yuzu-emu/mbedtls
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Rename and document mac_or_tag_lengths -> permitted_truncations

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No behavior change.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
This commit is contained in:
Gilles Peskine 2022-04-12 18:51:01 +02:00
parent f96e977584
commit dce7d8f51e
1 changed files with 9 additions and 3 deletions
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12
scripts/mbedtls_dev/crypto_knowledge.py
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@ -458,8 +458,14 @@ class Algorithm:
}
HMAC_RE = re.compile(r'PSA_ALG_HMAC\((.*)\)\Z')
@classmethod
def mac_or_tag_lengths(cls, base: str) -> FrozenSet[int]:
"""Return the set of permitted lengths for the given MAC or AEAD tag."""
def permitted_truncations(cls, base: str) -> FrozenSet[int]:
"""Permitted output lengths for the given MAC or AEAD base algorithm.
For a MAC algorithm, this is the set of truncation lengths that
Mbed TLS supports.
For an AEAD algorithm, this is the set of truncation lengths that
are permitted by the algorithm specification.
"""
if base in cls.PERMITTED_TAG_LENGTHS:
return cls.PERMITTED_TAG_LENGTHS[base]
max_length = cls.MAC_LENGTH.get(base, None)
@ -486,7 +492,7 @@ class Algorithm:
if m:
base = m.group('base')
to_length = int(m.group('length'), 0)
permitted_lengths = self.mac_or_tag_lengths(base)
permitted_lengths = self.permitted_truncations(base)
if to_length not in permitted_lengths:
return True
return False