CryptHashToBeSigned function (wincrypt.h)
Syntax
BOOL CryptHashToBeSigned(
[in] HCRYPTPROV_LEGACY hCryptProv,
[in] DWORD dwCertEncodingType,
[in] const BYTE *pbEncoded,
[in] DWORD cbEncoded,
[out] BYTE *pbComputedHash,
[in, out] DWORD *pcbComputedHash
);
Parameters
[in] hCryptProv
This parameter is not used and should be set to NULL.
Windows Server 2003 and Windows XP: A handle of the cryptographic service provider (CSP) to use to compute the hash.This parameter's data type is HCRYPTPROV.
Unless there is a strong reason for passing in a specific cryptographic provider in hCryptProv, zero is passed in. Passing in zero causes the default RSA or Digital Signature Standard (DSS) provider to be acquired before doing hash, signature verification, or recipient encryption operations.
[in] dwCertEncodingType
Specifies the encoding type used. It is always acceptable to specify both the certificate and message encoding types by combining them with a bitwise-OR operation as shown in the following example:
X509_ASN_ENCODING | PKCS_7_ASN_ENCODING
Currently defined encoding types are:
- X509_ASN_ENCODING
- PKCS_7_ASN_ENCODING
[in] pbEncoded
Address of a buffer that contains the content to be hashed. This is the encoded form of a CERT_SIGNED_CONTENT_INFO.
[in] cbEncoded
The size, in bytes, of the buffer.
[out] pbComputedHash
A pointer to a buffer to receive the computed hash.
This parameter can be NULL to set the size of this information for memory allocation purposes. For more information, see Retrieving Data of Unknown Length.
[in, out] pcbComputedHash
A pointer to a DWORD that contains the size, in bytes, of the buffer pointed to by the pbComputedHash parameter. When the function returns, the DWORD contains the number of bytes stored in the buffer.
Return value
If the function succeeds, the function returns nonzero (TRUE).
If the function fails, it returns zero (FALSE). For extended error information, call GetLastError.
Return code | Description |
---|---|
|
If the buffer specified by the pbComputedHash parameter is not large enough to hold the returned data, the function sets the ERROR_MORE_DATA code, and stores the required buffer size, in bytes, into the variable pointed to by pcbComputedHash. |
|
Invalid certificate encoding type. Currently only X509_ASN_ENCODING is supported. |
|
The object identifier (OID) of the signature algorithm does not map to a known or supported hash algorithm. |
If the function fails, GetLastError may return an Abstract Syntax Notation One (ASN.1) encoding/decoding error. For information about these errors, see ASN.1 Encoding/Decoding Return Values.
Requirements
Requirement | Value |
---|---|
Minimum supported client | Windows XP [desktop apps only] |
Minimum supported server | Windows Server 2003 [desktop apps only] |
Target Platform | Windows |
Header | wincrypt.h |
Library | Crypt32.lib |
DLL | Crypt32.dll |