diff options
Diffstat (limited to '')
-rw-r--r-- | debian/vendor-h2o/deps/picotls/deps/cifra/src/drbg.c | 434 |
1 files changed, 0 insertions, 434 deletions
diff --git a/debian/vendor-h2o/deps/picotls/deps/cifra/src/drbg.c b/debian/vendor-h2o/deps/picotls/deps/cifra/src/drbg.c deleted file mode 100644 index ae79067..0000000 --- a/debian/vendor-h2o/deps/picotls/deps/cifra/src/drbg.c +++ /dev/null @@ -1,434 +0,0 @@ -/* - * cifra - embedded cryptography library - * Written in 2016 by Joseph Birr-Pixton <jpixton@gmail.com> - * - * To the extent possible under law, the author(s) have dedicated all - * copyright and related and neighboring rights to this software to the - * public domain worldwide. This software is distributed without any - * warranty. - * - * You should have received a copy of the CC0 Public Domain Dedication - * along with this software. If not, see - * <http://creativecommons.org/publicdomain/zero/1.0/>. - */ - -#include "drbg.h" -#include "handy.h" -#include "bitops.h" -#include "sha2.h" -#include "tassert.h" - -#include <string.h> - -#define MAX_DRBG_GENERATE 0x10000ul - -static void hash_df(const cf_chash *H, - const void *in1, size_t nin1, - const void *in2, size_t nin2, - const void *in3, size_t nin3, - const void *in4, size_t nin4, - uint8_t *out, size_t nout) -{ - uint8_t counter = 1; - uint32_t bits_to_return = nout * 8; - uint8_t cbuf[4]; - uint8_t block[CF_MAXHASH]; - - write32_be(bits_to_return, cbuf); - - while (nout) - { - /* Make a block. This is the hash of: - * counter || bits_to_return || in1 || in2 || in3 | in4 - */ - cf_chash_ctx ctx; - H->init(&ctx); - H->update(&ctx, &counter, sizeof counter); - H->update(&ctx, cbuf, sizeof cbuf); - H->update(&ctx, in1, nin1); - H->update(&ctx, in2, nin2); - H->update(&ctx, in3, nin3); - H->update(&ctx, in4, nin4); - H->digest(&ctx, block); - - size_t take = MIN(H->hashsz, nout); - memcpy(out, block, take); - out += take; - nout -= take; - - counter += 1; - } -} - -void cf_hash_drbg_sha256_init(cf_hash_drbg_sha256 *ctx, - const void *entropy, size_t nentropy, - const void *nonce, size_t nnonce, - const void *persn, size_t npersn) -{ - mem_clean(ctx, sizeof *ctx); - - /* 1. seed_material = entropy_input || nonce || personalization_string - * 2. seed = Hash_df(seed_material, seedlen) - * 3. V = seed */ - hash_df(&cf_sha256, - entropy, nentropy, - nonce, nnonce, - persn, npersn, - NULL, 0, - ctx->V, sizeof ctx->V); - - /* 4. C = Hash_df(0x00 || V, seedlen) */ - uint8_t zero = 0; - hash_df(&cf_sha256, - &zero, sizeof zero, - ctx->V, sizeof ctx->V, - NULL, 0, - NULL, 0, - ctx->C, sizeof ctx->C); - - /* 5. reseed_counter = 1 */ - ctx->reseed_counter = 1; -} - -/* Add out += in, mod 2^nout. - * Runs in time dependent on nout and nin, but not the contents of out or in. - */ -static void add(uint8_t *out, size_t nout, const uint8_t *in, size_t nin) -{ - assert(nout >= nin); - - uint16_t carry = 0; - int oi, ii; - - for (oi = nout - 1, ii = nin - 1; - oi >= 0; - ii--, oi--) - { - carry += out[oi]; - if (ii >= 0) - carry += in[ii]; - out[oi] = carry & 0xff; - carry >>= 8; - } -} - -static void hash_process_addnl(const cf_chash *H, - const void *input, size_t ninput, - uint8_t *V, size_t nV) -{ - if (!ninput) - return; - - /* 2.1. w = Hash(0x02 || V || additional_input) */ - uint8_t two = 2; - uint8_t w[CF_MAXHASH]; - cf_chash_ctx ctx; - H->init(&ctx); - H->update(&ctx, &two, sizeof two); - H->update(&ctx, V, nV); - H->update(&ctx, input, ninput); - H->digest(&ctx, w); - - /* 2.2. V = (V + w) mod 2 ^ seedlen */ - add(V, nV, w, H->hashsz); -} - -static void hash_generate(const cf_chash *H, - uint8_t *data, size_t ndata, /* initialised with V */ - void *out, size_t nout) -{ - cf_chash_ctx ctx; - uint8_t w[CF_MAXHASH]; - uint8_t *bout = out; - uint8_t one = 1; - - while (nout) - { - /* 4.1. w = Hash(data) */ - H->init(&ctx); - H->update(&ctx, data, ndata); - H->digest(&ctx, w); - - /* 4.2. W = W || w */ - size_t take = MIN(H->hashsz, nout); - memcpy(bout, w, take); - bout += take; - nout -= take; - - /* 4.3. data = (data + 1) mod 2 ^ seedlen */ - add(data, ndata, &one, sizeof one); - } -} - -static void hash_step(const cf_chash *H, - uint8_t *V, size_t nV, - const uint8_t *C, size_t nC, - uint32_t *reseed_counter) -{ - /* 4. h = Hash(0x03 || V) */ - uint8_t h[CF_MAXHASH]; - uint8_t three = 3; - cf_chash_ctx ctx; - - H->init(&ctx); - H->update(&ctx, &three, sizeof three); - H->update(&ctx, V, nV); - H->digest(&ctx, h); - - /* 5. V = (V + h + C + reseed_counter) mod 2 ^ seedlen */ - uint8_t reseed_counter_buf[4]; - write32_be(*reseed_counter, reseed_counter_buf); - - add(V, nV, h, H->hashsz); - add(V, nV, C, nC); - add(V, nV, reseed_counter_buf, sizeof reseed_counter_buf); - - /* 6. reseed_counter = reseed_counter + 1 */ - *reseed_counter = *reseed_counter + 1; -} - -/* This is Hash_DRBG_Generate_algorithm. - * nout is a maximum of MAX_DRBG_GENERATE */ -static void hash_gen_request(cf_hash_drbg_sha256 *ctx, - const void *addnl, size_t naddnl, - void *out, size_t nout) -{ - uint8_t data[440/8]; /* a temporary copy of V, which gets incremented by generate */ - - assert(!cf_hash_drbg_sha256_needs_reseed(ctx)); - - hash_process_addnl(&cf_sha256, addnl, naddnl, ctx->V, sizeof ctx->V); - assert(sizeof data == sizeof ctx->V); - memcpy(data, ctx->V, sizeof ctx->V); - hash_generate(&cf_sha256, data, sizeof data, out, nout); - hash_step(&cf_sha256, ctx->V, sizeof ctx->V, ctx->C, sizeof ctx->C, &ctx->reseed_counter); -} - -void cf_hash_drbg_sha256_gen_additional(cf_hash_drbg_sha256 *ctx, - const void *addnl, size_t naddnl, - void *out, size_t nout) -{ - uint8_t *bout = out; - - /* Generate output in requests of MAX_DRBG_GENERATE in size. */ - while (nout != 0) - { - size_t take = MIN(MAX_DRBG_GENERATE, nout); - hash_gen_request(ctx, addnl, naddnl, bout, take); - bout += take; - nout -= take; - - /* Add additional data only once. */ - addnl = NULL; - naddnl = 0; - } -} - -void cf_hash_drbg_sha256_gen(cf_hash_drbg_sha256 *ctx, - void *out, size_t nout) -{ - cf_hash_drbg_sha256_gen_additional(ctx, - NULL, 0, - out, nout); -} - -void cf_hash_drbg_sha256_reseed(cf_hash_drbg_sha256 *ctx, - const void *entropy, size_t nentropy, - const void *addnl, size_t naddnl) -{ - /* 1. seed_material = 0x01 || V || entropy_input || additional_input - * 2. seed = Hash_df(seed_material, seedlen) - * 3. V = seed */ - uint8_t one = 1; - /* stash V in C, because it cannot alias output */ - memcpy(ctx->C, ctx->V, sizeof ctx->C); - hash_df(&cf_sha256, - &one, sizeof one, - ctx->C, sizeof ctx->C, - entropy, nentropy, - addnl, naddnl, - ctx->V, sizeof ctx->V); - - /* 4. C = Hash_df(0x00 || V, seedlen) */ - uint8_t zero = 0; - hash_df(&cf_sha256, - &zero, sizeof zero, - ctx->V, sizeof ctx->V, - NULL, 0, - NULL, 0, - ctx->C, sizeof ctx->C); - - /* 5. reseed_counter = 1 */ - ctx->reseed_counter = 1; -} - -uint32_t cf_hash_drbg_sha256_needs_reseed(const cf_hash_drbg_sha256 *ctx) -{ - /* we need reseeding after 2 ^ 32 - 1 requests. */ - return ctx->reseed_counter == 0; -} - -/* --- HMAC_DRBG --- */ - -/* provided_data is in1 || in2 || in3. - * K is already scheduled in ctx->hmac. */ -static void hmac_drbg_update(cf_hmac_drbg *ctx, - const void *in1, size_t nin1, - const void *in2, size_t nin2, - const void *in3, size_t nin3) -{ - cf_hmac_ctx local; - const cf_chash *H = ctx->hmac.hash; - uint8_t new_key[CF_MAXHASH]; - uint8_t zero = 0; - - /* 1. K = HMAC(K, V || 0x00 || provided_data) */ - local = ctx->hmac; - cf_hmac_update(&local, ctx->V, H->hashsz); - cf_hmac_update(&local, &zero, sizeof zero); - cf_hmac_update(&local, in1, nin1); - cf_hmac_update(&local, in2, nin2); - cf_hmac_update(&local, in3, nin3); - cf_hmac_finish(&local, new_key); - cf_hmac_init(&ctx->hmac, H, new_key, H->hashsz); - mem_clean(new_key, sizeof