diff options
Diffstat (limited to 'src/noscrypt.c')
-rw-r--r-- | src/noscrypt.c | 176 |
1 files changed, 45 insertions, 131 deletions
diff --git a/src/noscrypt.c b/src/noscrypt.c index 3719a08..9271353 100644 --- a/src/noscrypt.c +++ b/src/noscrypt.c @@ -15,35 +15,21 @@ * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License -* along with NativeHeapApi. If not, see http://www.gnu.org/licenses/. +* along with noscrypt. If not, see http://www.gnu.org/licenses/. */ #include "noscrypt.h" +#include "internal/nc-util.h" +#include "internal/nc-crypto.h" + #include <secp256k1_ecdh.h> #include <secp256k1_schnorrsig.h> -/* Setup mbedtls */ -#include <mbedtls/platform_util.h> -#include <mbedtls/md.h> -#include <mbedtls/hkdf.h> -#include <mbedtls/hmac_drbg.h> -#include <mbedtls/chacha20.h> -#include <mbedtls/sha256.h> -#include <mbedtls/constant_time.h> - -/* NULL */ -#ifndef NULL - #define NULL ((void*)0) -#endif /* !NULL */ - -#define CHACHA_NONCE_SIZE 0x0cu /* Size of 12 is set by the cipher spec */ -#define CHACHA_KEY_SIZE 0x20u /* Size of 32 is set by the cipher spec */ - /* * Local macro for secure zero buffer fill */ -#define ZERO_FILL(x, size) mbedtls_platform_zeroize(x, size) +#define ZERO_FILL(x, size) ncCryptoSecureZero(x, size) /* Include string for memmove */ #include <string.h> @@ -64,36 +50,6 @@ #define CHECK_ARG_RANGE(x, min, max, argPos) #endif /* !NC_DISABLE_INPUT_VALIDATION */ - -#ifdef DEBUG - /* Must include assert.h for assertions */ - #include <assert.h> - #define DEBUG_ASSERT(x) assert(x); - #define DEBUG_ASSERT2(x, message) assert(x && message); - - /* - * Compiler enabled static assertion keywords are - * only available in C11 and later. Later versions - * have macros built-in from assert.h so we can use - * the static_assert macro directly. - * - * Static assertions are only used for testing such as - * sanity checks and this library targets the c89 standard - * so static_assret very likely will not be available. - */ - #if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L - #define STATIC_ASSERT(x, m) static_assert(x, m) - #elif !defined(STATIC_ASSERT) - #define STATIC_ASSERT(x, m) - #pragma message("Static assertions are not supported by this language version") - #endif - -#else - #define DEBUG_ASSERT(x) - #define DEBUG_ASSERT2(x, message) - #define STATIC_ASSERT(x, m) -#endif - /* * The Nip44 constant salt * https://github.com/nostr-protocol/nips/blob/master/44.md#encryption @@ -129,6 +85,12 @@ struct nc_expand_keys { STATIC_ASSERT(sizeof(struct nc_expand_keys) == sizeof(struct message_key), "Expected struct nc_expand_keys to be the same size as struct message_key"); /* +* Check that the fallback hkdf extract internal buffer is large enough +* for full converstation key buffers +*/ +STATIC_ASSERT(HKDF_IN_BUF_SIZE >= NC_CONV_KEY_SIZE + 8, "HKDF Buffer size is too small for Safe HKDF operations") + +/* * Internal helper functions to do common structure conversions */ @@ -246,19 +208,8 @@ static NCResult _computeSharedSecret( return result == 1 ? NC_SUCCESS : E_OPERATION_FAILED; } -static _nc_fn_inline const mbedtls_md_info_t* _getSha256MdInfo(void) -{ - const mbedtls_md_info_t* info; - /* Get sha256 md info for hdkf operations */ - info = mbedtls_md_info_from_type(MBEDTLS_MD_SHA256); - DEBUG_ASSERT2(info != NULL, "Expected SHA256 md info struct to be valid") - return info; -} - - static _nc_fn_inline NCResult _computeConversationKey( const NCContext* ctx, - const mbedtls_md_info_t* mdInfo, const struct shared_secret* sharedSecret, struct conversation_key* ck ) @@ -267,12 +218,10 @@ static _nc_fn_inline