*/
static void SHA_BinarySink_write(BinarySink *bs, const void *p, size_t len);
void SHA_Init(SHA_State * s)
{
SHA_Core_Init(s->h);
s->blkused = 0;
s->lenhi = s->lenlo = 0;
if (supports_sha_ni())
s->sha1 = &sha1_ni;
else
s->sha1 = &sha1_sw;
BinarySink_INIT(s, SHA_BinarySink_write);
}
static void SHA_BinarySink_write(BinarySink *bs, const void *p, size_t len)
{
struct SHA_State *s = BinarySink_DOWNCAST(bs, struct SHA_State);
const unsigned char *q = (const unsigned char *) p;
uint32 lenw = len;
assert(lenw == len);
/*
* Update the length field.
*/
s->lenlo += lenw;
s->lenhi += (s->lenlo < lenw);
(*(s->sha1))(s, q, len);
}
static void sha1_sw(SHA_State * s, const unsigned char *q, int len)
{
uint32 wordblock[16];
int i;
if (s->blkused && s->blkused + len < 64) {
/*
* Trivial case: just add to the block.
*/
memcpy(s->block + s->blkused, q, len);
s->blkused += len;
} else {
/*
* We must complete and process at least one block.
*/
while (s->blkused + len >= 64) {
memcpy(s->block + s->blkused, q, 64 - s->blkused);
q += 64 - s->blkused;
len -= 64 - s->blkused;
/* Now process the block. Gather bytes big-endian into words */
for (i = 0; i < 16; i++) {
wordblock[i] =
(((uint32) s->block[i * 4 + 0]) << 24) |
(((uint32) s->block[i * 4 + 1]) << 16) |
(((uint32) s->block[i * 4 + 2]) << 8) |
(((uint32) s->block[i * 4 + 3]) << 0);
}
SHATransform(s->h, wordblock);
s->blkused = 0;
}
memcpy(s->block, q, len);
s->blkused = len;
}
}
void SHA_Final(SHA_State * s, unsigned char *output)
{
int i;
int pad;
unsigned char c[64];
uint32 lenhi, lenlo;
if (s->blkused >= 56)
pad = 56 + 64 - s->blkused;
else
pad = 56 - s->blkused;
lenhi = (s->lenhi << 3) | (s->lenlo >> (32 - 3));
lenlo = (s->lenlo << 3);
memset(c, 0, pad);
c[0] = 0x80;
put_data(s, &c, pad);
put_uint32(s, lenhi);
put_uint32(s, lenlo);
for (i = 0; i < 5; i++) {
output[i * 4] = (s->h[i] >> 24) & 0xFF;
output[i * 4 + 1] = (s->h[i] >> 16) & 0xFF;
output[i * 4 + 2] = (s->h[i] >> 8) & 0xFF;
output[i * 4 + 3] = (s->h[i]) & 0xFF;
}
}
void SHA_Simple(const void *p, int len, unsigned char *output)
{
SHA_State s;
SHA_Init(&s);
put_data(&s, p, len);
SHA_Final(&s, output);
smemclr(&s, sizeof(s));
}
/*
* Thin abstraction for things where hashes are pluggable.
*/
static void *sha1_init(void)
{
SHA_State *s;
s = snew(SHA_State);
SHA_Init(s);
return s;
}
static void *sha1_copy(const void *vold)
{
const SHA_State *old = (const SHA_State *)vold;
SHA_State *s;
s = snew(SHA_State);
*s = *old;
BinarySink_COPIED(s);
return s;
}
static void sha1_free(void *handle)
{
SHA_State *s = handle;
smemclr(s, sizeof(*s));
sfree(s);
}
static BinarySink *sha1_sink(void *handle)
{
SHA_State *s = handle;
return BinarySink_UPCAST(s);
}
static void sha1_final(void *handle, unsigned char *output)
{
SHA_State *s = handle;
SHA_Final(s, output);
sha1_free(s);
}
const struct ssh_hash ssh_sha1 = {
sha1_init, sha1_copy, sha1_sink, sha1_final, sha1_free, 20, "SHA-1"
};
/* ----------------------------------------------------------------------
* The above is the SHA-1 algorithm itself. Now we implement the
* HMAC wrapper on it.
