implemented some socket functions

src/cryptography/AES.c

@@ -0,0 +1,125 @@
+#include "cryptography.h"
+#include "BearSSL/inc/bearssl_block.h"
+#include <assert.h>
+
+// size must be multiple of 16
+#define __AES_BUFFER_SIZE 256
+
+typedef struct EncryptorAES {
+    br_aes_ct64_cbcenc_keys enc_ctx;
+    Array buf;
+    Array iv;
+} EncryptorAES;
+
+typedef struct DecryptorAES {
+    br_aes_ct64_cbcdec_keys dec_ctx;
+    Array buf;
+    Array iv;
+} DecryptorAES;
+
+EncryptorAES* EncryptorAES_create(Array key){
+    assert(key.size == 16 || key.size == 24 || key.size == 32);
+    
+    EncryptorAES* ptr = (EncryptorAES*)malloc(sizeof(EncryptorAES));
+    br_aes_ct64_cbcenc_init(&ptr->enc_ctx, key.data, key.size);
+
+    // size must be multiple of 16
+    ptr->buf = Array_alloc(u8, __AES_BUFFER_SIZE);
+    Array_memset(&ptr->buf, 0);
+
+    // size of one SHA block (16 bytes)
+    ptr->iv = Array_alloc(u8, 16); 
+    Array_memset(&ptr->iv, 0);
+
+    return ptr;
+}
+
+void EncryptorAES_destroy(EncryptorAES* ptr){
+    free(ptr->buf.data);
+    free(ptr->iv.data);
+}
+
+void EncryptorAES_encrypt(EncryptorAES* ptr, Array src, Array dst){
+    assert(dst.size >= EncryptorAES_calcDstSize(src.size));
+    
+    const EncryptedBlockInfo block_info = { .padding_size = 16 - src.size % 16 };
+    memcpy(ptr->buf.data, &block_info, sizeof(EncryptedBlockInfo));
+    // encrypt this struct
+    br_aes_ct64_cbcenc_run(&ptr->enc_ctx, ptr->iv.data, ptr->buf.data, sizeof(EncryptedBlockInfo));
+    // emit EncryptedBlockInfo to beginning of result
+    memcpy(dst.data, ptr->buf.data, sizeof(EncryptedBlockInfo));
+    dst.data += sizeof(EncryptedBlockInfo);
+    dst.size -= sizeof(EncryptedBlockInfo);
+    
+    // write full blocks
+    while(src.size > ptr->buf.size){
+        memcpy(ptr->buf.data, src.data, ptr->buf.size);
+        src.data += ptr->buf.size;
+        src.size -= ptr->buf.size;
+        br_aes_ct64_cbcenc_run(&ptr->enc_ctx, ptr->iv.data, ptr->buf.data, ptr->buf.size);
+        memcpy(dst.data, ptr->buf.data, ptr->buf.size);
+        dst.data += ptr->buf.size;
+        dst.size -= ptr->buf.size;
+    }
+    
+    // write incomplete block
+    Array_memset(&ptr->buf, 0);
+    memcpy(ptr->buf.data, src.data, src.size);
+    u32 src_size_padded = src.size + block_info.padding_size;
+    br_aes_ct64_cbcenc_run(&ptr->enc_ctx, ptr->iv.data, ptr->buf.data, src_size_padded);
+    memcpy(dst.data, ptr->buf.data, src_size_padded);
+}
+
+
+DecryptorAES* DecryptorAES_create(Array key){
+    assert(key.size == 16 || key.size == 24 || key.size == 32);
+    
+    DecryptorAES* ptr = (DecryptorAES*)malloc(sizeof(DecryptorAES));
+    br_aes_ct64_cbcdec_init(&ptr->dec_ctx, key.data, key.size);
+
+    // size must be multiple of 16
+    ptr->buf = Array_alloc(u8, __AES_BUFFER_SIZE);
+    Array_memset(&ptr->buf, 0);
+
+    // size of one SHA block (16 bytes)
+    ptr->iv = Array_alloc(u8, 16); 
+    Array_memset(&ptr->iv, 0);
+
+    return ptr;
+}
+
+void DecryptorAES_destroy(DecryptorAES* ptr){
+    free(ptr->buf.data);
+    free(ptr->iv.data);
+}
+
+void DecryptorAES_decrypt(DecryptorAES* ptr, Array src, Array dst, u32* decrypted_size){
+    assert(dst.size >= src.size);
+    
+    // read EncryptedBlockInfo from beginning of data
+    EncryptedBlockInfo block_info;
+    memcpy(&block_info, src.data, sizeof(EncryptedBlockInfo));
+    src.data += sizeof(EncryptedBlockInfo);
+    src.size -= sizeof(EncryptedBlockInfo);
+    // decrypt this struct
+    br_aes_ct64_cbcdec_run(&ptr->dec_ctx, ptr->iv.data, &block_info, sizeof(EncryptedBlockInfo));
+    *decrypted_size = src.size - block_info.padding_size;
+
+    // write full blocks
+    while(src.size > ptr->buf.size){
+        memcpy(ptr->buf.data, src.data, ptr->buf.size);
+        src.data += ptr->buf.size;
+        src.size -= ptr->buf.size;
+        br_aes_ct64_cbcdec_run(&ptr->dec_ctx, ptr->iv.data, ptr->buf.data, ptr->buf.size);
+        memcpy(dst.data, ptr->buf.data, ptr->buf.size);
+        dst.data += ptr->buf.size;
+        dst.size -= ptr->buf.size;
+    }
+    
+    // write incomplete block
+    Array_memset(&ptr->buf, 0);
+    memcpy(ptr->buf.data, src.data, src.size);
+    u32 src_size_padded = src.size + block_info.padding_size;
+    br_aes_ct64_cbcdec_run(&ptr->dec_ctx, ptr->iv.data, ptr->buf.data, src_size_padded);
+    memcpy(dst.data, ptr->buf.data, src_size_padded);
+}