遊んでみる。
遊びなのでキーは32bitでよい。（30以下だとエラーになった。31以上でOK）
$ openssl genrsa 32 | tee private.key Generating RSA private key, 32 bit long modulus .+++++++++++++++++++++++++++ .+++++++++++++++++++++++++++ e is 65537 (0x10001) -----BEGIN RSA PRIVATE KEY----- MCsCAQACBQC/gCgdAgMBAAECBFTpNXECAwD12wIDAMdnAgJ5LQICcT8CAh4/ -----END RSA PRIVATE KEY-----
$ openssl rsa -text < private.key Private-Key: (32 bit) modulus: 3212847133 (0xbf80281d) publicExponent: 65537 (0x10001) privateExponent: 1424569713 (0x54e93571) prime1: 62939 (0xf5db) prime2: 51047 (0xc767) exponent1: 31021 (0x792d) exponent2: 28991 (0x713f) coefficient: 7743 (0x1e3f) writing RSA key -----BEGIN RSA PRIVATE KEY----- MCsCAQACBQC/gCgdAgMBAAECBFTpNXECAwD12wIDAMdnAgJ5LQICcT8CAh4/ -----END RSA PRIVATE KEY-----