*/
struct hmacsha1 {
SHA_State sha[3];
ssh2_mac mac;
};
static ssh2_mac *hmacsha1_new(
const struct ssh2_macalg *alg, ssh2_cipher *cipher)
{
struct hmacsha1 *ctx = snew(struct hmacsha1);
ctx->mac.vt = alg;
BinarySink_DELEGATE_INIT(&ctx->mac, &ctx->sha[2]);
return &ctx->mac;
}
static void hmacsha1_free(ssh2_mac *mac)
{
struct hmacsha1 *ctx = FROMFIELD(mac, struct hmacsha1, mac);
smemclr(ctx, sizeof(*ctx));
sfree(ctx);
}
static void sha1_key_internal(SHA_State *keys,
const unsigned char *key, int len)
{
unsigned char foo[64];
int i;
memset(foo, 0x36, 64);
for (i = 0; i < len && i < 64; i++)
foo[i] ^= key[i];
SHA_Init(&keys[0]);
put_data(&keys[0], foo, 64);
memset(foo, 0x5C, 64);
for (i = 0; i < len && i < 64; i++)
foo[i] ^= key[i];
SHA_Init(&keys[1]);
put_data(&keys[1], foo, 64);
smemclr(foo, 64); /* burn the evidence */
}
static void hmacsha1_key(ssh2_mac *mac, const void *key)
{
struct hmacsha1 *ctx = FROMFIELD(mac, struct hmacsha1, mac);
/* Reading the key length out of the ssh2_macalg structure means
* this same method can be used for the _buggy variants which use
* a shorter key */
sha1_key_internal(ctx->sha, key, ctx->mac.vt->keylen);
}
static void hmacsha1_start(ssh2_mac *mac)
{
struct hmacsha1 *ctx = FROMFIELD(mac, struct hmacsha1, mac);
ctx->sha[2] = ctx->sha[0]; /* structure copy */
BinarySink_COPIED(&ctx->sha[2]);
}
static void hmacsha1_genresult(ssh2_mac *mac, unsigned char *hmac)
{
struct hmacsha1 *ctx = FROMFIELD(mac, struct hmacsha1, mac);
SHA_State s;
unsigned char intermediate[20];
s = ctx->sha[2]; /* structure copy */
BinarySink_COPIED(&s);
SHA_Final(&s, intermediate);
s = ctx->sha[1]; /* structure copy */
BinarySink_COPIED(&s);
put_data(&s, intermediate, 20);
SHA_Final(&s, intermediate);
memcpy(hmac, intermediate, ctx->mac.vt->len);
smemclr(intermediate, sizeof(intermediate));
}
void hmac_sha1_simple(void *key, int keylen, void *data, int datalen,
unsigned char *output) {
SHA_State states[2];
unsigned char intermediate[20];
sha1_key_internal(states, key, keylen);
put_data(&states[0], data, datalen);
SHA_Final(&states[0], intermediate);
put_data(&states[1], intermediate, 20);
SHA_Final(&states[1], output);
}
const struct ssh2_macalg ssh_hmac_sha1 = {
hmacsha1_new, hmacsha1_free, hmacsha1_key,
hmacsha1_start, hmacsha1_genresult,
"hmac-sha1", "hmac-sha1-etm@openssh.com",
20, 20,
"HMAC-SHA1"
};
const struct ssh2_macalg ssh_hmac_sha1_96 = {
hmacsha1_new, hmacsha1_free, hmacsha1_key,
hmacsha1_start, hmacsha1_genresult,
"hmac-sha1-96", "hmac-sha1-96-etm@openssh.com",
