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Split AES-CTR-HMAC and AES-GCM-SIV from e_aes.c. 

That file was getting too huge and we only need to de-static a single
function to do it.

Change-Id: Ie2c0bc90a7e538a74318c364a136c337ce8d9bbb
Reviewed-on: https://boringssl-review.googlesource.com/14884
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
kris/onging/CECPQ3_patch15
Adam Langley vor 7 Jahren
committed by CQ bot account: commit-bot@chromium.org
Ursprung
f55e2e7266
Commit
20422539b5
5 geänderte Dateien mit 635 neuen und 590 gelöschten Zeilen
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  1. +2
    -0
      crypto/cipher/CMakeLists.txt
  2. +8
    -590
      crypto/cipher/e_aes.c
  3. +289
    -0
      crypto/cipher/e_aesctrhmac.c
  4. +323
    -0
      crypto/cipher/e_aesgcmsiv.c
  5. +13
    -0
      crypto/cipher/internal.h

+ 2
- 0
crypto/cipher/CMakeLists.txt Datei anzeigen

@@ -22,6 +22,8 @@ add_library(
e_rc4.c
e_des.c
e_aes.c
e_aesgcmsiv.c
e_aesctrhmac.c
e_chacha20poly1305.c

tls_cbc.c


+ 8
- 590
crypto/cipher/e_aes.c Datei anzeigen

@@ -56,7 +56,6 @@
#include <openssl/mem.h>
#include <openssl/nid.h>
#include <openssl/rand.h>
#include <openssl/sha.h>

#include "internal.h"
#include "../internal.h"
@@ -399,11 +398,11 @@ static int aes_ofb_cipher(EVP_CIPHER_CTX *ctx, uint8_t *out, const uint8_t *in,

static char aesni_capable(void);

static ctr128_f aes_ctr_set_key(AES_KEY *aes_key, GCM128_CONTEXT *gcm_ctx,
block128_f *out_block, const uint8_t *key,
size_t key_len) {
ctr128_f aes_ctr_set_key(AES_KEY *aes_key, GCM128_CONTEXT *gcm_ctx,
block128_f *out_block, const uint8_t *key,
size_t key_bytes) {
if (aesni_capable()) {
aesni_set_encrypt_key(key, key_len * 8, aes_key);
aesni_set_encrypt_key(key, key_bytes * 8, aes_key);
if (gcm_ctx != NULL) {
CRYPTO_gcm128_init(gcm_ctx, aes_key, (block128_f)aesni_encrypt);
}
@@ -414,7 +413,7 @@ static ctr128_f aes_ctr_set_key(AES_KEY *aes_key, GCM128_CONTEXT *gcm_ctx,
}

if (hwaes_capable()) {
aes_hw_set_encrypt_key(key, key_len * 8, aes_key);
aes_hw_set_encrypt_key(key, key_bytes * 8, aes_key);
if (gcm_ctx != NULL) {
CRYPTO_gcm128_init(gcm_ctx, aes_key, (block128_f)aes_hw_encrypt);
}
@@ -425,7 +424,7 @@ static ctr128_f aes_ctr_set_key(AES_KEY *aes_key, GCM128_CONTEXT *gcm_ctx,
}

if (bsaes_capable()) {
AES_set_encrypt_key(key, key_len * 8, aes_key);
AES_set_encrypt_key(key, key_bytes * 8, aes_key);
if (gcm_ctx != NULL) {
CRYPTO_gcm128_init(gcm_ctx, aes_key, (block128_f)AES_encrypt);
}
@@ -436,7 +435,7 @@ static ctr128_f aes_ctr_set_key(AES_KEY *aes_key, GCM128_CONTEXT *gcm_ctx,
}

if (vpaes_capable()) {
vpaes_set_encrypt_key(key, key_len * 8, aes_key);
vpaes_set_encrypt_key(key, key_bytes * 8, aes_key);
if (out_block) {
*out_block = (block128_f) vpaes_encrypt;
}
@@ -446,7 +445,7 @@ static ctr128_f aes_ctr_set_key(AES_KEY *aes_key, GCM128_CONTEXT *gcm_ctx,
return NULL;
}

AES_set_encrypt_key(key, key_len * 8, aes_key);
AES_set_encrypt_key(key, key_bytes * 8, aes_key);
if (gcm_ctx != NULL) {
CRYPTO_gcm128_init(gcm_ctx, aes_key, (block128_f)AES_encrypt);
}
@@ -1179,587 +1178,6 @@ const EVP_AEAD *EVP_aead_aes_128_gcm(void) { return &aead_aes_128_gcm; }
const EVP_AEAD *EVP_aead_aes_256_gcm(void) { return &aead_aes_256_gcm; }


#define EVP_AEAD_AES_CTR_HMAC_SHA256_TAG_LEN SHA256_DIGEST_LENGTH
#define EVP_AEAD_AES_CTR_HMAC_SHA256_NONCE_LEN 12

struct aead_aes_ctr_hmac_sha256_ctx {
union {
double align;
AES_KEY ks;
} ks;
ctr128_f ctr;
block128_f block;
SHA256_CTX inner_init_state;
SHA256_CTX outer_init_state;
uint8_t tag_len;
};

static void hmac_init(SHA256_CTX *out_inner, SHA256_CTX *out_outer,
const uint8_t hmac_key[32]) {
static const size_t hmac_key_len = 32;
uint8_t block[SHA256_CBLOCK];
OPENSSL_memcpy(block, hmac_key, hmac_key_len);
OPENSSL_memset(block + hmac_key_len, 0x36, sizeof(block) - hmac_key_len);

unsigned i;
for (i = 0; i < hmac_key_len; i++) {
block[i] ^= 0x36;
}

SHA256_Init(out_inner);
SHA256_Update(out_inner, block, sizeof(block));

OPENSSL_memset(block + hmac_key_len, 0x5c, sizeof(block) - hmac_key_len);
for (i = 0; i < hmac_key_len; i++) {
block[i] ^= (0x36 ^ 0x5c);
}

