From 6b0b0fa2bce61db790efc8070ae6e5696435b0a8 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Sat, 2 May 2020 11:24:25 -0700 Subject: [PATCH] crypto: lib/sha1 - rename "sha" to "sha1" The library implementation of the SHA-1 compression function is confusingly called just "sha_transform()". Alongside it are some "SHA_" constants and "sha_init()". Presumably these are left over from a time when SHA just meant SHA-1. But now there are also SHA-2 and SHA-3, and moreover SHA-1 is now considered insecure and thus shouldn't be used. Therefore, rename these functions and constants to make it very clear that they are for SHA-1. Also add a comment to make it clear that these shouldn't be used. For the extra-misleadingly named "SHA_MESSAGE_BYTES", rename it to SHA1_BLOCK_SIZE and define it to just '64' rather than '(512/8)' so that it matches the same definition in . This prepares for merging into . Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu --- Documentation/security/siphash.rst | 2 +- crypto/sha1_generic.c | 4 ++-- drivers/char/random.c | 6 +++--- include/linux/cryptohash.h | 16 ++++++++++------ include/linux/filter.h | 2 +- kernel/bpf/core.c | 18 +++++++++--------- lib/sha1.c | 22 ++++++++++++---------- net/ipv6/addrconf.c | 10 +++++----- 8 files changed, 43 insertions(+), 37 deletions(-) diff --git a/Documentation/security/siphash.rst b/Documentation/security/siphash.rst index 4eba68cdf0a1..bd9363025fcb 100644 --- a/Documentation/security/siphash.rst +++ b/Documentation/security/siphash.rst @@ -7,7 +7,7 @@ SipHash - a short input PRF SipHash is a cryptographically secure PRF -- a keyed hash function -- that performs very well for short inputs, hence the name. It was designed by cryptographers Daniel J. Bernstein and Jean-Philippe Aumasson. It is intended -as a replacement for some uses of: `jhash`, `md5_transform`, `sha_transform`, +as a replacement for some uses of: `jhash`, `md5_transform`, `sha1_transform`, and so forth. SipHash takes a secret key filled with randomly generated numbers and either diff --git a/crypto/sha1_generic.c b/crypto/sha1_generic.c index 7c57b844c382..a16d9787dcd2 100644 --- a/crypto/sha1_generic.c +++ b/crypto/sha1_generic.c @@ -31,10 +31,10 @@ EXPORT_SYMBOL_GPL(sha1_zero_message_hash); static void sha1_generic_block_fn(struct sha1_state *sst, u8 const *src, int blocks) { - u32 temp[SHA_WORKSPACE_WORDS]; + u32 temp[SHA1_WORKSPACE_WORDS]; while (blocks--) { - sha_transform(sst->state, src, temp); + sha1_transform(sst->state, src, temp); src += SHA1_BLOCK_SIZE; } memzero_explicit(temp, sizeof(temp)); diff --git a/drivers/char/random.c b/drivers/char/random.c index 0d10e31fd342..a19a8984741b 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1397,14 +1397,14 @@ static void extract_buf(struct entropy_store *r, __u8 *out) __u32 w[5]; unsigned long l[LONGS(20)]; } hash; - __u32 workspace[SHA_WORKSPACE_WORDS]; + __u32 workspace[SHA1_WORKSPACE_WORDS]; unsigned long flags; /* * If we have an architectural hardware random number * generator, use it for SHA's initial vector */ - sha_init(hash.w); + sha1_init(hash.w); for (i = 0; i < LONGS(20); i++) { unsigned long v; if (!arch_get_random_long(&v)) @@ -1415,7 +1415,7 @@ static void extract_buf(struct