Remove CMAC_resume()

While it is a neat design detail of CMAC that you can resume it after
having finalized it, nothing uses this functionality and it adds some
gross things such as retaining intermediate secrets in the CMAC ctx.
Once this is gone, we can simplify the CMAC code a bit.

ok jsing

1 files changed, 2 insertions, 24 deletions

diff --git a/lib/libcrypto/man/CMAC_Init.3 b/lib/libcrypto/man/CMAC_Init.3
index 81cb8b8f0bb..f4143cf4512 100644
--- a/lib/libcrypto/man/CMAC_Init.3
+++ b/lib/libcrypto/man/CMAC_Init.3
@@ -1,4 +1,4 @@
-.\" $OpenBSD: CMAC_Init.3,v 1.5 2023/12/25 15:52:18 schwarze Exp $
+.\" $OpenBSD: CMAC_Init.3,v 1.6 2024/03/02 09:30:21 tb Exp $
 .\"
 .\" Copyright (c) 2020 Ingo Schwarze <schwarze@openbsd.org>
 .\"
@@ -14,7 +14,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: December 25 2023 $
+.Dd $Mdocdate: March 2 2024 $
 .Dt CMAC_INIT 3
 .Os
 .Sh NAME
@@ -22,7 +22,6 @@
 .Nm CMAC_Init ,
 .Nm CMAC_Update ,
 .Nm CMAC_Final ,
-.Nm CMAC_resume ,
 .Nm CMAC_CTX_copy ,
 .Nm CMAC_CTX_get0_cipher_ctx ,
 .Nm CMAC_CTX_cleanup ,
@@ -52,13 +51,6 @@
 .Fa "unsigned char *out_mac"
 .Fa "size_t *out_len"
 .Fc
-.Ft int
-.Fn CMAC_resume "CMAC_CTX *ctx"
-.Ft int
-.Fo CMAC_CTX_copy
-.Fa "CMAC_CTX *out_ctx"
-.Fa "CMAC_CTX *in_ctx"
-.Fc
 .Ft EVP_CIPHER_CTX *
 .Fn CMAC_CTX_get0_cipher_ctx "CMAC_CTX *ctx"
 .Ft void
@@ -183,19 +175,6 @@ resulting message authentication code to
 .Fa out_mac .
 The caller is responsible for providing a buffer of sufficient size.
 .Pp
-Calling
-.Fn CMAC_resume
-after
-.Fn CMAC_Final
-allows the user to subsequently append additional data with
-.Fn CMAC_Update .
-Otherwise, unless
-.Fn CMAC_Init
-is called to start from scratch,
-.Fn CMAC_Update
-can no longer be used after
-.Fn CMAC_Final .
-.Pp
 .Fn CMAC_CTX_copy
 performs a deep copy of the already initialized
 .Fa in_ctx
@@ -235,7 +214,6 @@ It succeeds unless memory is exhausted.
 .Fn CMAC_Init ,
 .Fn CMAC_Update ,
 .Fn CMAC_Final ,
-.Fn CMAC_resume ,
 and
 .Fn CMAC_CTX_copy
 return 1 on success or 0 on failure.