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2013-11-28crypto: authenc - Find proper IV address in ablkcipher callbackTom Lendacky
When performing an asynchronous ablkcipher operation the authenc completion callback routine is invoked, but it does not locate and use the proper IV. The callback routine, crypto_authenc_encrypt_done, is updated to use the same method of calculating the address of the IV as is done in crypto_authenc_encrypt function which sets up the callback. Cc: stable@vger.kernel.org Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2013-10-16crypto: authenc - Export key parsing helper functionMathias Krause
AEAD key parsing is duplicated to multiple places in the kernel. Add a common helper function to consolidate that functionality. Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Mathias Krause <mathias.krause@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2013-10-07crypto: crypto_memneq - add equality testing of memory regions w/o timing leaksJames Yonan
When comparing MAC hashes, AEAD authentication tags, or other hash values in the context of authentication or integrity checking, it is important not to leak timing information to a potential attacker, i.e. when communication happens over a network. Bytewise memory comparisons (such as memcmp) are usually optimized so that they return a nonzero value as soon as a mismatch is found. E.g, on x86_64/i5 for 512 bytes this can be ~50 cyc for a full mismatch and up to ~850 cyc for a full match (cold). This early-return behavior can leak timing information as a side channel, allowing an attacker to iteratively guess the correct result. This patch adds a new method crypto_memneq ("memory not equal to each other") to the crypto API that compares memory areas of the same length in roughly "constant time" (cache misses could change the timing, but since they don't reveal information about the content of the strings being compared, they are effectively benign). Iow, best and worst case behaviour take the same amount of time to complete (in contrast to memcmp). Note that crypto_memneq (unlike memcmp) can only be used to test for equality or inequality, NOT for lexicographical order. This, however, is not an issue for its use-cases within the crypto API. We tried to locate all of the places in the crypto API where memcmp was being used for authentication or integrity checking, and convert them over to crypto_memneq. crypto_memneq is declared noinline, placed in its own source file, and compiled with optimizations that might increase code size disabled ("Os") because a smart compiler (or LTO) might notice that the return value is always compared against zero/nonzero, and might then reintroduce the same early-return optimization that we are trying to avoid. Using #pragma or __attribute__ optimization annotations of the code for disabling optimization was avoided as it seems to be considered broken or unmaintained for long time in GCC [1]. Therefore, we work around that by specifying the compile flag for memneq.o directly in the Makefile. We found that this seems to be most appropriate. As we use ("Os"), this patch also provides a loop-free "fast-path" for frequently used 16 byte digests. Similarly to kernel library string functions, leave an option for future even further optimized architecture specific assembler implementations. This was a joint work of James Yonan and Daniel Borkmann. Also thanks for feedback from Florian Weimer on this and earlier proposals [2]. [1] http://gcc.gnu.org/ml/gcc/2012-07/msg00211.html [2] https://lkml.org/lkml/2013/2/10/131 Signed-off-by: James Yonan <james@openvpn.net> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Cc: Florian Weimer <fw@deneb.enyo.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2013-02-04crypto: use ERR_CASTJulia Lawall
Replace PTR_ERR followed by ERR_PTR by ERR_CAST, to be more concise. The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ expression err,x; @@ - err = PTR_ERR(x); if (IS_ERR(x)) - return ERR_PTR(err); + return ERR_CAST(x); // </smpl> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2012-09-11crypto: authenc - Fix crash with zero-length assoc dataHerbert Xu
The authenc code doesn't deal with zero-length associated data correctly and ends up constructing a zero-length sg entry which causes a crash when it's fed into the crypto system. This patch fixes this by avoiding the code-path that triggers the SG construction if we have no associated data. This isn't the most optimal fix as it means that we'll end up using the fallback code-path even when we could still execute the digest function. However, this isn't a big deal as nobody but the test path would supply zero-length associated data. Reported-by: Romain Francoise <romain@orebokech.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Tested-by: Romain Francoise <romain@orebokech.com>
2010-12-02crypto: Use scatterwalk_crypto_chainSteffen Klassert
Use scatterwalk_crypto_chain in favor of locally defined chaining functions. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2010-05-26crypto: Use ERR_CASTJulia Lawall
Use ERR_CAST(x) rather than ERR_PTR(PTR_ERR(x)). The former makes more clear what is the purpose of the operation, which otherwise looks like a no-op. The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ type T; T x; identifier f; @@ T f (...) { <+... - ERR_PTR(PTR_ERR(x)) + x ...+> } @@ expression x; @@ - ERR_PTR(PTR_ERR(x)) + ERR_CAST(x) // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2010-05-20crypto: authenc - Fix cryptlen calculationShikhar Khattar