new_key); - - /* 2. V = HMAC(K, V) */ - local = ctx->hmac; - cf_hmac_update(&local, ctx->V, H->hashsz); - cf_hmac_finish(&local, ctx->V); - - /* 3. if (provided_data = null) then return K and V */ - if (nin1 == 0 && nin2 == 0 && nin3 == 0) - return; - - /* 4. K = HMAC(K, V || 0x01 || provided_data) */ - uint8_t one = 1; - local = ctx->hmac; - cf_hmac_update(&local, ctx->V, H->hashsz); - cf_hmac_update(&local, &one, sizeof one); - cf_hmac_update(&local, in1, nin1); - cf_hmac_update(&local, in2, nin2); - cf_hmac_update(&local, in3, nin3); - cf_hmac_finish(&local, new_key); - cf_hmac_init(&ctx->hmac, H, new_key, H->hashsz); - mem_clean(new_key, sizeof new_key); - - /* 5. V = HMAC(K, V) */ - local = ctx->hmac; - cf_hmac_update(&local, ctx->V, H->hashsz); - cf_hmac_finish(&local, ctx->V); -} - -void cf_hmac_drbg_init(cf_hmac_drbg *ctx, - const cf_chash *hash, - const void *entropy, size_t nentropy, - const void *nonce, size_t nnonce, - const void *persn, size_t npersn) -{ - mem_clean(ctx, sizeof *ctx); - - assert(hash->hashsz <= CF_MAXHASH); - - /* 2. Key = 0x00 00 ... 00 - * 3. V = 0x01 01 ... 01 */ - uint8_t initial_key[CF_MAXHASH]; - memset(initial_key, 0x00, hash->hashsz); - memset(ctx->V, 0x01, hash->hashsz); - cf_hmac_init(&ctx->hmac, hash, initial_key, hash->hashsz); - - /* 1. seed_material = entropy_input || nonce || personalization_string - * 4. (Key, V) = HMAC_DRBG_Update(seed_material, Key, V) */ - hmac_drbg_update(ctx, entropy, nentropy, nonce, nnonce, persn, npersn); - - /* 5. reseed_counter = 1 */ - ctx->reseed_counter = 1; -} - -uint32_t cf_hmac_drbg_needs_reseed(const cf_hmac_drbg *ctx) -{ - return ctx->reseed_counter == 0; -} - -static void hmac_drbg_generate(cf_hmac_drbg *ctx, - const void *addnl, size_t naddnl, - void *out, size_t nout) -{ - /* 1. If reseed_counter > reseed_interval, then return an indication - * that a reseed is required */ - assert(!cf_hmac_drbg_needs_reseed(ctx)); - - /* 2. If additional_input != null, then - * (Key, V) = HMAC_DRBG_Update(additional_input, Key, V) - */ - if (naddnl) - hmac_drbg_update(ctx, addnl, naddnl, NULL, 0, NULL, 0); - - /* 3. temp = Null - * 4. While (len(temp) < requested_number_of_bits) do: - * 4.1. V = HMAC(Key, V) - * 4.2. temp = temp || V - * 5. returned_bits = leftmost(temp, requested_number_of_bits) - * - * We write the contents of temp directly into the caller's - * out buffer. - */ - uint8_t *bout = out; - cf_hmac_ctx local; - - while (nout) - { - local = ctx->hmac; - cf_hmac_update(&local, ctx->V, ctx->hmac.hash->hashsz); - cf_hmac_finish(&local, ctx->V); - - size_t take = MIN(ctx->hmac.hash->hashsz, nout); - memcpy(bout, ctx->V, take); - bout += take; - nout -= take; - } - - /* 6. (Key, V) = HMAC_DRBG_Update(additional_input, Key, V) */ - hmac_drbg_update(ctx, addnl, naddnl, NULL, 0, NULL, 0); - - /* 7. reseed_counter = reseed_counter + 1 */ - ctx->reseed_counter++; -} - -void cf_hmac_drbg_gen_additional(cf_hmac_drbg *ctx, - const void *addnl, size_t naddnl, - void *out, size_t nout) -{ - uint8_t *bout = out; - - while (nout != 0) - { - size_t take = MIN(MAX_DRBG_GENERATE, nout); - hmac_drbg_generate(ctx, addnl, naddnl, bout, take); - bout += take; - nout -= take; - - /* Add additional data only once. */ - addnl = NULL; - naddnl = 0; - } -} - -void cf_hmac_drbg_gen(cf_hmac_drbg *ctx, void *out, size_t nout) -{ - cf_hmac_drbg_gen_additional(ctx, - NULL, 0, - out, nout); -} - -void cf_hmac_drbg_reseed(cf_hmac_drbg *ctx, - const void *entropy, size_t nentropy, - const void *addnl, size_t naddnl) -{ - /* 1. seed_material = entropy_input || additional_input - * 2. (Key, V) = HMAC_DRBG_Update(seed_material, Key, V) */ - hmac_drbg_update(ctx, entropy, nentropy, addnl, naddnl, NULL, 0); - - /* 3. reseed_counter = 1 */ - ctx->reseed_counter = 1; -} |