decode.c

这是一个开放源代码的与WINNT/WIN2K/WIN2003兼容的操作系统

                else
                {
                    assert(blob->pbData);
                    memcpy(blob->pbData, pbEncoded, blob->cbData);
                }
            }
            else
            {
                SetLastError(CRYPT_E_ASN1_CORRUPT);
                ret = FALSE;
            }
        }
    }
    return ret;
}

/* Like CRYPT_AsnDecodeBitsInternal, but swaps the bytes */
static BOOL WINAPI CRYPT_AsnDecodeBitsSwapBytes(DWORD dwCertEncodingType,
 LPCSTR lpszStructType, const BYTE *pbEncoded, DWORD cbEncoded, DWORD dwFlags,
 PCRYPT_DECODE_PARA pDecodePara, void *pvStructInfo, DWORD *pcbStructInfo)
{
    BOOL ret;

    TRACE("(%p, %d, 0x%08x, %p, %p, %d)\n", pbEncoded, cbEncoded, dwFlags,
     pDecodePara, pvStructInfo, *pcbStructInfo);

    /* Can't use the CRYPT_DECODE_NOCOPY_FLAG, because we modify the bytes in-
     * place.
     */
    ret = CRYPT_AsnDecodeBitsInternal(dwCertEncodingType, lpszStructType,
     pbEncoded, cbEncoded, dwFlags & ~CRYPT_DECODE_NOCOPY_FLAG, pDecodePara,
     pvStructInfo, pcbStructInfo);
    if (ret && pvStructInfo)
    {
        CRYPT_BIT_BLOB *blob = (CRYPT_BIT_BLOB *)pvStructInfo;

        if (blob->cbData)
        {
            DWORD i;
            BYTE temp;

            for (i = 0; i < blob->cbData / 2; i++)
            {
                temp = blob->pbData[i];
                blob->pbData[i] = blob->pbData[blob->cbData - i - 1];
                blob->pbData[blob->cbData - i - 1] = temp;
            }
        }
    }
    TRACE("returning %d (%08x)\n", ret, GetLastError());
    return ret;
}

static BOOL WINAPI CRYPT_AsnDecodeCertSignedContent(DWORD dwCertEncodingType,
 LPCSTR lpszStructType, const BYTE *pbEncoded, DWORD cbEncoded, DWORD dwFlags,
 PCRYPT_DECODE_PARA pDecodePara, void *pvStructInfo, DWORD *pcbStructInfo)
{
    BOOL ret = TRUE;

    TRACE("%p, %d, %08x, %p, %p, %d\n", pbEncoded, cbEncoded, dwFlags,
     pDecodePara, pvStructInfo, *pcbStructInfo);

    __TRY
    {
        struct AsnDecodeSequenceItem items[] = {
         { 0, offsetof(CERT_SIGNED_CONTENT_INFO, ToBeSigned),
           CRYPT_AsnDecodeDerBlob, sizeof(CRYPT_DER_BLOB), FALSE, TRUE,
           offsetof(CERT_SIGNED_CONTENT_INFO, ToBeSigned.pbData), 0 },
         { ASN_SEQUENCEOF, offsetof(CERT_SIGNED_CONTENT_INFO,
           SignatureAlgorithm), CRYPT_AsnDecodeAlgorithmId,
           sizeof(CRYPT_ALGORITHM_IDENTIFIER), FALSE, TRUE,
           offsetof(CERT_SIGNED_CONTENT_INFO, SignatureAlgorithm.pszObjId), 0 },
         { ASN_BITSTRING, offsetof(CERT_SIGNED_CONTENT_INFO, Signature),
           CRYPT_AsnDecodeBitsSwapBytes, sizeof(CRYPT_BIT_BLOB), FALSE, TRUE,
           offsetof(CERT_SIGNED_CONTENT_INFO, Signature.pbData), 0 },
        };

        if (dwFlags & CRYPT_DECODE_NO_SIGNATURE_BYTE_REVERSAL_FLAG)
            items[2].decodeFunc = CRYPT_AsnDecodeBitsInternal;
        ret = CRYPT_AsnDecodeSequence(dwCertEncodingType, items,
         sizeof(items) / sizeof(items[0]), pbEncoded, cbEncoded, dwFlags,
         pDecodePara, pvStructInfo, pcbStructInfo, NULL);
    }
    __EXCEPT_PAGE_FAULT
    {
        SetLastError(STATUS_ACCESS_VIOLATION);
        ret = FALSE;
    }
    __ENDTRY