This patch (applied against 2.6.34) fixes the calculation of the length of the ABLKCIPHER decrypt request ("cryptlen") after an asynchronous hash request has been completed in the AUTHENC interface. Signed-off-by: Shikhar Khattar <shikhark@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2010-04-26crypto: authenc - Add EINPROGRESS checkHerbert Xu
When Steffen originally wrote the authenc async hash patch, he correctly had EINPROGRESS checks in place so that we did not invoke the original completion handler with it. Unfortuantely I told him to remove it before the patch was applied. As only MAY_BACKLOG request completion handlers are required to handle EINPROGRESS completions, those checks are really needed. This patch restores them. Reported-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2010-03-03crypto: authenc - Move saved IV in front of the ablkcipher requestSteffen Klassert
In crypto_authenc_encrypt() we save the IV behind the ablkcipher request. To save space on the request, we overwrite the ablkcipher request with a ahash request after encryption. So the IV may be overwritten by the ahash request. This patch fixes this by placing the IV in front of the ablkcipher/ahash request. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2010-03-02crypto: authenc - Use correct ahash complete functionsSteffen Klassert
We accidentally assigned the ahash update complete function to the wrong function pointer in crypto_authenc_verify. This patch fixes this. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2010-02-16crypto: authenc - Fix checkpatch errorsRichard Hartmann
Signed-off-by: Richard Hartmann <richih.mailinglist@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-08-05crypto: authenc - Convert to ahashSteffen Klassert
This patch converts authenc to the new ahash interface. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-07-14crypto: authenc - Remove reference to crypto_hashHerbert Xu
Now that there are no more legacy hash implementations we can remove the reference to crypto_hash. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-01-15crypto: authenc - Fix zero-length IV crashHerbert Xu
As it is if an algorithm with a zero-length IV is used (e.g., NULL encryption) with authenc, authenc may generate an SG entry of length zero, which will trigger a BUG check in the hash layer. This patch fixes it by skipping the IV SG generation if the IV size is zero. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-12-25crypto: hash - Export shash through hashHerbert Xu
This patch allows shash algorithms to be used through the old hash interface. This is a transitional measure so we can convert the underlying algorithms to shash before converting the users across. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-08-23crypto: authenc - Avoid using clobbered request pointerHerbert Xu
Authenc works in two stages for encryption, it first encrypts and then computes an ICV. The context memory of the request is used by both operations. The problem is that when an asynchronous encryption completes, we will compute the ICV and then reread the context memory of the encryption to get the original request. It just happens that we have a buffer of 16 bytes in front of the request pointer, so ICVs of 16 bytes (such as SHA1) do not trigger the bug. However, any attempt to uses a larger ICV instantly kills the machine when the first asynchronous encryption is completed. This patch fixes this by saving the request pointer before we start the ICV computation. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-05-01[CRYPTO] authenc: Fix async crypto crash in crypto_authenc_genicv()Patrick McHardy
crypto_authenc_givencrypt_done uses req->data as struct aead_givcrypt_request, while it really points to a struct aead_request, causing this crash: BUG: unable to handle kernel paging request at 6b6b6b6b IP: [<dc87517b>] :authenc:crypto_authenc_genicv+0x23/0x109 *pde = 00000000 Oops: 0000 [#1] PREEMPT DEBUG_PAGEALLOC Modules linked in: hifn_795x authenc esp4 aead xfrm4_mode_tunnel sha1_generic hmac crypto_hash] Pid: 3074, comm: ping Not tainted (2.6.25 #4) EIP: 0060:[<dc87517b>] EFLAGS: 00010296 CPU: 0 EIP is at crypto_authenc_genicv+0x23/0x109 [authenc] EAX: daa04690 EBX: daa046e0 ECX: dab0a100 EDX: daa046b0 ESI: 6b6b6b6b EDI: dc872054 EBP: c033ff60 ESP: c033ff0c DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068 Process ping (pid: 3074, ti=c033f000 task=db883a80 task.ti=dab6c000) Stack: 00000000 daa046b0 c0215a3e daa04690 dab0a100 00000000 ffffffff db9fd7f0 dba208c0 dbbb1720 00000001 daa04720 00000001 c033ff54 c0119ca9 dc852a75 c033ff60 c033ff60 daa046e0 00000000 00000001 c033ff6c dc87527b 00000001 Call Trace: [<c0215a3e>] ? dev_alloc_skb+0x14/0x29 [<c0119ca9>] ? printk+0x15/0x17 [<dc87527b>] ? crypto_authenc_givencrypt_done+0x1a/0x27 [authenc] [<dc850cca>] ? hifn_process_ready+0x34a/0x352 [hifn_795x] [<dc8353c7>] ? rhine_napipoll+0x3f2/0x3fd [via_rhine] [<dc851a56>] ? hifn_check_for_completion+0x4d/0xa6 [hifn_795x] [<dc851ab9>] ? hifn_tasklet_callback+0xa/0xc [hifn_795x] [<c011d046>] ? tasklet_action+0x3f/0x66 [<c011d230>] ? __do_softirq+0x38/0x7a [<c0105a5f>] ? do_softirq+0x3e/0x71 [<c011d17c>] ? irq_exit+0x2c/0x65 [<c010e0c0>] ? smp_apic_timer_interrupt+0x5f/0x6a [<c01042e4>] ? apic_timer_interrupt+0x28/0x30 [<dc851640>] ? hifn_handle_req+0x44a/0x50d [hifn_795x] ... Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11[CRYPTO] authenc: Add givencrypt operationHerbert Xu
This patch implements the givencrypt function for authenc. It simply calls the givencrypt operation on the underlying cipher instead of encrypt. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11[CRYPTO] authenc: Use crypto_grab_skcipherHerbert Xu
