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mirror of https://github.com/esphome/esphome.git synced 2025-04-15 07:10:33 +01:00
David Woodhouse a0c54504cd
Add HMAC-MD5 support for authenticating OTA updates (#7200)
Co-authored-by: Jesse Hills <3060199+jesserockz@users.noreply.github.com>
2024-08-16 11:27:23 +12:00

57 lines
1.3 KiB
C++

#include <cstdio>
#include <cstring>
#include "hmac_md5.h"
#include "esphome/core/helpers.h"
namespace esphome {
namespace hmac_md5 {
void HmacMD5::init(const uint8_t *key, size_t len) {
uint8_t ipad[64], opad[64];
memset(ipad, 0, sizeof(ipad));
if (len > 64) {
md5::MD5Digest keymd5;
keymd5.init();
keymd5.add(key, len);
keymd5.calculate();
keymd5.get_bytes(ipad);
} else {
memcpy(ipad, key, len);
}
memcpy(opad, ipad, sizeof(opad));
for (int i = 0; i < 64; i++) {
ipad[i] ^= 0x36;
opad[i] ^= 0x5c;
}
this->ihash_.init();
this->ihash_.add(ipad, sizeof(ipad));
this->ohash_.init();
this->ohash_.add(opad, sizeof(opad));
}
void HmacMD5::add(const uint8_t *data, size_t len) { this->ihash_.add(data, len); }
void HmacMD5::calculate() {
uint8_t ibytes[16];
this->ihash_.calculate();
this->ihash_.get_bytes(ibytes);
this->ohash_.add(ibytes, sizeof(ibytes));
this->ohash_.calculate();
}
void HmacMD5::get_bytes(uint8_t *output) { this->ohash_.get_bytes(output); }
void HmacMD5::get_hex(char *output) { this->ohash_.get_hex(output); }
bool HmacMD5::equals_bytes(const uint8_t *expected) { return this->ohash_.equals_bytes(expected); }
bool HmacMD5::equals_hex(const char *expected) { return this->ohash_.equals_hex(expected); }
} // namespace hmac_md5
} // namespace esphome