diff options
author | David Benjamin <davidben@chromium.org> | 2015-03-18 23:30:04 +0300 |
---|---|---|
committer | Adam Langley <agl@google.com> | 2015-03-19 00:45:42 +0300 |
commit | 067321502df66153f15c7cf032873b4f92bec6d9 (patch) | |
tree | 21cdc0ef31df0fd4415133e26b9072ff2273ed5e /include/openssl/evp.h | |
parent | 1df63e93f9d7a1d2ebf929d1fe99f1b9b46e237e (diff) |
Explicitly document EVP_PKEY_size vs EVP_PKEY_bits.
They do not quite measure the same value for EC keys. "size" is a really weird
notion to generalize on so we should document what it means for each key type.
EVP_PKEY_size's meaning is most tied to signatures, thanks to EVP_SignFinal
implicitly using it as output bounds.
Change-Id: I7504c142818f8f90f8bcf6891c97a6adaf2d574e
Reviewed-on: https://boringssl-review.googlesource.com/4000
Reviewed-by: Adam Langley <agl@google.com>
Diffstat (limited to 'include/openssl/evp.h')
-rw-r--r-- | include/openssl/evp.h | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/include/openssl/evp.h b/include/openssl/evp.h index b1497f13..f82a7117 100644 --- a/include/openssl/evp.h +++ b/include/openssl/evp.h @@ -119,12 +119,15 @@ OPENSSL_EXPORT int EVP_PKEY_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from); * parameters or zero if not, or if the algorithm doesn't take parameters. */ OPENSSL_EXPORT int EVP_PKEY_missing_parameters(const EVP_PKEY *pkey); -/* EVP_PKEY_size returns the "size", in bytes, of |pkey|. For example, for an - * RSA key this returns the number of bytes needed to represent the modulus. */ +/* EVP_PKEY_size returns the maximum size, in bytes, of a signature signed by + * |pkey|. For an RSA key, this returns the number of bytes needed to represent + * the modulus. For an EC key, this returns the maximum size of a DER-encoded + * ECDSA signature. */ OPENSSL_EXPORT int EVP_PKEY_size(const EVP_PKEY *pkey); -/* EVP_PKEY_bits returns the "size", in bits, of |pkey|. For example, for an - * RSA key, this returns the bit length of the modulus. */ +/* EVP_PKEY_bits returns the "size", in bits, of |pkey|. For an RSA key, this + * returns the bit length of the modulus. For an EC key, this returns the bit + * length of the group order. */ OPENSSL_EXPORT int EVP_PKEY_bits(EVP_PKEY *pkey); /* EVP_PKEY_id returns the type of |pkey|, which is one of the |EVP_PKEY_*| |