Zero key-length for HMAC is apparently OK.
[openssl.git] / crypto / hmac / hmac.c
index 5c349bbb56e47c23375aa2fb23acc139ff359645..16d95e08d52f44cf008f1911291b5308f07ec1f9 100644 (file)
 #include <stdlib.h>
 #include <string.h>
 #include <openssl/hmac.h>
+#include "cryptlib.h"
 
-void HMAC_Init(HMAC_CTX *ctx, const void *key, int len,
-              const EVP_MD *md)
+void HMAC_Init_ex(HMAC_CTX *ctx, const void *key, int len,
+                 const EVP_MD *md, ENGINE *impl)
        {
        int i,j,reset=0;
        unsigned char pad[HMAC_MAX_MD_CBLOCK];
@@ -78,40 +79,51 @@ void HMAC_Init(HMAC_CTX *ctx, const void *key, int len,
                {
                reset=1;
                j=EVP_MD_block_size(md);
+               OPENSSL_assert(j <= (int)sizeof(ctx->key));
                if (j < len)
                        {
-                       EVP_DigestInit(&ctx->md_ctx,md);
+                       EVP_DigestInit_ex(&ctx->md_ctx,md, impl);
                        EVP_DigestUpdate(&ctx->md_ctx,key,len);
-                       EVP_DigestFinal(&(ctx->md_ctx),ctx->key,
+                       EVP_DigestFinal_ex(&(ctx->md_ctx),ctx->key,
                                &ctx->key_length);
                        }
                else
                        {
+                       OPENSSL_assert(len>=0 && len<=(int)sizeof(ctx->key));
                        memcpy(ctx->key,key,len);
-                       memset(&(ctx->key[len]),0,sizeof(ctx->key)-len);
                        ctx->key_length=len;
                        }
+               if(ctx->key_length != HMAC_MAX_MD_CBLOCK)
+                       memset(&ctx->key[ctx->key_length], 0,
+                               HMAC_MAX_MD_CBLOCK - ctx->key_length);
                }
 
        if (reset)      
                {
                for (i=0; i<HMAC_MAX_MD_CBLOCK; i++)
                        pad[i]=0x36^ctx->key[i];
-               EVP_DigestInit(&ctx->i_ctx,md);
+               EVP_DigestInit_ex(&ctx->i_ctx,md, impl);
                EVP_DigestUpdate(&ctx->i_ctx,pad,EVP_MD_block_size(md));
 
                for (i=0; i<HMAC_MAX_MD_CBLOCK; i++)
                        pad[i]=0x5c^ctx->key[i];
-               EVP_DigestInit(&ctx->o_ctx,md);
+               EVP_DigestInit_ex(&ctx->o_ctx,md, impl);
                EVP_DigestUpdate(&ctx->o_ctx,pad,EVP_MD_block_size(md));
                }
+       EVP_MD_CTX_copy_ex(&ctx->md_ctx,&ctx->i_ctx);
+       }
 
-       memcpy(&ctx->md_ctx,&ctx->i_ctx,sizeof(ctx->i_ctx));
+void HMAC_Init(HMAC_CTX *ctx, const void *key, int len,
+              const EVP_MD *md)
+       {
+       if(key && md)
+           HMAC_CTX_init(ctx);
+       HMAC_Init_ex(ctx,key,len,md, NULL);
        }
 
-void HMAC_Update(HMAC_CTX *ctx, unsigned char *data, int len)
+void HMAC_Update(HMAC_CTX *ctx, const unsigned char *data, size_t len)
        {
-       EVP_DigestUpdate(&(ctx->md_ctx),data,len);
+       EVP_DigestUpdate(&ctx->md_ctx,data,len);
        }
 
 void HMAC_Final(HMAC_CTX *ctx, unsigned char *md, unsigned int *len)
@@ -122,29 +134,40 @@ void HMAC_Final(HMAC_CTX *ctx, unsigned char *md, unsigned int *len)
 
        j=EVP_MD_block_size(ctx->md);
 
-       EVP_DigestFinal(&(ctx->md_ctx),buf,&i);
-       memcpy(&(ctx->md_ctx),&(ctx->o_ctx),sizeof(ctx->o_ctx));
-       EVP_DigestUpdate(&(ctx->md_ctx),buf,i);
-       EVP_DigestFinal(&(ctx->md_ctx),md,len);
+       EVP_DigestFinal_ex(&ctx->md_ctx,buf,&i);
+       EVP_MD_CTX_copy_ex(&ctx->md_ctx,&ctx->o_ctx);
+       EVP_DigestUpdate(&ctx->md_ctx,buf,i);
+       EVP_DigestFinal_ex(&ctx->md_ctx,md,len);
+       }
+
+void 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);
        }
 
-void HMAC_cleanup(HMAC_CTX *ctx)
+void HMAC_CTX_cleanup(HMAC_CTX *ctx)
        {
-       memset(ctx,0,sizeof(HMAC_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);
        }
 
 unsigned char *HMAC(const EVP_MD *evp_md, const void *key, int key_len,
-                   unsigned char *d, int n, unsigned char *md,
+                   const unsigned char *d, size_t n, unsigned char *md,
                    unsigned int *md_len)
        {
        HMAC_CTX c;
        static unsigned char m[EVP_MAX_MD_SIZE];
 
        if (md == NULL) md=m;
+       HMAC_CTX_init(&c);
        HMAC_Init(&c,key,key_len,evp_md);
        HMAC_Update(&c,d,n);
        HMAC_Final(&c,md,md_len);
-       HMAC_cleanup(&c);
+       HMAC_CTX_cleanup(&c);
        return(md);
        }