HMAC breaking due to dangling OSSL_PARAM (#405)

This commit is contained in:
Davide De Rosa 2024-01-05 23:13:04 +01:00 committed by GitHub
parent faa3c94391
commit 3bafce9a8e
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
3 changed files with 32 additions and 11 deletions

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@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
### Fixed
- OpenVPN: HMAC breaking due to dangling OSSL_PARAM. [#405](https://github.com/passepartoutvpn/tunnelkit/pull/405)
- OpenVPN: Bad error mapping. [#404](https://github.com/passepartoutvpn/tunnelkit/pull/404)
- OpenVPN: Restore default security level. [#406](https://github.com/passepartoutvpn/tunnelkit/pull/406)

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@ -50,6 +50,8 @@ const NSInteger CryptoCBCMaxHMACLength = 100;
@property (nonatomic, unsafe_unretained) const EVP_CIPHER *cipher;
@property (nonatomic, unsafe_unretained) const EVP_MD *digest;
@property (nonatomic, unsafe_unretained) const char *utfCipherName;
@property (nonatomic, unsafe_unretained) const char *utfDigestName;
@property (nonatomic, assign) int cipherKeyLength;
@property (nonatomic, assign) int cipherIVLength;
@property (nonatomic, assign) int hmacKeyLength;
@ -75,10 +77,14 @@ const NSInteger CryptoCBCMaxHMACLength = 100;
self = [super init];
if (self) {
if (cipherName) {
self.cipher = EVP_get_cipherbyname([cipherName cStringUsingEncoding:NSASCIIStringEncoding]);
self.utfCipherName = calloc([cipherName length] + 1, sizeof(char));
strncpy(self.utfCipherName, [cipherName UTF8String], [cipherName length]);
self.cipher = EVP_get_cipherbyname(self.utfCipherName);
NSAssert(self.cipher, @"Unknown cipher '%@'", cipherName);
}
self.digest = EVP_get_digestbyname([digestName cStringUsingEncoding:NSASCIIStringEncoding]);
self.utfDigestName = calloc([digestName length] + 1, sizeof(char));
strncpy(self.utfDigestName, [digestName UTF8String], [digestName length]);
self.digest = EVP_get_digestbyname(self.utfDigestName);
NSAssert(self.digest, @"Unknown digest '%@'", digestName);
if (cipherName) {
@ -96,7 +102,7 @@ const NSInteger CryptoCBCMaxHMACLength = 100;
self.mac = EVP_MAC_fetch(NULL, "HMAC", NULL);
OSSL_PARAM *macParams = calloc(2, sizeof(OSSL_PARAM));
macParams[0] = OSSL_PARAM_construct_utf8_string("digest", (char *)[digestName cStringUsingEncoding:NSASCIIStringEncoding], 0);
macParams[0] = OSSL_PARAM_construct_utf8_string("digest", self.utfDigestName, 0);
macParams[1] = OSSL_PARAM_construct_end();
self.macParams = macParams;
@ -115,7 +121,12 @@ const NSInteger CryptoCBCMaxHMACLength = 100;
free(self.macParams);
bzero(self.bufferDecHMAC, CryptoCBCMaxHMACLength);
free(self.bufferDecHMAC);
if (self.utfCipherName) {
free(self.utfCipherName);
}
free(self.utfDigestName);
self.cipher = NULL;
self.digest = NULL;
}
@ -175,7 +186,6 @@ const NSInteger CryptoCBCMaxHMACLength = 100;
memcpy(outEncrypted, bytes, length);
l1 = (int)length;
}
EVP_MAC_CTX *ctx = EVP_MAC_CTX_new(self.mac);
TUNNEL_CRYPTO_TRACK_STATUS(code) EVP_MAC_init(ctx, self.hmacKeyEnc.bytes, self.hmacKeyEnc.count, self.macParams);
TUNNEL_CRYPTO_TRACK_STATUS(code) EVP_MAC_update(ctx, outIV, l1 + l2 + self.cipherIVLength);
@ -215,7 +225,7 @@ const NSInteger CryptoCBCMaxHMACLength = 100;
const uint8_t *encrypted = bytes + self.digestLength + self.cipherIVLength;
size_t l1 = 0, l2 = 0;
int code = 1;
EVP_MAC_CTX *ctx = EVP_MAC_CTX_new(self.mac);
TUNNEL_CRYPTO_TRACK_STATUS(code) EVP_MAC_init(ctx, self.hmacKeyDec.bytes, self.hmacKeyDec.count, self.macParams);
TUNNEL_CRYPTO_TRACK_STATUS(code) EVP_MAC_update(ctx, bytes + self.digestLength, length - self.digestLength);
@ -249,7 +259,7 @@ const NSInteger CryptoCBCMaxHMACLength = 100;
{
size_t l1 = 0;
int code = 1;
EVP_MAC_CTX *ctx = EVP_MAC_CTX_new(self.mac);
TUNNEL_CRYPTO_TRACK_STATUS(code) EVP_MAC_init(ctx, self.hmacKeyDec.bytes, self.hmacKeyDec.count, self.macParams);
TUNNEL_CRYPTO_TRACK_STATUS(code) EVP_MAC_update(ctx, bytes + self.digestLength, length - self.digestLength);

