5.8 Check the Signing Certificate

$ openssl x509 -in samkey.crt -text -noout
Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number:
            2c:d0:16:51:c6:ed:00:90:a8:29:71:62:0f:1a:15:51:49:6e:e2:53
        Signature Algorithm: sha256WithRSAEncryption
        Issuer: C = IN, ST = tamilnadu, L = chennai, O = Microchip Technology, OU = MPU32, CN = Mass Market
        Validity
            Not Before: Aug 22 10:59:32 2025 GMT
            Not After : Aug 22 10:59:32 2026 GMT
        Subject: C = IN, ST = tamilnadu, L = chennai, O = Microchip Technology, CN = "U-Boot Image Signing "
        Subject Public Key Info:
            Public Key Algorithm: rsaEncryption
                Public-Key: (4096 bit)
                Modulus:
                    00:ee:bc:7d:e2:3c:14:dc:68:7b:7a:2c:f7:b1:ff:
                    1c:fe:aa:59:e2:d7:73:a1:e7:16:d1:73:66:87:dc:
                    98:ff:53:94:0d:c5:a0:7c:09:df:d4:d2:20:58:3d:
                    45:80:fa:fa:d7:0d:47:33:c4:72:e6:00:62:82:ab:
                    66:8d:60:51:5e:37:65:0d:d0:8f:f7:53:c6:80:f4:
                    8e:b0:1d:99:6d:18:e1:79:98:c2:58:bb:1f:e9:f0:
                    90:d7:3a:96:66:f6:22:f5:99:d5:1f:5e:0d:0d:7d:
                    26:6f:be:be:0a:9f:1a:72:c0:47:97:f6:60:b2:45:
                    5e:65:72:25:ec:89:d1:66:96:49:d0:07:7c:64:97:
                    ae:b1:05:f5:2b:c7:4a:f3:19:3a:46:9a:6a:4a:8a:
                    ae:1d:a2:be:d7:d8:19:4f:8b:95:42:95:1b:45:08:
                    9a:cb:80:44:48:bc:36:45:cd:16:1c:e4:c2:e7:80:
                    3f:16:2f:8a:47:0f:1e:0a:06:cd:f4:ea:56:27:3d:
                    d1:53:41:b5:8a:42:06:8a:95:0d:6c:ce:23:5d:84:
		       31:34:e1:90:6a:5c:1f:9e:da:98:e8:b5:40:fb:b9:
                    f2:b8:76:88:77:60:68:de:25:68:9c:39:6a:ae:85:
                    59:ee:e3:0d:c2:6f:50:ec:37:e1:fb:7c:30:d7:2d:
                    6c:91:52:d0:9e:36:ac:e2:d9:a1:ff:1c:2f:12:9d:
                    8a:ef:4c:c5:0f:ec:d8:92:6d:f6:d8:2d:5e:b9:19:
                    14:27:1e:09:45:13:cb:1f:ce:ed:f7:50:54:72:d2:
			0f:0d:72:f2:a1:26:75:ab:42:47:1b:c8:67:57:95:
                    24:77:e5:82:b1:70:59:84:50:d3:7c:c3:3e:dd:f9:
f4:bf:42:57:91:c6:68:d2:20:34:77:3b:af:7c:23:
                    5f:e3:c5:8a:d8:48:41:37:9e:ff:07:e0:71:15:f4:
                    23:40:90:a6:aa:48:c0:9c:c8:15:9e:ca:69:8a:f0:
                    a1:86:3a:29:2d:bf:64:5c:c3:76:eb:f5:00:92:be:
                    b8:60:7d:3f:b3:5e:c7:97:63:71:a7:25:24:77:d8:
                    65:6e:01:7c:bf:00:8d:2b:7f:fc:46:c1:d4:e2:52:
                    7e:b2:05:fe:e5:ab:d3:d1:e3:49:44:a3:a9:21:7b:
                    9b:79:9d:68:cf:46:aa:18:d8:61:0f:b2:48:e2:ac:
                    ba:af:08:20:21:5b:ca:8d:87:03:91:4f:2c:8e:0a:
                    f7:da:dc:3d:17:28:47:76:60:df:4f:32:51:dd:96:
                    77:4d:70:d5:87:83:c5:be:fa:dc:12:c8:b6:8a:0a:
                    d4:2e:99:61:30:58:18:43:f5:54:0f:35:76:3c:39:
                    3c:18:59
                Exponent: 65537 (0x10001)
        X509v3 extensions:
            X509v3 Basic Constraints: 
                CA:FALSE
            X509v3 Key Usage: 
                Digital Signature
            X509v3 Extended Key Usage: 
                Code Signing
            X509v3 Subject Key Identifier: 
                5D:85:C2:BF:E9:B4:9D:F1:08:3A:E1:B7:C2:1C:0A:44:77:7C:F3:A6
            X509v3 Authority Key Identifier: 
                7D:E3:DB:8E:FC:4C:1A:1C:73:89:3D:97:FA:A0:FB:AD:6D:CA:51:A1
    Signature Algorithm: sha256WithRSAEncryption
    Signature Value:
        8f:4f:0e:84:d2:41:dd:7c:33:b7:cf:d6:80:82:32:10:1a:74:
        10:ad:76:a6:d9:dd:b5:73:a9:72:fd:08:3c:07:27:20:5f:88:
        75:bc:69:ef:71:6c:8b:5d:1d:69:53:bc:4f:23:f4:42:65:1e:
        d8:4f:ce:97:26:e9:c2:f7:2c:b0:42:fc:6a:e3:0d:af:d3:e0:
        93:52:a7:12:b7:57:26:90:a7:a8:47:b4:f8:96:37:7e:e5:83:
        cc:0a:2f:7a:c9:3c:2e:d3:a7:c8:ed:53:c6:9b:44:cb:e5:11:
        40:70:69:62:81:ca:01:a7:fd:7f:41:35:89:7c:1e:c3:5e:f6:
        9e:26:55:c2:7c:21:46:c9:91:02:c7:b8:38:3a:9f:4c:97:e0:
        5b:b4:a8:66:11:82:16:d7:ad:e9:47:e3:b0:11:ae:44:55:a7:
        88:36:76:8e:42:a6:0d:3e:8b:96:cc:a7:b5:5d:1f:21:e1:24:
        d2:3b:7f:78:04:ed:d8:74:d9:73:ab:c7:f1:2f:df:52:71:b9:
        41:ed:3f:ed:f0:ac:fd:2d:e3:be:0c:bb:2d:e4:d7:66:61:7b:
        74:1f:b7:7e:30:aa:84:44:6e:53:f3:59:77:48:9e:0d:86:32:
        98:7c:b9:d5:9b:7b:81:d0:5c:5e:9b:2d:7f:05:4d:0f:30:b7:
        48:1c:e4:cb:bf:8b:a8:df:a1:25:05:51:de:7b:75:da:eb:09:
        e3:67:6d:ff:e1:98:3b:c8:57:0f:0b:6e:9d:2f:4b:ca:28:b2:
        33:56:d0:8d:e2:12:05:3c:3d:56:10:25:e4:db:bd:ff:47:c7:
        71:1f:7d:66:e5:69:43:22:fa:5b:b3:47:9e:53:9a:fe:0d:2c:
        b4:57:2b:89:5b:dc:d7:8d:d8:8f:46:af:0c:d0:d5:d7:c9:eb:
        0e:40:f0:4f:f5:63:5c:9f:d4:fd:49:22:02:1b:14:79:02:be:
        cc:89:53:7c:69:00:7b:dd:a5:42:a2:46:b8:fd:63:21:9f:36:
        dd:31:6b:60:c0:33:c4:2d:ef:57:2b:6b:77:50:61:6e:96:e4:
        a8:40:c1:65:d6:e0:1d:8a:c6:61:cb:1d:5c:13:76:c2:b4:5a:
        57:2f:78:30:f9:33:ea:0b:ad:77:d1:4a:97:44:b3:34:2c:b9:
        65:8c:dc:36:ca:b2:d8:d3:7d:35:10:9f:82:48:58:9b:59:e7:
        02:ec:aa:66:ae:bb:d1:a8:1a:e2:77:37:ee:15:e4:71:df:84:
        38:e4:7b:09:cb:9f:4d:d8:df:ee:e7:eb:ba:36:82:2b:2d:7f:
        5e:c2:96:12:f5:1f:0e:5a:19:0a:e2:4f:4f:49:1b:5e:9e:76:
        de:f4:02:44:07:c4:46:c8