Skip to main content
The verify command validates GameCube and Wii disc images and computes cryptographic hashes for verification and identification.

​
Usage

dolphin-tool verify [options]

​
Options

​
-i FILE, --input=FILE
string
required
Path to the disc image file to verify.
dolphin-tool verify -i game.iso
Supported formats:
  • ISO/GCM
  • GCZ
  • WIA
  • RVZ
  • WBFS
​
-a ALGORITHM, --algorithm=ALGORITHM
string
Compute and print only the specified hash algorithm, then exit.
dolphin-tool verify -i game.iso -a sha1
Available algorithms:
  • crc32 - CRC-32 checksum (fast)
  • md5 - MD5 hash
  • sha1 - SHA-1 hash (commonly used for disc verification)
  • rchash - RetroAchievements hash (if compiled with RetroAchievements support)
If not specified, all default hashes are computed and a full report is generated.
​
-u USER, --user=USER
string
User folder path for temporary processing files.
dolphin-tool verify -i game.iso -u /tmp/dolphin
Will be automatically created if not set.

​
Output Formats

​
Full Report (No Algorithm Specified)

Without -a, verify outputs a comprehensive report: 
dolphin-tool verify -i game.iso
Example output: 
CRC32: 3a7d42f1
MD5: 6b5c8f9e2a3d1c4b7e8f9a0b1c2d3e4f
SHA1: a1b2c3d4e5f6g7h8i9j0k1l2m3n4o5p6q7r8s9t0
Problems Found: No
If problems are detected: 
CRC32: 3a7d42f1
MD5: 6b5c8f9e2a3d1c4b7e8f9a0b1c2d3e4f
SHA1: a1b2c3d4e5f6g7h8i9j0k1l2m3n4o5p6q7r8s9t0
Problems Found: Yes

Severity: Medium
Summary: Invalid disc header

Severity: Low
Summary: Unexpected partition table

​
Single Hash Output (Algorithm Specified)

With -a, only the hash value is printed: 
dolphin-tool verify -i game.iso -a sha1
Output: 
a1b2c3d4e5f6g7h8i9j0k1l2m3n4o5p6q7r8s9t0
This format is suitable for scripting and automation.

​
Examples

​
Verify Image Integrity

Check for problems and compute all hashes: 
dolphin-tool verify -i game.iso

​
Compute SHA-1 Hash Only

For Redump verification: 
dolphin-tool verify -i game.iso -a sha1

​
Compute CRC32 Checksum

Fast checksum for quick verification: 
dolphin-tool verify -i game.iso -a crc32

​
Compute MD5 Hash

dolphin-tool verify -i game.iso -a md5

​
Verify with Custom User Directory

dolphin-tool verify -i game.iso -u /tmp/dolphin-verify

​
Hash Algorithms

​
CRC32

Use case: Quick integrity checks, error detection
  • Fast computation
  • 32-bit checksum
  • Good for detecting corruption
  • Not cryptographically secure
dolphin-tool verify -i game.iso -a crc32

​
MD5

Use case: File identification, legacy compatibility
  • 128-bit hash
  • Widely supported
  • Cryptographically broken (use SHA-1 instead)
  • Still useful for non-security purposes
dolphin-tool verify -i game.iso -a md5

​
SHA-1

Use case: Disc verification, Redump database matching
  • 160-bit hash
  • Standard for disc image verification
  • Used by Redump and other preservation databases
  • Recommended for verification
dolphin-tool verify -i game.iso -a sha1

​
RetroAchievements Hash

Use case: RetroAchievements game identification
  • Specific to RetroAchievements platform
  • Only available if compiled with RetroAchievements support
  • Used for achievement tracking
dolphin-tool verify -i game.iso -a rchash

​
Problem Detection

The verifier checks for various issues:

​
Severity Levels

  • None - Informational only
  • Low - Minor issues, game likely works
  • Medium - Potential problems, may affect gameplay
  • High - Serious issues, game may not work

​
Common Problems

  • Invalid disc headers
  • Corrupted partitions
  • Missing or invalid encryption
  • Partition table errors
  • File system inconsistencies
  • Hash mismatches (for signed content)

​
Verification Workflow

​
1. Verify After Download

# Download game
wget https://example.com/game.iso

# Verify integrity
dolphin-tool verify -i game.iso

# If problems found, re-download

​
2. Verify After Conversion

# Convert format
dolphin-tool convert -i game.iso -o game.rvz -f rvz -b 131072 -c zstd -l 5

# Verify converted image
dolphin-tool verify -i game.rvz

​
3. Compare with Known Hash

# Compute SHA-1
HASH=$(dolphin-tool verify -i game.iso -a sha1)

# Compare with expected value
EXPECTED="a1b2c3d4e5f6g7h8i9j0k1l2m3n4o5p6q7r8s9t0"

if [ "$HASH" = "$EXPECTED" ]; then
  echo "✓ Hash matches!"
else
  echo "✗ Hash mismatch!"
fi

​
Scripting Examples

​
Verify Multiple Files

#!/bin/bash

for file in *.iso; do
  echo "Verifying $file..."
  dolphin-tool verify -i "$file"
  echo "---"
done

​
Check Against Database

#!/bin/bash

# database.txt format: filename sha1
while IFS=' ' read -r filename expected_hash; do
  if [ -f "$filename" ]; then
    actual_hash=$(dolphin-tool verify -i "$filename" -a sha1)
    
    if [ "$actual_hash" = "$expected_hash" ]; then
      echo "✓ $filename"
    else
      echo "✗ $filename (hash mismatch)"
    fi
  else
    echo "- $filename (not found)"
  fi
done < database.txt

​
Generate Hash Database

#!/bin/bash

for iso in *.iso; do
  hash=$(dolphin-tool verify -i "$iso" -a sha1)
  echo "$iso $hash" >> hashes.txt
done

​
Parallel Verification

#!/bin/bash

find . -name "*.iso" -print0 | \
  xargs -0 -P 4 -I {} sh -c '
    echo "Verifying {}..."
    dolphin-tool verify -i "{}"
  '

​
Performance

Verification speed depends on:
  • Storage speed - SSD much faster than HDD
  • Image size - Larger files take longer
  • Format - Compressed formats (RVZ, GCZ) slower than ISO
  • Algorithm - CRC32 fastest, SHA-1 slower
Typical verification times on modern hardware:
FormatSizeCRC32SHA-1Full Report
ISO4.3 GB15s25s30s
RVZ1.8 GB30s45s60s
GCZ2.1 GB25s40s50s
Times are approximate

​
Exit Codes

  • 0 - Success (verification completed)
  • 1 - Failure (could not verify)
Note: Exit code 0 means verification completed, not that the image is valid. Check the output for problems.

​
Troubleshooting

​
”Unable to open input file”

Check:
  • File exists and path is correct
  • You have read permissions
  • File is not corrupted or truncated

​
”No hash computed”

Occurs when:
  • Algorithm is not supported
  • Image format is invalid
  • File is too corrupted to process

​
Slow Verification

To speed up:
  • Use CRC32 instead of SHA-1 for quick checks
  • Use SSD storage
  • Verify ISO instead of compressed formats

​
Integration with Redump

Redump.org maintains verified disc image databases using SHA-1 hashes.

​
Verify Against Redump Database

  1. Compute SHA-1 hash: 
    dolphin-tool verify -i game.iso -a sha1
  2. Search hash on Redump.org
  3. Match confirms authentic dump

​
See Also