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Reorganise SHA-512 to match SHA-256.

Browse Source 
This builds on the previous refactoring by reworking the SHA-512
vtables and block layer to look more like the SHA-256 version, in
which the block and padding structure is a subroutine of the top-level
vtable methods instead of an owning layer around them.

This also organises the code in a way that makes it easy to drop in
hardware-accelerated versions alongside it: the block layer and the
big arrays of constants are now nicely separate from the inner
block-transform part.
This commit is contained in:
Simon Tatham 2020-12-24 15:20:03 +00:00
parent 43cdc3d910
commit c6d921add5
2 changed files with 201 additions and 252 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
ssh.h
View File

@ -748,6 +748,7 @@ struct ssh_hashalg {
const char *text_basename; /* the semantic name of the hash */ const char *text_basename; /* the semantic name of the hash */
const char *annotation; /* extra info, e.g. which of multiple impls */ const char *annotation; /* extra info, e.g. which of multiple impls */
const char *text_name; /* both combined, e.g. "SHA-n (unaccelerated)" */ const char *text_name; /* both combined, e.g. "SHA-n (unaccelerated)" */
const void *extra; /* private to the hash implementation */
}; };
static inline ssh_hash *ssh_hash_new(const ssh_hashalg *alg) static inline ssh_hash *ssh_hash_new(const ssh_hashalg *alg)

452
sshsh512.c
View File

@ -9,20 +9,124 @@
#include <assert.h> #include <assert.h>
#include "ssh.h" #include "ssh.h"
#define BLKSIZE 128 static const uint64_t sha512_initial_state[] = {
0x6a09e667f3bcc908ULL,
0xbb67ae8584caa73bULL,
0x3c6ef372fe94f82bULL,
0xa54ff53a5f1d36f1ULL,
0x510e527fade682d1ULL,
0x9b05688c2b3e6c1fULL,
0x1f83d9abfb41bd6bULL,
0x5be0cd19137e2179ULL,
};
typedef struct { static const uint64_t sha384_initial_state[] = {
uint64_t h[8]; 0xcbbb9d5dc1059ed8ULL,
unsigned char block[BLKSIZE]; 0x629a292a367cd507ULL,
int blkused; 0x9159015a3070dd17ULL,
0x152fecd8f70e5939ULL,
0x67332667ffc00b31ULL,
0x8eb44a8768581511ULL,
0xdb0c2e0d64f98fa7ULL,
0x47b5481dbefa4fa4ULL,
};
static const uint64_t sha512_round_constants[] = {
0x428a2f98d728ae22ULL, 0x7137449123ef65cdULL,
0xb5c0fbcfec4d3b2fULL, 0xe9b5dba58189dbbcULL,
0x3956c25bf348b538ULL, 0x59f111f1b605d019ULL,
0x923f82a4af194f9bULL, 0xab1c5ed5da6d8118ULL,
0xd807aa98a3030242ULL, 0x12835b0145706fbeULL,
0x243185be4ee4b28cULL, 0x550c7dc3d5ffb4e2ULL,
0x72be5d74f27b896fULL, 0x80deb1fe3b1696b1ULL,
0x9bdc06a725c71235ULL, 0xc19bf174cf692694ULL,
0xe49b69c19ef14ad2ULL, 0xefbe4786384f25e3ULL,
