OpenSSL的编程验证证书链中的C（内存证书） [英] OpenSSL programatically verify certificate chain in C (in-memory certs)
问题描述
这是非常类似的其他问题，但我看无论是那些没有答案或不太问同样的问题。我有一个自签名的CA证书，并与该CA证书签名的两个证书。我相当肯定的证书是正确的，因为'OpenSSL的验证的作品：
This is very similar to other questions but the ones I've looked at either don't have an answer or don't quite ask the same question. I have a self-signed CA certificate, and two other certificates that are signed with that CA certificate. I'm fairly sure the certificates are correct, because 'openssl verify' works:
$ openssl verify -CAfile ca.pem server.pem
server.pem: OK
（以上是从内存中，我没有让他们在我面前，所以它可能会稍微偏离）。
(The above is from memory, I don't have them in front of me, so it may be slightly off).
现在我想以编程方式验证证书。我有以下伪code效用函数：
Now I want to verify the certificates programatically. I have a utility function with pseudocode below:
int verify_cert(X509 *cert, X509 *cacert)
{
int ret;
X509_STORE *store;
X509_STORE_CTX *ctx;
store = X509_STORE_new();
X590_STORE_add_cert(store, cacert);
ctx = X509_STORE_CTX_new();
X509_STORE_CTX_init(ctx, store, cert, NULL);
ret = X590_verify_cert(ctx);
/* check for errors and clean up */
}
我的问题是，上述code总是返回'没能找到颁发者证书。我做了什么错？我相信，我创建一个新的商店，添加CACERT，创建一个新的环境，并增加孩子的证书进行验证上下文的指针商店包含CA.我是pretty明明做错了什么，但我不能确定什么。
My problem is that the above code always returns 'failed to find issuer certificate'. What have I done wrong? I believe I am creating a new store, adding the cacert, creating a new context, and adding the child cert to be verified to the context with a pointer to the store which contains the CA. I'm pretty obviously doing something wrong, but I'm unsure what.
任何想法？
更新：我知道我可以将这些证书保存到磁盘，并使用类似X509_LOOKUP_file或类似的东西。我找不触及磁盘不必要的解决方案。
Update: I'm aware I can save these certs to disk and use something like X509_LOOKUP_file or something similar. I'm looking for a solution that doesn't touch the disk unnecessarily.
推荐答案
您可以使用正常的验证程序（见<一href=\"http://stackoverflow.com/questions/3412032/openssl-c-how-do-you-verify-a-public-key-was-issued-by-your-private-ca\">OpenSSL + C ++：你如何验证公钥是由私有CA颁发），喜欢OpenSSL中-verify功能呢？您需要创建一个查找方法（X509_LOOKUP_METHOD）像X509_LOOKUP_file（），但它与一个字符串，而不是文件名的作品。对于X509_LOOKUP_buffer（的code）如下：
You can use the normal validation routines (see OpenSSL + c++: How do you verify a public key was issued by your private CA?), like the -verify function in OpenSSL does. You need to create a lookup method (X509_LOOKUP_METHOD) like X509_LOOKUP_file(), but which works with a character string instead of a filename. The code for X509_LOOKUP_buffer() is as follows.