    TRACE("Returning %d (%08x)\n", ret, GetLastError());
    return ret;
}

/* Internal function */
static BOOL WINAPI CRYPT_AsnDecodeCertVersion(DWORD dwCertEncodingType,
 LPCSTR lpszStructType, const BYTE *pbEncoded, DWORD cbEncoded, DWORD dwFlags,
 PCRYPT_DECODE_PARA pDecodePara, void *pvStructInfo, DWORD *pcbStructInfo)
{
    BOOL ret;
    DWORD dataLen;

    if ((ret = CRYPT_GetLen(pbEncoded, cbEncoded, &dataLen)))
    {
        BYTE lenBytes = GET_LEN_BYTES(pbEncoded[1]);

        ret = CRYPT_AsnDecodeInt(dwCertEncodingType, X509_INTEGER,
         pbEncoded + 1 + lenBytes, dataLen, dwFlags, pDecodePara,
         pvStructInfo, pcbStructInfo);
    }
    return ret;
}

static BOOL WINAPI CRYPT_AsnDecodeValidity(DWORD dwCertEncodingType,
 LPCSTR lpszStructType, const BYTE *pbEncoded, DWORD cbEncoded, DWORD dwFlags,
 PCRYPT_DECODE_PARA pDecodePara, void *pvStructInfo, DWORD *pcbStructInfo)
{
    BOOL ret;

    struct AsnDecodeSequenceItem items[] = {
     { 0, offsetof(CERT_PRIVATE_KEY_VALIDITY, NotBefore),
       CRYPT_AsnDecodeChoiceOfTime, sizeof(FILETIME), FALSE, FALSE, 0 },
     { 0, offsetof(CERT_PRIVATE_KEY_VALIDITY, NotAfter),
       CRYPT_AsnDecodeChoiceOfTime, sizeof(FILETIME), FALSE, FALSE, 0 },
    };

    ret = CRYPT_AsnDecodeSequence(dwCertEncodingType, items,
     sizeof(items) / sizeof(items[0]), pbEncoded, cbEncoded, dwFlags,
     pDecodePara, pvStructInfo, pcbStructInfo, NULL);
    return ret;
}

/* Internal function */
static BOOL WINAPI CRYPT_AsnDecodeCertExtensions(DWORD dwCertEncodingType,
 LPCSTR lpszStructType, const BYTE *pbEncoded, DWORD cbEncoded, DWORD dwFlags,
 PCRYPT_DECODE_PARA pDecodePara, void *pvStructInfo, DWORD *pcbStructInfo)
{
    BOOL ret;
    DWORD dataLen;

    if ((ret = CRYPT_GetLen(pbEncoded, cbEncoded, &dataLen)))
    {
        BYTE lenBytes = GET_LEN_BYTES(pbEncoded[1]);

        ret = CRYPT_AsnDecodeExtensionsInternal(dwCertEncodingType,
         X509_EXTENSIONS, pbEncoded + 1 + lenBytes, dataLen, dwFlags,
         pDecodePara, pvStructInfo, pcbStructInfo);
    }
    return ret;
}

