SHA-1 is weak and we need to transition to a new hash function. For some time, we have referred to this new function as NewHash. Recently, we decided to pick SHA-256 as NewHash. The reasons behind the choice of SHA-256 are outlined in the thread starting at [1] and in the commit history for the hash function transition document.
Add a basic implementation of SHA-256 based off libtomcrypt, which is in the public domain. Optimize it and restructure it to meet our coding standards. Pull in the update and final functions from the SHA-1 block implementation, as we know these function correctly with all compilers. This implementation is slower than SHA-1, but more performant implementations will be introduced in future commits. Wire up SHA-256 in the list of hash algorithms, and add a test that the algorithm works correctly. Note that with this patch, it is still not possible to switch to using SHA-256 in Git. Additional patches are needed to prepare the code to handle a larger hash algorithm and further test fixes are needed. [1] https://public-inbox.org/git/20180609224913.gc38...@genre.crustytoothpaste.net/ Signed-off-by: brian m. carlson <sand...@crustytoothpaste.net> --- Makefile | 4 + cache.h | 12 ++- hash.h | 19 +++- sha1-file.c | 45 ++++++++++ sha256/block/sha256.c | 196 +++++++++++++++++++++++++++++++++++++++++ sha256/block/sha256.h | 26 ++++++ t/helper/test-sha256.c | 7 ++ t/helper/test-tool.c | 1 + t/helper/test-tool.h | 1 + t/t0015-hash.sh | 25 ++++++ 10 files changed, 332 insertions(+), 4 deletions(-) create mode 100644 sha256/block/sha256.c create mode 100644 sha256/block/sha256.h create mode 100644 t/helper/test-sha256.c diff --git a/Makefile b/Makefile index 68169a7abb..e99b7712f6 100644 --- a/Makefile +++ b/Makefile @@ -739,6 +739,7 @@ TEST_BUILTINS_OBJS += test-run-command.o TEST_BUILTINS_OBJS += test-scrap-cache-tree.o TEST_BUILTINS_OBJS += test-sha1.o TEST_BUILTINS_OBJS += test-sha1-array.o +TEST_BUILTINS_OBJS += test-sha256.o TEST_BUILTINS_OBJS += test-sigchain.o TEST_BUILTINS_OBJS += test-strcmp-offset.o TEST_BUILTINS_OBJS += test-string-list.o @@ -1633,6 +1634,9 @@ endif endif endif +LIB_OBJS += sha256/block/sha256.o +BASIC_CFLAGS += -DSHA256_BLK + ifdef SHA1_MAX_BLOCK_SIZE LIB_OBJS += compat/sha1-chunked.o BASIC_CFLAGS += -DSHA1_MAX_BLOCK_SIZE="$(SHA1_MAX_BLOCK_SIZE)" diff --git a/cache.h b/cache.h index 9e5d1dd85a..48ce1565e6 100644 --- a/cache.h +++ b/cache.h @@ -48,11 +48,17 @@ unsigned long git_deflate_bound(git_zstream *, unsigned long); /* The block size of SHA-1. */ #define GIT_SHA1_BLKSZ 64 +/* The length in bytes and in hex digits of an object name (SHA-256 value). */ +#define GIT_SHA256_RAWSZ 32 +#define GIT_SHA256_HEXSZ (2 * GIT_SHA256_RAWSZ) +/* The block size of SHA-256. */ +#define GIT_SHA256_BLKSZ 64 + /* The length in byte and in hex digits of the largest possible hash value. */ -#define GIT_MAX_RAWSZ GIT_SHA1_RAWSZ -#define GIT_MAX_HEXSZ GIT_SHA1_HEXSZ +#define GIT_MAX_RAWSZ GIT_SHA256_RAWSZ +#define GIT_MAX_HEXSZ GIT_SHA256_HEXSZ /* The largest possible block size for any supported hash. */ -#define GIT_MAX_BLKSZ GIT_SHA1_BLKSZ +#define GIT_MAX_BLKSZ GIT_SHA256_BLKSZ struct object_id { unsigned char hash[GIT_MAX_RAWSZ]; diff --git a/hash.h b/hash.h index 1bcf7ab6fd..a9bc624020 100644 --- a/hash.h +++ b/hash.h @@ -15,6 +15,8 @@ #include "block-sha1/sha1.h" #endif +#include "sha256/block/sha256.h" + #ifndef platform_SHA_CTX /* * platform's underlying implementation of SHA-1; could be OpenSSL, @@ -34,6 +36,18 @@ #define git_SHA1_Update platform_SHA1_Update #define git_SHA1_Final platform_SHA1_Final +#ifndef platform_SHA256_CTX +#define platform_SHA256_CTX SHA256_CTX +#define platform_SHA256_Init SHA256_Init +#define