• Eric Biggers's avatar
    crypto: x86/sha256-mb - fix digest copy in sha256_mb_mgr_get_comp_job_avx2() · af839b4e
    Eric Biggers authored
    There is a copy-paste error where sha256_mb_mgr_get_comp_job_avx2()
    copies the SHA-256 digest state from sha256_mb_mgr::args::digest to
    job_sha256::result_digest.  Consequently, the sha256_mb algorithm
    sometimes calculates the wrong digest.  Fix it.
    
    Reproducer using AF_ALG:
    
        #include <assert.h>
        #include <linux/if_alg.h>
        #include <stdio.h>
        #include <string.h>
        #include <sys/socket.h>
        #include <unistd.h>
    
        static const __u8 expected[32] =
            "\xad\x7f\xac\xb2\x58\x6f\xc6\xe9\x66\xc0\x04\xd7\xd1\xd1\x6b\x02"
            "\x4f\x58\x05\xff\x7c\xb4\x7c\x7a\x85\xda\xbd\x8b\x48\x89\x2c\xa7";
    
        int main()
        {
            int fd;
            struct sockaddr_alg addr = {
                .salg_type = "hash",
                .salg_name = "sha256_mb",
            };
            __u8 data[4096] = { 0 };
            __u8 digest[32];
            int ret;
            int i;
    
            fd = socket(AF_ALG, SOCK_SEQPACKET, 0);
            bind(fd, (void *)&addr, sizeof(addr));
            fork();
            fd = accept(fd, 0, 0);
            do {
                ret = write(fd, data, 4096);
                assert(ret == 4096);
                ret = read(fd, digest, 32);
                assert(ret == 32);
            } while (memcmp(digest, expected, 32) == 0);
    
            printf("wrong digest: ");
            for (i = 0; i < 32; i++)
                printf("%02x", digest[i]);
            printf("\n");
        }
    
    Output was:
    
        wrong digest: ad7facb2000000000000000000000000ffffffef7cb47c7a85dabd8b48892ca7
    
    Fixes: 172b1d6b ("crypto: sha256-mb - fix ctx pointer and digest copy")
    Cc: <stable@vger.kernel.org> # v4.8+
    Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
    Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
    af839b4e
sha256_mb_mgr_flush_avx2.S 8.29 KB