static BOOL WINAPI CRYPT_AsnDecodeCertInfo(DWORD dwCertEncodingType,
 LPCSTR lpszStructType, const BYTE *pbEncoded, DWORD cbEncoded, DWORD dwFlags,
 PCRYPT_DECODE_PARA pDecodePara, void *pvStructInfo, DWORD *pcbStructInfo)
{
    BOOL ret = TRUE;
    struct AsnDecodeSequenceItem items[] = {
     { ASN_CONTEXT | ASN_CONSTRUCTOR, offsetof(CERT_INFO, dwVersion),
       CRYPT_AsnDecodeCertVersion, sizeof(DWORD), TRUE, FALSE, 0, 0 },
     { ASN_INTEGER, offsetof(CERT_INFO, SerialNumber),
       CRYPT_AsnDecodeIntegerInternal, sizeof(CRYPT_INTEGER_BLOB), FALSE,
       TRUE, offsetof(CERT_INFO, SerialNumber.pbData), 0 },
     { ASN_SEQUENCEOF, offsetof(CERT_INFO, SignatureAlgorithm),
       CRYPT_AsnDecodeAlgorithmId, sizeof(CRYPT_ALGORITHM_IDENTIFIER),
       FALSE, TRUE, offsetof(CERT_INFO, SignatureAlgorithm.pszObjId), 0 },
     { 0, offsetof(CERT_INFO, Issuer), CRYPT_AsnDecodeDerBlob,
       sizeof(CRYPT_DER_BLOB), FALSE, TRUE, offsetof(CERT_INFO,
       Issuer.pbData) },
     { ASN_SEQUENCEOF, offsetof(CERT_INFO, NotBefore),
       CRYPT_AsnDecodeValidity, sizeof(CERT_PRIVATE_KEY_VALIDITY), FALSE,
       FALSE, 0 },
     { 0, offsetof(CERT_INFO, Subject), CRYPT_AsnDecodeDerBlob,
       sizeof(CRYPT_DER_BLOB), FALSE, TRUE, offsetof(CERT_INFO,
       Subject.pbData) },
     { ASN_SEQUENCEOF, offsetof(CERT_INFO, SubjectPublicKeyInfo),
       CRYPT_AsnDecodePubKeyInfoInternal, sizeof(CERT_PUBLIC_KEY_INFO),
       FALSE, TRUE, offsetof(CERT_INFO,
       SubjectPublicKeyInfo.Algorithm.Parameters.pbData), 0 },
     { ASN_BITSTRING, offsetof(CERT_INFO, IssuerUniqueId),
       CRYPT_AsnDecodeBitsInternal, sizeof(CRYPT_BIT_BLOB), TRUE, TRUE,
       offsetof(CERT_INFO, IssuerUniqueId.pbData), 0 },
     { ASN_BITSTRING, offsetof(CERT_INFO, SubjectUniqueId),
       CRYPT_AsnDecodeBitsInternal, sizeof(CRYPT_BIT_BLOB), TRUE, TRUE,
       offsetof(CERT_INFO, SubjectUniqueId.pbData), 0 },
     { ASN_CONTEXT | ASN_CONSTRUCTOR | 3, offsetof(CERT_INFO, cExtension),
       CRYPT_AsnDecodeCertExtensions, sizeof(CERT_EXTENSIONS), TRUE, TRUE,
       offsetof(CERT_INFO, rgExtension), 0 },
    };

    TRACE("%p, %d, %08x, %p, %p, %d\n", pbEncoded, cbEncoded, dwFlags,
     pDecodePara, pvStructInfo, *pcbStructInfo);

    ret = CRYPT_AsnDecodeSequence(dwCertEncodingType, items,
     sizeof(items) / sizeof(items[0]), pbEncoded, cbEncoded, dwFlags,
     pDecodePara, pvStructInfo, pcbStructInfo, NULL);

    TRACE("Returning %d (%08x)\n", ret, GetLastError());
    return ret;
}

static BOOL WINAPI CRYPT_AsnDecodeCert(DWORD dwCertEncodingType,
 LPCSTR lpszStructType, const BYTE *pbEncoded, DWORD cbEncoded, DWORD dwFlags,
 PCRYPT_DECODE_PARA pDecodePara, void *pvStructInfo, DWORD *pcbStructInfo)
{
    BOOL ret = TRUE;