SHA256_Init(out_outer);
SHA256_Update(out_outer, block, sizeof(block));
}

static int aead_aes_ctr_hmac_sha256_init(EVP_AEAD_CTX *ctx, const uint8_t *key,
size_t key_len, size_t tag_len) {
struct aead_aes_ctr_hmac_sha256_ctx *aes_ctx;
static const size_t hmac_key_len = 32;

if (key_len < hmac_key_len) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BAD_KEY_LENGTH);
return 0; /* EVP_AEAD_CTX_init should catch this. */
}

const size_t aes_key_len = key_len - hmac_key_len;
if (aes_key_len != 16 && aes_key_len != 32) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BAD_KEY_LENGTH);
return 0; /* EVP_AEAD_CTX_init should catch this. */
}

if (tag_len == EVP_AEAD_DEFAULT_TAG_LENGTH) {
tag_len = EVP_AEAD_AES_CTR_HMAC_SHA256_TAG_LEN;
}

if (tag_len > EVP_AEAD_AES_CTR_HMAC_SHA256_TAG_LEN) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_TAG_TOO_LARGE);
return 0;
}

aes_ctx = OPENSSL_malloc(sizeof(struct aead_aes_ctr_hmac_sha256_ctx));
if (aes_ctx == NULL) {
OPENSSL_PUT_ERROR(CIPHER, ERR_R_MALLOC_FAILURE);
return 0;
}

aes_ctx->ctr =
aes_ctr_set_key(&aes_ctx->ks.ks, NULL, &aes_ctx->block, key, aes_key_len);
aes_ctx->tag_len = tag_len;
hmac_init(&aes_ctx->inner_init_state, &aes_ctx->outer_init_state,
key + aes_key_len);

ctx->aead_state = aes_ctx;

return 1;
}

static void aead_aes_ctr_hmac_sha256_cleanup(EVP_AEAD_CTX *ctx) {
struct aead_aes_ctr_hmac_sha256_ctx *aes_ctx = ctx->aead_state;
OPENSSL_cleanse(aes_ctx, sizeof(struct aead_aes_ctr_hmac_sha256_ctx));
OPENSSL_free(aes_ctx);
}

static void hmac_update_uint64(SHA256_CTX *sha256, uint64_t value) {
unsigned i;
uint8_t bytes[8];

for (i = 0; i < sizeof(bytes); i++) {
bytes[i] = value & 0xff;
value >>= 8;
}
SHA256_Update(sha256, bytes, sizeof(bytes));
}

static void hmac_calculate(uint8_t out[SHA256_DIGEST_LENGTH],
const SHA256_CTX *inner_init_state,
const SHA256_CTX *outer_init_state,
const uint8_t *ad, size_t ad_len,
const uint8_t *nonce, const uint8_t *ciphertext,
size_t ciphertext_len) {
SHA256_CTX sha256;
OPENSSL_memcpy(&sha256, inner_init_state, sizeof(sha256));
hmac_update_uint64(&sha256, ad_len);
hmac_update_uint64(&sha256, ciphertext_len);
SHA256_Update(&sha256, nonce, EVP_AEAD_AES_CTR_HMAC_SHA256_NONCE_LEN);
SHA256_Update(&sha256, ad, ad_len);

/* Pad with zeros to the end of the SHA-256 block. */
const unsigned num_padding =
(SHA256_CBLOCK - ((sizeof(uint64_t)*2 +
EVP_AEAD_AES_CTR_HMAC_SHA256_NONCE_LEN + ad_len) %
SHA256_CBLOCK)) %
SHA256_CBLOCK;
uint8_t padding[SHA256_CBLOCK];
OPENSSL_memset(padding, 0, num_padding);
SHA256_Update(&sha256, padding, num_padding);

SHA256_Update(&sha256, ciphertext, ciphertext_len);

uint8_t inner_digest[SHA256_DIGEST_LENGTH];
SHA256_Final(inner_digest, &sha256);

OPENSSL_memcpy(&sha256, outer_init_state, sizeof(sha256));
SHA256_Update(&sha256, inner_digest, sizeof(inner_digest));
SHA256_Final(out, &sha256);
}

static void aead_aes_ctr_hmac_sha256_crypt(
const struct aead_aes_ctr_hmac_sha256_ctx *aes_ctx, uint8_t *out,
const uint8_t *in, size_t len, const uint8_t *nonce) {
/* Since the AEAD operation is one-shot, keeping a buffer of unused keystream
* bytes is pointless. However, |CRYPTO_ctr128_encrypt| requires it. */
uint8_t partial_block_buffer[AES_BLOCK_SIZE];
unsigned partial_block_offset = 0;
OPENSSL_memset(partial_block_buffer, 0, sizeof(partial_block_buffer));

uint8_t counter[AES_BLOCK_SIZE];
OPENSSL_memcpy(counter, nonce, EVP_AEAD_AES_CTR_HMAC_SHA256_NONCE_LEN);
OPENSSL_memset(counter + EVP_AEAD_AES_CTR_HMAC_SHA256_NONCE_LEN, 0, 4);

if (aes_ctx->ctr) {
CRYPTO_ctr128_encrypt_ctr32(in, out, len, &aes_ctx->ks.ks, counter,
partial_block_buffer, &partial_block_offset,
aes_ctx->ctr);
} else {
CRYPTO_ctr128_encrypt(in, out, len, &aes_ctx->ks.ks, counter,
partial_block_buffer, &partial_block_offset,
aes_ctx->block);
}
}

static int aead_aes_ctr_hmac_sha256_seal(const EVP_AEAD_CTX *ctx, uint8_t *out,
size_t *out_len, size_t max_out_len,
const uint8_t *nonce, size_t nonce_len,
const uint8_t *in, size_t in_len,
const uint8_t *ad, size_t ad_len) {
const struct aead_aes_ctr_hmac_sha256_ctx *aes_ctx = ctx->aead_state;
const uint64_t in_len_64 = in_len;

if (in_len + aes_ctx->tag_len < in_len ||
/* This input is so large it would overflow the 32-bit block counter. */
in_len_64 >= (UINT64_C(1) << 32) * AES_BLOCK_SIZE) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_TOO_LARGE);
return 0;
}

if (max_out_len < in_len + aes_ctx->tag_len) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BUFFER_TOO_SMALL);
return 0;
}

if (nonce_len != EVP_AEAD_AES_CTR_HMAC_SHA256_NONCE_LEN) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_UNSUPPORTED_NONCE_SIZE);
return 0;
}

aead_aes_ctr_hmac_sha256_crypt(aes_ctx, out, in, in_len, nonce);

uint8_t hmac_result[SHA256_DIGEST_LENGTH];
hmac_calculate(hmac_result, &aes_ctx->inner_init_state,
&aes_ctx->outer_init_state, ad, ad_len, nonce, out, in_len);
OPENSSL_memcpy(out + in_len, hmac_result, aes_ctx->tag_len);
*out_len = in_len + aes_ctx->tag_len;

return 1;
}

static int aead_aes_ctr_hmac_sha256_open(const EVP_AEAD_CTX *ctx, uint8_t *out,
size_t *out_len, size_t max_out_len,
const uint8_t *nonce, size_t nonce_len,
const uint8_t *in, size_t in_len,
const uint8_t *ad, size_t ad_len) {
const struct aead_aes_ctr_hmac_sha256_ctx *aes_ctx = ctx->aead_state;
size_t plaintext_len;

if (in_len < aes_ctx->tag_len) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BAD_DECRYPT);
return 0;
}

plaintext_len = in_len - aes_ctx->tag_len;

if (max_out_len < plaintext_len) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BUFFER_TOO_SMALL);
return 0;
}

if (nonce_len != EVP_AEAD_AES_CTR_HMAC_SHA256_NONCE_LEN) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_UNSUPPORTED_NONCE_SIZE);
return 0;
}

uint8_t hmac_result[SHA256_DIGEST_LENGTH];
hmac_calculate(hmac_result, &aes_ctx->inner_init_state,
&aes_ctx->outer_init_state, ad, ad_len, nonce, in,
plaintext_len);
if (CRYPTO_memcmp(hmac_result, in + plaintext_len, aes_ctx->tag_len) != 0) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BAD_DECRYPT);
return 0;
}

aead_aes_ctr_hmac_sha256_crypt(aes_ctx, out, in, plaintext_len, nonce);

