Simplify EVP AES code for ECB.

AES_ecb_encrypt() does not really do ECB - provide an
aes_ecb_encrypt_internal that actually does multiple blocks and call this
from aes_ecb_cipher(). Provide ECB with its own key initialisation
function, which allows aes_init_key() to be simplified considerably.
The block function pointer is now unused, so mop this up.

ok joshua@ tb@

2 files changed, 46 insertions, 33 deletions

diff --git a/src/lib/libcrypto/aes/aes.c b/src/lib/libcrypto/aes/aes.c
index 712168e9fa..1c1c61a7a9 100644
--- a/src/lib/libcrypto/aes/aes.c
+++ b/src/lib/libcrypto/aes/aes.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: aes.c,v 1.6 2025/05/19 04:01:07 jsing Exp $ */
+/* $OpenBSD: aes.c,v 1.7 2025/05/19 04:32:51 jsing Exp $ */
 /* ====================================================================
  * Copyright (c) 2002-2006 The OpenSSL Project.  All rights reserved.
  *
@@ -191,6 +191,18 @@ AES_ecb_encrypt(const unsigned char *in, unsigned char *out,
 LCRYPTO_ALIAS(AES_ecb_encrypt);
 
 void
+aes_ecb_encrypt_internal(const unsigned char *in, unsigned char *out,
+    size_t len, const AES_KEY *key, int encrypt)
+{
+        while (len >= AES_BLOCK_SIZE) {
+                AES_ecb_encrypt(in, out, key, encrypt);
+                in += AES_BLOCK_SIZE;
+                out += AES_BLOCK_SIZE;
+                len -= AES_BLOCK_SIZE;
+        }
+}
+
+void
 AES_ofb128_encrypt(const unsigned char *in, unsigned char *out, size_t length,
     const AES_KEY *key, unsigned char *ivec, int *num)
 {
diff --git a/src/lib/libcrypto/evp/e_aes.c b/src/lib/libcrypto/evp/e_aes.c
index d0bcb2b3dd..bfdfed8172 100644
--- a/src/lib/libcrypto/evp/e_aes.c
+++ b/src/lib/libcrypto/evp/e_aes.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: e_aes.c,v 1.67 2025/05/19 03:55:09 jsing Exp $ */
+/* $OpenBSD: e_aes.c,v 1.68 2025/05/19 04:32:52 jsing Exp $ */
 /* ====================================================================
  * Copyright (c) 2001-2011 The OpenSSL Project.  All rights reserved.
  *
@@ -67,7 +67,6 @@
 
 typedef struct {
         AES_KEY ks;
-        block128_f block;
 } EVP_AES_KEY;
 
 typedef struct {
@@ -104,6 +103,9 @@ typedef struct {
 
 #define MAXBITCHUNK     ((size_t)1<<(sizeof(size_t)*8-4))
 
+void aes_ecb_encrypt_internal(const unsigned char *in, unsigned char *out,
+    size_t len, const AES_KEY *key, int encrypt);
+
 #ifdef AES_XTS_ASM
 void AES_xts_encrypt(const char *inp, char *out, size_t len,
     const AES_KEY *key1, const AES_KEY *key2, const unsigned char iv[16]);
@@ -164,7 +166,6 @@ aesni_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
     const unsigned char *iv, int enc)
 {
         int ret, mode;
-        EVP_AES_KEY *dat = (EVP_AES_KEY *)ctx->cipher_data;
 
         mode = ctx->cipher->flags & EVP_CIPH_MODE;
 
@@ -172,11 +173,9 @@ aesni_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
             !enc) {
                 ret = aesni_set_decrypt_key(key, ctx->key_len * 8,
                     ctx->cipher_data);
-                dat->block = (block128_f)aesni_decrypt;
         } else {
                 ret = aesni_set_encrypt_key(key, ctx->key_len * 8,
                     ctx->cipher_data);
-                dat->block = (block128_f)aesni_encrypt;
         }
 
         if (ret < 0) {
@@ -267,9 +266,7 @@ static int
 aesni_ecb_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
     const unsigned char *in, size_t len)
 {
-        size_t  bl = ctx->cipher->block_size;
-
-        if (len < bl)
+        if (len < ctx->cipher->block_size)
                 return 1;
 