NCResult _computeConversationKey( DEBUG_ASSERT2(ctx != NULL, "Expected valid context") DEBUG_ASSERT2(sharedSecret != NULL, "Expected a valid shared-point") - DEBUG_ASSERT2(mdInfo != NULL, "Expected valid md context") DEBUG_ASSERT2(ck != NULL, "Expected a valid conversation key") /* Derive the encryption key */ - opResult = mbedtls_hkdf_extract( - mdInfo, + opResult = ncCryptoSha256HkdfExtract( Nip44ConstantSalt, sizeof(Nip44ConstantSalt), (uint8_t*)sharedSecret, /* Shared secret is the input key */ @@ -293,23 +242,21 @@ static _nc_fn_inline const struct nc_expand_keys* _expandKeysFromHkdf(const stru return (const struct nc_expand_keys*)hkdf; } -static int _chachaEncipher(const struct nc_expand_keys* keys, NCCryptoData* args) +static int _chachaEncipher(const struct nc_expand_keys* keys, NCEncryptionArgs* args) { DEBUG_ASSERT2(keys != NULL, "Expected valid keys") DEBUG_ASSERT2(args != NULL, "Expected valid encryption args") - return mbedtls_chacha20_crypt( + return ncCryptoChacha20( keys->chacha_key, keys->chacha_nonce, - 0, /* Counter (always starts at 0) */ - args->dataSize, /* Data size (input and output are assumed to be the same size) */ args->inputData, /* Input data */ - args->outputData /* Output data */ + args->outputData, /* Output data */ + args->dataSize /* Data size (input and output are assumed to be the same size) */ ); } static _nc_fn_inline NCResult _getMessageKey( - const mbedtls_md_info_t* mdInfo, const struct conversation_key* converstationKey, const uint8_t* nonce, size_t nonceSize, @@ -317,14 +264,12 @@ static _nc_fn_inline NCResult _getMessageKey( ) { int result; - DEBUG_ASSERT2(mdInfo != NULL, "Expected valid md context") DEBUG_ASSERT2(nonce != NULL, "Expected valid nonce buffer") DEBUG_ASSERT2(converstationKey != NULL, "Expected valid conversation key") DEBUG_ASSERT2(messageKey != NULL, "Expected valid message key buffer") /* Another HKDF to derive the message key with nonce */ - result = mbedtls_hkdf_expand( - mdInfo, + result = ncCryptoSha256HkdfExpand( (uint8_t*)converstationKey, /* Conversation key is the input key */ NC_CONV_KEY_SIZE, nonce, @@ -338,10 +283,9 @@ static _nc_fn_inline NCResult _getMessageKey( static _nc_fn_inline NCResult _encryptEx( const NCContext* ctx, - const mbedtls_md_info_t* mdINfo, const struct conversation_key* ck, uint8_t hmacKey[NC_HMAC_KEY_SIZE], - NCCryptoData* args + NCEncryptionArgs* args ) { NCResult result; @@ -351,11 +295,10 @@ static _nc_fn_inline NCResult _encryptEx( DEBUG_ASSERT2(ctx != NULL, "Expected valid context") DEBUG_ASSERT2(ck != NULL, "Expected valid conversation key") DEBUG_ASSERT2(args != NULL, "Expected valid encryption args") - DEBUG_ASSERT2(mdINfo != NULL, "Expected valid md info struct") DEBUG_ASSERT2(hmacKey != NULL, "Expected valid hmac key buffer") /* Message key will be derrived on every encryption call */ - if ((result = _getMessageKey(mdINfo, ck, args->nonce32, NC_ENCRYPTION_NONCE_SIZE, &messageKey)) != NC_SUCCESS) + if ((result = _getMessageKey(ck, args->nonce32, NC_ENCRYPTION_NONCE_SIZE, &messageKey)) != NC_SUCCESS) { goto Cleanup; } @@ -377,9 +320,8 @@ Cleanup: static _nc_fn_inline NCResult _decryptEx( const NCContext* ctx, - const mbedtls_md_info_t* mdInfo, const struct conversation_key* ck, - NCCryptoData* args + NCEncryptionArgs* args ) { NCResult result; @@ -389,9 +331,8 @@ static _nc_fn_inline NCResult _decryptEx( DEBUG_ASSERT2(ctx != NULL, "Expected valid context") DEBUG_ASSERT2(ck != NULL, "Expected valid conversation key") DEBUG_ASSERT2(args != NULL, "Expected valid encryption args") - DEBUG_ASSERT2(mdInfo != NULL, "Expected valid md info