1 files changed, 18 insertions, 4 deletions

diff --git a/src/lib/libcrypto/hmac/hmac.c b/src/lib/libcrypto/hmac/hmac.c
index 8fd980b052..84917662ca 100644
--- a/src/lib/libcrypto/hmac/hmac.c
+++ b/src/lib/libcrypto/hmac/hmac.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: hmac.c,v 1.23 2017/01/29 17:49:23 beck Exp $ */
+/* $OpenBSD: hmac.c,v 1.24 2017/03/03 10:39:07 inoguchi Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -70,11 +70,17 @@ HMAC_Init_ex(HMAC_CTX *ctx, const void *key, int len, const EVP_MD *md,
         int i, j, reset = 0;
         unsigned char pad[HMAC_MAX_MD_CBLOCK];
 
+        /* If we are changing MD then we must have a key */
+        if (md != NULL && md != ctx->md && (key == NULL || len < 0))
+                return 0;
+
         if (md != NULL) {
                 reset = 1;
                 ctx->md = md;
-        } else
+        } else if (ctx->md != NULL)
                 md = ctx->md;
+        else
+                return 0;
 
         if (key != NULL) {
                 reset = 1;
@@ -92,7 +98,7 @@ HMAC_Init_ex(HMAC_CTX *ctx, const void *key, int len, const EVP_MD *md,
                             &ctx->key_length))
                                 goto err;
                 } else {
-                        if ((size_t)len > sizeof(ctx->key)) {
+                        if (len < 0 || (size_t)len > sizeof(ctx->key)) {
                                 EVPerror(EVP_R_BAD_KEY_LENGTH);
                                 goto err;
                         }
@@ -137,6 +143,9 @@ HMAC_Init(HMAC_CTX *ctx, const void *key, int len, const EVP_MD *md)
 int
 HMAC_Update(HMAC_CTX *ctx, const unsigned char *data, size_t len)
 {
+        if (ctx->md == NULL)
+                return 0;
+
         return EVP_DigestUpdate(&ctx->md_ctx, data, len);
 }
 
@@ -146,6 +155,9 @@ HMAC_Final(HMAC_CTX *ctx, unsigned char *md, unsigned int *len)
         unsigned int i;
         unsigned char buf[EVP_MAX_MD_SIZE];
 
+        if (ctx->md == NULL)
+                goto err;
+
         if (!EVP_DigestFinal_ex(&ctx->md_ctx, buf, &i))
                 goto err;
         if (!EVP_MD_CTX_copy_ex(&ctx->md_ctx, &ctx->o_ctx))
@@ -165,6 +177,7 @@ HMAC_CTX_init(HMAC_CTX *ctx)
         EVP_MD_CTX_init(&ctx->i_ctx);
         EVP_MD_CTX_init(&ctx->o_ctx);
         EVP_MD_CTX_init(&ctx->md_ctx);
+        ctx->md = NULL;
 }
 
 int
@@ -190,7 +203,7 @@ HMAC_CTX_cleanup(HMAC_CTX *ctx)
         EVP_MD_CTX_cleanup(&ctx->i_ctx);
         EVP_MD_CTX_cleanup(&ctx->o_ctx);
         EVP_MD_CTX_cleanup(&ctx->md_ctx);
-        memset(ctx, 0, sizeof *ctx);
+        explicit_bzero(ctx, sizeof(*ctx));
 }
 
 unsigned char *
@@ -212,6 +225,7 @@ HMAC(const EVP_MD *evp_md, const void *key, int key_len, const unsigned char *d,
         HMAC_CTX_cleanup(&c);
         return md;
 err:
+        HMAC_CTX_cleanup(&c);
         return NULL;
 }