entropy_store *r, __u8 *out) /* Generate a hash across the pool, 16 words (512 bits) at a time */ spin_lock_irqsave(&r->lock, flags); for (i = 0; i < r->poolinfo->poolwords; i += 16) - sha_transform(hash.w, (__u8 *)(r->pool + i), workspace); + sha1_transform(hash.w, (__u8 *)(r->pool + i), workspace); /* * We mix the hash back into the pool to prevent backtracking diff --git a/include/linux/cryptohash.h b/include/linux/cryptohash.h index f6ba4c3e60d7..c324ffca96e0 100644 --- a/include/linux/cryptohash.h +++ b/include/linux/cryptohash.h @@ -4,11 +4,15 @@ #include -#define SHA_DIGEST_WORDS 5 -#define SHA_MESSAGE_BYTES (512 /*bits*/ / 8) -#define SHA_WORKSPACE_WORDS 16 - -void sha_init(__u32 *buf); -void sha_transform(__u32 *digest, const char *data, __u32 *W); +/* + * An implementation of SHA-1's compression function. Don't use in new code! + * You shouldn't be using SHA-1, and even if you *have* to use SHA-1, this isn't + * the correct way to hash something with SHA-1 (use crypto_shash instead). + */ +#define SHA1_DIGEST_WORDS 5 +#define SHA1_BLOCK_SIZE 64 +#define SHA1_WORKSPACE_WORDS 16 +void sha1_init(__u32 *buf); +void sha1_transform(__u32 *digest, const char *data, __u32 *W); #endif diff --git a/include/linux/filter.h b/include/linux/filter.h index 9b5aa5c483cc..f42662adffe4 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -746,7 +746,7 @@ static inline u32 bpf_prog_insn_size(const struct bpf_prog *prog) static inline u32 bpf_prog_tag_scratch_size(const struct bpf_prog *prog) { return round_up(bpf_prog_insn_size(prog) + - sizeof(__be64) + 1, SHA_MESSAGE_BYTES); + sizeof(__be64) + 1, SHA1_BLOCK_SIZE); } static inline unsigned int bpf_prog_size(unsigned int proglen) diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 916f5132a984..14aa1f74dd10 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -262,10 +262,10 @@ void __bpf_prog_free(struct bpf_prog *fp) int bpf_prog_calc_tag(struct bpf_prog *fp) { - const u32 bits_offset = SHA_MESSAGE_BYTES - sizeof(__be64); + const u32 bits_offset = SHA1_BLOCK_SIZE - sizeof(__be64); u32 raw_size = bpf_prog_tag_scratch_size(fp); - u32 digest[SHA_DIGEST_WORDS]; - u32 ws[SHA_WORKSPACE_WORDS]; + u32 digest[SHA1_DIGEST_WORDS]; + u32 ws[SHA1_WORKSPACE_WORDS]; u32 i, bsize, psize, blocks; struct bpf_insn *dst; bool was_ld_map; @@ -277,7 +277,7 @@ int bpf_prog_calc_tag(struct bpf_prog *fp) if (!raw) return -ENOMEM; - sha_init(digest); + sha1_init(digest); memset(ws, 0, sizeof(ws)); /* We need to take out the map fd for the digest calculation @@ -308,8 +308,8 @@ int bpf_prog_calc_tag(struct bpf_prog *fp) memset(&raw[psize], 0, raw_size - psize); raw[psize++] = 0x80; - bsize = round_up(psize, SHA_MESSAGE_BYTES); - blocks = bsize / SHA_MESSAGE_BYTES; + bsize = round_up(psize, SHA1_BLOCK_SIZE); + blocks = bsize / SHA1_BLOCK_SIZE; todo = raw; if (bsize - psize >= sizeof(__be64)) { bits = (__be64 *)(todo + bsize - sizeof(__be64)); @@ -320,12 +320,12 @@ int bpf_prog_calc_tag(struct bpf_prog *fp) *bits = cpu_to_be64((psize - 1) << 3); while (blocks--) { - sha_transform(digest, todo, ws); - todo += SHA_MESSAGE_BYTES; + sha1_transform(digest, todo, ws); + todo += SHA1_BLOCK_SIZE; } result = (__force __be32 *)digest; - for (i = 0; i < SHA_DIGEST_WORDS; i++) + for (i = 0; i < SHA1_DIGEST_WORDS; i++) result[i] = cpu_to_be32(digest[i]); memcpy(fp->tag, result, sizeof(fp->tag)); diff --git a/lib/sha1.c b/lib/sha1.c index 1d96d2c02b82..b381e8cd4fe4 100644 --- a/lib/sha1.c +++ b/lib/sha1.c @@ -64,22 +64,24 @@ #define T_60_79(t, A, B, C, D, E) SHA_ROUND(t, SHA_MIX, (B^C^D) , 0xca62c1d6, A, B, C, D, E ) /** - * sha_transform - single block SHA1 transform + * sha1_transform - single block SHA1 transform (deprecated) * * @digest: 160 bit digest to update * @data: 512 bits of data to hash * @array: 16 words of workspace (see note) * - * This function generates a SHA1 digest for a single 512-bit block. - * Be warned, it does not handle padding and message digest, do not - * confuse it with the full FIPS 180-1 digest algorithm for variable - * length messages. + * This function executes SHA-1's internal compression function. It updates the + * 160-bit internal state (@digest) with a single 512-bit data block (@data). + * + * Don't use this function. SHA-1 is no longer considered secure. And even if + * you do have to use SHA-1, this isn't the correct way to hash something with + * SHA-1 as this doesn't handle padding and finalization. * * Note: If the hash is security sensitive, the caller should be sure * to clear the workspace. This is left to the caller to avoid * unnecessary clears between chained hashing operations. */ -void sha_transform(__u32 *digest, const char *data, __u32 *array) +void sha1_transform(__u32 *digest, const char *data, __u32 *array) { __u32 A, B, C, D, E; @@ -185,13 +187,13 @@ void sha_transform(__u32 *digest, const char *data, __u32 *array) digest[3] += D; digest[4] += E; } -EXPORT_SYMBOL(sha_transform); +EXPORT_SYMBOL(sha1_transform); /** - * sha_init - initialize the vectors for a SHA1 digest + * sha1_init - initialize the vectors for a SHA1 digest * @buf: vector to initialize */ -void sha_init(__u32 *buf) +void sha1_init(__u32 *buf) { buf[0] = 0x67452301; buf[1] = 0xefcdab89; @@ -199,4 +201,4 @@ void sha_init(__u32 *buf) buf[3] = 0x10325476; buf[4] = 0xc3d2e1f0; } -EXPORT_SYMBOL(sha_init); +EXPORT_SYMBOL(sha1_init); diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 24e319dfb510..f131cedf5ba6 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -3222,11 +3222,11 @@ static int ipv6_generate_stable_address(struct in6_addr *address, const struct inet6_dev *idev) { static DEFINE_SPINLOCK(lock); - static __u32 digest[SHA_DIGEST_WORDS]; - static __u32 workspace[SHA_WORKSPACE_WORDS]; + static __u32 digest[SHA1_DIGEST_WORDS]; + static __u32 workspace[SHA1_WORKSPACE_WORDS]; static union { - char __data[SHA_MESSAGE_BYTES]; + char __data[SHA1_BLOCK_SIZE]; struct { struct in6_addr secret; __be32 prefix[2]; @@ -3251,7 +3251,7 @@ static int ipv6_generate_stable_address(struct in6_addr *address, retry: spin_lock_bh(&lock); - sha_init(digest); + sha1_init(digest); memset(&data, 0, sizeof(data)); memset(workspace, 0, sizeof(workspace)); memcpy(data.hwaddr, idev->dev->perm_addr, idev->dev->addr_len); @@ -3260,7 +3260,7 @@ retry: data.secret = secret; data.dad_count = dad_count; - sha_transform(digest, data.__data, workspace); + sha1_transform(digest, data.__data, workspace); temp = *address; temp.s6_addr32[2] = (__force __be32)digest[0];