用过OpenSSL的DSA的请帮助解惑

2011-03-03 09:08:57 598 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

openssl DSA 数字签名与签名验证与RSA不同，DSA的主要功能是做数字签名与签名验证。DSA不具备对数据进行加密解密的功能，因此在使用上面请注意。往往有很多使用者误认为非对称加密算法都可以对数据进行加解密处理，其实不然，DSA就是一个很好的例子。使用C/C++ 调用openssl/crypt库进行DSA测试，代码如下： /* gcc -o test test_dsa.c ../../libcrypto.a 阅读详情

DSA算法中的签名包括R和S两项数据，但OpenSSL的签名验证函数DSA_verify中，对于签名参数只包含一个指针参数和指针长度参数，那么，R和S两项数据如何作为指针参数传递呢？？？

int DSA_verify(int type,const unsigned char *dgst,int dgst_len,
const unsigned char *sigbuf, int siglen, DSA *dsa);
第一个参数是加密方式，应该是NID_SHA1
第二个参数是摘要，第三个是摘要的长度
第四个参数是签名，第五个参数是签名的长度
第六个参数是公钥

现在如何把R和S传递给第四个参数呢？？？

如能成功解决，本贴再加100分感谢。

...全文

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t514901334 2013-06-06

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引用 8 楼 happyparrot 的回复:

[Quote=引用 5 楼 jennyvenus 的回复:] 验签时传数据与签名结果进去，验签再算一个签名比较。 R与S是一样长的吧。 [/Quote] R和S都是20个字节长。你说的第一句有点看不懂意思。

应该说r，s中都是32字节呢

shi5661 2013-03-26

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一点也不懂。

愤豆 2013-03-05

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DSA签名，验证（读取证书） 2012-01-03 09:47:27| 分类： OpenSSL | 标签： |字号大中小订阅 . 网上的资料，真的是参差不齐阿，有的完全是在浪费你的时间！签名的输入都用到了md5哈希。先用命令行生成整数，然后再进行DSA签名认证！ openssl dsaparam -noout -out dsakey－pri.pem -genkey 1024 openssl dsa -in dsakey-pri.pem -pubout -out dsakey-pub.pem #include <string.h> #include <openssl/pem.h> #include <openssl/err.h> #include <openssl/dsa.h> unsigned int sig_len; unsigned char* dsa_sign(unsigned char *input_string) { DSA *dsa; FILE *file; unsigned char* sign_string; if ((file = fopen("/home/zc/SSL/dsakey-pri.pem", "r")) == NULL) { perror("open pri key file error"); } //读取私钥 if ((dsa = PEM_read_DSAPrivateKey(file, NULL, NULL, NULL)) == NULL) { ERR_print_errors_fp(stdout); } //分配给签名的信息 sign_string = (unsigned char*) calloc(DSA_size(dsa), sizeof(unsigned char)); if (sign_string == NULL) { fprintf(stderr, "Unable to allocate memory for sign_string\n"); exit(-1); } // sign input_string if (DSA_sign(NID_md5, input_string, strlen((char*) input_string), sign_string, &sig_len, dsa) == 0) { printf("Sign Error.\n"); } return sign_string; } int dsa_verify(unsigned char* sign_string, unsigned char* input_string) { DSA *dsa; FILE *file; if ((file = fopen("/home/zc/SSL/dsakey-pub.pem", "r")) == NULL) { perror("open pub key file error"); } if ((dsa = PEM_read_DSA_PUBKEY(file, NULL, NULL, NULL)) == NULL) { ERR_print_errors_fp(stdout); return 0; } int is_valid_signature = DSA_verify(NID_md5, input_string, strlen( (char*) input_string), sign_string, sig_len, dsa); return is_valid_signature; } int DSA_func(unsigned char *input_str) { int i, ans; unsigned char* input_string; unsigned char* sign_string; //分配空间给哈希 input_string = (unsigned char*) calloc(128, sizeof(unsigned char)); if (input_string == NULL) { fprintf(stderr, "Unable to allocate memory for input_string\n"); exit(-1); } input_string = MD5_func(input_str); sign_string = dsa_sign(input_string); ans = dsa_verify(sign_string, input_string); printf("input string = %s\n", input_str); printf("signed string = "); for (i = 0; i < sig_len; ++i) { printf("%x%x", (sign_string[i] >> 4) & 0xf, sign_string[i] & 0xf); } printf("\n"); printf("is_valid_signature? = %d\n", ans); return ans; }