0x0fc19dc68b8cd5b5ULL, 0x240ca1cc77ac9c65ULL,
0x2de92c6f592b0275ULL, 0x4a7484aa6ea6e483ULL,
0x5cb0a9dcbd41fbd4ULL, 0x76f988da831153b5ULL,
0x983e5152ee66dfabULL, 0xa831c66d2db43210ULL,
0xb00327c898fb213fULL, 0xbf597fc7beef0ee4ULL,
0xc6e00bf33da88fc2ULL, 0xd5a79147930aa725ULL,
0x06ca6351e003826fULL, 0x142929670a0e6e70ULL,
0x27b70a8546d22ffcULL, 0x2e1b21385c26c926ULL,
0x4d2c6dfc5ac42aedULL, 0x53380d139d95b3dfULL,
0x650a73548baf63deULL, 0x766a0abb3c77b2a8ULL,
0x81c2c92e47edaee6ULL, 0x92722c851482353bULL,
0xa2bfe8a14cf10364ULL, 0xa81a664bbc423001ULL,
0xc24b8b70d0f89791ULL, 0xc76c51a30654be30ULL,
0xd192e819d6ef5218ULL, 0xd69906245565a910ULL,
0xf40e35855771202aULL, 0x106aa07032bbd1b8ULL,
0x19a4c116b8d2d0c8ULL, 0x1e376c085141ab53ULL,
0x2748774cdf8eeb99ULL, 0x34b0bcb5e19b48a8ULL,
0x391c0cb3c5c95a63ULL, 0x4ed8aa4ae3418acbULL,
0x5b9cca4f7763e373ULL, 0x682e6ff3d6b2b8a3ULL,
0x748f82ee5defb2fcULL, 0x78a5636f43172f60ULL,
0x84c87814a1f0ab72ULL, 0x8cc702081a6439ecULL,
0x90befffa23631e28ULL, 0xa4506cebde82bde9ULL,
0xbef9a3f7b2c67915ULL, 0xc67178f2e372532bULL,
0xca273eceea26619cULL, 0xd186b8c721c0c207ULL,
0xeada7dd6cde0eb1eULL, 0xf57d4f7fee6ed178ULL,
0x06f067aa72176fbaULL, 0x0a637dc5a2c898a6ULL,
0x113f9804bef90daeULL, 0x1b710b35131c471bULL,
0x28db77f523047d84ULL, 0x32caab7b40c72493ULL,
0x3c9ebe0a15c9bebcULL, 0x431d67c49c100d4cULL,
0x4cc5d4becb3e42b6ULL, 0x597f299cfc657e2aULL,
0x5fcb6fab3ad6faecULL, 0x6c44198c4a475817ULL,
};
#define SHA512_ROUNDS 80
typedef struct sha512_block sha512_block;
struct sha512_block {
uint8_t block[128];
size_t used;
uint64_t lenhi, lenlo; uint64_t lenhi, lenlo;
BinarySink_IMPLEMENTATION; };
} SHA512_State;
/* ---------------------------------------------------------------------- static inline void sha512_block_setup(sha512_block *blk)
* Core SHA512 algorithm: processes 16-doubleword blocks into a {
* message digest. blk->used = 0;
*/ blk->lenhi = blk->lenlo = 0;
}
static inline bool sha512_block_write(
sha512_block *blk, const void **vdata, size_t *len)
{
size_t blkleft = sizeof(blk->block) - blk->used;
size_t chunk = *len < blkleft ? *len : blkleft;
const uint8_t *p = *vdata;
memcpy(blk->block + blk->used, p, chunk);
*vdata = p + chunk;
*len -= chunk;
blk->used += chunk;
size_t chunkbits = chunk << 3;
blk->lenlo += chunkbits;
blk->lenhi += (blk->lenlo < chunkbits);
if (blk->used == sizeof(blk->block)) {
blk->used = 0;
return true;
}
return false;
}
static inline void sha512_block_pad(sha512_block *blk, BinarySink *bs)
{
uint64_t final_lenhi = blk->lenhi;
uint64_t final_lenlo = blk->lenlo;
