Ossfuzz

The issue is related to the functions `DH check()`, `DH check ex()`, and `EVP PKEY param check()` in the OpenSSL library. These functions can cause long delays when checking excessively long DH keys or parameters, potentially leading to a Denial of Service (DoS) attack if the key or parameters are obtained from an untrusted source. The `DH check()` function performs various checks on DH parameters, including confirming that the modulus (`p` parameter) is not too large. However, trying to use a very large modulus is slow, and OpenSSL will not normally use a modulus over 10,000 bits in length. The OpenSSL SSL/TLS implementation and the OpenSSL 3.0 and 3.1 FIPS providers are not affected by this issue.

The issue is related to the processing of specially crafted ASN.1 object identifiers, which can cause significant delays in applications using the OpenSSL library. This can lead to a Denial of Service (DoS) condition. The `OBJ obj2txt()` function is used to translate an ASN.1 OBJECT IDENTIFIER to its canonical numeric text form, and when dealing with very large sub-identifiers, the translation can take a very long time. The time complexity is O(n^2) with 'n' being the size of the sub-identifiers in bytes. The impact is relatively low on TLS due to the 100KiB limit on the peer's certificate chain. Applications that call `OBJ obj2txt()` directly with untrusted data are affected, with any version of OpenSSL.