Reimplement PKCS#12 key derivation.
This is avoids pulling in BIGNUM for doing a straight-forward addition on a
block-sized value, and avoids a ton of mallocs. It's also -Wconversion-clean,
unlike the old one.
In doing so, this replaces the HMAC_MAX_MD_CBLOCK with EVP_MAX_MD_BLOCK_SIZE.
By having the maximum block size available, most of the temporary values in the
key derivation don't need to be malloc'd.
BUG=22
Change-Id: I940a62bba4ea32bf82b1190098f3bf185d4cc7fe
Reviewed-on: https://boringssl-review.googlesource.com/7688
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
diff --git a/include/openssl/digest.h b/include/openssl/digest.h
index 9a5ec51..db3ead7 100644
--- a/include/openssl/digest.h
+++ b/include/openssl/digest.h
@@ -143,6 +143,9 @@
* at least this much space. */
#define EVP_MAX_MD_SIZE 64 /* SHA-512 is the longest so far. */
+/* EVP_MAX_MD_BLOCK_SIZE is the largest digest block size supported, in bytes. */
+#define EVP_MAX_MD_BLOCK_SIZE 128 /* SHA-512 is the longest so far. */
+
/* EVP_DigestFinal_ex finishes the digest in |ctx| and writes the output to
* |md_out|. At most |EVP_MAX_MD_SIZE| bytes are written. If |out_size| is not
* NULL then |*out_size| is set to the number of bytes written. It returns one.