size_t pad = 127 & (111 - blk->used);
put_byte(bs, 0x80);
put_padding(bs, pad, 0);
put_uint64(bs, final_lenhi);
put_uint64(bs, final_lenlo);
assert(blk->used == 0 && "Should have exactly hit a block boundary");
}
static inline uint64_t ror(uint64_t x, unsigned y) static inline uint64_t ror(uint64_t x, unsigned y)
{ {
@ -59,14 +163,13 @@ static inline uint64_t sigma_1(uint64_t x)
return ror(x,19) ^ ror(x,61) ^ (x >> 6); return ror(x,19) ^ ror(x,61) ^ (x >> 6);
} }
static inline void SHA512_Round( static inline void sha512_sw_round(
unsigned round_index, const uint64_t *round_constants, unsigned round_index, const uint64_t *schedule,
const uint64_t *schedule,
uint64_t *a, uint64_t *b, uint64_t *c, uint64_t *d, uint64_t *a, uint64_t *b, uint64_t *c, uint64_t *d,
uint64_t *e, uint64_t *f, uint64_t *g, uint64_t *h) uint64_t *e, uint64_t *f, uint64_t *g, uint64_t *h)
{ {
uint64_t t1 = *h + Sigma_1(*e) + Ch(*e,*f,*g) + uint64_t t1 = *h + Sigma_1(*e) + Ch(*e,*f,*g) +
round_constants[round_index] + schedule[round_index]; sha512_round_constants[round_index] + schedule[round_index];
uint64_t t2 = Sigma_0(*a) + Maj(*a,*b,*c); uint64_t t2 = Sigma_0(*a) + Maj(*a,*b,*c);
@ -74,279 +177,124 @@ static inline void SHA512_Round(
*h = t1 + t2; *h = t1 + t2;
} }
static void SHA512_Core_Init(SHA512_State *s) { static void sha512_sw_block(uint64_t *core, const uint8_t *block)
static const uint64_t iv[] = { {
0x6a09e667f3bcc908ULL, uint64_t w[SHA512_ROUNDS];
0xbb67ae8584caa73bULL,
0x3c6ef372fe94f82bULL,
0xa54ff53a5f1d36f1ULL,
0x510e527fade682d1ULL,
0x9b05688c2b3e6c1fULL,
0x1f83d9abfb41bd6bULL,
0x5be0cd19137e2179ULL,
};
int i;
for (i = 0; i < 8; i++)
s->h[i] = iv[i];
}
static void SHA384_Core_Init(SHA512_State *s) {
static const uint64_t iv[] = {
0xcbbb9d5dc1059ed8ULL,
0x629a292a367cd507ULL,
0x9159015a3070dd17ULL,
0x152fecd8f70e5939ULL,
0x67332667ffc00b31ULL,
0x8eb44a8768581511ULL,
0xdb0c2e0d64f98fa7ULL,
0x47b5481dbefa4fa4ULL,
};
int i;
for (i = 0; i < 8; i++)
s->h[i] = iv[i];
}
static void SHA512_Block(SHA512_State *s, uint64_t *block) {
uint64_t w[80];
uint64_t a,b,c,d,e,f,g,h; uint64_t a,b,c,d,e,f,g,h;
static const uint64_t k[] = {
0x428a2f98d728ae22ULL, 0x7137449123ef65cdULL,
0xb5c0fbcfec4d3b2fULL, 0xe9b5dba58189dbbcULL,
0x3956c25bf348b538ULL, 0x59f111f1b605d019ULL,
0x923f82a4af194f9bULL, 0xab1c5ed5da6d8118ULL,
0xd807aa98a3030242ULL, 0x12835b0145706fbeULL,
0x243185be4ee4b28cULL, 0x550c7dc3d5ffb4e2ULL,
0x72be5d74f27b896fULL, 0x80deb1fe3b1696b1ULL,
0x9bdc06a725c71235ULL, 0xc19bf174cf692694ULL,
0xe49b69c19ef14ad2ULL, 0xefbe4786384f25e3ULL,
0x0fc19dc68b8cd5b5ULL, 0x240ca1cc77ac9c65ULL,
0x2de92c6f592b0275ULL, 0x4a7484aa6ea6e483ULL,
0x5cb0a9dcbd41fbd4ULL, 0x76f988da831153b5ULL,
0x983e5152ee66dfabULL, 0xa831c66d2db43210ULL,
0xb00327c898fb213fULL, 0xbf597fc7beef0ee4ULL,
0xc6e00bf33da88fc2ULL, 0xd5a79147930aa725ULL,
0x06ca6351e003826fULL, 0x142929670a0e6e70ULL,
0x27b70a8546d22ffcULL, 0x2e1b21385c26c926ULL,
0x4d2c6dfc5ac42aedULL, 0x53380d139d95b3dfULL,
0x650a73548baf63deULL, 0x766a0abb3c77b2a8ULL,
0x81c2c92e47edaee6ULL, 0x92722c851482353bULL,
0xa2bfe8a14cf10364ULL, 0xa81a664bbc423001ULL,
0xc24b8b70d0f89791ULL, 0xc76c51a30654be30ULL,
0xd192e819d6ef5218ULL, 0xd69906245565a910ULL,
0xf40e35855771202aULL, 0x106aa07032bbd1b8ULL,
0x19a4c116b8d2d0c8ULL, 0x1e376c085141ab53ULL,
0x2748774cdf8eeb99ULL, 0x34b0bcb5e19b48a8ULL,
0x391c0cb3c5c95a63ULL, 0x4ed8aa4ae3418acbULL,
0x5b9cca4f7763e373ULL, 0x682e6ff3d6b2b8a3ULL,
0x748f82ee5defb2fcULL, 0x78a5636f43172f60ULL,
0x84c87814a1f0ab72ULL, 0x8cc702081a6439ecULL,
0x90befffa23631e28ULL, 0xa4506cebde82bde9ULL,
0xbef9a3f7b2c67915ULL, 0xc67178f2e372532bULL,
0xca273eceea26619cULL, 0xd186b8c721c0c207ULL,
0xeada7dd6cde0eb1eULL, 0xf57d4f7fee6ed178ULL,
0x06f067aa72176fbaULL, 0x0a637dc5a2c898a6ULL,
0x113f9804bef90daeULL, 0x1b710b35131c471bULL,
0x28db77f523047d84ULL, 0x32caab7b40c72493ULL,
0x3c9ebe0a15c9bebcULL, 0x431d67c49c100d4cULL,
0x4cc5d4becb3e42b6ULL, 0x597f299cfc657e2aULL,
0x5fcb6fab3ad6faecULL, 0x6c44198c4a475817ULL,
};
int t; int t;
for (t = 0; t < 16; t++) for (t = 0; t < 16; t++)
w[t] = block[t]; w[t] = GET_64BIT_MSB_FIRST(block + 8*t);
for (t = 16; t < 80; t++) for (t = 16; t < SHA512_ROUNDS; t++)
w[t] = w[t-16] + w[t-7] + sigma_0(w[t-15]) + sigma_1(w[t-2]); w[t] = w[t-16] + w[t-7] + sigma_0(w[t-15]) + sigma_1(w[t-2]);
a = s->h[0]; b = s->h[1]; c = s->h[2]; d = s->h[3]; a = core[0]; b = core[1]; c = core[2]; d = core[3];
e = s->h[4]; f = s->h[5]; g = s->h[6]; h = s->h[7]; e = core[4]; f = core[5]; g = core[6]; h = core[7];
for (t = 0; t < 80; t+=8) { for (t = 0; t < SHA512_ROUNDS; t+=8) {
SHA512_Round(t+0, k,w, &a,&b,&c,&d,&e,&f,&g,&h); sha512_sw_round(t+0, w, &a,&b,&c,&d,&e,&f,&g,&h);
SHA512_Round(t+1, k,w, &h,&a,&b,&c,&d,&e,&f,&g); sha512_sw_round(t+1, w, &h,&a,&b,&c,&d,&e,&f,&g);
SHA512_Round(t+2, k,w, &g,&h,&a,&b,&c,&d,&e,&f); sha512_sw_round(t+2, w, &g,&h,&a,&b,&c,&d,&e,&f);
SHA512_Round(t+3, k,w, &f,&g,&h,&a,&b,&c,&d,&e); sha512_sw_round(t+3, w, &f,&g,&h,&a,&b,&c,&d,&e);
SHA512_Round(t+4, k,w, &e,&f,&g,&h,&a,&b,&c,&d); sha512_sw_round(t+4, w, &e,&f,&g,&h,&a,&b,&c,&d);
SHA512_Round(t+5, k,w, &d,&e,&f,&g,&h,&a,&b,&c); sha512_sw_round(t+5, w, &d,&e,&f,&g,&h,&a,&b,&c);
