mac: add a getter for the MAC block size.

Fixes #12342
Reviewed-by: NRichard Levitte <levitte@openssl.org>
Reviewed-by: NTomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/15427)

crypto/evp/mac_lib.c

@@ -82,14 +82,14 @@ EVP_MAC *EVP_MAC_CTX_mac(EVP_MAC_CTX *ctx)
     return ctx->meth;
 }
 
-size_t EVP_MAC_CTX_get_mac_size(EVP_MAC_CTX *ctx)
+static size_t get_size_t_ctx_param(EVP_MAC_CTX *ctx, const char *name)
 {
     size_t sz = 0;
 
     if (ctx->algctx != NULL) {
         OSSL_PARAM params[2] = { OSSL_PARAM_END, OSSL_PARAM_END };
 
-        params[0] = OSSL_PARAM_construct_size_t(OSSL_MAC_PARAM_SIZE, &sz);
+        params[0] = OSSL_PARAM_construct_size_t(name, &sz);
         if (ctx->meth->get_ctx_params != NULL) {
             if (ctx->meth->get_ctx_params(ctx->algctx, params))
                 return sz;
@@ -105,6 +105,16 @@ size_t EVP_MAC_CTX_get_mac_size(EVP_MAC_CTX *ctx)
     return 0;
 }
 
+size_t EVP_MAC_CTX_get_mac_size(EVP_MAC_CTX *ctx)
+{
+    return get_size_t_ctx_param(ctx, OSSL_MAC_PARAM_SIZE);
+}
+
+size_t EVP_MAC_CTX_get_block_size(EVP_MAC_CTX *ctx)
+{
+    return get_size_t_ctx_param(ctx, OSSL_MAC_PARAM_BLOCK_SIZE);
+}
+
 int EVP_MAC_init(EVP_MAC_CTX *ctx, const unsigned char *key, size_t keylen,
                  const OSSL_PARAM params[])
 {

include/openssl/core_names.h

@@ -169,6 +169,7 @@ extern "C" {
 #define OSSL_MAC_PARAM_DIGEST           OSSL_ALG_PARAM_DIGEST     /* utf8 string */
 #define OSSL_MAC_PARAM_PROPERTIES       OSSL_ALG_PARAM_PROPERTIES /* utf8 string */
 #define OSSL_MAC_PARAM_SIZE             "size"                    /* size_t */
+#define OSSL_MAC_PARAM_BLOCK_SIZE       "block-size"              /* size_t */
 #define OSSL_MAC_PARAM_TLS_DATA_SIZE    "tls-data-size"           /* size_t */
 
 /* Known MAC names */

include/openssl/evp.h

@@ -1179,6 +1179,7 @@ int EVP_MAC_CTX_get_params(EVP_MAC_CTX *ctx, OSSL_PARAM params[]);
 int EVP_MAC_CTX_set_params(EVP_MAC_CTX *ctx, const OSSL_PARAM params[]);
 
 size_t EVP_MAC_CTX_get_mac_size(EVP_MAC_CTX *ctx);
+size_t EVP_MAC_CTX_get_block_size(EVP_MAC_CTX *ctx);
 unsigned char *EVP_Q_mac(OSSL_LIB_CTX *libctx, const char *name, const char *propq,
                          const char *subalg, const OSSL_PARAM *params,
                          const void *key, size_t keylen,

providers/implementations/macs/blake2_mac_impl.c

@@ -146,6 +146,7 @@ static int blake2_mac_final(void *vmacctx,
 
 static const OSSL_PARAM known_gettable_ctx_params[] = {
     OSSL_PARAM_size_t(OSSL_MAC_PARAM_SIZE, NULL),
+    OSSL_PARAM_size_t(OSSL_MAC_PARAM_BLOCK_SIZE, NULL),
     OSSL_PARAM_END
 };
 static const OSSL_PARAM *blake2_gettable_ctx_params(ossl_unused void *ctx,
@@ -158,8 +159,13 @@ static int blake2_get_ctx_params(void *vmacctx, OSSL_PARAM params[])
 {
     OSSL_PARAM *p;
 