platform_SHA256_Update SHA256_Update +#define platform_SHA256_Final SHA256_Final +#endif + +#define git_SHA256_CTX platform_SHA256_CTX +#define git_SHA256_Init platform_SHA256_Init +#define git_SHA256_Update platform_SHA256_Update +#define git_SHA256_Final platform_SHA256_Final + #ifdef SHA1_MAX_BLOCK_SIZE #include "compat/sha1-chunked.h" #undef git_SHA1_Update @@ -52,12 +66,15 @@ #define GIT_HASH_UNKNOWN 0 /* SHA-1 */ #define GIT_HASH_SHA1 1 +/* SHA-256 */ +#define GIT_HASH_SHA256 2 /* Number of algorithms supported (including unknown). */ -#define GIT_HASH_NALGOS (GIT_HASH_SHA1 + 1) +#define GIT_HASH_NALGOS (GIT_HASH_SHA256 + 1) /* A suitably aligned type for stack allocations of hash contexts. */ union git_hash_ctx { git_SHA_CTX sha1; + git_SHA256_CTX sha256; }; typedef union git_hash_ctx git_hash_ctx; diff --git a/sha1-file.c b/sha1-file.c index 9bdd04ea45..c97d93a14a 100644 --- a/sha1-file.c +++ b/sha1-file.c @@ -40,10 +40,20 @@ #define EMPTY_TREE_SHA1_BIN_LITERAL \ "\x4b\x82\x5d\xc6\x42\xcb\x6e\xb9\xa0\x60" \ "\xe5\x4b\xf8\xd6\x92\x88\xfb\xee\x49\x04" +#define EMPTY_TREE_SHA256_BIN_LITERAL \ + "\x6e\xf1\x9b\x41\x22\x5c\x53\x69\xf1\xc1" \ + "\x04\xd4\x5d\x8d\x85\xef\xa9\xb0\x57\xb5" \ + "\x3b\x14\xb4\xb9\xb9\x39\xdd\x74\xde\xcc" \ + "\x53\x21" #define EMPTY_BLOB_SHA1_BIN_LITERAL \ "\xe6\x9d\xe2\x9b\xb2\xd1\xd6\x43\x4b\x8b" \ "\x29\xae\x77\x5a\xd8\xc2\xe4\x8c\x53\x91" +#define EMPTY_BLOB_SHA256_BIN_LITERAL \ + "\x47\x3a\x0f\x4c\x3b\xe8\xa9\x36\x81\xa2" \ + "\x67\xe3\xb1\xe9\xa7\xdc\xda\x11\x85\x43" \ + "\x6f\xe1\x41\xf7\x74\x91\x20\xa3\x03\x72" \ + "\x18\x13" const unsigned char null_sha1[GIT_MAX_RAWSZ]; const struct object_id null_oid; @@ -53,6 +63,12 @@ static const struct object_id empty_tree_oid = { static const struct object_id empty_blob_oid = { EMPTY_BLOB_SHA1_BIN_LITERAL }; +static const struct object_id empty_tree_oid_sha256 = { + EMPTY_TREE_SHA256_BIN_LITERAL +}; +static const struct object_id empty_blob_oid_sha256 = { + EMPTY_BLOB_SHA256_BIN_LITERAL +}; static void git_hash_sha1_init(git_hash_ctx *ctx) { @@ -69,6 +85,22 @@ static void git_hash_sha1_final(unsigned char *hash, git_hash_ctx *ctx) git_SHA1_Final(hash, &ctx->sha1); } + +static void git_hash_sha256_init(git_hash_ctx *ctx) +{ + git_SHA256_Init(&ctx->sha256); +} + +static void git_hash_sha256_update(git_hash_ctx *ctx, const void *data, size_t len) +{ + git_SHA256_Update(&ctx->sha256, data, len); +} + +static void git_hash_sha256_final(unsigned char *hash, git_hash_ctx *ctx) +{ + git_SHA256_Final(hash, &ctx->sha256); +} + static void git_hash_unknown_init(git_hash_ctx *ctx) { BUG("trying to init unknown hash"); @@ -110,6 +142,19 @@ const struct git_hash_algo hash_algos[GIT_HASH_NALGOS] = { &empty_tree_oid, &empty_blob_oid, }, + { + "sha256", + /* "s256", big-endian */ + 0x73323536, + GIT_SHA256_RAWSZ, + GIT_SHA256_HEXSZ, + GIT_SHA256_BLKSZ, + git_hash_sha256_init, + git_hash_sha256_update, + git_hash_sha256_final, + &empty_tree_oid_sha256, + &empty_blob_oid_sha256, + } }; const char *empty_tree_oid_hex(void) diff --git a/sha256/block/sha256.c b/sha256/block/sha256.c new file mode 100644 index 0000000000..37850b4e52 --- /dev/null +++ b/sha256/block/sha256.c @@ -0,0 +1,196 @@ +#include "git-compat-util.h" +#include "./sha256.h" + +#undef RND +#undef BLKSIZE + +#define BLKSIZE blk_SHA256_BLKSIZE + +void blk_SHA256_Init(blk_SHA256_CTX *ctx) +{ + ctx->offset = 0; + ctx->size = 0; + ctx->state[0] = 0x6a09e667ul; + ctx->state[1] = 0xbb67ae85ul; + ctx->state[2] = 0x3c6ef372ul; + ctx->state[3] = 0xa54ff53aul; + ctx->state[4] = 0x510e527ful; + ctx->state[5] = 0x9b05688cul; + ctx->state[6] = 0x1f83d9abul; + ctx->state[7] = 0x5be0cd19ul; +} + +static inline uint32_t ror(uint32_t x, unsigned n) +{ + return (x >> n) | (x << (32 - n)); +} + +static inline uint32_t ch(uint32_t x, uint32_t y, uint32_t z) +{ + return z ^ (x & (y ^ z)); +} + +static inline uint32_t maj(uint32_t x, uint32_t y, uint32_t z) +{ + return ((x | y) & z) | (x & y); +} + +static inline uint32_t sigma0(uint32_t x) +{ + return ror(x, 2) ^ ror(x, 13) ^ ror(x, 22); +} + +static inline uint32_t sigma1(uint32_t x) +{ + return ror(x, 6) ^ ror(x, 11) ^ ror(x, 25); +} + +static inline uint32_t gamma0(uint32_t x) +{ + return ror(x, 7) ^ ror(x, 18) ^ (x >> 3); +} + +static inline uint32_t gamma1(uint32_t x) +{ + return ror(x, 17) ^ ror(x, 19) ^ (x >> 10); +} + +static void blk_SHA256_Transform(blk_SHA256_CTX *ctx, const unsigned char *buf) +{ + + uint32_t S[8], W[64], t0, t1; + int i; + + /* copy state into S */ + for (i = 0; i < 8; i++) + S[i] = ctx->state[i]; + + /* copy the state into 512-bits into W[0..15] */ + for (i = 0; i < 16; i++, buf += sizeof(uint32_t)) + W[i] = get_be32(buf); + + /* fill W[16..63] */ + for (i = 16; i < 64; i++) + W[i] = gamma1(W[i - 2]) + W[i - 7] + gamma0(W[i - 15]) + W[i - 16]; + +#define RND(a,b,c,d,e,f,g,h,i,ki) \ + t0 = h + sigma1(e) + ch(e, f, g) + ki + W[i]; \ + t1 = sigma0(a) + maj(a, b, c); \ + d += t0; \ + h = t0 + t1; + + RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],0,0x428a2f98); + RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],1,0x71374491); + RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],2,0xb5c0fbcf); + RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],3,0xe9b5dba5); + RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],4,0x3956c25b); + RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],5,0x59f111f1); + RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],6,0x923f82a4); + RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],7,0xab1c5ed5); + RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],8,0xd807aa98); + RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],9,0x12835b01); + RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],10,0x243185be); + RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],11,0x550c7dc3); + RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],12,0x72be5d74); + RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],13,0x80deb1fe); + RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],14,0x9bdc06a7); + RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],15,0xc19bf174); + RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],16,0xe49b69c1); + RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],17,0xefbe4786); + RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],18,0x0fc19dc6); + RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],19,0x240ca1cc); + RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],20,0x2de92c6f); + RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],21,0x4a7484aa); + RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],22,0x5cb0a9dc); + RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],23,0x76f988da); + RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],24,0x983e5152); + RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],25,0xa831c66d); + RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],26,0xb00327c8); + RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],27,0xbf597fc7); + RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],28,0xc6e00bf3); + RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],29,0xd5a79147); + RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],30,0x06ca6351); + RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],31,0x14292967); + RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],32,0x27b70a85); + RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],33,0x2e1b2138); + RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],34,0x4d2c6dfc); + RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],35,0x53380d13); + RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],36,0x650a7354); + RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],37,0x766a0abb); + RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],38,0x81c2c92e); + RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],39,0x92722c85); + RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],40,0xa2bfe8a1); + RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],41,0xa81a664b); + RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],42,0xc24b8b70); + RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],43,0xc76c51a3); + RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],44,0xd192e819); + RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],45,0xd6990624); + RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],46,0xf40e3585); + RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],47,0x106aa070); + RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],48,0x19a4c116); + RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],49,0x1e376c08); + RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],50,0x2748774c); + RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],51,0x34b0bcb5); + RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],52,0x391c0cb3); + RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],53,0x4ed8aa4a); + RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],54,0x5b9cca4f); + RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],55,0x682e6ff3); + RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],56,0x748f82ee); + RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],57,0x78a5636f); + RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],58,0x84c87814); + RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],59,0x8cc70208); + RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],60,0x90befffa); + RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],61,0xa4506ceb); + RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],62,0xbef9a3f7); + RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],63,0xc67178f2); + + for (i = 0; i < 8; i++) + ctx->state[i] += S[i]; +} + +void blk_SHA256_Update(blk_SHA256_CTX *ctx, const void *data, size_t len) +{ + unsigned int len_buf = ctx->size & 63; + + ctx->size += len; + + /* Read the data into buf and process blocks as they get full */ + if (len_buf) { + unsigned int left = 64 - len_buf; + if (len < left) + left = len; + memcpy(len_buf + ctx->buf, data, left); + len_buf = (len_buf + left) & 63; + len -= left; + data = ((const char *)data + left); + if (len_buf) + return; + blk_SHA256_Transform(ctx, ctx->buf); + } + while (len >= 64) { + blk_SHA256_Transform(ctx, data); + data = ((const char *)data + 64); + len -= 64; + } + if (len) + memcpy(ctx->buf, data, len); +} + +void blk_SHA256_Final(unsigned char *digest, blk_SHA256_CTX *ctx) +{ + static const unsigned char pad[64] = { 0x80 }; + unsigned int padlen[2]; + int i; + + /* Pad with a binary 1 (ie 0x80), then zeroes, then length */ + padlen[0] = htonl((uint32_t)(ctx->size >> 29)); + padlen[1] = htonl((uint32_t)(ctx->size << 3)); + + i = ctx->size & 63; + blk_SHA256_Update(ctx, pad, 1 + (63 & (55 - i))); + blk_SHA256_Update(ctx, padlen, 8); + + /* copy output */ + for (i = 0; i < 8; i++, digest += sizeof(uint32_t)) + put_be32(digest, ctx->state[i]); +} diff --git a/sha256/block/sha256.h b/sha256/block/sha256.h new file mode 100644 index 0000000000..38f02f7e6c --- /dev/null +++ b/sha256/block/sha256.h @@ -0,0 +1,26 @@ +#ifndef