*out_len = plaintext_len;
return 1;
}

static const EVP_AEAD aead_aes_128_ctr_hmac_sha256 = {
16 /* AES key */ + 32 /* HMAC key */,
12, /* nonce length */
EVP_AEAD_AES_CTR_HMAC_SHA256_TAG_LEN, /* overhead */
EVP_AEAD_AES_CTR_HMAC_SHA256_TAG_LEN, /* max tag length */

aead_aes_ctr_hmac_sha256_init,
NULL /* init_with_direction */,
aead_aes_ctr_hmac_sha256_cleanup,
aead_aes_ctr_hmac_sha256_seal,
aead_aes_ctr_hmac_sha256_open,
NULL /* get_iv */,
};

static const EVP_AEAD aead_aes_256_ctr_hmac_sha256 = {
32 /* AES key */ + 32 /* HMAC key */,
12, /* nonce length */
EVP_AEAD_AES_CTR_HMAC_SHA256_TAG_LEN, /* overhead */
EVP_AEAD_AES_CTR_HMAC_SHA256_TAG_LEN, /* max tag length */

aead_aes_ctr_hmac_sha256_init,
NULL /* init_with_direction */,
aead_aes_ctr_hmac_sha256_cleanup,
aead_aes_ctr_hmac_sha256_seal,
aead_aes_ctr_hmac_sha256_open,
NULL /* get_iv */,
};

const EVP_AEAD *EVP_aead_aes_128_ctr_hmac_sha256(void) {
return &aead_aes_128_ctr_hmac_sha256;
}

const EVP_AEAD *EVP_aead_aes_256_ctr_hmac_sha256(void) {
return &aead_aes_256_ctr_hmac_sha256;
}

#if !defined(OPENSSL_SMALL)

#define EVP_AEAD_AES_GCM_SIV_NONCE_LEN 12
#define EVP_AEAD_AES_GCM_SIV_TAG_LEN 16

struct aead_aes_gcm_siv_ctx {
union {
double align;
AES_KEY ks;
} ks;
block128_f kgk_block;
unsigned is_256:1;
};

static int aead_aes_gcm_siv_init(EVP_AEAD_CTX *ctx, const uint8_t *key,
size_t key_len, size_t tag_len) {
const size_t key_bits = key_len * 8;

if (key_bits != 128 && key_bits != 256) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BAD_KEY_LENGTH);
return 0; /* EVP_AEAD_CTX_init should catch this. */
}

if (tag_len == EVP_AEAD_DEFAULT_TAG_LENGTH) {
tag_len = EVP_AEAD_AES_GCM_SIV_TAG_LEN;
}

if (tag_len != EVP_AEAD_AES_GCM_SIV_TAG_LEN) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_TAG_TOO_LARGE);
return 0;
}

struct aead_aes_gcm_siv_ctx *gcm_siv_ctx =
OPENSSL_malloc(sizeof(struct aead_aes_gcm_siv_ctx));
if (gcm_siv_ctx == NULL) {
return 0;
}
OPENSSL_memset(gcm_siv_ctx, 0, sizeof(struct aead_aes_gcm_siv_ctx));

if (aesni_capable()) {
aesni_set_encrypt_key(key, key_len * 8, &gcm_siv_ctx->ks.ks);
gcm_siv_ctx->kgk_block = (block128_f)aesni_encrypt;
} else if (hwaes_capable()) {
aes_hw_set_encrypt_key(key, key_len * 8, &gcm_siv_ctx->ks.ks);
gcm_siv_ctx->kgk_block = (block128_f)aes_hw_encrypt;
} else if (vpaes_capable()) {
vpaes_set_encrypt_key(key, key_len * 8, &gcm_siv_ctx->ks.ks);
gcm_siv_ctx->kgk_block = (block128_f)vpaes_encrypt;
} else {
AES_set_encrypt_key(key, key_len * 8, &gcm_siv_ctx->ks.ks);
gcm_siv_ctx->kgk_block = (block128_f)AES_encrypt;
}

gcm_siv_ctx->is_256 = (key_len == 32);
ctx->aead_state = gcm_siv_ctx;

return 1;
}

static void aead_aes_gcm_siv_cleanup(EVP_AEAD_CTX *ctx) {
struct aead_aes_gcm_siv_ctx *gcm_siv_ctx = ctx->aead_state;
OPENSSL_cleanse(gcm_siv_ctx, sizeof(struct aead_aes_gcm_siv_ctx));
OPENSSL_free(gcm_siv_ctx);
}

/* gcm_siv_crypt encrypts (or decrypts—it's the same thing) |in_len| bytes from
* |in| to |out|, using the block function |enc_block| with |key| in counter
* mode, starting at |initial_counter|. This differs from the traditional
* counter mode code in that the counter is handled little-endian, only the
* first four bytes are used and the GCM-SIV tweak to the final byte is
* applied. The |in| and |out| pointers may be equal but otherwise must not
* alias. */
static void gcm_siv_crypt(uint8_t *out, const uint8_t *in, size_t in_len,
const uint8_t initial_counter[AES_BLOCK_SIZE],
block128_f enc_block, const AES_KEY *key) {
union {
uint32_t w[4];
uint8_t c[16];
} counter;

OPENSSL_memcpy(counter.c, initial_counter, AES_BLOCK_SIZE);
counter.c[15] |= 0x80;

for (size_t done = 0; done < in_len;) {
uint8_t keystream[AES_BLOCK_SIZE];
enc_block(counter.c, keystream, key);
counter.w[0]++;

size_t todo = AES_BLOCK_SIZE;
if (in_len - done < todo) {
todo = in_len - done;
}

for (size_t i = 0; i < todo; i++) {
out[done + i] = keystream[i] ^ in[done + i];
}

done += todo;
}
}

/* gcm_siv_polyval evaluates POLYVAL at |auth_key| on the given plaintext and
* AD. The result is written to |out_tag|. */
static void gcm_siv_polyval(
uint8_t out_tag[16], const uint8_t *in, size_t in_len, const uint8_t *ad,
size_t ad_len, const uint8_t auth_key[16],
const uint8_t nonce[EVP_AEAD_AES_GCM_SIV_NONCE_LEN]) {
struct polyval_ctx polyval_ctx;
CRYPTO_POLYVAL_init(&polyval_ctx, auth_key);

