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Proper state management for AES GCM and CCM #112

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Merged
mamckee merged 4 commits into from
Mar 27, 2025
Merged

Proper state management for AES GCM and CCM #112

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fca7353
Only reset IV for new IV length. Track iv and tag state in ccm
mamckee Mar 19, 2025
d439e24
Update tagSet after ccm encrypt
mamckee Mar 19, 2025
07ca0d8
Free rsa private exponent in import
mamckee Mar 26, 2025
2f01cb4
Secure malloc and free primes and private exponent
mamckee Mar 27, 2025
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2 changes: 2 additions & 0 deletions ScosslCommon/inc/scossl_aes_aead.h
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Original file line number Diff line number Diff line change
Expand Up @@ -88,10 +88,12 @@ typedef struct
SCOSSL_CCM_STAGE ccmStage;
BYTE iv[SCOSSL_CCM_MAX_IV_LENGTH];
SIZE_T ivlen;
INT32 ivSet;
SYMCRYPT_CCM_STATE state;
SYMCRYPT_AES_EXPANDED_KEY key;
BYTE tag[EVP_CCM_TLS_TAG_LEN];
SIZE_T taglen;
INT32 tagSet;
UINT64 cbData;
BYTE tlsAad[EVP_AEAD_TLS1_AAD_LEN];
INT32 tlsAadSet;
Expand Down
42 changes: 35 additions & 7 deletions ScosslCommon/src/scossl_aes_aead.c
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Original file line number Diff line number Diff line change
Expand Up @@ -287,12 +287,15 @@ SCOSSL_STATUS scossl_aes_gcm_set_iv_len(SCOSSL_CIPHER_GCM_CTX *ctx, size_t ivlen
return SCOSSL_FAILURE;
}

ctx->ivlen = ivlen;

if (ctx->iv != NULL)
if (ivlen != ctx->ivlen)
{
OPENSSL_free(ctx->iv);
ctx->iv = NULL;
ctx->ivlen = ivlen;

if (ctx->iv != NULL)
{
OPENSSL_free(ctx->iv);
ctx->iv = NULL;
}
}

return SCOSSL_SUCCESS;
Expand Down Expand Up @@ -429,6 +432,8 @@ void scossl_aes_ccm_init_ctx(SCOSSL_CIPHER_CCM_CTX *ctx,
memcpy(ctx->iv, iv, ctx->ivlen);
}
ctx->taglen = SCOSSL_CCM_MAX_TAG_LENGTH;
ctx->ivSet = 0;
ctx->tagSet = 0;
ctx->tlsAadSet = 0;
}

Expand All @@ -450,6 +455,7 @@ SCOSSL_STATUS scossl_aes_ccm_init_key(SCOSSL_CIPHER_CCM_CTX *ctx,

ctx->ivlen = ivlen;
memcpy(ctx->iv, iv, ctx->ivlen);
ctx->ivSet = 1;
}
if (key)
{
Expand Down Expand Up @@ -618,6 +624,13 @@ SCOSSL_STATUS scossl_aes_ccm_cipher(SCOSSL_CIPHER_CCM_CTX *ctx, INT32 encrypt,

if (ctx->ccmStage == SCOSSL_CCM_STAGE_SET_CBDATA)
{
if (!ctx->ivSet)
{
SCOSSL_LOG_ERROR(SCOSSL_ERR_F_AES_CCM_CIPHER, ERR_R_PASSED_INVALID_ARGUMENT,
"No IV provided to CCM");
return SCOSSL_FAILURE;
}

if (out == NULL)
{
// Auth Data Passed in
Expand Down Expand Up @@ -653,10 +666,17 @@ SCOSSL_STATUS scossl_aes_ccm_cipher(SCOSSL_CIPHER_CCM_CTX *ctx, INT32 encrypt,
SymCryptCcmEncryptPart(&ctx->state, in, out, inl);
}
SymCryptCcmEncryptFinal(&ctx->state, ctx->tag, ctx->taglen);
ctx->tagSet = 1;
ctx->ccmStage = SCOSSL_CCM_STAGE_COMPLETE;
}
else
{
if (!ctx->tagSet)
{
SCOSSL_LOG_ERROR(SCOSSL_ERR_F_AES_CCM_CIPHER, ERR_R_PASSED_INVALID_ARGUMENT,
"No tag provided to CCM Decrypt");
return SCOSSL_FAILURE;
}
// Decryption
if (in != NULL)
{
Expand All @@ -680,7 +700,7 @@ SCOSSL_STATUS scossl_aes_ccm_get_aead_tag(SCOSSL_CIPHER_CCM_CTX *ctx, INT32 encr
unsigned char *tag, size_t taglen)
{
if ((taglen & 1) || taglen < SCOSSL_CCM_MIN_TAG_LENGTH || taglen > SCOSSL_CCM_MAX_TAG_LENGTH ||
taglen > ctx->taglen || !encrypt)
taglen > ctx->taglen || !encrypt || !ctx->tagSet)
{
return SCOSSL_FAILURE;
}
Expand All @@ -702,6 +722,7 @@ SCOSSL_STATUS scossl_aes_ccm_set_aead_tag(SCOSSL_CIPHER_CCM_CTX *ctx, INT32 encr
memcpy(ctx->tag, tag, taglen);
}
ctx->taglen = taglen;
ctx->tagSet = 1;

return SCOSSL_SUCCESS;
}
Expand All @@ -717,7 +738,12 @@ SCOSSL_STATUS scossl_aes_ccm_set_iv_len(SCOSSL_CIPHER_CCM_CTX *ctx, size_t ivlen
return SCOSSL_FAILURE;
}

ctx->ivlen = ivlen;
if (ctx->ivlen != ivlen)
{
ctx->ivlen = ivlen;
ctx->ivSet = 0;
}

return SCOSSL_SUCCESS;
}

Expand Down Expand Up @@ -751,6 +777,8 @@ SCOSSL_STATUS scossl_aes_ccm_set_iv_fixed(SCOSSL_CIPHER_CCM_CTX *ctx, INT32 encr
return SCOSSL_FAILURE;
}

ctx->ivSet = 1;

return SCOSSL_SUCCESS;
}

Expand Down
1 change: 1 addition & 0 deletions SymCryptProvider/src/keymgmt/p_scossl_rsa_keymgmt.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1271,6 +1271,7 @@ static SCOSSL_STATUS p_scossl_rsa_keymgmt_import(_Inout_ SCOSSL_PROV_RSA_KEY_CTX
ret = SCOSSL_SUCCESS;

cleanup:
OPENSSL_free(pbPrivateExponent);
OPENSSL_free(pbModulus);
OPENSSL_free(ppbPrimes[0]);
OPENSSL_free(ppbPrimes[1]);
Expand Down