-    if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_SIZE)) != NULL)
-        return OSSL_PARAM_set_size_t(p, blake2_mac_size(vmacctx));
+    if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_SIZE)) != NULL
+            && !OSSL_PARAM_set_size_t(p, blake2_mac_size(vmacctx)))
+        return 0;
+
+    if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_BLOCK_SIZE)) != NULL
+            && !OSSL_PARAM_set_size_t(p, BLAKE2_BLOCKBYTES))
+        return 0;
 
     return 1;
 }

providers/implementations/macs/blake2b_mac.c

@@ -14,6 +14,7 @@
 #define BLAKE2_OUTBYTES BLAKE2B_OUTBYTES
 #define BLAKE2_PERSONALBYTES BLAKE2B_PERSONALBYTES
 #define BLAKE2_SALTBYTES BLAKE2B_SALTBYTES
+#define BLAKE2_BLOCKBYTES BLAKE2B_BLOCKBYTES
 
 /* Function names */
 #define BLAKE2_PARAM_INIT ossl_blake2b_param_init

providers/implementations/macs/blake2s_mac.c

@@ -14,6 +14,7 @@
 #define BLAKE2_OUTBYTES BLAKE2S_OUTBYTES
 #define BLAKE2_PERSONALBYTES BLAKE2S_PERSONALBYTES
 #define BLAKE2_SALTBYTES BLAKE2S_SALTBYTES
+#define BLAKE2_BLOCKBYTES BLAKE2S_BLOCKBYTES
 
 /* Function names */
 #define BLAKE2_PARAM_INIT ossl_blake2s_param_init

providers/implementations/macs/cmac_prov.c

@@ -145,6 +145,7 @@ static int cmac_final(void *vmacctx, unsigned char *out, size_t *outl,
 
 static const OSSL_PARAM known_gettable_ctx_params[] = {
     OSSL_PARAM_size_t(OSSL_MAC_PARAM_SIZE, NULL),
+    OSSL_PARAM_size_t(OSSL_MAC_PARAM_BLOCK_SIZE, NULL),
     OSSL_PARAM_END
 };
 static const OSSL_PARAM *cmac_gettable_ctx_params(ossl_unused void *ctx,
@@ -157,8 +158,13 @@ static int cmac_get_ctx_params(void *vmacctx, OSSL_PARAM params[])
 {
     OSSL_PARAM *p;
 
-    if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_SIZE)) != NULL)
-        return OSSL_PARAM_set_size_t(p, cmac_size(vmacctx));
+    if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_SIZE)) != NULL
+            && !OSSL_PARAM_set_size_t(p, cmac_size(vmacctx)))
+        return 0;
+
+    if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_BLOCK_SIZE)) != NULL
+            && !OSSL_PARAM_set_size_t(p, cmac_size(vmacctx)))
+        return 0;
 
     return 1;
 }

providers/implementations/macs/hmac_prov.c

@@ -134,13 +134,20 @@ static void *hmac_dup(void *vsrc)
     return dst;
 }
 
-static size_t hmac_size(void *vmacctx)
+static size_t hmac_size(struct hmac_data_st *macctx)
 {
-    struct hmac_data_st *macctx = vmacctx;
-
     return HMAC_size(macctx->ctx);
 }
 