cnfitc 2012-12-14

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int DSA_do_verify(const unsigned char *dgst,int dgst_len, DSA_SIG *sig,DSA *dsa); typedef struct DSA_SIG_st { BIGNUM *r; BIGNUM *s; } DSA_SIG;

快乐鹦鹉 2011-03-04

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伊人何在

用户　昵称 2011-03-04

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[Quote=引用 8 楼 happyparrot 的回复:]
引用 5 楼 jennyvenus 的回复:
验签时传数据与签名结果进去，验签再算一个签名比较。

R与S是一样长的吧。

R和S都是20个字节长。
你说的第一句有点看不懂意思。
[/Quote]
DSA不懂，rsa和ecc知道一点，rsa验签跟签名的流程一样，最后就是一个memcmp，ecc的验签是传签名时生成的R和S，DSA平时没遇到过。

快乐鹦鹉 2011-03-03

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这个例子对我没啥用啊。现在找到的例子总是这样：
DSA_sign(0, str1, 20, sig, &siglen, dsa);
if (DSA_verify(0, str1, 20, sig, siglen, dsa) == 1)
ret=1;

这没有意义啊，自己先签名，然后再验证，当然没有问题啊。这种样例根本没有参考价值。

实际情况都是有文件形式的证书，然后对证书进行验证，也就是不可能同时进行签名和验证，这两个过程分别由数据提供方和接收方进行，怎么可能一起使用呢。

现在的问题是，DSA_verify函数的参数sig怎么传递？实际得到的签名是在一个文本文件中，并且两个参数R和S是分别给出的，而这个函数的参数却只有一个指针，不知道怎么把两个字符串传递给这一个指针啊。

Chivalry 2011-03-03

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曾经用它做过rsa，当时花了一些时间研究了一下，所以了解一点~

Chivalry 2011-03-03

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上面是OpenSSL库下面的test目录下的dsatest.c的内容，看看对你有没有用，呵呵~

Chivalry 2011-03-03

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/* crypto/dsa/dsatest.c */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.]
*/

/* Until the key-gen callbacks are modified to use newer prototypes, we allow
* deprecated functions for openssl-internal code */
#ifdef OPENSSL_NO_DEPRECATED
#undef OPENSSL_NO_DEPRECATED
#endif

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>

#include "../e_os.h"

#include <openssl/crypto.h>
#include <openssl/rand.h>
#include <openssl/bio.h>
#include <openssl/err.h>
#include <openssl/bn.h>

#ifdef OPENSSL_NO_DSA
int main(int argc, char *argv[])
{
printf("No DSA support\n");
return(0);
}
#else
#include <openssl/dsa.h>

#ifdef OPENSSL_SYS_WIN16
#define MS_CALLBACK _far _loadds
#else
#define MS_CALLBACK
#endif

static int MS_CALLBACK dsa_cb(int p, int n, BN_GENCB *arg);

/* seed, out_p, out_q, out_g are taken from the updated Appendix 5 to
* FIPS PUB 186 and also appear in Appendix 5 to FIPS PIB 186-1 */
static unsigned char seed[20]={
0xd5,0x01,0x4e,0x4b,0x60,0xef,0x2b,0xa8,0xb6,0x21,0x1b,0x40,
0x62,0xba,0x32,0x24,0xe0,0x42,0x7d,0xd3,
};