SHA512_Round(t+6, k,w, &c,&d,&e,&f,&g,&h,&a,&b); sha512_sw_round(t+6, w, &c,&d,&e,&f,&g,&h,&a,&b);
SHA512_Round(t+7, k,w, &b,&c,&d,&e,&f,&g,&h,&a); sha512_sw_round(t+7, w, &b,&c,&d,&e,&f,&g,&h,&a);
} }
s->h[0] += a; s->h[1] += b; s->h[2] += c; s->h[3] += d; core[0] += a; core[1] += b; core[2] += c; core[3] += d;
s->h[4] += e; s->h[5] += f; s->h[6] += g; s->h[7] += h; core[4] += e; core[5] += f; core[6] += g; core[7] += h;
smemclr(w, sizeof(w));
} }
/* ---------------------------------------------------------------------- typedef struct sha512_sw {
* Outer SHA512 algorithm: take an arbitrary length byte string, uint64_t core[8];
* convert it into 16-doubleword blocks with the prescribed padding sha512_block blk;
* at the end, and pass those blocks to the core SHA512 algorithm. BinarySink_IMPLEMENTATION;
*/
static void SHA512_BinarySink_write(BinarySink *bs,
const void *p, size_t len);
static void SHA512_Init(SHA512_State *s) {
SHA512_Core_Init(s);
s->blkused = 0;
s->lenhi = s->lenlo = 0;
BinarySink_INIT(s, SHA512_BinarySink_write);
}
static void SHA384_Init(SHA512_State *s) {
SHA384_Core_Init(s);
s->blkused = 0;
s->lenhi = s->lenlo = 0;
BinarySink_INIT(s, SHA512_BinarySink_write);
}
static void SHA512_BinarySink_write(BinarySink *bs,
const void *p, size_t len)
{
SHA512_State *s = BinarySink_DOWNCAST(bs, SHA512_State);
unsigned char *q = (unsigned char *)p;
uint64_t wordblock[16];
int i;
/*
* Update the length field.
*/
s->lenlo += len;
s->lenhi += (s->lenlo < len);
if (s->blkused && s->blkused+len < BLKSIZE) {
/*
* 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 >= BLKSIZE) {
memcpy(s->block + s->blkused, q, BLKSIZE - s->blkused);
q += BLKSIZE - s->blkused;
len -= BLKSIZE - s->blkused;
/* Now process the block. Gather bytes big-endian into words */
for (i = 0; i < 16; i++)
wordblock[i] = GET_64BIT_MSB_FIRST(s->block + i*8);
SHA512_Block(s, wordblock);
s->blkused = 0;
}
memcpy(s->block, q, len);
s->blkused = len;
}
}
static void SHA512_Final(SHA512_State *s, unsigned char *digest) {
int i;
int pad;
unsigned char c[BLKSIZE];
uint64_t lenhi, lenlo;
if (s->blkused >= BLKSIZE-16)
pad = (BLKSIZE-16) + BLKSIZE - s->blkused;
else
pad = (BLKSIZE-16) - 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_uint64(s, lenhi);
put_uint64(s, lenlo);
for (i = 0; i < 8; i++)
PUT_64BIT_MSB_FIRST(digest + i*8, s->h[i]);
}
static void SHA384_Final(SHA512_State *s, unsigned char *digest) {
unsigned char biggerDigest[512 / 8];
SHA512_Final(s, biggerDigest);
memcpy(digest, biggerDigest, 384 / 8);
}
/*
* Thin abstraction for things where hashes are pluggable.
