When you encounter a "CA certificate key too weak" error, it typically indicates one of these cryptographic weaknesses:

• Key Length Below 2048-bit: RSA keys shorter than 2048 bits are now considered insecure
• Weak Hash Algorithm: SHA-1 or MD5 hashes in the certificate chain
• Outdated Signature Algorithm: Using obsolete algorithms like DSA

Use OpenSSL to inspect the certificate properties:

openssl x509 -in /path/to/cert.pem -text -noout | grep -E "Public Key Algorithm|Signature Algorithm|RSA Public-Key"

Sample output showing problematic certificate:

Public Key Algorithm: rsaEncryption
   RSA Public-Key: (1024 bit)
Signature Algorithm: sha1WithRSAEncryption

For development/testing environments where security isn't critical, you can bypass the check:

CURL Solution:

curl --cacert /path/to/weak_ca.crt --insecure https://example.com

OpenSSL Configuration:

openssl s_client -connect example.com:443 -CAfile /path/to/weak_ca.crt -verify_return_error

To modify system-wide security policies:

1. Edit the OpenSSL configuration:

sudo nano /etc/ssl/openssl.cnf

2. Add this section to relax security:

[system_default_sect]
MinProtocol = TLSv1.2
CipherString = DEFAULT:@SECLEVEL=1

For Python applications using the requests library:

import requests
import ssl

session = requests.Session()
session.verify = '/path/to/weak_ca.crt'
# Disable certificate verification (not recommended for production)
session.verify = False

For production environments, consider:

• Generating a new CA certificate with 2048-bit RSA or 256-bit ECDSA key
• Using modern hash algorithms (SHA-256 or SHA-3)
• Implementing proper certificate rotation

While bypassing these checks solves immediate problems, be aware that:

• Weak CA certificates compromise entire PKI security
• Modern browsers will reject such certificates
• Regulatory compliance (PCI DSS, HIPAA) may prohibit this

The "CA certificate key too weak" error typically occurs when:

• The CA certificate uses RSA keys shorter than 2048 bits
• SHA-1 hash algorithm is used (deprecated in modern OpenSSL)
• Outdated cryptographic parameters exist in the certificate chain

To inspect certificate weaknesses:

# Check certificate details
openssl x509 -in ca_certificate.pem -text -noout

# Verify key length
openssl x509 -in ca_certificate.pem -noout -text | grep "Public-Key"

# Check signature algorithm
openssl x509 -in ca_certificate.pem -noout -text | grep "Signature Algorithm"

For curl

# Solution 1: Lower security level (temporary workaround)
curl --cacert weak_ca.pem --tlsv1.2 --tls-max 1.2 https://example.com

# Solution 2: Modify OpenSSL config
# Edit /etc/ssl/openssl.cnf and add:
openssl_conf = default_conf
[default_conf]
ssl_conf = ssl_sect
[ssl_sect]
system_default = system_default_sect
[system_default_sect]
CipherString = DEFAULT:@SECLEVEL=1

For Python Requests

import requests
import ssl

# Create custom context
ctx = ssl.create_default_context()
ctx.set_ciphers('DEFAULT:@SECLEVEL=1')

# Use with verification
response = requests.get('https://example.com', verify='/path/to/ca.pem', auth=('user', 'pass'), context=ctx)

While workarounds exist, the proper solutions are:

• Request a new CA certificate with stronger encryption (RSA 2048+ or ECC)
• Implement certificate pinning for specific services
• Create a separate trust store for legacy systems

Before implementing workarounds:

• Assess the risk profile of the service
• Isolate affected systems from critical infrastructure
• Document the security exception and review periodically