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feat(types)!: delete Turin fallback and change TCB class #14

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Merged
hyperfinitism merged 1 commit into from
Jan 14, 2026
Merged

feat(types)!: delete Turin fallback and change TCB class #14

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55 changes: 18 additions & 37 deletions pysnputils/types.py
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Original file line number Diff line number Diff line change
Expand Up @@ -24,7 +24,6 @@
"AttestationReport",
# Functions
"report_version_to_variant",
"turin_like",
"detect_processor_model",
]

Expand Down Expand Up @@ -92,23 +91,10 @@ def report_version_to_variant(version: int) -> ReportVariant:
raise ValueError(f"invalid or unsupported report version: {version}")


def turin_like(chip_id: bytes) -> bool:
"""Determine if the Chip ID is from a Turin-like processor."""
if len(chip_id) != 64:
raise ValueError("invalid chip ID length: expected 64 bytes, got {len(chip_id)}")
if chip_id[8:64] == bytes(56):
return True
return False


def detect_processor_model(report_version: int, cpuid_fam_id: int | None, cpuid_mod_id: int | None, chip_id: bytes) -> ProcessorModel:
"""Detect the processor model from the CPUID family, model, stepping, and Chip ID."""
def detect_processor_model(report_version: int, cpuid_fam_id: int | None, cpuid_mod_id: int | None) -> ProcessorModel:
"""Detect the processor model from the CPUID family and model."""
if report_version < 3:
if chip_id == bytes(64):
raise ValueError("chip ID may be masked; check host's MASK_CHIP_ID setting")
if turin_like(chip_id):
return ProcessorModel.TURIN
raise ValueError("Processor model could not be determined; update SEV-SNP firmware to bump report version")
raise ValueError("Processor model could not be determined; update SEV-SNP firmware to bump report version to V3 or later")
if cpuid_fam_id is None:
raise ValueError("missing CPUID family ID")
if cpuid_mod_id is None:
Expand Down Expand Up @@ -446,14 +432,14 @@ class TcbVersion:
"""
# Fields
raw: bytes = bytes(TCB_VERSION_SIZE)
turin: bool = False
processor_model: ProcessorModel = ProcessorModel.MILAN

# Methods
def __init__(self, raw: bytes, turin: bool = False):
def __init__(self, raw: bytes, processor_model: ProcessorModel):
if len(raw) != TCB_VERSION_SIZE:
raise ValueError(f"Invalid TcbVersion length: expected {TCB_VERSION_SIZE} bytes, got {len(raw)}")
self.raw = raw
self.turin = turin
self.processor_model = processor_model

def to_dict(self) -> dict:
"""Convert TcbVersion to a dictionary."""
Expand All @@ -467,37 +453,37 @@ def to_dict(self) -> dict:

# Class Methods
@classmethod
def from_bytes(cls, data: bytes, turin: bool = False) -> "TcbVersion":
def from_bytes(cls, data: bytes, processor_model: ProcessorModel) -> "TcbVersion":
"""Create TcbVersion from 8 bytes (64 bits).

Args:
data: bytes
turin: bool (default: False)
processor_model: ProcessorModel

Returns:
TcbVersion
"""
return cls(raw=data, turin=turin)
return cls(raw=data, processor_model=processor_model)

# Properties
@property
def boot_loader(self) -> int:
"""Boot loader version."""
if self.turin:
if self.processor_model == ProcessorModel.TURIN:
return int.from_bytes(self.raw[1:2], "little")
return int.from_bytes(self.raw[0:1], "little")

@property
def tee(self) -> int:
"""TEE version."""
if self.turin:
if self.processor_model == ProcessorModel.TURIN:
return int.from_bytes(self.raw[2:3], "little")
return int.from_bytes(self.raw[1:2], "little")

@property
def snp(self) -> int:
"""SNP version."""
if self.turin:
if self.processor_model == ProcessorModel.TURIN:
return int.from_bytes(self.raw[3:4], "little")
return int.from_bytes(self.raw[6:7], "little")

Expand All @@ -509,7 +495,7 @@ def microcode(self) -> int:
@property
def fmc(self) -> int | None:
"""FMC version. Turin or later models only."""
if self.turin:
if self.processor_model == ProcessorModel.TURIN:
return int.from_bytes(self.raw[0:1], "little")
return None

Expand Down Expand Up @@ -644,8 +630,7 @@ def __init__(self, raw: bytes, processor_model: ProcessorModel | None = None):
raise ValueError("Report version must be 3+ or processor model must be specified")
cpuid_fam_id = int.from_bytes(raw[0x188:0x189], "little")
cpuid_mod_id = int.from_bytes(raw[0x189:0x18A], "little")
chip_id = raw[0x1A0:0x1E0]
self.processor_model = detect_processor_model(version, cpuid_fam_id, cpuid_mod_id, chip_id)
self.processor_model = detect_processor_model(version, cpuid_fam_id, cpuid_mod_id)
else:
self.processor_model = ProcessorModel(processor_model)

Expand Down Expand Up @@ -743,8 +728,7 @@ def signature_algorithm(self) -> SignatureAlgorithm:
@property
def current_tcb(self) -> TcbVersion:
"""Current TCB."""
turin = self.processor_model == ProcessorModel.TURIN
return TcbVersion.from_bytes(self.raw[0x38:0x40], turin=turin)
return TcbVersion.from_bytes(self.raw[0x38:0x40], self.processor_model)

@property
def platform_info(self) -> PlatformInfo:
Expand Down Expand Up @@ -794,8 +778,7 @@ def report_id_ma(self) -> bytes:
@property
def reported_tcb(self) -> TcbVersion:
"""Reported TCB."""
turin = self.processor_model == ProcessorModel.TURIN
return TcbVersion.from_bytes(self.raw[0x180:0x188], turin=turin)
return TcbVersion.from_bytes(self.raw[0x180:0x188], self.processor_model)

@property
def cpuid_fam_id(self) -> int | None:
Expand Down Expand Up @@ -826,8 +809,7 @@ def chip_id(self) -> bytes:
@property
def committed_tcb(self) -> TcbVersion:
"""Committed TCB."""
turin = self.processor_model == ProcessorModel.TURIN
return TcbVersion.from_bytes(self.raw[0x1E0:0x1E8], turin=turin)
return TcbVersion.from_bytes(self.raw[0x1E0:0x1E8], self.processor_model)

@property
def current_build(self) -> int:
Expand Down Expand Up @@ -862,8 +844,7 @@ def committed_major(self) -> int:
@property
def launch_tcb(self) -> TcbVersion:
"""Launch TCB."""
turin = self.processor_model == ProcessorModel.TURIN
return TcbVersion.from_bytes(self.raw[0x1F0:0x1F8], turin=turin)
return TcbVersion.from_bytes(self.raw[0x1F0:0x1F8], self.processor_model)

@property
def launch_mit_vector(self) -> bytes | None:
Expand Down