+static int hmac_block_size(struct hmac_data_st *macctx)
+{
+    const EVP_MD *md = ossl_prov_digest_md(&macctx->digest);
+
+    if (md == NULL)
+        return 0;
+    return EVP_MD_block_size(md);
+}
+
 static int hmac_setkey(struct hmac_data_st *macctx,
                        const unsigned char *key, size_t keylen)
 {
@@ -234,6 +241,7 @@ static int hmac_final(void *vmacctx, unsigned char *out, size_t *outl,
 
 static const OSSL_PARAM known_gettable_ctx_params[] = {
     OSSL_PARAM_size_t(OSSL_MAC_PARAM_SIZE, NULL),
+    OSSL_PARAM_size_t(OSSL_MAC_PARAM_BLOCK_SIZE, NULL),
     OSSL_PARAM_END
 };
 static const OSSL_PARAM *hmac_gettable_ctx_params(ossl_unused void *ctx,
@@ -244,10 +252,16 @@ static const OSSL_PARAM *hmac_gettable_ctx_params(ossl_unused void *ctx,
 
 static int hmac_get_ctx_params(void *vmacctx, OSSL_PARAM params[])
 {
+    struct hmac_data_st *macctx = vmacctx;
     OSSL_PARAM *p;
 
-    if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_SIZE)) != NULL)
-        return OSSL_PARAM_set_size_t(p, hmac_size(vmacctx));
+    if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_SIZE)) != NULL
+            && !OSSL_PARAM_set_size_t(p, hmac_size(macctx)))
+        return 0;
+
+    if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_BLOCK_SIZE)) != NULL
+            && !OSSL_PARAM_set_int(p, hmac_block_size(macctx)))
+        return 0;
 
     return 1;
 }

providers/implementations/macs/kmac_prov.c

@@ -239,13 +239,6 @@ static void *kmac_dup(void *vsrc)
     return dst;
 }
 
-static size_t kmac_size(void *vmacctx)
-{
-    struct kmac_data_st *kctx = vmacctx;
-
-    return kctx->out_len;
-}
-
 static int kmac_setkey(struct kmac_data_st *kctx, const unsigned char *key,
                        size_t keylen)
 {
@@ -361,6 +354,7 @@ static int kmac_final(void *vmacctx, unsigned char *out, size_t *outl,
 
 static const OSSL_PARAM known_gettable_ctx_params[] = {
     OSSL_PARAM_size_t(OSSL_MAC_PARAM_SIZE, NULL),
+    OSSL_PARAM_size_t(OSSL_MAC_PARAM_BLOCK_SIZE, NULL),
     OSSL_PARAM_END
 };
 static const OSSL_PARAM *kmac_gettable_ctx_params(ossl_unused void *ctx,
@@ -371,10 +365,19 @@ static const OSSL_PARAM *kmac_gettable_ctx_params(ossl_unused void *ctx,
 
 static int kmac_get_ctx_params(void *vmacctx, OSSL_PARAM params[])
 {
+    struct kmac_data_st *kctx = vmacctx;
     OSSL_PARAM *p;
+    int sz;
+
+    if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_SIZE)) != NULL
+            && !OSSL_PARAM_set_size_t(p, kctx->out_len))
+        return 0;
 
-    if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_SIZE)) != NULL)
-        return OSSL_PARAM_set_size_t(p, kmac_size(vmacctx));
+    if ((p = OSSL_PARAM_locate(params, OSSL_MAC_PARAM_BLOCK_SIZE)) != NULL) {
+        sz = EVP_MD_block_size(ossl_prov_digest_md(&kctx->digest));
+        if (!OSSL_PARAM_set_int(p, sz))
+            return 0;
+    }
 
     return 1;
 }

util/libcrypto.num

@@ -5414,3 +5414,4 @@ OSSL_LIB_CTX_new_from_dispatch          5541	3_0_0	EXIST::FUNCTION:
 OSSL_LIB_CTX_new_child                  5542	3_0_0	EXIST::FUNCTION:
 OSSL_PROVIDER_get0_dispatch             5543	3_0_0	EXIST::FUNCTION:
 PKCS5_PBE_keyivgen_ex                   5544	3_0_0	EXIST::FUNCTION:
+EVP_MAC_CTX_get_block_size              5545	3_0_0	EXIST::FUNCTION: