ssl - openssl的不同输出

Question

我一直在问自己，如何解释 openssl 关于证书的输出，具体取决于选项(-text 或 - purpose)。有时我不清楚，例如，证书是否应该是 CA。

例子:

openssl x509 -in /path/to/cert1.pem -purpose -noout
Certificate purposes:
SSL client : Yes
SSL client CA : Yes (WARNING code=3)
SSL server : Yes
SSL server CA : Yes (WARNING code=3)
...

但:

openssl x509 -in /path/to/cert1.pem -text -noout | grep CA

这显示没有结果。然而:

openssl x509 -in /path/to/cert2.pem -purpose -noout 
Certificate purposes:
SSL client : Yes
SSL client CA : Yes
SSL server : Yes
SSL server CA : Yes
...

和:

openssl x509 -in /path/to/cert2.pem -text -noout | grep CA
CA:TRUE

Answer 1

从您提供的有限输出来看，您的 cert1.pem是 X509v1 类型.因此，它的-text输出不包含 X509v3显示在您的 grep 中的扩展名cert2.pem 的结果.

对这个假设的一些支持始于 cert1.pem 的输出。 ， 包括

SSL client CA : Yes (WARNING code=3)

围绕此警告含义的 OpenSSL 文档是有限的，但通过检查其源代码，从 apps/x509.c 开始申请，追溯至the following function :

static int check_ca(const X509 *x)
{
    /* keyUsage if present should allow cert signing */
    if (ku_reject(x, KU_KEY_CERT_SIGN))
        return 0;
    if (x->ex_flags & EXFLAG_BCONS) {
        if (x->ex_flags & EXFLAG_CA)
            return 1;
        /* If basicConstraints says not a CA then say so */
        else
            return 0;
    } else {
        /* we support V1 roots for...  uh, I don't really know why. */
        if ((x->ex_flags & V1_ROOT) == V1_ROOT)
            return 3;
        /*
         * If key usage present it must have certSign so tolerate it
         */
        else if (x->ex_flags & EXFLAG_KUSAGE)
            return 4;
        /* Older certificates could have Netscape-specific CA types */
        else if (x->ex_flags & EXFLAG_NSCERT && x->ex_nscert & NS_ANY_CA)
            return 5;
        /* can this still be regarded a CA certificate?  I doubt it */
        return 0;
    }
}

您在哪里看到代码值 3出现。

要验证是否是这种情况，只需查看不同证书的文本转储中的第一行，如下所示:

Certificate:
    Data:
        Version: 1 (0x0)

返回 the X509 tool documentation page ，以下现在是有意义的:

If the certificate is a V1 certificate (and thus has no extensions) and it is self signed it is also assumed to be a CA but a warning is again given: this is to work around the problem of Verisign roots which are V1 self signed certificates.