sha2: Write final hash directly to output buffer

This avoids having the last output in internal memory that's not wiped.

References #2388.

diff --git a/src/libstrongswan/plugins/sha2/sha2_hasher.c b/src/libstrongswan/plugins/sha2/sha2_hasher.c
index 89e7675..2c56a2f 100644 (file)
--- a/src/libstrongswan/plugins/sha2/sha2_hasher.c
+++ b/src/libstrongswan/plugins/sha2/sha2_hasher.c
@@ -226,7 +226,7 @@ static void sha256_write(private_sha256_hasher_t *ctx,
 /**
  * finalize SHA256 hash
  */
-static void sha256_final(private_sha256_hasher_t *ctx)
+static void sha256_final(private_sha256_hasher_t *ctx, u_char *buf, size_t len)
 {
        register int    j;
        uint64_t       bitLength;
@@ -255,8 +255,7 @@ static void sha256_final(private_sha256_hasher_t *ctx)
        ctx->sha_out[63] = bitLength;
        sha256_transform(ctx, &ctx->sha_out[0]);
 
-       /* return results in ctx->sha_out[0...31] */
-       datap = &ctx->sha_out[0];
+       datap = buf;
        j = 0;
        do {
                i = ctx->sha_H[j];
@@ -265,7 +264,7 @@ static void sha256_final(private_sha256_hasher_t *ctx)
                datap[2] = i >> 8;
                datap[3] = i;
                datap += 4;
-       } while(++j < 8);
+       } while(++j < len / 4);
 }
 
 /* update macros for SHA512 */
@@ -371,7 +370,7 @@ static void sha512_write(private_sha512_hasher_t *ctx,
 /**
  * Finalize a SHA384/SHA512 hash
  */
-static void sha512_final(private_sha512_hasher_t *ctx)
+static void sha512_final(private_sha512_hasher_t *ctx, u_char *buf, size_t len)
 {
        register int    j;
        uint64_t       bitLength, bitLengthMSB;
@@ -409,8 +408,7 @@ static void sha512_final(private_sha512_hasher_t *ctx)
        ctx->sha_out[127] = bitLength;
        sha512_transform(ctx, &ctx->sha_out[0]);
 
-       /* return results in ctx->sha_out[0...63] */
-       datap = &ctx->sha_out[0];
+       datap = buf;
        j = 0;
        do {
                i = ctx->sha_H[j];
@@ -423,7 +421,7 @@ static void sha512_final(private_sha512_hasher_t *ctx)
                datap[6] = i >> 8;
                datap[7] = i;
                datap += 8;
-       } while(++j < 8);
+       } while(++j < len / 8);
 }
 
 METHOD(hasher_t, reset224, bool,
@@ -432,7 +430,6 @@ METHOD(hasher_t, reset224, bool,
        memcpy(&this->sha_H[0], &sha224_hashInit[0], sizeof(this->sha_H));
        this->sha_blocks = 0;
        this->sha_bufCnt = 0;
-
        return TRUE;
 }
 
@@ -442,7 +439,6 @@ METHOD(hasher_t, reset256, bool,
        memcpy(&this->sha_H[0], &sha256_hashInit[0], sizeof(this->sha_H));
        this->sha_blocks = 0;
        this->sha_bufCnt = 0;
-
        return TRUE;
 }
 
@@ -453,7 +449,6 @@ METHOD(hasher_t, reset384, bool,
        this->sha_blocks = 0;
        this->sha_blocksMSB = 0;
        this->sha_bufCnt = 0;
-
        return TRUE;
 }
 
@@ -464,7 +459,6 @@ METHOD(hasher_t, reset512, bool,
        this->sha_blocks = 0;
        this->sha_blocksMSB = 0;
        this->sha_bufCnt = 0;
-
        return TRUE;
 }
 