头文件by_buffer.h：
Header file by_buffer.h:
/* File: by_buffer.h */
#ifndef BY_BUFFER_H
#define BY_BUFFER_H
#include <openssl/x509.h>
#ifdef __cplusplus
extern "C" {
#endif
#define X509_L_BUF_LOAD 1
#define X509_LOOKUP_load_buf(x,name,type) \
X509_LOOKUP_ctrl((x),X509_L_BUF_LOAD,(name),(long)(type),NULL)
X509_LOOKUP_METHOD *X509_LOOKUP_buffer(void);
#ifdef __cplusplus
}
#endif
#endif /* BY_BUFFER_H */
C程序by_buffer.c：
The c program by_buffer.c:
/* by_buffer.c - copied and modified from crypto/x509/by_file.c */
/* Copyright (C) - should be the same as for OpenSSL
*/
#include "by_buffer.h"
#include <stdio.h>
#include <time.h>
#include <errno.h>
#include "../crypto/cryptlib.h"
#include <openssl/lhash.h>
#include <openssl/buffer.h>
#include <openssl/pem.h>
#include <openssl/err.h>
static int by_buffer_ctrl(X509_LOOKUP *ctx, int cmd, const char *argc,
long argl, char **ret);
X509_LOOKUP_METHOD x509_buffer_lookup=
{
"Load buffer into cache",
NULL, /* new */
NULL, /* free */
NULL, /* init */
NULL, /* shutdown */
by_buffer_ctrl, /* ctrl */
NULL, /* get_by_subject */
NULL, /* get_by_issuer_serial */
NULL, /* get_by_fingerprint */
NULL, /* get_by_alias */
};
X509_LOOKUP_METHOD *X509_LOOKUP_buffer(void)
{
return(&x509_buffer_lookup);
}
static int by_buffer_ctrl(X509_LOOKUP *ctx, int cmd, const char *argp, long argl,
char **ret)
{
int ok=0;
char *certBuf;
switch (cmd)
{
case X509_L_BUF_LOAD:
if (argl == X509_FILETYPE_DEFAULT)
{
X509err(X509_F_BY_FILE_CTRL,X509_R_LOADING_DEFAULTS);
}
else
{
if(argl == X509_FILETYPE_PEM)
ok = (X509_load_cert_crl_buf(ctx,argp,
X509_FILETYPE_PEM) != 0);
else
ok = (X509_load_cert_buf(ctx,argp,(int)argl) != 0);
}
break;
}
return(ok);
}
int X509_load_cert_buf(X509_LOOKUP *ctx, const char *certBuf, int type)
{
int ret=0;
BIO *in=NULL;
int i,count=0;
X509 *x=NULL;
if (certBuf == NULL) return(1);
in=BIO_new(BIO_s_mem());
if(in==NULL) goto err;
if (type == X509_FILETYPE_PEM)
{
for (;;)
{
x=PEM_read_bio_X509_AUX(in,NULL,NULL,NULL);
if (x == NULL)
{
if ((ERR_GET_REASON(ERR_peek_last_error()) ==
PEM_R_NO_START_LINE) && (count > 0))
{
ERR_clear_error();
break;
}
else
{
X509err(X509_F_X509_LOAD_CERT_FILE,
ERR_R_PEM_LIB);
goto err;
}
}
i=X509_STORE_add_cert(ctx->store_ctx,x);
if (!i) goto err;
count++;
X509_free(x);
x=NULL;
}
ret=count;
}
else if (type == X509_FILETYPE_ASN1)
{
x=d2i_X509_bio(in,NULL);
if (x == NULL)
{
X509err(X509_F_X509_LOAD_CERT_FILE,ERR_R_ASN1_LIB);
goto err;
}
i=X509_STORE_add_cert(ctx->store_ctx,x);
if (!i) goto err;
ret=i;
}
else
{
X509err(X509_F_X509_LOAD_CERT_FILE,X509_R_BAD_X509_FILETYPE);
goto err;
}
err:
if (x != NULL) X509_free(x);
if (in != NULL) BIO_free(in);
return(ret);
}
int X509_load_crl_buf(X509_LOOKUP *ctx, const char *certBuf, int type)
{
int ret=0;
BIO *in=NULL;
int i,count=0;
X509_CRL *x=NULL;
if (certBuf == NULL) return(1);
//in=BIO_new(BIO_s_file_internal());
in=BIO_new(BIO_s_mem());
if(in==NULL) goto err;
if (type == X509_FILETYPE_PEM)
{
for (;;)
{
x=PEM_read_bio_X509_CRL(in,NULL,NULL,NULL);
if (x == NULL)
{
if ((ERR_GET_REASON(ERR_peek_last_error()) ==
PEM_R_NO_START_LINE) && (count > 0))