SHA256_BLOCK_SHA256_H +#define SHA256_BLOCK_SHA256_H + +#include "git-compat-util.h" + +#define blk_SHA256_BLKSIZE 64 + +struct blk_SHA256_CTX { + uint32_t state[8]; + uint64_t size; + uint32_t offset; + uint8_t buf[blk_SHA256_BLKSIZE]; +}; + +typedef struct blk_SHA256_CTX blk_SHA256_CTX; + +void blk_SHA256_Init(blk_SHA256_CTX *ctx); +void blk_SHA256_Update(blk_SHA256_CTX *ctx, const void *data, size_t len); +void blk_SHA256_Final(unsigned char *digest, blk_SHA256_CTX *ctx); + +#define platform_SHA256_CTX blk_SHA256_CTX +#define platform_SHA256_Init blk_SHA256_Init +#define platform_SHA256_Update blk_SHA256_Update +#define platform_SHA256_Final blk_SHA256_Final + +#endif diff --git a/t/helper/test-sha256.c b/t/helper/test-sha256.c new file mode 100644 index 0000000000..0ac6a99d5f --- /dev/null +++ b/t/helper/test-sha256.c @@ -0,0 +1,7 @@ +#include "test-tool.h" +#include "cache.h" + +int cmd__sha256(int ac, const char **av) +{ + return cmd_hash_impl(ac, av, GIT_HASH_SHA256); +} diff --git a/t/helper/test-tool.c b/t/helper/test-tool.c index e009c8186d..2a65193514 100644 --- a/t/helper/test-tool.c +++ b/t/helper/test-tool.c @@ -43,6 +43,7 @@ static struct test_cmd cmds[] = { { "scrap-cache-tree", cmd__scrap_cache_tree }, { "sha1", cmd__sha1 }, { "sha1-array", cmd__sha1_array }, + { "sha256", cmd__sha256 }, { "sigchain", cmd__sigchain }, { "strcmp-offset", cmd__strcmp_offset }, { "string-list", cmd__string_list }, diff --git a/t/helper/test-tool.h b/t/helper/test-tool.h index 19a7e8332a..2e66a8e47b 100644 --- a/t/helper/test-tool.h +++ b/t/helper/test-tool.h @@ -39,6 +39,7 @@ int cmd__run_command(int argc, const char **argv); int cmd__scrap_cache_tree(int argc, const char **argv); int cmd__sha1(int argc, const char **argv); int cmd__sha1_array(int argc, const char **argv); +int cmd__sha256(int argc, const char **argv); int cmd__sigchain(int argc, const char **argv); int cmd__strcmp_offset(int argc, const char **argv); int cmd__string_list(int argc, const char **argv); diff --git a/t/t0015-hash.sh b/t/t0015-hash.sh index 8e763c2c3d..f8e639743f 100755 --- a/t/t0015-hash.sh +++ b/t/t0015-hash.sh @@ -26,4 +26,29 @@ test_expect_success 'test basic SHA-1 hash values' ' grep 4b825dc642cb6eb9a060e54bf8d69288fbee4904 actual ' +test_expect_success 'test basic SHA-256 hash values' ' + test-tool sha256 </dev/null >actual && + grep e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855 actual && + printf "a" | test-tool sha256 >actual && + grep ca978112ca1bbdcafac231b39a23dc4da786eff8147c4e72b9807785afee48bb actual && + printf "abc" | test-tool sha256 >actual && + grep ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad actual && + printf "message digest" | test-tool sha256 >actual && + grep f7846f55cf23e14eebeab5b4e1550cad5b509e3348fbc4efa3a1413d393cb650 actual && + printf "abcdefghijklmnopqrstuvwxyz" | test-tool sha256 >actual && + grep 71c480df93d6ae2f1efad1447c66c9525e316218cf51fc8d9ed832f2daf18b73 actual && + perl -E "for (1..100000) { print q{aaaaaaaaaa}; }" | \ + test-tool sha256 >actual && + grep cdc76e5c9914fb9281a1c7e284d73e67f1809a48a497200e046d39ccc7112cd0 actual && + perl -E "for (1..100000) { print q{abcdefghijklmnopqrstuvwxyz}; }" | \ + test-tool sha256 >actual && + grep e406ba321ca712ad35a698bf0af8d61fc4dc40eca6bdcea4697962724ccbde35 actual && + printf "blob 0\0" | test-tool sha256 >actual && + grep 473a0f4c3be8a93681a267e3b1e9a7dcda1185436fe141f7749120a303721813 actual && + printf "blob 3\0abc" | test-tool sha256 >actual && + grep c1cf6e465077930e88dc5136641d402f72a229ddd996f627d60e9639eaba35a6 actual && + printf "tree 0\0" | test-tool sha256 >actual && + grep 6ef19b41225c5369f1c104d45d8d85efa9b057b53b14b4b9b939dd74decc5321 actual +' + test_done