12, 20,
"HMAC-SHA1-96"
};
const struct ssh2_macalg ssh_hmac_sha1_buggy = {
hmacsha1_new, hmacsha1_free, hmacsha1_key,
hmacsha1_start, hmacsha1_genresult,
"hmac-sha1", NULL,
20, 16,
"bug-compatible HMAC-SHA1"
};
const struct ssh2_macalg ssh_hmac_sha1_96_buggy = {
hmacsha1_new, hmacsha1_free, hmacsha1_key,
hmacsha1_start, hmacsha1_genresult,
"hmac-sha1-96", NULL,
12, 16,
"bug-compatible HMAC-SHA1-96"
};
#ifdef COMPILER_SUPPORTS_SHA_NI
#if defined _MSC_VER && defined _M_AMD64
# include <intrin.h>
#endif
/*
* Set target architecture for Clang and GCC
*/
#if !defined(__clang__) && defined(__GNUC__)
# pragma GCC target("sha")
# pragma GCC target("sse4.1")
#endif
#if defined(__clang__) || (defined(__GNUC__) && (__GNUC__ >= 5))
# define FUNC_ISA __attribute__ ((target("sse4.1,sha")))
#else
# define FUNC_ISA
#endif
#include <wmmintrin.h>
#include <smmintrin.h>
#include <immintrin.h>
#if defined(__clang__) || defined(__GNUC__)
#include <shaintrin.h>
#endif
/*
* Determinators of CPU type
*/
#if defined(__clang__) || defined(__GNUC__)
#include <cpuid.h>
int supports_sha_ni(void)
{
unsigned int CPUInfo[4];
__cpuid(0, CPUInfo[0], CPUInfo[1], CPUInfo[2], CPUInfo[3]);
if (CPUInfo[0] < 7)
return 0;
__cpuid_count(7, 0, CPUInfo[0], CPUInfo[1], CPUInfo[2], CPUInfo[3]);
return CPUInfo[1] & (1 << 29); /* SHA */
}
#else /* defined(__clang__) || defined(__GNUC__) */
int supports_sha_ni(void)
{
unsigned int CPUInfo[4];
__cpuid(CPUInfo, 0);
if (CPUInfo[0] < 7)
return 0;
__cpuidex(CPUInfo, 7, 0);
return CPUInfo[1] & (1 << 29); /* Check SHA */
}
#endif /* defined(__clang__) || defined(__GNUC__) */
/* SHA1 implementation using new instructions
The code is based on Jeffrey Walton's SHA1 implementation:
https://github.com/noloader/SHA-Intrinsics
*/
FUNC_ISA
static void sha1_ni_(SHA_State * s, const unsigned char *q, int len)
{
if (s->blkused && s->blkused + len < 64) {
/*
* Trivial case: just add to the block.
*/
memcpy(s->block + s->blkused, q, len);
s->blkused += len;
} else {
__m128i ABCD, ABCD_SAVE, E0, E0_SAVE, E1;
const __m128i MASK = _mm_set_epi64x(0x0001020304050607ULL, 0x08090a0b0c0d0e0fULL);
ABCD = _mm_loadu_si128((const __m128i*) s->h);
E0 = _mm_set_epi32(s->h[4], 0, 0, 0);
ABCD = _mm_shuffle_epi32(ABCD, 0x1B);
/*
* We must complete and process at least one block.
*/
while (s->blkused + len >= 64)
{
__m128i MSG0, MSG1, MSG2, MSG3;
memcpy(s->block + s->blkused, q, 64 - s->blkused);
q += 64 - s->blkused;
len -= 64 - s->blkused;
/* Save current state */
ABCD_SAVE = ABCD;