{
ERR_clear_error();
break;
}
else
{
X509err(X509_F_X509_LOAD_CRL_FILE,
ERR_R_PEM_LIB);
goto err;
}
}
i=X509_STORE_add_crl(ctx->store_ctx,x);
if (!i) goto err;
count++;
X509_CRL_free(x);
x=NULL;
}
ret=count;
}
else if (type == X509_FILETYPE_ASN1)
{
x=d2i_X509_CRL_bio(in,NULL);
if (x == NULL)
{
X509err(X509_F_X509_LOAD_CRL_FILE,ERR_R_ASN1_LIB);
goto err;
}
i=X509_STORE_add_crl(ctx->store_ctx,x);
if (!i) goto err;
ret=i;
}
else
{
X509err(X509_F_X509_LOAD_CRL_FILE,X509_R_BAD_X509_FILETYPE);
goto err;
}
err:
if (x != NULL) X509_CRL_free(x);
if (in != NULL) BIO_free(in);
return(ret);
}
int X509_load_cert_crl_buf(X509_LOOKUP *ctx, const char *certBuf, int type)
{
STACK_OF(X509_INFO) *inf;
X509_INFO *itmp;
BIO *in;
int i, count = 0;
if(type != X509_FILETYPE_PEM)
return X509_load_cert_buf(ctx, certBuf, type);
in = BIO_new(BIO_s_mem());
if(!in) {
X509err(X509_F_X509_LOAD_CERT_CRL_FILE,ERR_R_SYS_LIB);
return 0;
}
BIO_write(in, certBuf, strlen(certBuf));
inf = PEM_X509_INFO_read_bio(in, NULL, NULL, NULL);
BIO_free(in);
if(!inf) {
X509err(X509_F_X509_LOAD_CERT_CRL_FILE,ERR_R_PEM_LIB);
return 0;
}
for(i = 0; i < sk_X509_INFO_num(inf); i++) {
itmp = sk_X509_INFO_value(inf, i);
if(itmp->x509) {
X509_STORE_add_cert(ctx->store_ctx, itmp->x509);
count++;
}
if(itmp->crl) {
X509_STORE_add_crl(ctx->store_ctx, itmp->crl);
count++;
}
}
sk_X509_INFO_pop_free(inf, X509_INFO_free);
return count;
}
常规在C ++中它调用上述套路：
Routine in C++ which calls the above routines:
#include "by_buffer.h"
static int check(X509_STORE *ctx, const char *certBuf);
static X509 *load_cert(const char *certBuf);
int validateKey(const char *rsaKeyCA, const char *rsaCertificate) {
int ret=0;
X509_STORE *cert_ctx=NULL;
X509_LOOKUP *lookup=NULL;
cert_ctx=X509_STORE_new();
if (cert_ctx == NULL) goto end;
OpenSSL_add_all_algorithms();
lookup=X509_STORE_add_lookup(cert_ctx,X509_LOOKUP_buffer());
if (lookup == NULL)
goto end;
if(!X509_LOOKUP_load_buf(lookup,rsaKeyCA,X509_FILETYPE_PEM))
goto end;
lookup=X509_STORE_add_lookup(cert_ctx,X509_LOOKUP_hash_dir());
if (lookup == NULL)
goto end;
X509_LOOKUP_add_dir(lookup,NULL,X509_FILETYPE_DEFAULT);
ret = check(cert_ctx, rsaCertificate);
end:
if (cert_ctx != NULL) X509_STORE_free(cert_ctx);
return ret;
}
static X509 *load_cert(const char *certBuf)
{
X509 *x=NULL;
BIO *cert;
if ((cert=BIO_new(BIO_s_mem())) == NULL)
goto end;
BIO_write(cert, certBuf, strlen(certBuf));
x=PEM_read_bio_X509_AUX(cert,NULL, NULL, NULL);
end:
if (cert != NULL) BIO_free(cert);
return(x);
}
static int check(X509_STORE *ctx, const char *certBuf)
{
X509 *x=NULL;
int i=0,ret=0;
X509_STORE_CTX *csc;
x = load_cert(certBuf);
if (x == NULL)
goto end;
csc = X509_STORE_CTX_new();
if (csc == NULL)
goto end;
X509_STORE_set_flags(ctx, 0);
if(!X509_STORE_CTX_init(csc,ctx,x,0))
goto end;
////// See crypto/asn1/t_x509.c for ideas on how to access and print the values
//printf("X.509 name: %s\n", x->name);
i=X509_verify_cert(csc);
X509_STORE_CTX_free(csc);
ret=0;
end:
ret = (i > 0);
if (x != NULL)
X509_free(x);
return(ret);
}
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