         aesni_ecb_encrypt(in, out, len, ctx->cipher_data, ctx->encrypt);
@@ -390,20 +387,9 @@ static int
 aes_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
     const unsigned char *iv, int enc)
 {
-        int ret, mode;
-        EVP_AES_KEY *dat = (EVP_AES_KEY *)ctx->cipher_data;
-
-        mode = ctx->cipher->flags & EVP_CIPH_MODE;
-
-        if ((mode == EVP_CIPH_ECB_MODE || mode == EVP_CIPH_CBC_MODE) && !enc) {
-                ret = AES_set_decrypt_key(key, ctx->key_len * 8, &dat->ks);
-                dat->block = (block128_f)AES_decrypt;
-        } else {
-                ret = AES_set_encrypt_key(key, ctx->key_len * 8, &dat->ks);
-                dat->block = (block128_f)AES_encrypt;
-        }
+        EVP_AES_KEY *eak = ctx->cipher_data;
 
-        if (ret < 0) {
+        if (AES_set_encrypt_key(key, ctx->key_len * 8, &eak->ks) < 0) {
                 EVPerror(EVP_R_AES_KEY_SETUP_FAILED);
                 return 0;
         }
@@ -444,18 +430,33 @@ aes_cbc_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
 }
 
 static int
+aes_ecb_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
+    const unsigned char *iv, int encrypt)
+{
+        EVP_AES_KEY *eak = ctx->cipher_data;
+
+        if (encrypt) {
+                if (AES_set_encrypt_key(key, ctx->key_len * 8, &eak->ks) < 0) {
+                        EVPerror(EVP_R_AES_KEY_SETUP_FAILED);
+                        return 0;
+                }
+        } else {
+                if (AES_set_decrypt_key(key, ctx->key_len * 8, &eak->ks) < 0) {
+                        EVPerror(EVP_R_AES_KEY_SETUP_FAILED);
+                        return 0;
+                }
+        }
+
+        return 1;
+}
+
+static int
 aes_ecb_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
     const unsigned char *in, size_t len)
 {
-        size_t  bl = ctx->cipher->block_size;
-        size_t  i;
-        EVP_AES_KEY *dat = (EVP_AES_KEY *)ctx->cipher_data;
-
-        if (len < bl)
-                return 1;
+        EVP_AES_KEY *eak = ctx->cipher_data;
 
-        for (i = 0, len -= bl; i <= len; i += bl)
-                (*dat->block)(in + i, out + i, &dat->ks);
+        aes_ecb_encrypt_internal(in, out, len, &eak->ks, ctx->encrypt);
 
         return 1;
 }
@@ -590,7 +591,7 @@ static const EVP_CIPHER aes_128_ecb = {
         .key_len = 16,
         .iv_len = 0,
         .flags = EVP_CIPH_FLAG_DEFAULT_ASN1 | EVP_CIPH_ECB_MODE,
-        .init = aes_init_key,
+        .init = aes_ecb_init_key,
         .do_cipher = aes_ecb_cipher,
         .ctx_size = sizeof(EVP_AES_KEY),
 };
@@ -836,7 +837,7 @@ static const EVP_CIPHER aes_192_ecb = {
         .key_len = 24,
         .iv_len = 0,
         .flags = EVP_CIPH_FLAG_DEFAULT_ASN1 | EVP_CIPH_ECB_MODE,
-        .init = aes_init_key,
+        .init = aes_ecb_init_key,
         .do_cipher = aes_ecb_cipher,
         .ctx_size = sizeof(EVP_AES_KEY),
 };
@@ -1082,7 +1083,7 @@ static const EVP_CIPHER aes_256_ecb = {
         .key_len = 32,
         .iv_len = 0,
         .flags = EVP_CIPH_FLAG_DEFAULT_ASN1 | EVP_CIPH_ECB_MODE,
-        .init = aes_init_key,
+        .init = aes_ecb_init_key,
         .do_cipher = aes_ecb_cipher,
         .ctx_size = sizeof(EVP_AES_KEY),
 };