Remove EVP_PKEY_HMAC.

This removes EVP_PKEY_HMAC and all the support code around it. EVP_MD requires
a lot of extra glue to support HMAC. This lets us prune it all away.

As a bonus, it removes a (minor) dependency from EVP to the legacy ASN.1 stack.

Change-Id: I5a9e3e39f518429828dbf13d14647fb37d9dc35a
Reviewed-on: https://boringssl-review.googlesource.com/5120
Reviewed-by: Adam Langley <agl@google.com>

2 files changed, 4 insertions, 33 deletions

diff --git a/crypto/digest/digest.c b/crypto/digest/digest.c
index f09948bb..4096fc53 100644
--- a/crypto/digest/digest.c
+++ b/crypto/digest/digest.c
@@ -164,12 +164,11 @@ int EVP_MD_CTX_copy(EVP_MD_CTX *out, const EVP_MD_CTX *in) {
 
 int EVP_DigestInit_ex(EVP_MD_CTX *ctx, const EVP_MD *type, ENGINE *engine) {
   if (ctx->digest != type) {
-    if (ctx->digest && ctx->digest->ctx_size) {
+    if (ctx->digest && ctx->digest->ctx_size > 0) {
       OPENSSL_free(ctx->md_data);
     }
     ctx->digest = type;
-    if (!(ctx->flags & EVP_MD_CTX_FLAG_NO_INIT) && type->ctx_size) {
-      ctx->update = type->update;
+    if (type->ctx_size > 0) {
       ctx->md_data = OPENSSL_malloc(type->ctx_size);
       if (ctx->md_data == NULL) {
         OPENSSL_PUT_ERROR(DIGEST, EVP_DigestInit_ex, ERR_R_MALLOC_FAILURE);
@@ -179,15 +178,6 @@ int EVP_DigestInit_ex(EVP_MD_CTX *ctx, const EVP_MD *type, ENGINE *engine) {
   }
 
   assert(ctx->pctx == NULL || ctx->pctx_ops != NULL);
-  if (ctx->pctx_ops) {
-    if (!ctx->pctx_ops->begin_digest(ctx)) {
-      return 0;
-    }
-  }
-
-  if (ctx->flags & EVP_MD_CTX_FLAG_NO_INIT) {
-    return 1;
-  }
 
   ctx->digest->init(ctx);
   return 1;
@@ -199,7 +189,7 @@ int EVP_DigestInit(EVP_MD_CTX *ctx, const EVP_MD *type) {
 }
 
 int EVP_DigestUpdate(EVP_MD_CTX *ctx, const void *data, size_t len) {
-  ctx->update(ctx, data, len);
+  ctx->digest->update(ctx, data, len);
   return 1;
 }
 
@@ -253,10 +243,6 @@ int EVP_MD_CTX_type(const EVP_MD_CTX *ctx) {
   return EVP_MD_type(EVP_MD_CTX_md(ctx));
 }
 
-void EVP_MD_CTX_set_flags(EVP_MD_CTX *ctx, uint32_t flags) {
-  ctx->flags |= flags;
-}
-
 int EVP_add_digest(const EVP_MD *digest) {
   return 1;
 }
diff --git a/crypto/digest/internal.h b/crypto/digest/internal.h
index 1572fa82..e3d812ad 100644
--- a/crypto/digest/internal.h
+++ b/crypto/digest/internal.h
@@ -92,7 +92,7 @@ struct env_md_st {
 };
 
 /* evp_md_pctx_ops contains function pointers to allow the |pctx| member of
- * |EVP_MD_CTX| to be manipulated without breaking laying by calling EVP
+ * |EVP_MD_CTX| to be manipulated without breaking layering by calling EVP
  * functions. */
 struct evp_md_pctx_ops {
   /* free is called when an |EVP_MD_CTX| is being freed and the |pctx| also
@@ -102,23 +102,8 @@ struct evp_md_pctx_ops {
   /* dup is called when an |EVP_MD_CTX| is copied and so the |pctx| also needs
    * to be copied. */
   EVP_PKEY_CTX* (*dup) (EVP_PKEY_CTX *pctx);
-
-  /* begin_digest is called when a new digest operation is started. It returns
-   * one on success and zero otherwise. */
-  int (*begin_digest) (EVP_MD_CTX *ctx);
 };
 
-/* EVP_MD_CTX_set_flags ORs |flags| into the flags member of |ctx|. */
-OPENSSL_EXPORT void EVP_MD_CTX_set_flags(EVP_MD_CTX *ctx, uint32_t flags);
-
-/* EVP_MD_CTX_FLAG_NO_INIT causes the |EVP_MD|'s |init| function not to be
- * called, the |update| member not to be copied from the |EVP_MD| in
- * |EVP_DigestInit_ex| and for |md_data| not to be initialised.
- *
- * TODO(davidben): This is an implementation detail of |EVP_PKEY_HMAC| and can
- * be removed when it is gone. */
-#define EVP_MD_CTX_FLAG_NO_INIT 1
-
 
 #if defined(__cplusplus)
 }  /* extern C */