@@ -474,8 +468,7 @@ METHOD(hasher_t, get_hash224, bool,
        sha256_write(this, chunk.ptr, chunk.len);
        if (buffer != NULL)
        {
-               sha256_final(this);
-               memcpy(buffer, this->sha_out, HASH_SIZE_SHA224);
+               sha256_final(this, buffer, HASH_SIZE_SHA224);
                reset224(this);
        }
        return TRUE;
@@ -487,8 +480,7 @@ METHOD(hasher_t, get_hash256, bool,
        sha256_write(this, chunk.ptr, chunk.len);
        if (buffer != NULL)
        {
-               sha256_final(this);
-               memcpy(buffer, this->sha_out, HASH_SIZE_SHA256);
+               sha256_final(this, buffer, HASH_SIZE_SHA256);
                reset256(this);
        }
        return TRUE;
@@ -500,8 +492,7 @@ METHOD(hasher_t, get_hash384, bool,
        sha512_write(this, chunk.ptr, chunk.len);
        if (buffer != NULL)
        {
-               sha512_final(this);
-               memcpy(buffer, this->sha_out, HASH_SIZE_SHA384);
+               sha512_final(this, buffer, HASH_SIZE_SHA384);
                reset384(this);
        }
        return TRUE;
@@ -513,8 +504,7 @@ METHOD(hasher_t, get_hash512, bool,
        sha512_write(this, chunk.ptr, chunk.len);
        if (buffer != NULL)
        {
-               sha512_final(this);
-               memcpy(buffer, this->sha_out, HASH_SIZE_SHA512);
+               sha512_final(this, buffer, HASH_SIZE_SHA512);
                reset512(this);
        }
        return TRUE;
@@ -523,69 +513,49 @@ METHOD(hasher_t, get_hash512, bool,
 METHOD(hasher_t, allocate_hash224, bool,
        private_sha256_hasher_t *this, chunk_t chunk, chunk_t *hash)
 {
-       chunk_t allocated_hash;
+       chunk_t allocated_hash = chunk_empty;
 
-       sha256_write(this, chunk.ptr, chunk.len);
-       if (hash != NULL)
+       if (hash)
        {
-               sha256_final(this);
-               allocated_hash = chunk_alloc(HASH_SIZE_SHA224);
-               memcpy(allocated_hash.ptr, this->sha_out, HASH_SIZE_SHA224);
-               reset224(this);
-               *hash = allocated_hash;
+               *hash = allocated_hash = chunk_alloc(HASH_SIZE_SHA224);
        }
-       return TRUE;
+       return get_hash224(this, chunk, allocated_hash.ptr);
 }
 
 METHOD(hasher_t, allocate_hash256, bool,
        private_sha256_hasher_t *this, chunk_t chunk, chunk_t *hash)
 {
-       chunk_t allocated_hash;
+       chunk_t allocated_hash = chunk_empty;
 
-       sha256_write(this, chunk.ptr, chunk.len);
-       if (hash != NULL)
+       if (hash)
        {
-               sha256_final(this);
-               allocated_hash = chunk_alloc(HASH_SIZE_SHA256);
-               memcpy(allocated_hash.ptr, this->sha_out, HASH_SIZE_SHA256);
-               reset256(this);
-               *hash = allocated_hash;
+               *hash = allocated_hash = chunk_alloc(HASH_SIZE_SHA256);
        }
-       return TRUE;
+       return get_hash256(this, chunk, allocated_hash.ptr);
 }
 
 METHOD(hasher_t, allocate_hash384, bool,
        private_sha512_hasher_t *this, chunk_t chunk, chunk_t *hash)
 {
-       chunk_t allocated_hash;
+       chunk_t allocated_hash = chunk_empty;
 
-       sha512_write(this, chunk.ptr, chunk.len);
-       if (hash != NULL)
+       if (hash)
        {
-               sha512_final(this);
-               allocated_hash = chunk_alloc(HASH_SIZE_SHA384);
-               memcpy(allocated_hash.ptr, this->sha_out, HASH_SIZE_SHA384);
-               reset384(this);
-               *hash = allocated_hash;
+               *hash = allocated_hash = chunk_alloc(HASH_SIZE_SHA384);
        }
-       return TRUE;
+       return get_hash384(this, chunk, allocated_hash.ptr);
 }
 
 METHOD(hasher_t, allocate_hash512, bool,
        private_sha512_hasher_t *this, chunk_t chunk, chunk_t *hash)
 {
-       chunk_t allocated_hash;
+       chunk_t allocated_hash = chunk_empty;
 
-       sha512_write(this, chunk.ptr, chunk.len);
-       if (hash != NULL)
+       if (hash)
        {
-               sha512_final(this);
-               allocated_hash = chunk_alloc(HASH_SIZE_SHA512);
-               memcpy(allocated_hash.ptr, this->sha_out, HASH_SIZE_SHA512);
-               reset512(this);
-               *hash = allocated_hash;
+               *hash = allocated_hash = chunk_alloc(HASH_SIZE_SHA512);
        }
-       return TRUE;
+       return get_hash512(this, chunk, allocated_hash.ptr);
 }
 
 METHOD(hasher_t, get_hash_size224, size_t,