Wessel Nieboer
4 months ago
No known key found for this signature in database
GPG Key ID: 929C8E45E33B5FD2
1 changed files with
2 additions and
4 deletions
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src/Utils.cpp
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@ -1,5 +1,6 @@ |
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#include "Utils.h" |
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#include <AES.h> |
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#include <Crypto.h> |
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#include <SHA256.h> |
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#ifdef ARDUINO |
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@ -81,10 +82,7 @@ int Utils::MACThenDecrypt(const uint8_t* shared_secret, uint8_t* dest, const uin |
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sha.update(src + CIPHER_MAC_SIZE, src_len - CIPHER_MAC_SIZE); |
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sha.finalizeHMAC(shared_secret, PUB_KEY_SIZE, hmac, CIPHER_MAC_SIZE); |
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} |
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// constant-time comparison to prevent timing side-channel attacks
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uint8_t diff = 0; |
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for (int i = 0; i < CIPHER_MAC_SIZE; i++) diff |= hmac[i] ^ src[i]; |
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if (diff == 0) { |
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if (secure_compare(hmac, src, CIPHER_MAC_SIZE)) { |
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return decrypt(shared_secret, dest, src + CIPHER_MAC_SIZE, src_len - CIPHER_MAC_SIZE); |
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} |
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return 0; // invalid HMAC
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