E0_SAVE = E0;
/* Rounds 0-3 */
MSG0 = _mm_loadu_si128((const __m128i*)(s->block + 0));
MSG0 = _mm_shuffle_epi8(MSG0, MASK);
E0 = _mm_add_epi32(E0, MSG0);
E1 = ABCD;
ABCD = _mm_sha1rnds4_epu32(ABCD, E0, 0);
/* Rounds 4-7 */
MSG1 = _mm_loadu_si128((const __m128i*)(s->block + 16));
MSG1 = _mm_shuffle_epi8(MSG1, MASK);
E1 = _mm_sha1nexte_epu32(E1, MSG1);
E0 = ABCD;
ABCD = _mm_sha1rnds4_epu32(ABCD, E1, 0);
MSG0 = _mm_sha1msg1_epu32(MSG0, MSG1);
/* Rounds 8-11 */
MSG2 = _mm_loadu_si128((const __m128i*)(s->block + 32));
MSG2 = _mm_shuffle_epi8(MSG2, MASK);
E0 = _mm_sha1nexte_epu32(E0, MSG2);
E1 = ABCD;
ABCD = _mm_sha1rnds4_epu32(ABCD, E0, 0);
MSG1 = _mm_sha1msg1_epu32(MSG1, MSG2);
MSG0 = _mm_xor_si128(MSG0, MSG2);
/* Rounds 12-15 */
MSG3 = _mm_loadu_si128((const __m128i*)(s->block + 48));
MSG3 = _mm_shuffle_epi8(MSG3, MASK);
E1 = _mm_sha1nexte_epu32(E1, MSG3);
E0 = ABCD;
MSG0 = _mm_sha1msg2_epu32(MSG0, MSG3);
ABCD = _mm_sha1rnds4_epu32(ABCD, E1, 0);
MSG2 = _mm_sha1msg1_epu32(MSG2, MSG3);
MSG1 = _mm_xor_si128(MSG1, MSG3);
/* Rounds 16-19 */
E0 = _mm_sha1nexte_epu32(E0, MSG0);
E1 = ABCD;
MSG1 = _mm_sha1msg2_epu32(MSG1, MSG0);
ABCD = _mm_sha1rnds4_epu32(ABCD, E0, 0);
MSG3 = _mm_sha1msg1_epu32(MSG3, MSG0);
MSG2 = _mm_xor_si128(MSG2, MSG0);
/* Rounds 20-23 */
E1 = _mm_sha1nexte_epu32(E1, MSG1);
E0 = ABCD;
MSG2 = _mm_sha1msg2_epu32(MSG2, MSG1);
ABCD = _mm_sha1rnds4_epu32(ABCD, E1, 1);
MSG0 = _mm_sha1msg1_epu32(MSG0, MSG1);
MSG3 = _mm_xor_si128(MSG3, MSG1);
/* Rounds 24-27 */
E0 = _mm_sha1nexte_epu32(E0, MSG2);
E1 = ABCD;
MSG3 = _mm_sha1msg2_epu32(MSG3, MSG2);
ABCD = _mm_sha1rnds4_epu32(ABCD, E0, 1);
MSG1 = _mm_sha1msg1_epu32(MSG1, MSG2);
MSG0 = _mm_xor_si128(MSG0, MSG2);
/* Rounds 28-31 */
E1 = _mm_sha1nexte_epu32(E1, MSG3);
E0 = ABCD;
MSG0 = _mm_sha1msg2_epu32(MSG0, MSG3);
ABCD = _mm_sha1rnds4_epu32(ABCD, E1, 1);
MSG2 = _mm_sha1msg1_epu32(MSG2, MSG3);
MSG1 = _mm_xor_si128(MSG1, MSG3);
/* Rounds 32-35 */
E0 = _mm_sha1nexte_epu32(E0, MSG0);
E1 = ABCD;
MSG1 = _mm_sha1msg2_epu32(MSG1, MSG0);
ABCD = _mm_sha1rnds4_epu32(ABCD, E0, 1);
MSG3 = _mm_sha1msg1_epu32(MSG3, MSG0);
MSG2 = _mm_xor_si128(MSG2, MSG0);
/* Rounds 36-39 */
E1 = _mm_sha1nexte_epu32(E1, MSG1);
E0 = ABCD;
MSG2 = _mm_sha1msg2_epu32(MSG2, MSG1);
ABCD = _mm_sha1rnds4_epu32(ABCD, E1, 1);
MSG0 = _mm_sha1msg1_epu32(MSG0, MSG1);
MSG3 = _mm_xor_si128(MSG3, MSG1);
/* Rounds 40-43 */
E0 = _mm_sha1nexte_epu32(E0, MSG2);
E1 = ABCD;
MSG3 = _mm_sha1msg2_epu32(MSG3, MSG2);
ABCD = _mm_sha1rnds4_epu32(ABCD, E0, 2);
MSG1 = _mm_sha1msg1_epu32(MSG1, MSG2);
