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fix function and variable names
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@balika011
balika011 committed Apr 3, 2021
1 parent e1c1dd6 commit ffa7b32
Showing 1 changed file with 28 additions and 32 deletions.
60 changes: 28 additions & 32 deletions ipl_decrypt.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -115,34 +115,30 @@ void SHA256_Final2(u8 *digest, SHA256_CTX *ctx)
}
}

void scrambleBuf(u8 *in1, u32 inSize1, u8 *in2, u32 inSize2, u8 *out) // at 0x040F0C08 in 2.60
void sha256hmac(u8 *key, u32 inSize1, u8 *data, u32 datalen, u8 *out) // at 0x040F0C08 in 2.60
{
SHA256_CTX ctx; // sp
u8 buf1[32]; // sp + 112 // actually 28 in 3.80+
u8 buf2[64]; // sp + 144
if (inSize2 == 0 || in2 == NULL) {
sha256Digest(in1, inSize1, out);
if (datalen == 0 || data == NULL) {
sha256Digest(key, inSize1, out);
return;
}
// 0C78
memset(buf2, 0, 64);
if (inSize1 > 64) {
// 0D5C
sha256Digest(in1, inSize1, buf2);
sha256Digest(key, inSize1, buf2);
} else {
memcpy(buf2, in1, inSize1);
memcpy(buf2, key, inSize1);
}
// 0CAC
for (s32 i = 0; i < 64; i++) {
buf2[i] ^= 0x36;
buf2[i] ^= 0x36; // I_PAD
}
SHA256_Init2(&ctx);
SHA256_Update(&ctx, buf2, 64);
SHA256_Update(&ctx, in2, inSize2);
SHA256_Update(&ctx, data, datalen);
SHA256_Final2(buf1, &ctx);
// 0D04
for (s32 i = 0; i < 64; i++) {
buf2[i] ^= 0x6A;
buf2[i] ^= 0x6A; // I_PAD ^ O_OPAD
}
SHA256_Init2(&ctx);
SHA256_Update(&ctx, buf2, 64);
Expand Down Expand Up @@ -365,20 +361,20 @@ s32 sfmtInit(SceKernelUtilsMt19937Context *ctx, u32 *seed, u32 seedSize) // 0x04
return 0;
}

void decrypt(void *preipl, u32 preiplSize, void *unk1, void *unk2, void *encryptedImg, s32 encryptedSize) // at 0x040F0D70 in 2.60
void decrypt(void *preipl, u32 preiplSize, void *preiplHmacKey, void *dataHmacKey, void *encryptedImg, s32 encryptedSize) // at 0x040F0D70 in 2.60
{
SceKernelUtilsMt19937Context ctx; // sp..sp+2500
u32 hash[8]; // sp + 2512
u32 hmac[8]; // sp + 2512
u32 buf1[16]; // sp + 2544
u32 buf2[8]; // sp + 2608
u32 hmac2[8]; // sp + 2608
if (g_usePrecomp) {
memcpy(hash, g_precompKey.data(), 32);
memcpy(hmac, g_precompKey.data(), 32);
} else {
scrambleBuf((u8*)unk1, 64, (u8*)preipl, preiplSize, (u8*)hash);
sha256hmac((u8*)preiplHmacKey, 64, (u8*)preipl, preiplSize, (u8*)hmac);
if (preipl != NULL && g_debug) {
printf("using hash = {0x%08x, {", *(u32*)unk1);
printf("using hmac = {0x%08x, {", *(u32*)preiplHmacKey);
for (s32 i = 0; i < 8; i++) {
printf("0x%08x", hash[i]);
printf("0x%08x", hmac[i]);
if (i < 7) {
printf(", ");
}
Expand All @@ -388,17 +384,17 @@ void decrypt(void *preipl, u32 preiplSize, void *unk1, void *unk2, void *encrypt
}
ctx.count = 0;
if (g_useSfmt) {
sfmtInit(&ctx, hash, g_customSha ? 7 : 8);
sfmtInit(&ctx, hmac, g_customSha ? 7 : 8);
} else {
// 0DCC
for (s32 i = 0; i < 624; i += 8) {
memcpy(&ctx.state[i], hash, g_customSha ? 28 : 32);
memcpy(&ctx.state[i], hmac, g_customSha ? 28 : 32);
if (g_customSha) {
ctx.state[i + 7] = 0;
}
}
}
memset(hash, 0, sizeof(hash));
memset(hmac, 0, sizeof(hmac));
if (!g_useSfmt) {
// 0E40
for (s32 i = 0; i < 624; i++) {
Expand All @@ -421,24 +417,24 @@ void decrypt(void *preipl, u32 preiplSize, void *unk1, void *unk2, void *encrypt
mt19937UInt(&ctx); // version 3.1x only
}
}
scrambleBuf((u8*)unk2, 64, (u8*)buf1, 64, (u8*)buf2);
s32 hashSize = g_customSha ? 28 : 32;
if (i + hashSize > encryptedSize) {
sha256hmac((u8*)dataHmacKey, 64, (u8*)buf1, 64, (u8*)hmac2);
s32 hmacSize = g_customSha ? 28 : 32;
if (i + hmacSize > encryptedSize) {
for (s32 j = 0; i + j < encryptedSize; j++) {
*(decryptBuf++) ^= ((u8*)buf2)[j];
*(decryptBuf++) ^= ((u8*)hmac2)[j];
}
} else {
for (s32 j = 0; j < hashSize / 4; j++) {
*(u32*)decryptBuf ^= buf2[j];
for (s32 j = 0; j <hmacSize / 4; j++) {
*(u32*)decryptBuf ^= hmac2[j];
decryptBuf += 4;
}
}
}
// in 3.30+, here ctx, buf1 and buf2 are memset to 0
// in 3.30+, here ctx, buf1 and hmac2 are memset to 0
}

// for 3.30+ part1
void decrypt330(u32 *preipl, u32 preiplSize, void *unk1, void *unk2, void *encryptedImg, s32 encryptedSize, u32 realPreiplSize) // at 0x040F1018 in 3.30 part1
void decrypt330(u32 *preipl, u32 preiplSize, void *preiplHmacKey, void *dataHmacKey, void *encryptedImg, s32 encryptedSize, u32 realPreiplSize) // at 0x040F1018 in 3.30 part1
{
u8 buf1[32];
SceKernelUtilsMt19937Context ctx;
Expand All @@ -448,7 +444,7 @@ void decrypt330(u32 *preipl, u32 preiplSize, void *unk1, void *unk2, void *encry
for (s32 i = 0; i < realPreiplSize / 4; i++) {
buf2[i] = preipl[i] + mt19937UInt(&ctx);
}
scrambleBuf(g_newKey, preiplSize, (u8*)buf2, realPreiplSize, buf1);
sha256hmac(g_newKey, preiplSize, (u8*)buf2, realPreiplSize, buf1);
memset(buf2, 0, 4096);
memset(&ctx, 0, 2500);
// Note the checksum part does not exist for testing tools since it only allows one preipl format (but the XOR doesn't seem to be triggered anyway)
Expand All @@ -464,7 +460,7 @@ void decrypt330(u32 *preipl, u32 preiplSize, void *unk1, void *unk2, void *encry
buf1[i] ^= g_xorKey[i];
}
}
decrypt(buf1, 32, unk1, unk2, encryptedImg, encryptedSize);
decrypt(buf1, 32, preiplHmacKey, dataHmacKey, encryptedImg, encryptedSize);
}

s32 sha256Digest(u8 *data, u32 size, u8 *digest) // at 0x040F12CC
Expand Down

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