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我试图为摘要生成一个大文件。当我在下面使用 openssl rand 8096 | head -c 8096 > rnddata，没关系。

./hash_test sha1
摘要为：a0a4dab4a16d247fb625ca2abf07373d2123e4a5
openssl dgst -sha1 rnddata
SHA1(rnddata)= a0a4dab4a16d247fb625ca2abf07373d2123e4a5

但是当 rnddata 的大小等于或大于 9000 时，摘要结果会有所不同。

openssl 兰特 9000 | head -c 9000 > rnddata
openssl dgst -sha1 rnddata
SHA1(rnddata)= 4ef5b73ee39f0f2ac6d341c55467c182786cab65
./hash_test sha1
摘要是：691747a97aee32ddf04b3bf5644b5d74c4b69657

下面是我用于测试的 c 代码

#include <stdio.h>
#include <openssl/evp.h>

main(int argc, char *argv[])
{
    EVP_MD_CTX mdctx;
    const EVP_MD *md;
    FILE *fr;
    size_t bytes;
    char mystring[32];

    fr = fopen("/home/root/rnddata", "r");
    if(fr == NULL) 
        printf("Error opening file\n");

    unsigned char md_value[EVP_MAX_MD_SIZE];
    int md_len, i; 

    OpenSSL_add_all_digests();
    //OpenSSL_add_all_algorithms();
    if(!argv[1]) {
        printf("Usage: mdtest digestname\n");
        exit(1);
    }

    //md = EVP_get_digestbyname(argv[1]);
    md = EVP_sha1();
    if(!md) {
        printf("Unknown message digest %s\n", argv[1]);
        exit(1);
    }

    EVP_MD_CTX_init(&mdctx);
    EVP_DigestInit_ex(&mdctx, md, NULL);
    while ((bytes = fread (mystring, 1, 32, fr)) != 0)
        EVP_DigestUpdate(&mdctx, mystring, bytes);
    EVP_DigestFinal_ex(&mdctx, md_value, &md_len);
    EVP_MD_CTX_cleanup(&mdctx);

    printf("Digest is: ");
    for(i = 0; i < md_len; i++)
        printf("%02x", md_value[i]);
    printf("\n");
    fclose(fr);
}

任何帮助表示赞赏。

4

3 回答 3

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我已经在 Ubuntu 10.04 上测试了我的代码。结果在命令行和 C 代码之间是相同的。

gary@ubuntu:~/crypto$ gcc -v
Using built-in specs.
Target: i486-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 4.4.3-4ubuntu5' --with-bugurl=file:///usr/share/doc/gcc-4.4/README.Bugs --enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --enable-shared --enable-multiarch --enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.4 --program-suffix=-4.4 --enable-nls --enable-clocale=gnu --enable-libstdcxx-debug --enable-plugin --enable-objc-gc --enable-targets=all --disable-werror --with-arch-32=i486 --with-tune=generic --enable-checking=release --build=i486-linux-gnu --host=i486-linux-gnu --target=i486-linux-gnu
Thread model: posix
gcc version 4.4.3 (Ubuntu 4.4.3-4ubuntu5) 


gary@ubuntu:/usr/local/ssl/bin$ ./openssl 
OpenSSL> version
OpenSSL 1.0.0a 1 Jun 2010
OpenSSL> ^C
gary@ubuntu:/usr/local/ssl/bin$ ./openssl 
OpenSSL> dgst -sha1 /home/gary/crypto/rnddata
SHA1(/home/gary/crypto/rnddata)= 34c7dd77ce6fbc56875bca2bd916f42464b9bab0



gcc sha1_test.c -o h1 -I/usr/local/ssl/include -L/usr/local/ssl/lib -l

gary@ubuntu:~/crypto$ ./h1 rnddata 
Read 1024 bytes
Read 1024 bytes
Read 1024 bytes
Read 1024 bytes
Read 1024 bytes
Read 1024 bytes
Read 1024 bytes
Read 1024 bytes
Read 808 bytes
34c7dd77ce6fbc56875bca2bd916f42464b9bab0 rnddata
于 2012-10-10T15:39:57.597 回答
0

我已经测试了这两个代码以及命令行。下面是我的测试结果。

root@am335x-evm:~# openssl rand 9000 | head -c 9000 > rnddata
root@am335x-evm:~# ./hash_test sha1
Digest is: 691747a97aee32ddf04b3bf5644b5d74c4b69657
root@am335x-evm:~# ./sha1_test 
691747a97aee32ddf04b3bf5644b5d74c4b69657 rnddata
root@am335x-evm:~# openssl dgst -sha1 rnddata
SHA1(rnddata)= 4ef5b73ee39f0f2ac6d341c55467c182786cab65
于 2012-10-05T20:03:06.803 回答
0

I have tested your code, and it works as it should:

for i in $( seq 1 100 ); do
    openssl rand 9000 | head -c 9000 > test
    YOUR=$( ./sha1 test | cut -b 12- )
    SHA1=$( openssl dgst -sha1 test | cut -b 13- )
    if [ "$YOUR" == "$SHA1" ]; then
         echo $YOUR OK
    else
         echo $YOUR $SHA1 FAIL
    fi
done

Also works with lengths 8000, 9100, 10000.

Tested your second code, this too appears to work correctly. This is the modified version I wrote to test on different files by supplying the name on command line:

#include <stdio.h>
#include <openssl/sha.h>

int main(int argc, char **argv)
{
    unsigned char c[SHA_DIGEST_LENGTH];
    int i;

    FILE *inFile = fopen (argv[1], "rb");
    SHA_CTX shaContext;
    int bytes;
    unsigned char data[1024];

    if (inFile == NULL) {
            printf ("%s can't be opened.\n", argv[1]);
            return 0;
    }

    SHA1_Init (&shaContext);

    while ((bytes = fread (data, 1, 1024, inFile)) != 0)
    {
            printf("Read %d bytes\n", bytes);
            SHA1_Update (&shaContext, data, bytes);
    }
    SHA1_Final (c,&shaContext);

    for(i = 0; i < SHA_DIGEST_LENGTH; i++)
            printf("%02x", c[i]);

    printf (" %s\n", argv[1]);
    fclose (inFile);

    return 0;
}

There must be something in how the code is compiled that yields the wrong results.

I checked with gcc version 4.7.1 20120723 [gcc-4_7-branch revision 189773] (SUSE Linux) on kernel 3.4.6 x86_64.

I have modified the code above to print some information about its operation. I tested it with a file made up of 9000 zeroes (dd if=/dev/zero of=/tmp/zeroes bs=1 count=9000) and got:

Read 1024 bytes
Read 1024 bytes
Read 1024 bytes
Read 1024 bytes
Read 1024 bytes
Read 1024 bytes
Read 1024 bytes
Read 1024 bytes
Read 808 bytes
980eb7886d6d6ce206b9ce5371042d32c96d2714 /tmp/zeroes

If block sizes do match, then we'll try printing the sum of all bytes (which ought to be always zero), or check the buffer one byte at a time.

If you have the same SHA1 as me, we'll try with a sequence of 9000 0x80's.

于 2012-10-04T16:54:38.703 回答