MSG0 = _mm_xor_si128(MSG0, MSG2);
/* Rounds 44-47 */
E1 = _mm_sha1nexte_epu32(E1, MSG3);
E0 = ABCD;
MSG0 = _mm_sha1msg2_epu32(MSG0, MSG3);
ABCD = _mm_sha1rnds4_epu32(ABCD, E1, 2);
MSG2 = _mm_sha1msg1_epu32(MSG2, MSG3);
MSG1 = _mm_xor_si128(MSG1, MSG3);
/* Rounds 48-51 */
E0 = _mm_sha1nexte_epu32(E0, MSG0);
E1 = ABCD;
MSG1 = _mm_sha1msg2_epu32(MSG1, MSG0);
ABCD = _mm_sha1rnds4_epu32(ABCD, E0, 2);
MSG3 = _mm_sha1msg1_epu32(MSG3, MSG0);
MSG2 = _mm_xor_si128(MSG2, MSG0);
/* Rounds 52-55 */
E1 = _mm_sha1nexte_epu32(E1, MSG1);
E0 = ABCD;
MSG2 = _mm_sha1msg2_epu32(MSG2, MSG1);
ABCD = _mm_sha1rnds4_epu32(ABCD, E1, 2);
MSG0 = _mm_sha1msg1_epu32(MSG0, MSG1);
MSG3 = _mm_xor_si128(MSG3, MSG1);
/* Rounds 56-59 */
E0 = _mm_sha1nexte_epu32(E0, MSG2);
E1 = ABCD;
MSG3 = _mm_sha1msg2_epu32(MSG3, MSG2);
ABCD = _mm_sha1rnds4_epu32(ABCD, E0, 2);
MSG1 = _mm_sha1msg1_epu32(MSG1, MSG2);
MSG0 = _mm_xor_si128(MSG0, MSG2);
/* Rounds 60-63 */
E1 = _mm_sha1nexte_epu32(E1, MSG3);
E0 = ABCD;
MSG0 = _mm_sha1msg2_epu32(MSG0, MSG3);
ABCD = _mm_sha1rnds4_epu32(ABCD, E1, 3);
MSG2 = _mm_sha1msg1_epu32(MSG2, MSG3);
MSG1 = _mm_xor_si128(MSG1, MSG3);
/* Rounds 64-67 */
E0 = _mm_sha1nexte_epu32(E0, MSG0);
E1 = ABCD;
MSG1 = _mm_sha1msg2_epu32(MSG1, MSG0);
ABCD = _mm_sha1rnds4_epu32(ABCD, E0, 3);
MSG3 = _mm_sha1msg1_epu32(MSG3, MSG0);
MSG2 = _mm_xor_si128(MSG2, MSG0);
/* Rounds 68-71 */
E1 = _mm_sha1nexte_epu32(E1, MSG1);
E0 = ABCD;
MSG2 = _mm_sha1msg2_epu32(MSG2, MSG1);
ABCD = _mm_sha1rnds4_epu32(ABCD, E1, 3);
MSG3 = _mm_xor_si128(MSG3, MSG1);
/* Rounds 72-75 */
E0 = _mm_sha1nexte_epu32(E0, MSG2);
E1 = ABCD;
MSG3 = _mm_sha1msg2_epu32(MSG3, MSG2);
ABCD = _mm_sha1rnds4_epu32(ABCD, E0, 3);
/* Rounds 76-79 */
E1 = _mm_sha1nexte_epu32(E1, MSG3);
E0 = ABCD;
ABCD = _mm_sha1rnds4_epu32(ABCD, E1, 3);
/* Combine state */
E0 = _mm_sha1nexte_epu32(E0, E0_SAVE);
ABCD = _mm_add_epi32(ABCD, ABCD_SAVE);
s->blkused = 0;
}
ABCD = _mm_shuffle_epi32(ABCD, 0x1B);
/* Save state */
_mm_storeu_si128((__m128i*) s->h, ABCD);
s->h[4] = _mm_extract_epi32(E0, 3);
memcpy(s->block, q, len);
s->blkused = len;
}
}
/*
* Workaround LLVM bug https://bugs.llvm.org/show_bug.cgi?id=34980
*/
static void sha1_ni(SHA_State * s, const unsigned char *q, int len)
{
sha1_ni_(s, q, len);
}
#else /* COMPILER_SUPPORTS_AES_NI */
static void sha1_ni(SHA_State * s, const unsigned char *q, int len)
{
assert(0);
}
int supports_sha_ni(void)
{
return 0;
}
#endif /* COMPILER_SUPPORTS_AES_NI */
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