This patch converts the authenc algorithm over to crypto_grab_skcipher which is a prerequisite for IV generation. This patch also changes authenc to set its ASYNC status depending on the ASYNC status of the underlying skcipher. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11[CRYPTO] authenc: Merge common hashing codeHerbert Xu
This patch merges the common hashing code between encryption and decryption. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11[CRYPTO] authenc: Use RTA_OK to check lengthHerbert Xu
This patch changes setkey to use RTA_OK to check the validity of the setkey request. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11[CRYPTO] authenc: Fix typo in ivsizeHerbert Xu
The ivsize should be fetched from ablkcipher, not blkcipher. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11[CRYPTO] scatterwalk: Move scatterwalk.h to linux/cryptoHerbert Xu
The scatterwalk infrastructure is used by algorithms so it needs to move out of crypto for future users that may live in drivers/crypto or asm/*/crypto. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11[CRYPTO] aead: Return EBADMSG for ICV mismatchHerbert Xu
This patch changes gcm/authenc to return EBADMSG instead of EINVAL for ICV mismatches. This convention has already been adopted by IPsec. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11[CRYPTO] authenc: Fix hash verificationHerbert Xu
The previous code incorrectly included the hash in the verification which also meant that we'd crash and burn when it comes to actually verifying the hash since we'd go past the end of the SG list. This patch fixes that by subtracting authsize from cryptlen at the start. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11[CRYPTO] authenc: Move enckeylen into key itselfHerbert Xu
Having enckeylen as a template parameter makes it a pain for hardware devices that implement ciphers with many key sizes since each one would have to be registered separately. Since the authenc algorithm is mainly used for legacy purposes where its key is going to be constructed out of two separate keys, we can in fact embed this value into the key itself. This patch does this by prepending an rtnetlink header to the key that contains the encryption key length. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11[CRYPTO] aead: Make authsize a run-time parameterHerbert Xu
As it is authsize is an algorithm paramter which cannot be changed at run-time. This is inconvenient because hardware that implements such algorithms would have to register each authsize that they support separately. Since authsize is a property common to all AEAD algorithms, we can add a function setauthsize that sets it at run-time, just like setkey. This patch does exactly that and also changes authenc so that authsize is no longer a parameter of its template. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11[CRYPTO] authenc: Use or instead of max on alignment masksHerbert Xu
Since alignment masks are always one less than a power of two, we can use binary or to find their maximum. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-01-11[CRYPTO] ablkcipher: Add distinct ABLKCIPHER typeHerbert Xu
Up until now we have ablkcipher algorithms have been identified as type BLKCIPHER with the ASYNC bit set. This is suboptimal because ablkcipher refers to two things. On the one hand it refers to the top-level ablkcipher interface with requests. On the other hand it refers to and algorithm type underneath. As it is you cannot request a synchronous block cipher algorithm with the ablkcipher interface on top. This is a problem because we want to be able to eventually phase out the blkcipher top-level interface. This patch fixes this by making ABLKCIPHER its own type, just as we have distinct types for HASH and DIGEST. The type it associated with the algorithm implementation only. Which top-level interface is used for synchronous block ciphers is then determined by the mask that's used. If it's a specific mask then the old blkcipher interface is given, otherwise we go with the new ablkcipher interface. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2007-11-23[CRYPTO] authenc: Move initialisations up to shut up gccHerbert Xu
It seems that newer versions of gcc have regressed in their abilities to analyse initialisations. This patch moves the initialisations up to avoid the warnings. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2007-10-10[CRYPTO] authenc: Kill spaces in algorithm namesHerbert Xu
We do not allow spaces in algorithm names or parameters. Thanks to Joy Latten for pointing this out. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2007-10-10[CRYPTO] aead: Add authencHerbert Xu
This patch adds the authenc algorithm which constructs an AEAD algorithm from an asynchronous block cipher and a hash. The construction is done by concatenating the encrypted result from the cipher with the output from the hash, as is used by the IPsec ESP protocol. The authenc algorithm exists as a template with four parameters: authenc(auth, authsize, enc, enckeylen). The authentication algorithm, the authentication size (i.e., truncating the output of the authentication algorithm), the encryption algorithm, and the encryption key length. Both the size field and the key length field are in bytes. For example, AES-128 with SHA1-HMAC would be represented by authenc(hmac(sha1), 12, cbc(aes), 16) The key for the authenc algorithm is the concatenation of the keys for the authentication algorithm with the encryption algorithm. For the above example, if a key of length 36 bytes is given, then hmac(sha1) would receive the first 20 bytes while the last 16 would be given to cbc(aes). Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>