struct") - if ((result = _getMessageKey(mdInfo, ck, args->nonce32, NC_ENCRYPTION_NONCE_SIZE, &messageKey)) != NC_SUCCESS) + if ((result = _getMessageKey(ck, args->nonce32, NC_ENCRYPTION_NONCE_SIZE, &messageKey)) != NC_SUCCESS) { goto Cleanup; } @@ -419,12 +360,9 @@ static _nc_fn_inline int _computeHmac( DEBUG_ASSERT2(hmacOut != NULL, "Expected valid hmac output buffer") DEBUG_ASSERT(args->payload != NULL) - return mbedtls_md_hmac( - _getSha256MdInfo(), - key, - NC_HMAC_KEY_SIZE, - args->payload, - args->payloadSize, + return ncCryptoHmacSha256( + key, NC_HMAC_KEY_SIZE, + args->payload, args->payloadSize, hmacOut ); } @@ -448,7 +386,6 @@ static NCResult _verifyMacEx( * Message key is again required for the hmac verification */ result = _getMessageKey( - _getSha256MdInfo(), (struct conversation_key*)conversationKey, args->nonce32, NC_ENCRYPTION_NONCE_SIZE, @@ -473,7 +410,7 @@ static NCResult _verifyMacEx( } /* constant time compare the macs */ - result = mbedtls_ct_memcmp(hmacOut, args->mac32, NC_ENCRYPTION_MAC_SIZE) == 0 ? NC_SUCCESS : E_OPERATION_FAILED; + result = ncCryptoFixedTimeComp(hmacOut, args->mac32, NC_ENCRYPTION_MAC_SIZE) == 0 ? NC_SUCCESS : E_OPERATION_FAILED; Cleanup: ZERO_FILL(&messageKey, sizeof(messageKey)); @@ -493,7 +430,7 @@ NC_EXPORT uint32_t NC_CC NCGetContextStructSize(void) NC_EXPORT NCResult NC_CC NCInitContext( NCContext* ctx, - const uint8_t entropy[32] + const uint8_t entropy[NC_CONTEXT_ENTROPY_SIZE] ) { CHECK_NULL_ARG(ctx, 0) @@ -510,7 +447,7 @@ NC_EXPORT NCResult NC_CC NCInitContext( NC_EXPORT NCResult NC_CC NCReInitContext( NCContext* ctx, - const uint8_t entropy[32] + const uint8_t entropy[NC_CONTEXT_ENTROPY_SIZE] ) { CHECK_NULL_ARG(ctx, 0) @@ -638,7 +575,7 @@ NC_EXPORT NCResult NC_CC NCSignData( uint8_t sig64[64] ) { - uint8_t digest[32]; + uint8_t digest[SHA256_DIGEST_SIZE]; /* Double check is required because arg position differs */ CHECK_NULL_ARG(ctx, 0) @@ -649,7 +586,7 @@ NC_EXPORT NCResult NC_CC NCSignData( CHECK_NULL_ARG(sig64, 5) /* Compute sha256 of the data before signing */ - if(mbedtls_sha256(data, dataSize, digest, 0) != 0) + if(ncCryptoDigestSha256(data, dataSize, digest) != 0) { return E_INVALID_ARG; } @@ -696,7 +633,7 @@ NC_EXPORT NCResult NC_CC NCVerifyData( const uint8_t sig64[64] ) { - uint8_t digest[32]; + uint8_t digest[SHA256_DIGEST_SIZE]; CHECK_NULL_ARG(ctx, 0) CHECK_NULL_ARG(pk, 1) @@ -705,7 +642,7 @@ NC_EXPORT NCResult NC_CC NCVerifyData( CHECK_NULL_ARG(sig64, 4) /* Compute sha256 of the data before verifying */ - if (mbedtls_sha256(data, dataSize, digest, 0) != 0) + if (ncCryptoDigestSha256(data, dataSize, digest) != 0) { return E_INVALID_ARG; } @@ -729,12 +666,7 @@ NC_EXPORT NCResult NC_CC NCGetSharedSecret( CHECK_NULL_ARG(otherPk, 2) CHECK_NULL_ARG(sharedPoint, 3) - return _computeSharedSecret( - ctx, - sk, - otherPk, - (struct shared_secret*)sharedPoint - ); + return _computeSharedSecret(ctx, sk, otherPk, (struct shared_secret*)sharedPoint); } NC_EXPORT NCResult NC_CC NCGetConversationKeyEx( @@ -750,8 +682,7 @@ NC_EXPORT NCResult NC_CC NCGetConversationKeyEx( /* Cast the shared point to the shared secret type */ return _computeConversationKey( - ctx, - _getSha256MdInfo(), + ctx, (struct shared_secret*)sharedPoint, (struct conversation_key*)conversationKey ); @@ -779,12 +710,7 @@ NC_EXPORT NCResult NC_CC NCGetConversationKey( goto Cleanup; } - result = _computeConversationKey( - ctx, - _getSha256MdInfo(), - &sharedSecret, - (struct conversation_key*)conversationKey - ); + result = _computeConversationKey(ctx, &sharedSecret, (struct conversation_key*)conversationKey); Cleanup: /* Clean up sensitive data */ @@ -797,7 +723,7 @@ NC_EXPORT NCResult NC_CC NCEncryptEx( const NCContext* ctx, const uint8_t conversationKey[NC_CONV_KEY_SIZE], uint8_t hmacKeyOut[NC_HMAC_KEY_SIZE], - NCCryptoData* args + NCEncryptionArgs* args ) { CHECK_NULL_ARG(ctx, 0) @@ -813,8 +739,7 @@ NC_EXPORT NCResult NC_CC NCEncryptEx( CHECK_ARG_RANGE(args->dataSize, NIP44_MIN_ENC_MESSAGE_SIZE, NIP44_MAX_ENC_MESSAGE_SIZE, 3) return _encryptEx( - ctx, - _getSha256MdInfo(), + ctx, (struct conversation_key*)conversationKey, hmacKeyOut, args @@ -826,11 +751,10 @@ NC_EXPORT NCResult NC_CC NCEncrypt( const NCSecretKey* sk, const NCPublicKey* pk, uint8_t hmacKeyOut[NC_HMAC_KEY_SIZE], - NCCryptoData* args + NCEncryptionArgs* args ) { NCResult result; - const mbedtls_md_info_t* mdInfo; struct shared_secret sharedSecret; struct conversation_key conversationKey; @@ -847,8 +771,6 @@ NC_EXPORT NCResult NC_CC NCEncrypt( CHECK_INVALID_ARG(args->nonce32, 4) CHECK_ARG_RANGE(args->dataSize, NIP44_MIN_ENC_MESSAGE_SIZE, NIP44_MAX_ENC_MESSAGE_SIZE, 4) - mdInfo = _getSha256MdInfo(); - /* Compute the shared point */ if ((result = _computeSharedSecret(ctx, sk, pk, &sharedSecret)) != NC_SUCCESS) { @@ -856,12 +778,12 @@ NC_EXPORT NCResult NC_CC NCEncrypt( } /* Compute the conversation key from secret and pubkic keys */ - if ((result = _computeConversationKey(ctx, mdInfo, &sharedSecret, &conversationKey)) != NC_SUCCESS) + if ((result = _computeConversationKey(ctx, &sharedSecret, &conversationKey)) != NC_SUCCESS) { goto Cleanup; } - result = _encryptEx(ctx, mdInfo, &conversationKey, hmacKeyOut, args); + result = _encryptEx(ctx, &conversationKey, hmacKeyOut, args); Cleanup: /* Clean up sensitive data */ @@ -874,7 +796,7 @@ Cleanup: NC_EXPORT NCResult NC_CC NCDecryptEx( const NCContext* ctx, const uint8_t conversationKey[NC_CONV_KEY_SIZE], - NCCryptoData* args + NCEncryptionArgs* args ) { CHECK_NULL_ARG(ctx, 0) @@ -888,25 +810,19 @@ NC_EXPORT NCResult NC_CC NCDecryptEx( CHECK_INVALID_ARG(args->nonce32, 2) CHECK_ARG_RANGE(args->dataSize, NIP44_MIN_ENC_MESSAGE_SIZE, NIP44_MAX_ENC_MESSAGE_SIZE, 2) - return _decryptEx( - ctx, - _getSha256MdInfo(), - (struct conversation_key*)conversationKey, - args - ); + return _decryptEx(ctx, (struct conversation_key*)conversationKey, args); } NC_EXPORT NCResult NC_CC NCDecrypt( const NCContext* ctx, const NCSecretKey* sk, const NCPublicKey* pk, - NCCryptoData* args + NCEncryptionArgs* args ) { NCResult result; struct shared_secret sharedSecret; struct conversation_key conversationKey; - const mbedtls_md_info_t* mdInfo; CHECK_NULL_ARG(ctx, 0) CHECK_INVALID_ARG(ctx->secpCtx, 0) @@ -920,19 +836,17 @@ NC_EXPORT NCResult NC_CC NCDecrypt( CHECK_INVALID_ARG(args->nonce32, 3) CHECK_ARG_RANGE(args->dataSize, NIP44_MIN_ENC_MESSAGE_SIZE, NIP44_MAX_ENC_MESSAGE_SIZE, 3) - mdInfo = _getSha256MdInfo(); - if ((result = _computeSharedSecret(ctx, sk, pk, &sharedSecret)) != NC_SUCCESS) { goto Cleanup; } - if ((result = _computeConversationKey(ctx, mdInfo, &sharedSecret, &conversationKey)) != NC_SUCCESS) + if ((result = _computeConversationKey(ctx, &sharedSecret, &conversationKey)) != NC_SUCCESS) { goto Cleanup; } - result = _decryptEx(ctx, mdInfo, &conversationKey, args); + result = _decryptEx(ctx, &conversationKey, args); Cleanup: /* Clean up sensitive data */ @@ -1018,7 +932,7 @@ NC_EXPORT NCResult NC_CC NCVerifyMac( goto Cleanup; } - if ((result = _computeConversationKey(ctx, _getSha256MdInfo(), &sharedSecret, &conversationKey)) != NC_SUCCESS) + if ((result = _computeConversationKey(ctx, &sharedSecret, &conversationKey)) != NC_SUCCESS) { goto Cleanup; } |