static unsigned char out_p[]={
0x8d,0xf2,0xa4,0x94,0x49,0x22,0x76,0xaa,
0x3d,0x25,0x75,0x9b,0xb0,0x68,0x69,0xcb,
0xea,0xc0,0xd8,0x3a,0xfb,0x8d,0x0c,0xf7,
0xcb,0xb8,0x32,0x4f,0x0d,0x78,0x82,0xe5,
0xd0,0x76,0x2f,0xc5,0xb7,0x21,0x0e,0xaf,
0xc2,0xe9,0xad,0xac,0x32,0xab,0x7a,0xac,
0x49,0x69,0x3d,0xfb,0xf8,0x37,0x24,0xc2,
0xec,0x07,0x36,0xee,0x31,0xc8,0x02,0x91,
};

static unsigned char out_q[]={
0xc7,0x73,0x21,0x8c,0x73,0x7e,0xc8,0xee,
0x99,0x3b,0x4f,0x2d,0xed,0x30,0xf4,0x8e,
0xda,0xce,0x91,0x5f,
};

static unsigned char out_g[]={
0x62,0x6d,0x02,0x78,0x39,0xea,0x0a,0x13,
0x41,0x31,0x63,0xa5,0x5b,0x4c,0xb5,0x00,
0x29,0x9d,0x55,0x22,0x95,0x6c,0xef,0xcb,
0x3b,0xff,0x10,0xf3,0x99,0xce,0x2c,0x2e,
0x71,0xcb,0x9d,0xe5,0xfa,0x24,0xba,0xbf,
0x58,0xe5,0xb7,0x95,0x21,0x92,0x5c,0x9c,
0xc4,0x2e,0x9f,0x6f,0x46,0x4b,0x08,0x8c,
0xc5,0x72,0xaf,0x53,0xe6,0xd7,0x88,0x02,
};

static const unsigned char str1[]="12345678901234567890";

static const char rnd_seed[] = "string to make the random number generator think it has entropy";

static BIO *bio_err=NULL;

int main(int argc, char **argv)
{
BN_GENCB cb;
DSA *dsa=NULL;
int counter,ret=0,i,j;
unsigned char buf[256];
unsigned long h;
unsigned char sig[256];
unsigned int siglen;

if (bio_err == NULL)
bio_err=BIO_new_fp(stderr,BIO_NOCLOSE);

CRYPTO_malloc_debug_init();
CRYPTO_dbg_set_options(V_CRYPTO_MDEBUG_ALL);
CRYPTO_mem_ctrl(CRYPTO_MEM_CHECK_ON);

ERR_load_crypto_strings();
RAND_seed(rnd_seed, sizeof rnd_seed);

BIO_printf(bio_err,"test generation of DSA parameters\n");

BN_GENCB_set(&cb, dsa_cb, bio_err);
if(((dsa = DSA_new()) == NULL) || !DSA_generate_parameters_ex(dsa, 512,
seed, 20, &counter, &h, &cb))
goto end;

BIO_printf(bio_err,"seed\n");
for (i=0; i<20; i+=4)
{
BIO_printf(bio_err,"%02X%02X%02X%02X ",
seed[i],seed[i+1],seed[i+2],seed[i+3]);
}
BIO_printf(bio_err,"\ncounter=%d h=%ld\n",counter,h);

if (dsa == NULL) goto end;
DSA_print(bio_err,dsa,0);
if (counter != 105)
{
BIO_printf(bio_err,"counter should be 105\n");
goto end;
}
if (h != 2)
{
BIO_printf(bio_err,"h should be 2\n");
goto end;
}

i=BN_bn2bin(dsa->q,buf);
j=sizeof(out_q);
if ((i != j) || (memcmp(buf,out_q,i) != 0))
{
BIO_printf(bio_err,"q value is wrong\n");
goto end;
}

i=BN_bn2bin(dsa->p,buf);
j=sizeof(out_p);
if ((i != j) || (memcmp(buf,out_p,i) != 0))
{
BIO_printf(bio_err,"p value is wrong\n");
goto end;
}

i=BN_bn2bin(dsa->g,buf);
j=sizeof(out_g);
if ((i != j) || (memcmp(buf,out_g,i) != 0))
{
BIO_printf(bio_err,"g value is wrong\n");
goto end;
}

dsa->flags |= DSA_FLAG_NO_EXP_CONSTTIME;
DSA_generate_key(dsa);
DSA_sign(0, str1, 20, sig, &siglen, dsa);
if (DSA_verify(0, str1, 20, sig, siglen, dsa) == 1)
ret=1;

dsa->flags &= ~DSA_FLAG_NO_EXP_CONSTTIME;
DSA_generate_key(dsa);
DSA_sign(0, str1, 20, sig, &siglen, dsa);
if (DSA_verify(0, str1, 20, sig, siglen, dsa) == 1)
ret=1;

end:
if (!ret)
ERR_print_errors(bio_err);
if (dsa != NULL) DSA_free(dsa);
CRYPTO_cleanup_all_ex_data();
ERR_remove_state(0);
ERR_free_strings();
CRYPTO_mem_leaks(bio_err);
if (bio_err != NULL)
{
BIO_free(bio_err);
bio_err = NULL;
}
#ifdef OPENSSL_SYS_NETWARE
if (!ret) printf("ERROR\n");
#endif
EXIT(!ret);
return(0);
}

static int MS_CALLBACK dsa_cb(int p, int n, BN_GENCB *arg)
{
char c='*';
static int ok=0,num=0;

if (p == 0) { c='.'; num++; };
if (p == 1) c='+';
if (p == 2) { c='*'; ok++; }
if (p == 3) c='\n';
BIO_write(arg->arg,&c,1);
(void)BIO_flush(arg->arg);

if (!ok && (p == 0) && (num > 1))
{
BIO_printf((BIO *)arg,"error in dsatest\n");
return 0;
}
return 1;
}
#endif

xengine-qyt 2011-03-03

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我只是拷贝过去的。没弄过！能帮就帮呗，别这么大意见没弄过！

快乐鹦鹉 2011-03-03

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[Quote=引用 5 楼 jennyvenus 的回复:]
验签时传数据与签名结果进去，验签再算一个签名比较。

R与S是一样长的吧。
[/Quote]
R和S都是20个字节长。
你说的第一句有点看不懂意思。

快乐鹦鹉 2011-03-03

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楼上的，拜托看完贴再回好不好哦......

xengine-qyt 2011-03-03

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 #include <string.h>



       #include <openssl/objects.h>



       #include <openssl/dsa.h>



       



       int    main()



       {



              int                         ret;



              DSA                            *d;



              int                         i,bits=1024,signlen,datalen,alg,nid;



              unsigned chardata[100],signret[200];



       



              d=DSA_new();



              ret=DSA_generate_parameters_ex(d,512,NULL,0,NULL,NULL,NULL);



              if(ret!=1)



              {



                     DSA_free(d);



                     return -1;



              }



              ret=DSA_generate_key(d);



              if(ret!=1)



              {



                     DSA_free(d);



                     return -1;



              }



              for(i=0;i<100;i++)



                     memset(&data[i],i+1,1);



              printf("please select digest alg: \n");



              printf("1.NID_md5\n");



              printf("2.NID_sha\n");



              printf("3.NID_sha1\n");



              printf("4.NID_md5_sha1\n");



              scanf("%d",&alg);



              if(alg==1)



              {



                     datalen=20;



                     nid=NID_md5;



              }



              else if(alg==2)



              {



                     datalen=20;



                     nid=NID_sha;



              }



              else if(alg==3)



              {



                     datalen=20;



                     nid=NID_sha1;



              }



              else if(alg==4)



              {



                     datalen=20;



                     nid=NID_md5_sha1;



              }



              ret=DSA_sign(nid,data,datalen,signret,&signlen,d);



              if(ret!=1)



              {



                     printf("DSA_sign err!\n");



                     DSA_free(d);



                     return -1;



              }



              ret=DSA_verify(nid,data,datalen,signret,signlen,d);



              if(ret!=1)



              {



                     printf("DSA_verify err!\n");



                     DSA_free(d);



                     return -1;



              }



              DSA_free(d);



              printf("test ok!\n");



              return 0;



       }

用户　昵称 2011-03-03

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验签时传数据与签名结果进去，验签再算一个签名比较。

R与S是一样长的吧。

用过OpenSSL的DSA的请帮助解惑

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