*/
struct sha512_hash {
SHA512_State state;
ssh_hash hash; ssh_hash hash;
}; } sha512_sw;
static ssh_hash *sha512_new(const ssh_hashalg *alg) static void sha512_sw_write(BinarySink *bs, const void *vp, size_t len);
static ssh_hash *sha512_sw_new(const ssh_hashalg *alg)
{ {
struct sha512_hash *h = snew(struct sha512_hash); sha512_sw *s = snew(sha512_sw);
h->hash.vt = alg;
BinarySink_DELEGATE_INIT(&h->hash, &h->state); s->hash.vt = alg;
return ssh_hash_reset(&h->hash); BinarySink_INIT(s, sha512_sw_write);
BinarySink_DELEGATE_INIT(&s->hash, s);
return &s->hash;
} }
static void sha512_reset(ssh_hash *hash) static void sha512_sw_reset(ssh_hash *hash)
{ {
struct sha512_hash *h = container_of(hash, struct sha512_hash, hash); sha512_sw *s = container_of(hash, sha512_sw, hash);
SHA512_Init(&h->state);
/* The 'extra' field in the ssh_hashalg indicates which
* initialisation vector we're using */
memcpy(s->core, hash->vt->extra, sizeof(s->core));
sha512_block_setup(&s->blk);
} }
static void sha512_copyfrom(ssh_hash *hashnew, ssh_hash *hashold) static void sha512_sw_copyfrom(ssh_hash *hcopy, ssh_hash *horig)
{ {
struct sha512_hash *hold = container_of(hashold, struct sha512_hash, hash); sha512_sw *copy = container_of(hcopy, sha512_sw, hash);
struct sha512_hash *hnew = container_of(hashnew, struct sha512_hash, hash); sha512_sw *orig = container_of(horig, sha512_sw, hash);
hnew->state = hold->state; memcpy(copy, orig, sizeof(*copy));
BinarySink_COPIED(&hnew->state); BinarySink_COPIED(copy);
BinarySink_DELEGATE_INIT(&copy->hash, copy);
} }
static void sha512_free(ssh_hash *hash) static void sha512_sw_free(ssh_hash *hash)
{ {
struct sha512_hash *h = container_of(hash, struct sha512_hash, hash); sha512_sw *s = container_of(hash, sha512_sw, hash);
smemclr(h, sizeof(*h)); smemclr(s, sizeof(*s));
sfree(h); sfree(s);
} }
static void sha512_digest(ssh_hash *hash, unsigned char *output) static void sha512_sw_write(BinarySink *bs, const void *vp, size_t len)
{ {
struct sha512_hash *h = container_of(hash, struct sha512_hash, hash); sha512_sw *s = BinarySink_DOWNCAST(bs, sha512_sw);
SHA512_Final(&h->state, output);
while (len > 0)
if (sha512_block_write(&s->blk, &vp, &len))
sha512_sw_block(s->core, s->blk.block);
}
static void sha512_sw_digest(ssh_hash *hash, uint8_t *digest)
{
sha512_sw *s = container_of(hash, sha512_sw, hash);
sha512_block_pad(&s->blk, BinarySink_UPCAST(s));
for (size_t i = 0; i < hash->vt->hlen / 8; i++)
PUT_64BIT_MSB_FIRST(digest + 8*i, s->core[i]);
} }
const ssh_hashalg ssh_sha512 = { const ssh_hashalg ssh_sha512 = {
.new = sha512_new, .new = sha512_sw_new,
.reset = sha512_reset, .reset = sha512_sw_reset,
.copyfrom = sha512_copyfrom, .copyfrom = sha512_sw_copyfrom,
.digest = sha512_digest, .digest = sha512_sw_digest,
.free = sha512_free, .free = sha512_sw_free,
.hlen = 64, .hlen = 64,
.blocklen = BLKSIZE, .blocklen = 128,
HASHALG_NAMES_BARE("SHA-512"), HASHALG_NAMES_ANNOTATED("SHA-512", "unaccelerated"),
.extra = sha512_initial_state,
}; };
static void sha384_reset(ssh_hash *hash)
{
struct sha512_hash *h = container_of(hash, struct sha512_hash, hash);
SHA384_Init(&h->state);
}
static void sha384_digest(ssh_hash *hash, unsigned char *output)
{
struct sha512_hash *h = container_of(hash, struct sha512_hash, hash);
SHA384_Final(&h->state, output);
}
const ssh_hashalg ssh_sha384 = { const ssh_hashalg ssh_sha384 = {
.new = sha512_new, .new = sha512_sw_new,
.reset = sha384_reset, .reset = sha512_sw_reset,
.copyfrom = sha512_copyfrom, .copyfrom = sha512_sw_copyfrom,
.digest = sha384_digest, .digest = sha512_sw_digest,
.free = sha512_free, .free = sha512_sw_free,
.hlen = 48, .hlen = 48,
.blocklen = BLKSIZE, .blocklen = 128,
HASHALG_NAMES_BARE("SHA-384"), HASHALG_NAMES_ANNOTATED("SHA-384", "unaccelerated"),
.extra = sha384_initial_state,
}; };