def _truncate_digest_for_dsa(dsa_cdata, digest, backend):
"""
This function truncates digests that are longer than a given DS
key's length so they can be signed. OpenSSL does this for us in
1.0.0c+ and it isn't needed in 0.9.8, but that leaves us with three
releases (1.0.0, 1.0.0a, and 1.0.0b) where this is a problem. This
truncation is not required in 0.9.8 because DSA is limited to SHA-1.
"""
order_bits = backend._lib.BN_num_bits(dsa_cdata.q)
return _truncate_digest(digest, order_bits)
def _truncate_digest_for_dsa(dsa_cdata, digest, backend):
"""
This function truncates digests that are longer than a given DS
key's length so they can be signed. OpenSSL does this for us in
1.0.0c+ and it isn't needed in 0.9.8, but that leaves us with three
releases (1.0.0, 1.0.0a, and 1.0.0b) where this is a problem. This
truncation is not required in 0.9.8 because DSA is limited to SHA-1.
"""
order_bits = backend._lib.BN_num_bits(dsa_cdata.q)
return _truncate_digest(digest, order_bits)
def _truncate_digest_for_dsa(dsa_cdata, digest, backend):
"""
This function truncates digests that are longer than a given DS
key's length so they can be signed. OpenSSL does this for us in
1.0.0c+, leaving us with three releases (1.0.0, 1.0.0a, and 1.0.0b) where
this is a problem.
"""
q = backend._ffi.new("BIGNUM **")
backend._lib.DSA_get0_pqg(dsa_cdata, backend._ffi.NULL, q,
backend._ffi.NULL)
backend.openssl_assert(q[0] != backend._ffi.NULL)
order_bits = backend._lib.BN_num_bits(q[0])
return _truncate_digest(digest, order_bits)
def _truncate_digest_for_dsa(dsa_cdata, digest, backend):
"""
This function truncates digests that are longer than a given DS
key's length so they can be signed. OpenSSL does this for us in
1.0.0c+, leaving us with three releases (1.0.0, 1.0.0a, and 1.0.0b) where
this is a problem.
"""
q = backend._ffi.new("BIGNUM **")
backend._lib.DSA_get0_pqg(
dsa_cdata, backend._ffi.NULL, q, backend._ffi.NULL
)
backend.openssl_assert(q[0] != backend._ffi.NULL)
order_bits = backend._lib.BN_num_bits(q[0])
return _truncate_digest(digest, order_bits)
def _truncate_digest_for_dsa(dsa_cdata, digest, backend):
"""
This function truncates digests that are longer than a given DS
key's length so they can be signed. OpenSSL does this for us in
1.0.0c+ and it isn't needed in 0.9.8, but that leaves us with three
releases (1.0.0, 1.0.0a, and 1.0.0b) where this is a problem. This
truncation is not required in 0.9.8 because DSA is limited to SHA-1.
"""
q = backend._ffi.new("BIGNUM **")
backend._lib.DSA_get0_pqg(dsa_cdata, backend._ffi.NULL, q,
backend._ffi.NULL)
backend.openssl_assert(q[0] != backend._ffi.NULL)
order_bits = backend._lib.BN_num_bits(q[0])
return _truncate_digest(digest, order_bits)
def _truncate_digest_for_dsa(dsa_cdata, digest, backend):
"""
This function truncates digests that are longer than a given DS
key's length so they can be signed. OpenSSL does this for us in
1.0.0c+ and it isn't needed in 0.9.8, but that leaves us with three
releases (1.0.0, 1.0.0a, and 1.0.0b) where this is a problem. This
truncation is not required in 0.9.8 because DSA is limited to SHA-1.
"""
q = backend._ffi.new("BIGNUM **")
backend._lib.DSA_get0_pqg(
dsa_cdata, backend._ffi.NULL, q, backend._ffi.NULL
)
backend.openssl_assert(q[0] != backend._ffi.NULL)
order_bits = backend._lib.BN_num_bits(q[0])
return _truncate_digest(digest, order_bits)
def _truncate_digest_for_ecdsa(ec_key_cdata, digest, backend):
"""
This function truncates digests that are longer than a given elliptic
curve key's length so they can be signed. Since elliptic curve keys are
much shorter than RSA keys many digests (e.g. SHA-512) may require
truncation.
"""
_lib = backend._lib
_ffi = backend._ffi
group = _lib.EC_KEY_get0_group(ec_key_cdata)
with backend._tmp_bn_ctx() as bn_ctx:
order = _lib.BN_CTX_get(bn_ctx)
backend.openssl_assert(order != _ffi.NULL)
res = _lib.EC_GROUP_get_order(group, order, bn_ctx)
backend.openssl_assert(res == 1)
order_bits = _lib.BN_num_bits(order)
return _truncate_digest(digest, order_bits)