    TRACE("%p, %d, %08x, %p, %p, %d\n", pbEncoded, cbEncoded, dwFlags,
     pDecodePara, pvStructInfo, *pcbStructInfo);

    __TRY
    {
        PCERT_SIGNED_CONTENT_INFO signedCert = NULL;
        DWORD size = 0;

        /* First try to decode it as a signed cert. */
        ret = CRYPT_AsnDecodeCertSignedContent(dwCertEncodingType, X509_CERT,
         pbEncoded, cbEncoded, CRYPT_DECODE_ALLOC_FLAG, NULL,
         (BYTE *)&signedCert, &size);
        if (ret)
        {
            size = 0;
            ret = CRYPT_AsnDecodeCertInfo(dwCertEncodingType,
             X509_CERT_TO_BE_SIGNED, signedCert->ToBeSigned.pbData,
             signedCert->ToBeSigned.cbData, dwFlags, pDecodePara, pvStructInfo,
             pcbStructInfo);
            LocalFree(signedCert);
        }
        /* Failing that, try it as an unsigned cert */
        if (!ret)
        {
            size = 0;
            ret = CRYPT_AsnDecodeCertInfo(dwCertEncodingType,
             X509_CERT_TO_BE_SIGNED, pbEncoded, cbEncoded, dwFlags,
             pDecodePara, pvStructInfo, pcbStructInfo);
        }
    }
    __EXCEPT_PAGE_FAULT
    {
        SetLastError(STATUS_ACCESS_VIOLATION);
        ret = FALSE;
    }
    __ENDTRY

    TRACE("Returning %d (%08x)\n", ret, GetLastError());
    return ret;
}

static BOOL WINAPI CRYPT_AsnDecodeCRLEntry(DWORD dwCertEncodingType,
 LPCSTR lpszStructType, const BYTE *pbEncoded, DWORD cbEncoded, DWORD dwFlags,
 PCRYPT_DECODE_PARA pDecodePara, void *pvStructInfo, DWORD *pcbStructInfo)
{
    BOOL ret;
    struct AsnDecodeSequenceItem items[] = {
     { ASN_INTEGER, offsetof(CRL_ENTRY, SerialNumber),
       CRYPT_AsnDecodeIntegerInternal, sizeof(CRYPT_INTEGER_BLOB), FALSE, TRUE,
       offsetof(CRL_ENTRY, SerialNumber.pbData), 0 },
     { 0, offsetof(CRL_ENTRY, RevocationDate), CRYPT_AsnDecodeChoiceOfTime,
       sizeof(FILETIME), FALSE, FALSE, 0 },
     { ASN_SEQUENCEOF, offsetof(CRL_ENTRY, cExtension),
       CRYPT_AsnDecodeExtensionsInternal, sizeof(CERT_EXTENSIONS), TRUE, TRUE,
       offsetof(CRL_ENTRY, rgExtension), 0 },
    };
    PCRL_ENTRY entry = (PCRL_ENTRY)pvStructInfo;

    TRACE("%p, %d, %08x, %p, %d\n", pbEncoded, cbEncoded, dwFlags, entry,
     *pcbStructInfo);

    ret = CRYPT_AsnDecodeSequence(X509_ASN_ENCODING, items,
     sizeof(items) / sizeof(items[0]), pbEncoded, cbEncoded, dwFlags,
     NULL, entry, pcbStructInfo, entry ? entry->SerialNumber.pbData : NULL);
    return ret;
}

/* Warning: assumes pvStructInfo is a struct GenericArray whose rgItems has
 * been set prior to calling.
 */
static BOOL WINAPI CRYPT_AsnDecodeCRLEntries(DWORD dwCertEncodingType,
 LPCSTR lpszStructType, const BYTE *pbEncoded, DWORD cbEncoded, DWORD dwFlags,
 PCRYPT_DECODE_PARA pDecodePara, void *pvStructInfo, DWORD *pcbStructInfo)
{
    BOOL ret;
    struct AsnArrayDescriptor arrayDesc = { ASN_SEQUENCEOF,
     CRYPT_AsnDecodeCRLEntry, sizeof(CRL_ENTRY), TRUE,
     offsetof(CRL_ENTRY, SerialNumber.pbData) };
    struct GenericArray *entries = (struct GenericArray *)pvStructInfo;