CRYPTO_POLYVAL_update_blocks(&polyval_ctx, ad, ad_len & ~15);

uint8_t scratch[16];
if (ad_len & 15) {
OPENSSL_memset(scratch, 0, sizeof(scratch));
OPENSSL_memcpy(scratch, &ad[ad_len & ~15], ad_len & 15);
CRYPTO_POLYVAL_update_blocks(&polyval_ctx, scratch, sizeof(scratch));
}

CRYPTO_POLYVAL_update_blocks(&polyval_ctx, in, in_len & ~15);
if (in_len & 15) {
OPENSSL_memset(scratch, 0, sizeof(scratch));
OPENSSL_memcpy(scratch, &in[in_len & ~15], in_len & 15);
CRYPTO_POLYVAL_update_blocks(&polyval_ctx, scratch, sizeof(scratch));
}

union {
uint8_t c[16];
struct {
uint64_t ad;
uint64_t in;
} bitlens;
} length_block;

length_block.bitlens.ad = ad_len * 8;
length_block.bitlens.in = in_len * 8;
CRYPTO_POLYVAL_update_blocks(&polyval_ctx, length_block.c,
sizeof(length_block));

CRYPTO_POLYVAL_finish(&polyval_ctx, out_tag);
for (size_t i = 0; i < EVP_AEAD_AES_GCM_SIV_NONCE_LEN; i++) {
out_tag[i] ^= nonce[i];
}
out_tag[15] &= 0x7f;
}

/* gcm_siv_record_keys contains the keys used for a specific GCM-SIV record. */
struct gcm_siv_record_keys {
uint8_t auth_key[16];
union {
double align;
AES_KEY ks;
} enc_key;
block128_f enc_block;
};

/* gcm_siv_keys calculates the keys for a specific GCM-SIV record with the
* given nonce and writes them to |*out_keys|. */
static void gcm_siv_keys(
const struct aead_aes_gcm_siv_ctx *gcm_siv_ctx,
struct gcm_siv_record_keys *out_keys,
const uint8_t nonce[EVP_AEAD_AES_GCM_SIV_NONCE_LEN]) {
const AES_KEY *const key = &gcm_siv_ctx->ks.ks;
uint8_t key_material[(128 /* POLYVAL key */ + 256 /* max AES key */) / 8];
const size_t blocks_needed = gcm_siv_ctx->is_256 ? 6 : 4;

uint8_t counter[AES_BLOCK_SIZE];
OPENSSL_memset(counter, 0, AES_BLOCK_SIZE - EVP_AEAD_AES_GCM_SIV_NONCE_LEN);
OPENSSL_memcpy(counter + AES_BLOCK_SIZE - EVP_AEAD_AES_GCM_SIV_NONCE_LEN,
nonce, EVP_AEAD_AES_GCM_SIV_NONCE_LEN);
for (size_t i = 0; i < blocks_needed; i++) {
counter[0] = i;

uint8_t ciphertext[AES_BLOCK_SIZE];
gcm_siv_ctx->kgk_block(counter, ciphertext, key);
OPENSSL_memcpy(&key_material[i * 8], ciphertext, 8);
}

OPENSSL_memcpy(out_keys->auth_key, key_material, 16);
aes_ctr_set_key(&out_keys->enc_key.ks, NULL, &out_keys->enc_block,
key_material + 16, gcm_siv_ctx->is_256 ? 32 : 16);
}

static int aead_aes_gcm_siv_seal(const EVP_AEAD_CTX *ctx, uint8_t *out,
size_t *out_len, size_t max_out_len,
const uint8_t *nonce, size_t nonce_len,
const uint8_t *in, size_t in_len,
const uint8_t *ad, size_t ad_len) {
const struct aead_aes_gcm_siv_ctx *gcm_siv_ctx = ctx->aead_state;
const uint64_t in_len_64 = in_len;
const uint64_t ad_len_64 = ad_len;

if (in_len + EVP_AEAD_AES_GCM_SIV_TAG_LEN < in_len ||
in_len_64 > (UINT64_C(1) << 36) ||
ad_len_64 >= (UINT64_C(1) << 61)) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_TOO_LARGE);
return 0;
}

if (max_out_len < in_len + EVP_AEAD_AES_GCM_SIV_TAG_LEN) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BUFFER_TOO_SMALL);
return 0;
}

if (nonce_len != EVP_AEAD_AES_GCM_SIV_NONCE_LEN) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_UNSUPPORTED_NONCE_SIZE);
return 0;
}

struct gcm_siv_record_keys keys;
gcm_siv_keys(gcm_siv_ctx, &keys, nonce);

uint8_t tag[16];
gcm_siv_polyval(tag, in, in_len, ad, ad_len, keys.auth_key, nonce);
keys.enc_block(tag, tag, &keys.enc_key.ks);

gcm_siv_crypt(out, in, in_len, tag, keys.enc_block, &keys.enc_key.ks);

OPENSSL_memcpy(&out[in_len], tag, EVP_AEAD_AES_GCM_SIV_TAG_LEN);
*out_len = in_len + EVP_AEAD_AES_GCM_SIV_TAG_LEN;

return 1;
}

static int aead_aes_gcm_siv_open(const EVP_AEAD_CTX *ctx, uint8_t *out,
size_t *out_len, size_t max_out_len,
const uint8_t *nonce, size_t nonce_len,
const uint8_t *in, size_t in_len,
const uint8_t *ad, size_t ad_len) {
const uint64_t ad_len_64 = ad_len;
if (ad_len_64 >= (UINT64_C(1) << 61)) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_TOO_LARGE);
return 0;
}

const uint64_t in_len_64 = in_len;
if (in_len < EVP_AEAD_AES_GCM_SIV_TAG_LEN ||
in_len_64 > (UINT64_C(1) << 36) + AES_BLOCK_SIZE) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BAD_DECRYPT);
return 0;
}

if (nonce_len != EVP_AEAD_AES_GCM_SIV_NONCE_LEN) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_UNSUPPORTED_NONCE_SIZE);
return 0;
}

const struct aead_aes_gcm_siv_ctx *gcm_siv_ctx = ctx->aead_state;
const size_t plaintext_len = in_len - EVP_AEAD_AES_GCM_SIV_TAG_LEN;

if (max_out_len < plaintext_len) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BUFFER_TOO_SMALL);
return 0;
}

struct gcm_siv_record_keys keys;
gcm_siv_keys(gcm_siv_ctx, &keys, nonce);

gcm_siv_crypt(out, in, plaintext_len, &in[plaintext_len], keys.enc_block,
&keys.enc_key.ks);

uint8_t expected_tag[EVP_AEAD_AES_GCM_SIV_TAG_LEN];
gcm_siv_polyval(expected_tag, out, plaintext_len, ad, ad_len, keys.auth_key,
nonce);
keys.enc_block(expected_tag, expected_tag, &keys.enc_key.ks);

if (CRYPTO_memcmp(expected_tag, &in[plaintext_len], sizeof(expected_tag)) !=
0) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BAD_DECRYPT);
return 0;
}

