nettle-bugs August 2021

nettle-bugs@lists.lysator.liu.se

4 participants
8 discussions

Add RSA-OAEP encryption/decryption to Nettle
by Nicolas Mora 09 Mar '24

09 Mar '24

Hello, I've made a new Merge Request in the nettle gitlab repo to provide RSA-OAEP encryption and decryption: https://git.lysator.liu.se/nettle/nettle/-/merge_requests/20 It adds 2 new functions: int pkcs1_oaep_encrypt (size_t key_size, void *random_ctx, nettle_random_func *random, size_t hlen, size_t label_length, const uint8_t *label, size_t message_length, const uint8_t *message, mpz_t m); int pkcs1_oaep_decrypt (size_t key_size, const mpz_t m, size_t hlen, size_t label_length, const uint8_t *label, size_t *length, uint8_t *message); The parameter hlen is the output length of the SHA function used for masking data: - SHA1_DIGEST_SIZE - SHA256_DIGEST_SIZE - SHA384_DIGEST_SIZE - SHA512_DIGEST_SIZE Is it possible to get feedback for this MR and eventually push it to the master branch? Thanks in advance /Nicolas

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Re: Build problem on ppc64be + musl
by Maamoun TK 04 Jan '22

04 Jan '22

On Wed, Aug 18, 2021 at 11:38 PM Stijn Tintel <stijn(a)linux-ipv6.be> wrote: > On 18/08/2021 22:29, Maamoun TK wrote: > > On Tue, Aug 17, 2021 at 9:40 AM Niels Möller <nisse(a)lysator.liu.se > > <mailto:nisse@lysator.liu.se>> wrote: > > > > The configuration where it didn't work was > > powerpc64-openwrt-linux-musl. I'd like Nettle to work on embedded > > systems whenever practical. But support depends on assistance from > > users > > of those systems. > > > > As I understood it, this system needs to use the v2 ABI. I would hope > > it's easy to detect the abi used by the configured C compiler, and > > then > > select the same prologue sequence as is currently used for > > little-endian. I.e., one more configure test, and changing the > > "ifelse(WORDS_BIGENDIAN,no," condition in powerpc64/machine.m4 to > > check > > a different configure variable. > > > > > > I skipped processing the assembly files with a different approach, I > > made the configuration check for musl and endianness variant to > > trigger assembly processing. You can check the fix in this branch > > https://git.lysator.liu.se/mamonet/nettle/-/tree/ppc64_musl_fix > > <https://git.lysator.liu.se/mamonet/nettle/-/tree/ppc64_musl_fix> > > Apparently, the bug reporter uses a cross-compiler for powerpc arch. > > It would be great to run this fix at the same bug environment since I > > tested the patch in different circumstances. > > Your patch has no effect in my environment (OpenWrt build system), as > host_os is linux-gnu, according to config.log, so it doesn't match > *musl. See [1] for config.log and [2] for full compile log. > > The output of powerpc64-openwrt-linux-musl-gcc -E -dM - </dev/null | > sort, which was requested earlier in this thread can be seen at [3]. > > Thanks, > Stijn > > [1] https://gist.github.com/9e0ecb025033dda1d0d58094da84c308 > [2] https://gist.github.com/stintel/0e7046df511cf4d1ca20edb56df50b1b > [3] https://gist.github.com/stintel/b3651a7db87edea9e8bd0aef242bcdae config.guess detects the C standard library based on a result from the compiler defined in "CC_FOR_BUILD" variable, for some reason OpenWrt build system failed to set that variable properly, from your config.log I can see CC_FOR_BUILD='gcc -O -g' but when I use bare musl tools I get CC_FOR_BUILD='musl-gcc' There is nothing specific in the output of powerpc64-openwrt-linux-musl-gcc -E -dM log as I can see. In musl libc FAQ, they stated that there is no __MUSL__ in the preprocessor macros https://wiki.musl-libc.org/faq.html regards, Mamone

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Curve point decompression
by Wim Lewis 10 Nov '21

10 Nov '21

I'm looking at implementing elliptic curve point compression a la SEC1 (admittedly, mostly to reduce the number of "feature not supported" code paths in a library, but it seems like a somewhat useful ability). Nettle/Hogweed already implements it internally for curve25519, but I want to implement it for the "secp" curves as well. Point compression is easy enough, but point decompression requires some curve math, potentially dependent on the specific curve, and some of it is redundant with what's already done in ecc_point_set(). So I was thinking about moving this functionality into Hogweed as a function along the lines of ecc_point_set_compressed(), which would take, instead of a y-coordinate, an int containing the sign/parity of the y-coordinate. So my question for the list and for the maintainers is, is this a reasonable API to add to Hogweed? Is there interest in including it in Hogweed if I were to take the time to turn it into a tidy patch?

