macOS - md5 | md5sum

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大文件传输是否完整，你可以使用 md5 进行校验
linux 上使用 md5sum 命令，在macOS 上 md5 命令是和 md5sum 等效的

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简单使用介绍

参考：https://blog.csdn.net/cnds123321/article/details/124946370

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Linux

# 字符串
$ echo "hello" |  md5sum
b1946ac92492d2347c6235b4d2611184  -# 文件
$ md5sum a.txt
177dcfd6909426793115fec5397724ac  a.txt

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macOS

$ echo "hello" | md5
b1946ac92492d2347c6235b4d2611184$ md5 a.txt
MD5 (a.txt) = 0a61ff81d3ed58dc1828b17e46fcbd9c

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文档

Linux - md5sum

md5sum --help

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Usage:

md5sum [OPTION]… [FILE]…

Print or check MD5 (128-bit) checksums.
With no FILE, or when FILE is -, read standard input.

• -b, –binary`, read in binary mode
• -c, –check`, read MD5 sums from the FILEs and check them
• --tag, create a BSD-style checksum
• -t, –text`, read in text mode (default)

Note: There is no difference between binary and text mode option on GNU system.

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The following four options are useful only when verifying checksums:

• --quiet, don’t print OK for each successfully verified file
• --status, don’t output anything, status code shows success
• --strict, exit non-zero for improperly formatted checksum lines
• -w, --warn, warn about improperly formatted checksum lines
• --help, display this help and exit
• --version, output version information and exit

The sums are computed as described in RFC 1321. When checking, the input
should be a former output of this program. The default mode is to print
a line with checksum, a character indicating input mode (‘*’ for binary,
space for text), and name for each FILE.

GNU coreutils online help: http://www.gnu.org/software/coreutils/
For complete documentation, run: info coreutils ‘md5sum invocation’

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macOS - md5

man md5

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NAME
md5 – calculate a message-digest fingerprint (checksum) for a file

SYNOPSIS

md5 [-pqrtx] [-s string] [file …]

DESCRIPTION
The md5 utility takes as input a message of arbitrary length and produces as output a “fingerprint” or “message digest” of the input.
It is conjectured that it is computationally infeasible to produce two messages having the same message digest, or to produce any message having a given prespecified target message digest.
The MD5 algorithm is intended for digital signature applications, where a large file must be “compressed” in a secure manner before being encrypted with a private (secret) key under a public-key cryptosystem such as RSA.

MD5’s designer Ron Rivest has stated “md5 and sha1 are both clearly broken (in terms of collision-resistance)”.
So MD5 should be avoided when creating new protocols, or implementing protocols with better options. SHA256 and SHA512 are better options as they have been more resilient to attacks (as of 2009).

The following options may be used in any combination and must precede any files named on the command line.
The hexadecimal checksum of each file listed on the command line is printed after the options are processed.

• -s string, Print a checksum of the given string.
• -p, Echo stdin to stdout and append the checksum to stdout.
• -q, Quiet mode - only the checksum is printed out. Overrides the -r option.
• -r, Reverses the format of the output. This helps with visual diffs. Does nothing when combined with the -ptx options.
• -t, Run a built-in time trial.
• -x, Run a built-in test script.

EXIT STATUS
The md5 utility exits 0 on success, and 1 if at least one of the input files could not be read.

SEE ALSO
cksum(1), CC_SHA256_Init(3), md5(3), ripemd(3), sha(3)

R. Rivest, The MD5 Message-Digest Algorithm, RFC1321.

Vlastimil Klima, Finding MD5 Collisions - a Toy For a Notebook, Cryptology ePrint Archive: Report 2005/075.

ACKNOWLEDGMENTS
This program is placed in the public domain for free general use by RSA Data Security.

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伊织 2024-01-17 (三)