| Previous | Next |
| CRYPT_E_MSG_ERROR | CRYPT_E_OID_FORMAT |
CRYPT_E_UNKNOWN_ALGO
The encoded CMS/PKCS#7 message names a cryptographic algorithm that the current CryptoAPI path does not recognize or support.
What to check for CRYPT_E_UNKNOWN_ALGO
- Inspect the message algorithm identifier and object identifier (OID) before changing any system cryptography policy.
- Confirm that the sender and recipient agree on the CMS message profile and supported algorithms.
- Do not re-enable legacy algorithms merely to suppress the error; choose a supported algorithm or update the producing system.
Microsoft: CryptMsgOpenToDecode
Microsoft: CryptVerifyMessageSignature
Diagnostic interpretation
CRYPT_E_UNKNOWN_ALGO has the HRESULT value 0x80091002. AllStat records the condition as “Unknown cryptographic algorithm.”.
Evidence to capture
- Capture any IErrorInfo text, activity identifier, event-log entry, and subsystem trace that mentions this result or the crypt / unknown / algo operation.
- Preserve the first failure in the call chain; a later HRESULT can describe cleanup rather than the original crypt / unknown / algo condition.
Retry and recovery
” has changed.
Looking for a different code? Search another status or error code.