3 10

[S390x] Optimize SHA1 with fat build support
by Maamoun TK 20 Sep '21

20 Sep '21

I made a merge request in the main repository that optimizes SHA1 for s390x architecture with fat build support !33 <https://git.lysator.liu.se/nettle/nettle/-/merge_requests/33>. regards, Mamone

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[S390x] Optimize AES modes
by Maamoun TK 19 Sep '21

19 Sep '21

I made a merge request for optimizing AES modes on s390x architecture, the patch implements the optimized cores using cipher instructions that have been added to s390x arch in message security assist extensions. The patch uses the following functions: KM-AES-128 (ECB-AES128) KM-AES-192 (ECB-AES192) KM-AES-256 (ECB-AES256) KMC-AES-128 (CBC-AES128) KMC-AES-192 (CBC-AES192) KMC-AES-256 (CBC-AES256) KMAC-AES-128 (CCM-AES128, CMAC-AES128) KMAC-AES-192 (CCM-AES192) KMAC-AES-256 (CCM-AES256, CMAC-AES256) KMF-AES-128 (CFB-AES128, CFB8-AES128) KMF-AES-192 (CFB-AES192, CFB8-AES192) KMF-AES-256 (CFB-AES256, CFB8-AES256) KM-XTS-AES-128 (XTS-AES128) KM-XTS-AES-256 (XTS-AES256) KIMD-GHASH (GHASH) KMCTR-AES-128, KMA-GCM-AES-128 (CTR-AES128) KMCTR-AES-192, KMA-GCM-AES-192 (CTR-AES192) KMCTR-AES-256, KMA-GCM-AES-256 (CTR-AES256) KMA-GCM-AES-128 (GCM-AES128) KMA-GCM-AES-192 (GCM-AES192) KMA-GCM-AES-256 (GCM-AES256) The merge request has also a benchmark that measures the speed of optimized cores on s390x arch. I can't set up gitlab CI for automatic testing on s390x arch because qemu hasn't implemented cipher functions for this arch. However, there is an easy way to test the patch manually by requesting a free account on the LinuxONE Community Cloud, both short-term and long-term access are available. https://linuxone.cloud.marist.edu/#/register?flag=VM regards, Mamone

4 39

Re: Build problem on ppc64be + musl
by Maamoun TK 20 Aug '21

20 Aug '21

Forcing ELFv2 abi doesn't work for big-endian mode as this mode has no support for ELFv2. ppc64 linux big-endian is deprecated, it' not unexpected to get such issues. Dropping big-endian support for powerpc could be an option to solve this issue but that will be a drawback for AIX (BE) systems. regards, Maamoun On Mon, Aug 16, 2021 at 10:54 PM Niels Möller <nisse(a)lysator.liu.se> wrote: > Stijn Tintel <stijn(a)linux-ipv6.be> writes: > > > I suspect this is because musl doesn't support the ELFv1 ABI on ppc64 at > > all, regardless of endianness. I've tried adding -mabi=elfv2 to CFLAGS, > > to force using the ELFv2 ABI, but the problem persists. Suggestions > welcome. > > I don't know that much about ppc64 abi issues myself. From your > description, it seems clear that it's a linker error, and that object > files corresponding to C source files somehow carry different "abi > version attributes" than object files corresponding to nettle's assembly > source files. > > As you've found, configuring with --disable-assembler works around the > problem, but to solve it properly, we'd need to understand why that is. > The assembler should not be invoked directly, but via the same $(CC) and > $(CFLAGS) as the C compiler. > > You'd need to compare those object files and how they're generated. > Compare the compiler command lines. You could perhaps use gcc -v to see > how gcc invokes the assembler in both cases. You can use gcc -save-temps > to look at the assembly files generated by gcc, and check if they use > some special pseudoops to specify the abi. You can use tools like > objdump or readelf to compare attributes in the object files. > > If you can figure out how to produce object files that are compatible > according to the linker, that may not be sufficient, though. You also > need to tweak the assembly files and related macros and configure checks > to use the right api. See powerpc64/README and powerpc64/machine.m4. As > I understand it, abi is currently selected depending on the endianness, > using v1 for big endian and v2 for little endian. > > It may need a configure test independent of endianness. Maybe there's > some predefined symbol we can check, similar to 32-bit/64-bit ABI checks > on other platforms? You could run something like > > powerpc64-openwrt-linux-musl-gcc -E -dM - </dev/null | sort > > With the powerpc64le-linux-gnu-gcc cross compiler I have, the closest > suspect I see is > > #define _CALL_ELF 2 > > Maybe that's the right thing to check? I don't have a big-endian system > or crosscompiler close at hand, but at least there's a bigendian > powerpc64-linux-gnu cross compile setup in the ci system hosted at gitlab. > > Regards, > /Niels > > -- > Niels Möller. PGP-encrypted email is preferred. Keyid 368C6677. > Internet email is subject to wholesale government surveillance. >

3 8

Is there an equivalent to curve25519_mul for ECC keys?
by Nicolas Mora 16 Aug '21

16 Aug '21

Hello, I'm wondering if there is a function of a combination of functions to perform a DH computation using ECC keys and their parameters "struct ecc_point *pub1, struct ecc_scalar *key2"? /Nicolas

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[S390x] Optimize SHA256 and SHA512 compress functions
by Maamoun TK 13 Aug '21

13 Aug '21

I made a merge request in the main repository that optimizes SHA256 and SHA512 compress functions for s390x architecture with fat build support !35 <https://git.lysator.liu.se/nettle/nettle/-/merge_requests/35>. regards, Mamone

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nettle-bugs August 2021