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Extending NIST's CAVP Testing of Cryptographic Hash Function Implementations



Nicky W. Mouha, Christopher T. Celi


This paper describes a vulnerability in Apple's CoreCrypto library, which affects 11 out of the 12 implemented hash functions: every implemented hash function except MD2 (Message Digest 2), as well as several higher-level operations such as the Hash-based Message Authentication Code (HMAC) and the Ed25519 signature scheme. The vulnerability is present in each of Apple's CoreCrypto libraries that are currently validated under FIPS 140-2 (Federal Information Processing Standard). For inputs of about 2^32 bytes (4 GiB) or more, the implementations do not produce the correct output, but instead enter into an infinite loop. The vulnerability shows a limitation in the Cryptographic Algorithm Validation Program (CAVP) of the National Institute of Standards and Technology (NIST), which currently does not perform tests on hash functions for inputs larger than 65 535 bits. To overcome this limitation of NIST's CAVP, we introduce a new test type called the Large Data Test (LDT). The LDT detects vulnerabilities similar to that in CoreCrypto in implementations submitted for validation under FIPS 140-2.
Proceedings Title
CT-RSA 2020: Cryptographers' Track at the RSA Conference
Conference Dates
February 24-28, 2020
Conference Location
San Francisco, CA


CVE-2019-8741, FIPS, CAVP, ACVP, Apple, CoreCrypto, hash function, vulnerability


Mouha, N. and Celi, C. (2020), Extending NIST's CAVP Testing of Cryptographic Hash Function Implementations, CT-RSA 2020: Cryptographers' Track at the RSA Conference, San Francisco, CA, [online], (Accessed June 21, 2024)


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Created February 14, 2020, Updated April 20, 2020