*out_len = plaintext_len;
return 1;
}

static const EVP_AEAD aead_aes_128_gcm_siv = {
16, /* key length */
EVP_AEAD_AES_GCM_SIV_NONCE_LEN, /* nonce length */
EVP_AEAD_AES_GCM_SIV_TAG_LEN, /* overhead */
EVP_AEAD_AES_GCM_SIV_TAG_LEN, /* max tag length */

aead_aes_gcm_siv_init,
NULL /* init_with_direction */,
aead_aes_gcm_siv_cleanup,
aead_aes_gcm_siv_seal,
aead_aes_gcm_siv_open,
NULL /* get_iv */,
};

static const EVP_AEAD aead_aes_256_gcm_siv = {
32, /* key length */
EVP_AEAD_AES_GCM_SIV_NONCE_LEN, /* nonce length */
EVP_AEAD_AES_GCM_SIV_TAG_LEN, /* overhead */
EVP_AEAD_AES_GCM_SIV_TAG_LEN, /* max tag length */

aead_aes_gcm_siv_init,
NULL /* init_with_direction */,
aead_aes_gcm_siv_cleanup,
aead_aes_gcm_siv_seal,
aead_aes_gcm_siv_open,
NULL /* get_iv */,
};

const EVP_AEAD *EVP_aead_aes_128_gcm_siv(void) {
return &aead_aes_128_gcm_siv;
}

const EVP_AEAD *EVP_aead_aes_256_gcm_siv(void) {
return &aead_aes_256_gcm_siv;
}

#endif /* !OPENSSL_SMALL */

int EVP_has_aes_hardware(void) {
#if defined(OPENSSL_X86) || defined(OPENSSL_X86_64)
return aesni_capable() && crypto_gcm_clmul_enabled();


+ 289
- 0
crypto/cipher/e_aesctrhmac.c Datei anzeigen

@@ -0,0 +1,289 @@
/* Copyright (c) 2017, Google Inc.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */

#include <openssl/aead.h>
#include <openssl/cipher.h>
#include <openssl/crypto.h>
#include <openssl/err.h>
#include <openssl/sha.h>

#include "internal.h"


#define EVP_AEAD_AES_CTR_HMAC_SHA256_TAG_LEN SHA256_DIGEST_LENGTH
#define EVP_AEAD_AES_CTR_HMAC_SHA256_NONCE_LEN 12

struct aead_aes_ctr_hmac_sha256_ctx {
union {
double align;
AES_KEY ks;
} ks;
ctr128_f ctr;
block128_f block;
SHA256_CTX inner_init_state;
SHA256_CTX outer_init_state;
uint8_t tag_len;
};

static void hmac_init(SHA256_CTX *out_inner, SHA256_CTX *out_outer,
const uint8_t hmac_key[32]) {
static const size_t hmac_key_len = 32;
uint8_t block[SHA256_CBLOCK];
OPENSSL_memcpy(block, hmac_key, hmac_key_len);
OPENSSL_memset(block + hmac_key_len, 0x36, sizeof(block) - hmac_key_len);

unsigned i;
for (i = 0; i < hmac_key_len; i++) {
block[i] ^= 0x36;
}

SHA256_Init(out_inner);
SHA256_Update(out_inner, block, sizeof(block));

OPENSSL_memset(block + hmac_key_len, 0x5c, sizeof(block) - hmac_key_len);
for (i = 0; i < hmac_key_len; i++) {
block[i] ^= (0x36 ^ 0x5c);
}

SHA256_Init(out_outer);
SHA256_Update(out_outer, block, sizeof(block));
}

static int aead_aes_ctr_hmac_sha256_init(EVP_AEAD_CTX *ctx, const uint8_t *key,
size_t key_len, size_t tag_len) {
struct aead_aes_ctr_hmac_sha256_ctx *aes_ctx;
static const size_t hmac_key_len = 32;

if (key_len < hmac_key_len) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BAD_KEY_LENGTH);
return 0; /* EVP_AEAD_CTX_init should catch this. */
}

const size_t aes_key_len = key_len - hmac_key_len;
if (aes_key_len != 16 && aes_key_len != 32) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BAD_KEY_LENGTH);
return 0; /* EVP_AEAD_CTX_init should catch this. */
}

if (tag_len == EVP_AEAD_DEFAULT_TAG_LENGTH) {
tag_len = EVP_AEAD_AES_CTR_HMAC_SHA256_TAG_LEN;
}

if (tag_len > EVP_AEAD_AES_CTR_HMAC_SHA256_TAG_LEN) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_TAG_TOO_LARGE);
return 0;
}

aes_ctx = OPENSSL_malloc(sizeof(struct aead_aes_ctr_hmac_sha256_ctx));
if (aes_ctx == NULL) {
OPENSSL_PUT_ERROR(CIPHER, ERR_R_MALLOC_FAILURE);
return 0;
}

aes_ctx->ctr =
aes_ctr_set_key(&aes_ctx->ks.ks, NULL, &aes_ctx->block, key, aes_key_len);
aes_ctx->tag_len = tag_len;
hmac_init(&aes_ctx->inner_init_state, &aes_ctx->outer_init_state,
key + aes_key_len);

ctx->aead_state = aes_ctx;

return 1;
}

static void aead_aes_ctr_hmac_sha256_cleanup(EVP_AEAD_CTX *ctx) {
struct aead_aes_ctr_hmac_sha256_ctx *aes_ctx = ctx->aead_state;
OPENSSL_cleanse(aes_ctx, sizeof(struct aead_aes_ctr_hmac_sha256_ctx));
OPENSSL_free(aes_ctx);
}

static void hmac_update_uint64(SHA256_CTX *sha256, uint64_t value) {
unsigned i;
uint8_t bytes[8];

for (i = 0; i < sizeof(bytes); i++) {
bytes[i] = value & 0xff;
value >>= 8;
}
SHA256_Update(sha256, bytes, sizeof(bytes));
}

static void hmac_calculate(uint8_t out[SHA256_DIGEST_LENGTH],
const SHA256_CTX *inner_init_state,
const SHA256_CTX *outer_init_state,
const uint8_t *ad, size_t ad_len,
const uint8_t *nonce, const uint8_t *ciphertext,
size_t ciphertext_len) {
SHA256_CTX sha256;
OPENSSL_memcpy(&sha256, inner_init_state, sizeof(sha256));
hmac_update_uint64(&sha256, ad_len);
hmac_update_uint64(&sha256, ciphertext_len);
SHA256_Update(&sha256, nonce, EVP_AEAD_AES_CTR_HMAC_SHA256_NONCE_LEN);
SHA256_Update(&sha256, ad, ad_len);