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@ -38,6 +38,8 @@ static const NSInteger CryptoCTRTagLength = 32;
@property (nonatomic, unsafe_unretained) const EVP_CIPHER *cipher;
@property (nonatomic, unsafe_unretained) const EVP_MD *digest;
@property (nonatomic, unsafe_unretained) const char *utfCipherName;
@property (nonatomic, unsafe_unretained) const char *utfDigestName;
@property (nonatomic, assign) int cipherKeyLength;
@property (nonatomic, assign) int cipherIVLength;
@property (nonatomic, assign) int hmacKeyLength;
@ -61,9 +63,14 @@ static const NSInteger CryptoCTRTagLength = 32;
self = [super init];
if (self) {
self.cipher = EVP_get_cipherbyname([cipherName cStringUsingEncoding:NSASCIIStringEncoding]);
self.utfCipherName = calloc([cipherName length] + 1, sizeof(char));
strncpy(self.utfCipherName, [cipherName UTF8String], [cipherName length]);
self.cipher = EVP_get_cipherbyname(self.utfCipherName);
NSAssert(self.cipher, @"Unknown cipher '%@'", cipherName);
self.digest = EVP_get_digestbyname([digestName cStringUsingEncoding:NSASCIIStringEncoding]);
self.utfDigestName = calloc([digestName length] + 1, sizeof(char));
strncpy(self.utfDigestName, [digestName UTF8String], [digestName length]);
self.digest = EVP_get_digestbyname(self.utfDigestName);
NSAssert(self.digest, @"Unknown digest '%@'", digestName);
self.cipherKeyLength = EVP_CIPHER_key_length(self.cipher);
@ -77,7 +84,7 @@ static const NSInteger CryptoCTRTagLength = 32;
self.mac = EVP_MAC_fetch(NULL, "HMAC", NULL);
OSSL_PARAM *macParams = calloc(2, sizeof(OSSL_PARAM));
macParams[0] = OSSL_PARAM_construct_utf8_string("digest", (char *)[digestName cStringUsingEncoding:NSASCIIStringEncoding], 0);
macParams[0] = OSSL_PARAM_construct_utf8_string("digest", self.utfDigestName, 0);
macParams[1] = OSSL_PARAM_construct_end();
self.macParams = macParams;
@ -94,7 +101,10 @@ static const NSInteger CryptoCTRTagLength = 32;
free(self.macParams);
bzero(self.bufferDecHMAC, CryptoCTRTagLength);
free(self.bufferDecHMAC);
free(self.utfCipherName);
free(self.utfDigestName);
self.cipher = NULL;
self.digest = NULL;
}