Milestone 5: deliver embedded RDP sessions and lifecycle hardening

third_party/FreeRDP/winpr/libwinpr/crypto/hmac_md5.c

@@ -0,0 +1,56 @@
+#include <assert.h>
+#include <string.h>
+
+#include "hmac_md5.h"
+#include "md5.h"
+
+void hmac_md5_init(WINPR_HMAC_MD5_CTX* ctx, const unsigned char* key, size_t key_len)
+{
+	const WINPR_HMAC_MD5_CTX empty = WINPR_C_ARRAY_INIT;
+	unsigned char k_ipad[KEY_IOPAD_SIZE] = WINPR_C_ARRAY_INIT;
+	unsigned char k_opad[KEY_IOPAD_SIZE] = WINPR_C_ARRAY_INIT;
+
+	assert(ctx);
+	*ctx = empty;
+
+	if (key_len <= KEY_IOPAD_SIZE)
+	{
+		memcpy(k_ipad, key, key_len);
+		memcpy(k_opad, key, key_len);
+	}
+	else
+	{
+		WINPR_MD5_CTX lctx = WINPR_C_ARRAY_INIT;
+
+		winpr_MD5_Init(&lctx);
+		winpr_MD5_Update(&lctx, key, key_len);
+		winpr_MD5_Final(k_ipad, &lctx);
+		memcpy(k_opad, k_ipad, KEY_IOPAD_SIZE);
+	}
+	for (size_t i = 0; i < KEY_IOPAD_SIZE; i++)
+	{
+		k_ipad[i] ^= 0x36;
+		k_opad[i] ^= 0x5c;
+	}
+
+	winpr_MD5_Init(&ctx->icontext);
+	winpr_MD5_Update(&ctx->icontext, k_ipad, KEY_IOPAD_SIZE);
+
+	winpr_MD5_Init(&ctx->ocontext);
+	winpr_MD5_Update(&ctx->ocontext, k_opad, KEY_IOPAD_SIZE);
+}
+
+void hmac_md5_update(WINPR_HMAC_MD5_CTX* ctx, const unsigned char* text, size_t text_len)
+{
+	assert(ctx);
+	winpr_MD5_Update(&ctx->icontext, text, text_len);
+}
+
+void hmac_md5_finalize(WINPR_HMAC_MD5_CTX* ctx, unsigned char* hmac)
+{
+	assert(ctx);
+	winpr_MD5_Final(hmac, &ctx->icontext);
+
+	winpr_MD5_Update(&ctx->ocontext, hmac, 16);
+	winpr_MD5_Final(hmac, &ctx->ocontext);
+}