/* Pad with zeros to the end of the SHA-256 block. */
const unsigned num_padding =
(SHA256_CBLOCK - ((sizeof(uint64_t)*2 +
EVP_AEAD_AES_CTR_HMAC_SHA256_NONCE_LEN + ad_len) %
SHA256_CBLOCK)) %
SHA256_CBLOCK;
uint8_t padding[SHA256_CBLOCK];
OPENSSL_memset(padding, 0, num_padding);
SHA256_Update(&sha256, padding, num_padding);

SHA256_Update(&sha256, ciphertext, ciphertext_len);

uint8_t inner_digest[SHA256_DIGEST_LENGTH];
SHA256_Final(inner_digest, &sha256);

OPENSSL_memcpy(&sha256, outer_init_state, sizeof(sha256));
SHA256_Update(&sha256, inner_digest, sizeof(inner_digest));
SHA256_Final(out, &sha256);
}

static void aead_aes_ctr_hmac_sha256_crypt(
const struct aead_aes_ctr_hmac_sha256_ctx *aes_ctx, uint8_t *out,
const uint8_t *in, size_t len, const uint8_t *nonce) {
/* Since the AEAD operation is one-shot, keeping a buffer of unused keystream
* bytes is pointless. However, |CRYPTO_ctr128_encrypt| requires it. */
uint8_t partial_block_buffer[AES_BLOCK_SIZE];
unsigned partial_block_offset = 0;
OPENSSL_memset(partial_block_buffer, 0, sizeof(partial_block_buffer));

uint8_t counter[AES_BLOCK_SIZE];
OPENSSL_memcpy(counter, nonce, EVP_AEAD_AES_CTR_HMAC_SHA256_NONCE_LEN);
OPENSSL_memset(counter + EVP_AEAD_AES_CTR_HMAC_SHA256_NONCE_LEN, 0, 4);

if (aes_ctx->ctr) {
CRYPTO_ctr128_encrypt_ctr32(in, out, len, &aes_ctx->ks.ks, counter,
partial_block_buffer, &partial_block_offset,
aes_ctx->ctr);
} else {
CRYPTO_ctr128_encrypt(in, out, len, &aes_ctx->ks.ks, counter,
partial_block_buffer, &partial_block_offset,
aes_ctx->block);
}
}

static int aead_aes_ctr_hmac_sha256_seal(const EVP_AEAD_CTX *ctx, uint8_t *out,
size_t *out_len, size_t max_out_len,
const uint8_t *nonce, size_t nonce_len,
const uint8_t *in, size_t in_len,
const uint8_t *ad, size_t ad_len) {
const struct aead_aes_ctr_hmac_sha256_ctx *aes_ctx = ctx->aead_state;
const uint64_t in_len_64 = in_len;

if (in_len + aes_ctx->tag_len < in_len ||
/* This input is so large it would overflow the 32-bit block counter. */
in_len_64 >= (UINT64_C(1) << 32) * AES_BLOCK_SIZE) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_TOO_LARGE);
return 0;
}

if (max_out_len < in_len + aes_ctx->tag_len) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BUFFER_TOO_SMALL);
return 0;
}

if (nonce_len != EVP_AEAD_AES_CTR_HMAC_SHA256_NONCE_LEN) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_UNSUPPORTED_NONCE_SIZE);
return 0;
}

aead_aes_ctr_hmac_sha256_crypt(aes_ctx, out, in, in_len, nonce);

uint8_t hmac_result[SHA256_DIGEST_LENGTH];
hmac_calculate(hmac_result, &aes_ctx->inner_init_state,
&aes_ctx->outer_init_state, ad, ad_len, nonce, out, in_len);
OPENSSL_memcpy(out + in_len, hmac_result, aes_ctx->tag_len);
*out_len = in_len + aes_ctx->tag_len;

return 1;
}

static int aead_aes_ctr_hmac_sha256_open(const EVP_AEAD_CTX *ctx, uint8_t *out,
size_t *out_len, size_t max_out_len,
const uint8_t *nonce, size_t nonce_len,
const uint8_t *in, size_t in_len,
const uint8_t *ad, size_t ad_len) {
const struct aead_aes_ctr_hmac_sha256_ctx *aes_ctx = ctx->aead_state;
size_t plaintext_len;

if (in_len < aes_ctx->tag_len) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BAD_DECRYPT);
return 0;
}

plaintext_len = in_len - aes_ctx->tag_len;

if (max_out_len < plaintext_len) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BUFFER_TOO_SMALL);
return 0;
}

if (nonce_len != EVP_AEAD_AES_CTR_HMAC_SHA256_NONCE_LEN) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_UNSUPPORTED_NONCE_SIZE);
return 0;
}

uint8_t hmac_result[SHA256_DIGEST_LENGTH];
hmac_calculate(hmac_result, &aes_ctx->inner_init_state,
&aes_ctx->outer_init_state, ad, ad_len, nonce, in,
plaintext_len);
if (CRYPTO_memcmp(hmac_result, in + plaintext_len, aes_ctx->tag_len) != 0) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BAD_DECRYPT);
return 0;
}

aead_aes_ctr_hmac_sha256_crypt(aes_ctx, out, in, plaintext_len, nonce);

*out_len = plaintext_len;
return 1;
}

static const EVP_AEAD aead_aes_128_ctr_hmac_sha256 = {
16 /* AES key */ + 32 /* HMAC key */,
12, /* nonce length */
EVP_AEAD_AES_CTR_HMAC_SHA256_TAG_LEN, /* overhead */
EVP_AEAD_AES_CTR_HMAC_SHA256_TAG_LEN, /* max tag length */

aead_aes_ctr_hmac_sha256_init,
NULL /* init_with_direction */,
aead_aes_ctr_hmac_sha256_cleanup,
aead_aes_ctr_hmac_sha256_seal,
aead_aes_ctr_hmac_sha256_open,
NULL /* get_iv */,
};

static const EVP_AEAD aead_aes_256_ctr_hmac_sha256 = {
32 /* AES key */ + 32 /* HMAC key */,
12, /* nonce length */
EVP_AEAD_AES_CTR_HMAC_SHA256_TAG_LEN, /* overhead */
EVP_AEAD_AES_CTR_HMAC_SHA256_TAG_LEN, /* max tag length */

aead_aes_ctr_hmac_sha256_init,
NULL /* init_with_direction */,
aead_aes_ctr_hmac_sha256_cleanup,
aead_aes_ctr_hmac_sha256_seal,
aead_aes_ctr_hmac_sha256_open,
NULL /* get_iv */,
};

const EVP_AEAD *EVP_aead_aes_128_ctr_hmac_sha256(void) {
return &aead_aes_128_ctr_hmac_sha256;
}

const EVP_AEAD *EVP_aead_aes_256_ctr_hmac_sha256(void) {
return &aead_aes_256_ctr_hmac_sha256;
}

+ 323
- 0
crypto/cipher/e_aesgcmsiv.c Datei anzeigen

@@ -0,0 +1,323 @@
/* Copyright (c) 2017, Google Inc.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */

#include <openssl/aead.h>
#include <openssl/cipher.h>
#include <openssl/crypto.h>
#include <openssl/err.h>

#include "internal.h"


#if !defined(OPENSSL_SMALL)

#define EVP_AEAD_AES_GCM_SIV_NONCE_LEN 12
#define EVP_AEAD_AES_GCM_SIV_TAG_LEN 16

struct aead_aes_gcm_siv_ctx {
union {
double align;
AES_KEY ks;
} ks;
block128_f kgk_block;
unsigned is_256:1;
};

static int aead_aes_gcm_siv_init(EVP_AEAD_CTX *ctx, const uint8_t *key,
size_t key_len, size_t tag_len) {
const size_t key_bits = key_len * 8;

if (key_bits != 128 && key_bits != 256) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BAD_KEY_LENGTH);
return 0; /* EVP_AEAD_CTX_init should catch this. */
}

if (tag_len == EVP_AEAD_DEFAULT_TAG_LENGTH) {
tag_len = EVP_AEAD_AES_GCM_SIV_TAG_LEN;
}

if (tag_len != EVP_AEAD_AES_GCM_SIV_TAG_LEN) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_TAG_TOO_LARGE);
return 0;
}

struct aead_aes_gcm_siv_ctx *gcm_siv_ctx =
OPENSSL_malloc(sizeof(struct aead_aes_gcm_siv_ctx));
if (gcm_siv_ctx == NULL) {
return 0;
}
OPENSSL_memset(gcm_siv_ctx, 0, sizeof(struct aead_aes_gcm_siv_ctx));

aes_ctr_set_key(&gcm_siv_ctx->ks.ks, NULL, &gcm_siv_ctx->kgk_block, key,
key_len);
gcm_siv_ctx->is_256 = (key_len == 32);
ctx->aead_state = gcm_siv_ctx;

return 1;
}

static void aead_aes_gcm_siv_cleanup(EVP_AEAD_CTX *ctx) {
struct aead_aes_gcm_siv_ctx *gcm_siv_ctx = ctx->aead_state;
OPENSSL_cleanse(gcm_siv_ctx, sizeof(struct aead_aes_gcm_siv_ctx));
OPENSSL_free(gcm_siv_ctx);
}

/* gcm_siv_crypt encrypts (or decrypts—it's the same thing) |in_len| bytes from
* |in| to |out|, using the block function |enc_block| with |key| in counter
* mode, starting at |initial_counter|. This differs from the traditional
* counter mode code in that the counter is handled little-endian, only the
* first four bytes are used and the GCM-SIV tweak to the final byte is
* applied. The |in| and |out| pointers may be equal but otherwise must not
* alias. */
static void gcm_siv_crypt(uint8_t *out, const uint8_t *in, size_t in_len,
const uint8_t initial_counter[AES_BLOCK_SIZE],
block128_f enc_block, const AES_KEY *key) {
union {
uint32_t w[4];
uint8_t c[16];
} counter;

OPENSSL_memcpy(counter.c, initial_counter, AES_BLOCK_SIZE);
counter.c[15] |= 0x80;

for (size_t done = 0; done < in_len;) {
uint8_t keystream[AES_BLOCK_SIZE];
enc_block(counter.c, keystream, key);
counter.w[0]++;

size_t todo = AES_BLOCK_SIZE;
if (in_len - done < todo) {
todo = in_len - done;
}

for (size_t i = 0; i < todo; i++) {
out[done + i] = keystream[i] ^ in[done + i];
}

done += todo;
}
}

/* gcm_siv_polyval evaluates POLYVAL at |auth_key| on the given plaintext and
* AD. The result is written to |out_tag|. */
static void gcm_siv_polyval(
uint8_t out_tag[16], const uint8_t *in, size_t in_len, const uint8_t *ad,
size_t ad_len, const uint8_t auth_key[16],
const uint8_t nonce[EVP_AEAD_AES_GCM_SIV_NONCE_LEN]) {
struct polyval_ctx polyval_ctx;
CRYPTO_POLYVAL_init(&polyval_ctx, auth_key);

CRYPTO_POLYVAL_update_blocks(&polyval_ctx, ad, ad_len & ~15);

uint8_t scratch[16];
if (ad_len & 15) {
OPENSSL_memset(scratch, 0, sizeof(scratch));
OPENSSL_memcpy(scratch, &ad[ad_len & ~15], ad_len & 15);
CRYPTO_POLYVAL_update_blocks(&polyval_ctx, scratch, sizeof(scratch));
}

CRYPTO_POLYVAL_update_blocks(&polyval_ctx, in, in_len & ~15);
if (in_len & 15) {
OPENSSL_memset(scratch, 0, sizeof(scratch));
OPENSSL_memcpy(scratch, &in[in_len & ~15], in_len & 15);
CRYPTO_POLYVAL_update_blocks(&polyval_ctx, scratch, sizeof(scratch));
}

union {
uint8_t c[16];
struct {
uint64_t ad;
uint64_t in;
} bitlens;
} length_block;

length_block.bitlens.ad = ad_len * 8;
length_block.bitlens.in = in_len * 8;
CRYPTO_POLYVAL_update_blocks(&polyval_ctx, length_block.c,
sizeof(length_block));

CRYPTO_POLYVAL_finish(&polyval_ctx, out_tag);
for (size_t i = 0; i < EVP_AEAD_AES_GCM_SIV_NONCE_LEN; i++) {
out_tag[i] ^= nonce[i];
}
out_tag[15] &= 0x7f;
}

/* gcm_siv_record_keys contains the keys used for a specific GCM-SIV record. */
struct gcm_siv_record_keys {
uint8_t auth_key[16];
union {
double align;
AES_KEY ks;
} enc_key;
block128_f enc_block;
};

/* gcm_siv_keys calculates the keys for a specific GCM-SIV record with the
* given nonce and writes them to |*out_keys|. */
static void gcm_siv_keys(
const struct aead_aes_gcm_siv_ctx *gcm_siv_ctx,
struct gcm_siv_record_keys *out_keys,
const uint8_t nonce[EVP_AEAD_AES_GCM_SIV_NONCE_LEN]) {
const AES_KEY *const key = &gcm_siv_ctx->ks.ks;
uint8_t key_material[(128 /* POLYVAL key */ + 256 /* max AES key */) / 8];
const size_t blocks_needed = gcm_siv_ctx->is_256 ? 6 : 4;

uint8_t counter[AES_BLOCK_SIZE];
OPENSSL_memset(counter, 0, AES_BLOCK_SIZE - EVP_AEAD_AES_GCM_SIV_NONCE_LEN);
OPENSSL_memcpy(counter + AES_BLOCK_SIZE - EVP_AEAD_AES_GCM_SIV_NONCE_LEN,
nonce, EVP_AEAD_AES_GCM_SIV_NONCE_LEN);
for (size_t i = 0; i < blocks_needed; i++) {
counter[0] = i;

uint8_t ciphertext[AES_BLOCK_SIZE];
gcm_siv_ctx->kgk_block(counter, ciphertext, key);
OPENSSL_memcpy(&key_material[i * 8], ciphertext, 8);
}