    TRACE("%p, %d, %08x, %p, %p, %d\n", pbEncoded, cbEncoded, dwFlags,
     pDecodePara, pvStructInfo, *pcbStructInfo);

    ret = CRYPT_AsnDecodeArray(&arrayDesc, pbEncoded, cbEncoded, dwFlags,
     pDecodePara, pvStructInfo, pcbStructInfo,
     entries ? entries->rgItems : NULL);
    TRACE("Returning %d (%08x)\n", ret, GetLastError());
    return ret;
}

static BOOL WINAPI CRYPT_AsnDecodeCRLInfo(DWORD dwCertEncodingType,
 LPCSTR lpszStructType, const BYTE *pbEncoded, DWORD cbEncoded, DWORD dwFlags,
 PCRYPT_DECODE_PARA pDecodePara, void *pvStructInfo, DWORD *pcbStructInfo)
{
    struct AsnDecodeSequenceItem items[] = {
     { ASN_INTEGER, offsetof(CRL_INFO, dwVersion),
       CRYPT_AsnDecodeInt, sizeof(DWORD), TRUE, FALSE, 0, 0 },
     { ASN_SEQUENCEOF, offsetof(CRL_INFO, SignatureAlgorithm),
       CRYPT_AsnDecodeAlgorithmId, sizeof(CRYPT_ALGORITHM_IDENTIFIER),
       FALSE, TRUE, offsetof(CRL_INFO, SignatureAlgorithm.pszObjId), 0 },
     { 0, offsetof(CRL_INFO, Issuer), CRYPT_AsnDecodeDerBlob,
       sizeof(CRYPT_DER_BLOB), FALSE, TRUE, offsetof(CRL_INFO,
       Issuer.pbData) },
     { 0, offsetof(CRL_INFO, ThisUpdate), CRYPT_AsnDecodeChoiceOfTime,
       sizeof(FILETIME), FALSE, FALSE, 0 },
     { 0, offsetof(CRL_INFO, NextUpdate), CRYPT_AsnDecodeChoiceOfTime,
       sizeof(FILETIME), TRUE, FALSE, 0 },
     { ASN_SEQUENCEOF, offsetof(CRL_INFO, cCRLEntry),
       CRYPT_AsnDecodeCRLEntries, sizeof(struct GenericArray), TRUE, TRUE,
       offsetof(CRL_INFO, rgCRLEntry), 0 },
     { ASN_CONTEXT | ASN_CONSTRUCTOR | 0, offsetof(CRL_INFO, cExtension),
       CRYPT_AsnDecodeCertExtensions, sizeof(CERT_EXTENSIONS), TRUE, TRUE,
       offsetof(CRL_INFO, rgExtension), 0 },
    };
    BOOL ret = TRUE;

    TRACE("%p, %d, %08x, %p, %p, %d\n", pbEncoded, cbEncoded, dwFlags,
     pDecodePara, pvStructInfo, *pcbStructInfo);

    ret = CRYPT_AsnDecodeSequence(dwCertEncodingType, items,
     sizeof(items) / sizeof(items[0]), pbEncoded, cbEncoded, dwFlags,
     pDecodePara, pvStructInfo, pcbStructInfo, NULL);

    TRACE("Returning %d (%08x)\n", ret, GetLastError());
    return ret;
}

static BOOL WINAPI CRYPT_AsnDecodeCRL(DWORD dwCertEncodingType,
 LPCSTR lpszStructType, const BYTE *pbEncoded, DWORD cbEncoded, DWORD dwFlags,
 PCRYPT_DECODE_PARA pDecodePara, void *pvStructInfo, DWORD *pcbStructInfo)
{
    BOOL ret = TRUE;

    TRACE("%p, %d, %08x, %p, %p, %d\n", pbEncoded, cbEncoded, dwFlags,