OPENSSL_memcpy(out_keys->auth_key, key_material, 16);
aes_ctr_set_key(&out_keys->enc_key.ks, NULL, &out_keys->enc_block,
key_material + 16, gcm_siv_ctx->is_256 ? 32 : 16);
}

static int aead_aes_gcm_siv_seal(const EVP_AEAD_CTX *ctx, uint8_t *out,
size_t *out_len, size_t max_out_len,
const uint8_t *nonce, size_t nonce_len,
const uint8_t *in, size_t in_len,
const uint8_t *ad, size_t ad_len) {
const struct aead_aes_gcm_siv_ctx *gcm_siv_ctx = ctx->aead_state;
const uint64_t in_len_64 = in_len;
const uint64_t ad_len_64 = ad_len;

if (in_len + EVP_AEAD_AES_GCM_SIV_TAG_LEN < in_len ||
in_len_64 > (UINT64_C(1) << 36) ||
ad_len_64 >= (UINT64_C(1) << 61)) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_TOO_LARGE);
return 0;
}

if (max_out_len < in_len + EVP_AEAD_AES_GCM_SIV_TAG_LEN) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BUFFER_TOO_SMALL);
return 0;
}

if (nonce_len != EVP_AEAD_AES_GCM_SIV_NONCE_LEN) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_UNSUPPORTED_NONCE_SIZE);
return 0;
}

struct gcm_siv_record_keys keys;
gcm_siv_keys(gcm_siv_ctx, &keys, nonce);

uint8_t tag[16];
gcm_siv_polyval(tag, in, in_len, ad, ad_len, keys.auth_key, nonce);
keys.enc_block(tag, tag, &keys.enc_key.ks);

gcm_siv_crypt(out, in, in_len, tag, keys.enc_block, &keys.enc_key.ks);

OPENSSL_memcpy(&out[in_len], tag, EVP_AEAD_AES_GCM_SIV_TAG_LEN);
*out_len = in_len + EVP_AEAD_AES_GCM_SIV_TAG_LEN;

return 1;
}

static int aead_aes_gcm_siv_open(const EVP_AEAD_CTX *ctx, uint8_t *out,
size_t *out_len, size_t max_out_len,
const uint8_t *nonce, size_t nonce_len,
const uint8_t *in, size_t in_len,
const uint8_t *ad, size_t ad_len) {
const uint64_t ad_len_64 = ad_len;
if (ad_len_64 >= (UINT64_C(1) << 61)) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_TOO_LARGE);
return 0;
}

const uint64_t in_len_64 = in_len;
if (in_len < EVP_AEAD_AES_GCM_SIV_TAG_LEN ||
in_len_64 > (UINT64_C(1) << 36) + AES_BLOCK_SIZE) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BAD_DECRYPT);
return 0;
}

if (nonce_len != EVP_AEAD_AES_GCM_SIV_NONCE_LEN) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_UNSUPPORTED_NONCE_SIZE);
return 0;
}

const struct aead_aes_gcm_siv_ctx *gcm_siv_ctx = ctx->aead_state;
const size_t plaintext_len = in_len - EVP_AEAD_AES_GCM_SIV_TAG_LEN;

if (max_out_len < plaintext_len) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BUFFER_TOO_SMALL);
return 0;
}

struct gcm_siv_record_keys keys;
gcm_siv_keys(gcm_siv_ctx, &keys, nonce);

gcm_siv_crypt(out, in, plaintext_len, &in[plaintext_len], keys.enc_block,
&keys.enc_key.ks);

uint8_t expected_tag[EVP_AEAD_AES_GCM_SIV_TAG_LEN];
gcm_siv_polyval(expected_tag, out, plaintext_len, ad, ad_len, keys.auth_key,
nonce);
keys.enc_block(expected_tag, expected_tag, &keys.enc_key.ks);

if (CRYPTO_memcmp(expected_tag, &in[plaintext_len], sizeof(expected_tag)) !=
0) {
OPENSSL_PUT_ERROR(CIPHER, CIPHER_R_BAD_DECRYPT);
return 0;
}

*out_len = plaintext_len;
return 1;
}

static const EVP_AEAD aead_aes_128_gcm_siv = {
16, /* key length */
EVP_AEAD_AES_GCM_SIV_NONCE_LEN, /* nonce length */
EVP_AEAD_AES_GCM_SIV_TAG_LEN, /* overhead */
EVP_AEAD_AES_GCM_SIV_TAG_LEN, /* max tag length */

aead_aes_gcm_siv_init,
NULL /* init_with_direction */,
aead_aes_gcm_siv_cleanup,
aead_aes_gcm_siv_seal,
aead_aes_gcm_siv_open,
NULL /* get_iv */,
};

static const EVP_AEAD aead_aes_256_gcm_siv = {
32, /* key length */
EVP_AEAD_AES_GCM_SIV_NONCE_LEN, /* nonce length */
EVP_AEAD_AES_GCM_SIV_TAG_LEN, /* overhead */
EVP_AEAD_AES_GCM_SIV_TAG_LEN, /* max tag length */

aead_aes_gcm_siv_init,
NULL /* init_with_direction */,
aead_aes_gcm_siv_cleanup,
aead_aes_gcm_siv_seal,
aead_aes_gcm_siv_open,
NULL /* get_iv */,
};

const EVP_AEAD *EVP_aead_aes_128_gcm_siv(void) {
return &aead_aes_128_gcm_siv;
}

const EVP_AEAD *EVP_aead_aes_256_gcm_siv(void) {
return &aead_aes_256_gcm_siv;
}

#endif /* !OPENSSL_SMALL */

+ 13
- 0
crypto/cipher/internal.h Datei anzeigen

@@ -60,6 +60,9 @@
#include <openssl/base.h>

#include <openssl/aead.h>
#include <openssl/aes.h>

#include "../modes/internal.h"

#if defined(__cplusplus)
extern "C" {
@@ -154,6 +157,16 @@ int EVP_tls_cbc_digest_record(const EVP_MD *md, uint8_t *md_out,
const uint8_t *mac_secret,
unsigned mac_secret_length);

/* aes_ctr_set_key initialises |*aes_key| using |key_bytes| bytes from |key|,
* where |key_bytes| must either be 16, 24 or 32. If not NULL, |*out_block| is
* set to a function that encrypts single blocks. If not NULL, |*gcm_ctx| is
* initialised to do GHASH with the given key. It returns a function for
* optimised CTR-mode, or NULL if CTR-mode should be built using
* |*out_block|. */
ctr128_f aes_ctr_set_key(AES_KEY *aes_key, GCM128_CONTEXT *gcm_ctx,
block128_f *out_block, const uint8_t *key,
size_t key_bytes);

#if defined(__cplusplus)
} /* extern C */
#endif


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